MadModder

The Breakroom => The Water Cooler => Topic started by: picclock on July 26, 2015, 03:48:07 AM

Title: 3D printing
Post by: picclock on July 26, 2015, 03:48:07 AM
I am considering investing in a 3d printer in the near future. Ideally one which would produce parts in nylon and abs. I have seen a very low cost kit called a two up :

http://www.productchart.com/3d_printers/5843

which looks too good to be true.

Does anyone have one of these or an alternate and what are the pros and cons of the machine you have ? What is the best UK website for info on these devices?

The idea of being able to produce custom gears and other small parts in nylon/abs seems very attractive to me.

Best Regards

picclock

Title: Re: 3D printing
Post by: Pete49 on July 27, 2015, 03:19:54 AM
More than happy with my Da Vinci 3D printer. A couple mods and now I use aftermarket filament. That one looks a tad under whelming.
Pete
Title: Re: 3D printing
Post by: Arbalist on July 27, 2015, 05:36:06 PM
I get the impression that any of them will produce pretty looking "prototypes" but you'll likely need something better than a budget model for working parts. If possible try a get some actual samples before committing. Surface finish from some of them also leaves a bit to be desired.
Title: Re: 3D printing
Post by: picclock on July 28, 2015, 03:15:05 AM
@ Pete49, Arbalist

I looked at the Da Vinci one but was put off by the need to use filament cartridges. My limited research has shown that some very exotic materials are now available, and that nylon can be used with little alteration. The two up is very much a budget machine, but from what I have read may be too troublesome.  I am now considering a Prusa i3 kit, which has a water jet cut aluminium frame. As you can specify the extruder head, I can select one which will do the higher temperatures needed for stronger materials.

The link to the kit is slow to load, http://semiu.co.uk/product/prusa-i3-complete-kit/ ,  the photographs are poor, however the information I can find about it seems to indicate that it will do the job. Will try to get some actual prints from the chap. AFAIK, the surface finish is determined by the nozzle size. So a small nozzle size will give a good finish but will take a long time to print. The mechanical positioning resolution of the printer is 0.0125 mm in X and Y and 0.00025 mm in z. Intend using E3D-online v6 nozzle which will go down to 0.25mm. 

Still very much at the considering stage - far too much work on to do anything about it at this moment, but I like the possibility.

Best Regards

picclock
Title: Re: 3D printing
Post by: awemawson on July 28, 2015, 06:48:50 AM
I'll be extremely interested to hear how you get on with your investigations of 3D printers. It's my next intended acquisition once I've properly set up and got used to my laser engraver.

Most of the 3D printers I've seen to date have been little more than toys (with a nice low price) or top end industrial kit using exotic materials and a matching price tag. I'm looking for something in between these extremes that can do useful work to a fair finish and reasonable working volume.
Title: Re: 3D printing
Post by: Pete W. on July 28, 2015, 08:23:46 AM
Hi there, all,

This may be a touch   :offtopic:  but here goes anyway:

Some modern microscopes have plastic gear in the focus mechanism.  These fail soon after the microscopes get into the amateur community (presumably, professional users can afford their service contractors' charge to replace the gear).

There has been some discussion on the Yahoo Microscopes group as to whether 3D printing is capable of making replacement gears with the necessary precision.

My reading of the various posts, pro and con, is that the jury is still out.

Having said that, the various posters aren't usually very specific about how much they've paid for their 3D printer.  It may be that top-end machines can do it but the cheapies can't. 
Title: Re: 3D printing
Post by: Joules on July 28, 2015, 09:27:26 AM
Don't ignore PLA as an engineering material, it is much underestimated in what it can do as long as you keep its operating temperature below 50℃

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/Hyperboloid%20Test%20Gears_zpsrb6lgzsi.jpeg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/Hyperboloid%20Test%20Gears_zpsrb6lgzsi.jpeg.html)

Those ring gears are 62mm diameter and I printed them for destructive testing, mix the pinions and see where colours get transferred to improve the design if needed.   These are going to be for an experimental extruder for another 3D printer.   I use a lot of parts like this for prototyping and maintenance, PLA is very unreactive to solvents and oils.

The printer these were made on cost 470.  It's a Createbot Mini, however what makes this machine a gem is its welded steel chassis and direct drive extruder.  All the cheap machines in the Prusa i3 vane suffer from rigidity problems and this in turn appears as lines and blobs on your prints where the machine is RINGING as it prints.  You want something with a sturdy chassis and good quality bearings, not bushes if you expect any sort of life from it.  I use this machine daily in my business and hobby applications, got through about 6kgs of PLA so far, or about 2.1km of filament so very happy with the extruder mechanism on this one.

http://www.technologyoutlet.co.uk/collections/3d-printers/products/3d-printer-mini-by-technologyoutlet-2015-model

This is my machine.  The downside is the lousy electronics it used, BUT even that is not insurmountable as they are pretty bog standard and can be replaced by off the shelf parts available in the UK.
Title: Re: 3D printing
Post by: picclock on July 28, 2015, 02:36:35 PM
@ Joules

The gears look impressive although the surface finish looks a bit rough. This is one of the aspects I am concerned about, because as parts get smaller the roughness becomes a greater percentage of the part. Like the idea of using the different colours for a visual mesh check. At 400 your printer seems a very reasonable choice. Which software package did you use to design the parts?

The mechanics of the Prusa kit seem fairly OK. It has 10 linear ball races used with precision ground rod (0.03mm) and a water jet cut aluminium frame, which to me looks pretty good. I don't think they could get the head position accuracy figures otherwise. The only part that concerns me is that the vertical metal plate (gantry) attaches to the base with just two nuts and washers to keep it vertical. To be fair there is no load to move it from vertical but the dynamic loads caused by the movement of the head may cause some accuracy issues here. If I go ahead with the purchase I will measure the repeat accuracy with a gauge and anything that I find which reduces it I will stiffen up with custom mods. It looks like just mounting it on a known flat surface with brackets at right angles to the gantry (vertical plate) would sort it.

There is a computer generated assembly video which seems quite well done (and entertaining :-) ) :


Best Regards

picclock
Title: Re: 3D printing
Post by: Joules on July 28, 2015, 04:43:24 PM
Don't be fooled by the surface reflections, that roughness is about 0.1mm that being the layer height.

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/Close%20up%20Pinion_zpsfbfymdrm.jpeg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/Close%20up%20Pinion_zpsfbfymdrm.jpeg.html)

This is a close up of the pinion you can see the layers, the plastic is very slippy so little friction.   Most prints can be treated as precision castings, PLA machines quite nicely and can be wet sanded with fine emory and then lacquered for a tough finish.

The parts were designed in Rhino, and output as STL files I then used in Simplify3D, but you could use (Free) Cura for this.   The Prusa is a bold claim considering they are using tie wraped pipe as couplings onto unsupported hardware store threaded rod.   If you plan on building tall models, you aren't going to see 25 micron accuracy !   My software has rounding errors for Z so expect >0.1mm in say 50mm.  I use the printing in association with my lathe and mill for precision parts, just like you would a casting.

What is the smallest size gear you are trying to make ?  By swapping to a 0.2mm nozzle you could expect a blob of accuracy 0.25mm x 0.25mm in X,Y even if your Z does 50micron steps.  The blob size dictates your minimum detail, if that makes sense.
Title: Re: 3D printing
Post by: Arbalist on July 28, 2015, 05:34:11 PM
Not suitable for parts like gears but I understand the surface finish can be improved cosmetically on some materials by giving them a wipe over with some type of solvent.

Plastic gears are often the weak link in some products. Two for no particular reason spring to mind and those are telescopic sights and milling machines!
Title: Re: 3D printing
Post by: picclock on July 28, 2015, 05:41:40 PM
Hi Joules

Thanks for replying. The surface roughness on that pinion gear looks really good - and the part about the blob size makes perfect sense. Finding that kind of info about surface finishes is quite difficult.

I was less than enthralled with the coupling used for the z axis - seems strange that a conventional shaft adapter wasn't used. Having said that it appears that the ends of the threaded rod are supported by the motor spindle and the tubing is just to allow for some lateral or angular misalignment whilst providing rotational drive. Difficult to know how accurate it might be.

Best Regards

picclock


 
Title: Re: 3D printing
Post by: Joules on July 28, 2015, 05:43:32 PM
LOL shock loading......  They do cushion the blow.    These gears are meant for light loading applications or test prior to casting.  You can do a lost PLA casting, and even print the gear oversize for shrinkage just by altering the software.  They are a great "prototyping" tool and very quick to get a useable result that I personally couldn't machine.

 :drool:  Eeeeerrrrrr yeah, suppose I am addicted to 3D printing so ignore the bias.....   :thumbup:
Title: Re: 3D printing
Post by: tom osselton on July 28, 2015, 08:35:49 PM
Not suitable for parts like gears but I understand the surface finish can be improved cosmetically on some materials by giving them a wipe over with some type of solvent.

Plastic gears are often the weak link in some products. Two for no particular reason spring to mind and those are telescopic sights and milling machines!

And those cigarette compressors the gear only lasts about 1/2hr
Title: Re: 3D printing
Post by: vtsteam on July 28, 2015, 09:31:35 PM
You can do a lost PLA casting, and even print the gear oversize for shrinkage just by altering the software.

Joules, have you tried to lost PLA cast? Because even with lost foam (and therefore a much lower level of flammable material) it's not easy to get accurate thin section results with good fill, because the foam is burned up during the pour. I would definitely like to see those gears cast with a lost PLA process.

Lost wax is an accurate process, but the wax is carefully removed from an invested mold before casting, it's quite different from lost foam. Lost foam is much more approximate and iffy for small intricate parts, and I imagine that lost plastic would pose even more difficulties... I'm talking about thin section complex and undercut shapes, a major reason for people seem to promote a 3D printer for pattern making at the home shop machinist level.

Now if the 3D printer made an accurate melt-out wax pattern, that would work with traditional lost wax casting methods. Perhaps that's what you mean?
Title: Re: 3D printing
Post by: Pete49 on July 28, 2015, 11:21:36 PM
Just for information but the Da Vinci filament requirement is very easy to work around. I use aftermarket 1 Kilogram spools as do many others without modifying the software that is supplied by Da Vinci so that is not problem. You can set the layer height from .01 .02 or .03 and the print quality  and density is also adjustable. As to the layer lines they can be flashed off with a little acetone if it offends the recipient though I see no need.
Pete
Title: Re: 3D printing
Post by: Joules on July 29, 2015, 02:36:49 AM
Alas vtsteam, I have not cast anything but should have said lost wax style, not implied lost foam.  The plastic is too dense to even contemplate molten metal burn out, even as a shell print.

The best I could attempt here is burn out plaster mould then cast in lead....  An ideal gear material  :lol:


Anyone local to team up with for some lost wax style PLA casting experiments ?

http://3dtopo.com/lostPLA/
Title: Re: 3D printing
Post by: Joules on July 29, 2015, 05:28:02 AM
picclock, not sure if this one is outside your budget or a bit too big.

https://www.kickstarter.com/projects/e3dbigbox/the-e3d-bigbox-3d-printer

Its a project E3D are involved in.  I should have first hand experience of one in December if the project runs to plan.  My mates getting one, it looks more promising in perspex than plywood.  Best of all it will be Open Source after the Kickstarter.
Title: Re: 3D printing
Post by: awemawson on July 29, 2015, 07:27:39 AM
That looks quite a beast - I hope it comes to fruition as it looks the sort of thing I'm looking for.
Title: Re: 3D printing
Post by: vtsteam on July 29, 2015, 08:38:11 AM
Joules, it seems to me that that a mold melt-out filament material should be pretty easy to do, actually, since the pattern needs no special strength or longevity and the temperature for the extruder can be moderate. The main requirement being that material be able to melt (and burn) out of an investment mold completely with no ash or residue, and ideally do so with low fumes. Recovery for recycling would be nice, so actually a filament isn't the ideal form, rather, a hot chamber.

Seems like somebody ought to develop that, if they haven't already.

I'd like to see someone here develop a DIY 3D printer using an available commercial head, since the rest of the machine is straightforward. I don't get why they are generally built so flimsy compared to, say, a simple CNC router.

Welded square steel  tube for the base structure, and lightweight but high stiffness traveling components -- aluminum or even epoxy coated box section birch ply structure for the gantry would have very high specific modulus. Basically light aircraft construction, would be the way I'd go.

It seeems people are enamored of the concept of the machines building their own components so they try to design complex plastic structures, but plastic is so elastic it seems a bad idea to me. I realize birch is considered antiquated in our so-called high tech society, but it does have very good stiffness and fatigue properties compared to other materials, at low density, and I personally have no prejudices against mixing materials to achieve a superior performance goal.

Wood can also, depending on the design, do a good job of damping the ringing that seems to be a problem

Title: Re: 3D printing
Post by: picclock on July 29, 2015, 09:05:06 AM
Hi Joules

That's interesting, though I think a bit too large for me. I notice it uses the same head as the Prusa I3, along with 2 Z motors. 

Research on the internet has confirmed that unless you mount the prusa on something flat it will have to be recalibrated every time its moved. I know a guy who cuts stone kitchen tops to size and he has loads of scrap pieces in his yard. As we are likely to order our next kitchen tops from him I would think a granite or synthetic stone base would sort out that issue. The other thing I didn't like was that the end stops used on these machines are microswitches. Replacing these with opto sensors, especially the smd variety will give orders of improvement. Likely only really necessary on the z axis.

Just need more hours in a day to get the time to play with this technology.

Best Regards

picclock

Title: Re: 3D printing
Post by: Joules on July 29, 2015, 10:22:23 AM
vtsteam, you raise some interesting questions.  Number one PLA is a consumable, whilst I hate throwing things away at least this one is biodegradable, eventually.  One ring gear and pinion weighs 9gram.  Printing with wax, I guess the problem is wax has a low viscosity when fluid and would be harder to meter from the head, it just doesn't behave like molten plastic.  That said you could do a rubber mould of the printed part then shoot wax for lost wax casting, just seems a lot more work unless you plan on making many of them.

Now the tricky bit.   Printers...  The technology has taken many years to reach the point we are at now, yes there has been obsession with getting the machine to make itself.  I am not at all interested in that side of things, I am an end user with applications.   The printer for small parts usually has to be an order of magnitude more accurate than a hobby cnc router, but at a push you could use one.  Having an enclosed cabinet helps the consistency of layer building no end, it keeps the heat in and the drafts out that can cause warping and delamination.  Again the printer is a huge compromise, you actually want a very light weight printhead so you can move it about rapidly without shaking the machine all over the place.  Add to this the need for as close coupling of the feed motor to extruder.  Bowden fed extruders are a lot more difficult to control than a direct drive, especially with flexible filaments where they easily compress.   Printing has loads of variables that must be balanced to achieve good printing, it really is juggling with jelly that we tend to take for granted now the hard work is done.  Hit a snag and you are back on the learning curve of how this all works, this is why I concentrate my efforts on PLA and work within its constraints for now.  Printed nylon does not have the same characteristics as moulded or machined nylon, it may be touted as stronger but it ultimately depends on your end use and understanding of its limits, and we are back at compromise.

picclock, the results of my morning in the workshop.

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/Splined%20Shaft%20and%20Pinion_zpszar0zmws.jpg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/Splined%20Shaft%20and%20Pinion_zpszar0zmws.jpg.html)

Brass splined shaft made ready to fit pinion.

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/Check%20Mate_zps6um79uad.jpg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/Check%20Mate_zps6um79uad.jpg.html)

Partly mated, they are a tight fit, I can remove the pinion without the printed splines being torn out of the pinion.   This is a test part and something new I am trying, I am very happy with the result so far.  The gear is centred with no slip on the shaft.  Next up is design the bearing carrier for the two gears and then start load testing them.

I have about 2 years 3D printing experience with current hobby machines, about 10 months on my Createbot mini.  In my collection is a deltabot  that I play with, but it is a whole different beast to this current one.

Don't fret over some of the details in printing.   That first layer is usually your most inaccurate as you are trying to lay a foundation layer that is usually thicker than those to come.  A microswitch is adequate for sensing the bed home position.   Granite slab, great idea that should be standard for ALL 3D printers and bolt them too it.  Always plan how you are going to print something before you print it, each print in effect has grain that can work against you or for you in some applications.   Don't be afraid to print something at an angle with support material, or break up a model into parts and weld them together at the end with a soldering iron.

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/Jenesis%20Sound%20Labs_zpsxtcvi3f3.jpg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/Jenesis%20Sound%20Labs_zpsxtcvi3f3.jpg.html)

Like the above example.   Guy's this is what I have learn't about printing and printers.  It's my experience and my journey, yours will be different, always happy to answer questions where I can or just comment on what you see.

Title: Re: 3D printing
Post by: vtsteam on July 29, 2015, 03:56:53 PM
Joules, I wasn't suggesting wax per se, but that a printer medium be deveoped that could be melted out of an investment mold before casting. Otherwise, the claims for using a low cost 3D printer to make accurate thin metal molding patterns for complex small parts like gears via "lost" plastic molding is uhhhh, let's say on "optimistc" side of the truth. I'm sure you can make simple shapes with a machining allowance, but then, you can do that with just about any pattern making method, and a lot quicker and cheaper the trditional way.

When I was suggesting welded square steel tube base rather than the flimsy construction I've seen on some of these printers, the reference to router bases had nothing to do with precision. I was talking about simple constructional stiffness. the ways and bearings determine positioning accuracy, not the base that supports them. And for the moving gantry and parts I was talking abut reducing mass, not increasing it.

I haven't seen very impressive work in the design of machines themselves in terms of an understanding of stiffness and damping. I've seen a lot of futuristic maker-culture design, which often seems to hint at a lack of basic design and manual metalworking fabrication skills. I think these mchines are fine if you enjoy modeling in plastic, but when people start talking about producing machine parts, I think there needs to be a shift in design understanding, not necessarily cost.

I do believe that a machine to produce strong long wearing mechanical parts could be designed better, and not necessarily more expensively, and that was what I was suggesting.

Title: Re: 3D printing
Post by: awemawson on July 30, 2015, 11:26:37 AM
 :bugeye: Well I've signed the pledge  :bugeye:

Just signed up as a backer for the BigBox full works dual head jobby  :ddb: Hopefully they start delivering in December but I reckon that's a date that might well slip a bit as these things do. Speaking to them they seem a nice crowd but the proof is in the product when it arrives  :scratch:
Title: Re: 3D printing
Post by: PekkaNF on July 30, 2015, 01:38:55 PM
I have never been really excited about these hobby 3D printters. Too much hype.

There are some mention and reference to anual make magazine 3D Printing Shootout, I found pretty nice "test". I don't knw how many makes are test.
http://makezine.com/2014/11/07/how-to-evaluate-the-2015-make-3dp-test-probes/

Unfortunately this is in Finnish, I could not simply click "English" to have these articles English, maybe google translator would do some kind of job?
http://www.minifactory.fi/yleinen/minifactory-3d-tulostin-ja-make-magazinen-tarkkuustesti/#more-2877
http://www.minifactory.fi/uutiset/minifactory-tarkkuustesti-osa-2/#more-3456

This was interesting though "The structural strength of Carbon Fiber PLA is around 90% of the structural strength of traditional pure carbon fiber.":
http://www.minifactory.fi/en/news-articles/minifactory-took-part-worlds-largest-3d-printing-event/
Hard to believe it. Maybe someting lost in "translation".

End of this page there is shor mention about casting:
http://makezine.com/volume/guide-to-3d-printing-2014/

Pekka
Title: Re: 3D printing
Post by: tom osselton on July 30, 2015, 03:00:02 PM
Here is some more about 3d / lostwax casting.

http://makezine.com/2015/02/02/new-3d-printer-filament-brings-lost-wax-casting-to-your-desktop/
Title: Re: 3D printing
Post by: awemawson on July 30, 2015, 05:25:20 PM
There are some really quite exciting materials being offered as 3d printing filaments. So long as the hot end is capable of the correct temperature regulation you can print metallic filled materials, carbon fibre, wax investment, and even conductive materials. It's this capability and the dual heads that attracted me to the 'BigBox' as it ticks all my boxes. No doubt a step learning curve though.
Title: Re: 3D printing
Post by: vtsteam on July 30, 2015, 08:33:27 PM
Quote
Moldlay is designed specifically for the use of creating positives for investment casting molds. Moldlay is a wax-like material that can be printed on a normal desktop 3D printer, at temperatures of 170-180C.

That's just what I was suggesting..

Now we need a diy heavy square steel tube base with rigid ways (NOT end supported 1" dia rod) , and a gantry of epoxy coated box section birch ply for low specific modulus, aircraft style, and a commercial head.

Then we're talking making adequate patterns for intricate lost medium casting with a DIY machine at reasonable cost.
Title: Re: 3D printing
Post by: efrench on August 02, 2015, 01:20:54 AM
What do you mean by a commercial head?  Do you have any links to one?  Cast iron or epoxy granite might make a better base than steel. 
Title: Re: 3D printing
Post by: vtsteam on August 02, 2015, 08:10:31 AM
A head that is purchased. I don't have links, but I haven't looked for any -- I'm not interested in building a 3D printer.

In speaking of a DIY machine I'd admire of low cost, the suggestion of welded steel square tubing is generally within the range of capabilities and budget of folks here. If you cast iron in pours of, say 100 lbs, or better, or mine and surface granite, I'd say go with those. Personally I'd likely want steel tube anyway above the granite.
Title: Re: 3D printing
Post by: Swarfing on August 02, 2015, 02:49:45 PM
I recently built an i3 Prusa for a friend, first out of steel box because I thought it would be much better. Had so many problems trying to tweak it, ended up rebuilding it out of laminate 10mm birch ply to a nice thickness  x3 (30mm) and it turned out much better. I fixed this down onto some 50mm mdf for the base making the whole thing very stable rather than the thin sheets of material they recommend in the build plans. Had to cnc the bed out of aluminium so there are some thing that are not available to everybody. The parts are available for the build off ebay at quite reasonable prices from others replicating the parts.
Title: Re: 3D printing
Post by: efrench on August 02, 2015, 10:19:38 PM
I suspect most DIY printers have commercial heads using that definition :) The E3d v6 (http://e3d-online.com/index.php?route=extras/blog/getblog&blog_id=21) is probably the most popular.  It sells for around $80. Clones from China are anywhere from $10 to $30. 

Quality control is probably the biggest problem with most of the kits on the market today.

I'm in the finishing stages of building a delta printer with a 350mm build circle.  It's all aluminum with a torsion box base.  I expect that it will be more than rigid enough for the forces being generated.
Title: Re: 3D printing
Post by: vtsteam on August 02, 2015, 10:45:21 PM
I suspect most DIY printers have commercial heads using that definition :)

Those which don't would have non-commercial heads. Besides the adjective, there's also a noun, commerce that describes the convention of buying and selling. No matter that say, barter, is less common, the word still finds a use. Sorry for any confusion.
Title: Re: 3D printing
Post by: picclock on August 03, 2015, 02:32:28 AM
@swarfing
>> I recently built an i3 Prusa for a friend, first out of steel box because I thought it would be much better. Had so many problems trying to tweak it, ended up rebuilding it out of laminate 10mm birch ply to a nice thickness  x3 (30mm) and it turned out much better.

As this is the machine I am thinking of purchasing could you expand on the problems you encountered ?

@ EFrench 

The E3D-v6 online is the only head I have found to do the higher temperatures needed for nylon and polycarbonate. It is also self assembly.
See : -   http://wiki.e3d-online.com/wiki/E3D-v6_Assembly   M6 nozzles are available on ebay for not a lot.

Will be interested to see how your printer performs. My info is that the delta ones are much trickier to get properly set up, calibrated and working well. Good luck with it !! Could you post some pictures when done ?
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Having looked at the rest I am fairly certain the the Prusa I3 will be a good starting place for me. I am thinking of using a granite base and fixing the parts to it. May swap the plastic rod holders in the Y axis for aluminium ones. Not sure why both sides are fixed like that. IMHO you need one rod to keep the axis true and the other one merely to keep the platform level. By fixing both rods you are setting up forces working against one another. Also the linear bearings should be clamped and fixed by a narrow ring in the centre rather that along the whole length as this would allow them to find their true correct orientation (there are two bearings on one side and one on the other). Will build it as is and take measurements, then fix as needed. Will post build with pictures if anyone interestted.

Have been checking out 3d modelling software - think I am going to go with Designspark from RS. Its fast and quite easy to learn (and free !!). Love the way you can make threads (see link - no sound or root/tip radius but could be added). 
https://www.youtube.com./watch?v=6GZXIrbvh80
Still haven't figured out how to do cones yet !!.

Best Regards

picclock
Title: Re: 3D printing
Post by: Swarfing on August 03, 2015, 10:00:21 AM
The only problems I really found was rigitity. Making it out of steel (welded) throws up problems of alignment as you can imagine with heat twist etc. Making it out of Acrylic just seems a bit week for my stomach, yet a sensible build medium if you take my bias away. Birch ply in over engineered sizes works great in my book and it can all be glued together and fettled with ease. There is also the bonus of being able to make it much taller if you wish?

Using tubing for the couplers is a poor substitute for ridged ones, yet rigid ones allow noise transference which shows up in the finish which will not be as clean. Make sure you mount the base on rubber feet, Stainless steel threaded rod as the threads you will find are much cleaner and accurate instead of plain steel which usually is rolled thread and not as accurate (As accurate as threaded rod can be which is not very anyway)

Title: Re: 3D printing
Post by: awemawson on August 03, 2015, 10:36:25 AM
Can it not be made fairly simply using a frame of standard aluminium extrusions as are popular on CNC plasma and router machines ?
Title: Re: 3D printing
Post by: PekkaNF on August 03, 2015, 02:56:34 PM
Basically you want as light as possible structure, good 3d printer head must be able to accelerate and move relatively fast and fast stepper motors are small. Nevertheless should be rigid eneough, othervice printhead shakes all over the path.

Pekka
Title: Re: 3D printing
Post by: Swarfing on August 04, 2015, 04:47:00 AM
With the i3 we are only talking about the main static frame so weight does not come in to it. Yes it could be made from extrusion of course, but these days extrusion is a very hi cost in comparison to other materials.
Title: Re: 3D printing
Post by: picclock on August 05, 2015, 02:32:20 AM
@swarfing

Prusa I3 - I had already planned to s/s allthread for the m5 z axis because it always looks like the threads are better formed. I was under the opinion that they were still rolled - but if not what process is used to thread them ? IMHO this is one of the weak areas which may prove tricky to improve on - but as its only being made in plastic with all its dimensional issues (moisture absorbtion, high coefficicient of expansion etc.) it might just be good enough. The other axis of the machine are belt driven direct from a stepper motor. I suspect the reason for change on the Z axis was to improve the resolution to allow for thinner layers and achieve smoother finishes. 

@awemason

The Velleman printer sold by Farnell and maplins uses an extruded frame - although it only uses one z motor which will likely lead to droop on the undriven side. Could probably be compensated for by bed levelling to some extent. http://www.maplin.co.uk/p/velleman-k8200-3d-printer-kit-n82qg

----------------------------------------------------------------------------------------------------------------------------------------------------

The frame (gantry) weight with the Prusa I3 design is irrelevant as it is a static part, so can be made very stiff, to allow good accuracy for head positioning in the X and Z axis. The Y axis will have to accurately achieve position with the weight of the heater bed and glass sheet plus the model weight and the cable drag. I think thats why the I3 design is a good one. Two out of three axis sorted for stiffness.

Best Regards

picclock
Title: Re: 3D printing
Post by: S. Heslop on August 05, 2015, 07:51:02 AM
With the i3 we are only talking about the main static frame so weight does not come in to it. Yes it could be made from extrusion of course, but these days extrusion is a very hi cost in comparison to other materials.

http://www.valuframe.co.uk/

These kinds of extrusions seem very cheap if you're selling kits, since you can leave alot of the assembly and fitting to the guy buying it. Wonder how much the cost stacks up against paying for water jet/ laser cut plates though.
Title: Re: 3D printing
Post by: Swarfing on August 05, 2015, 05:19:44 PM
Ha ha! yes is reasonable priced until you add delivery cost? It's all horses for courses, you choose your material of choice and go for it. Judging by the comments so far you can see people just have their preferences for different materials. I have used a lot of extrusion for my past CNC projects, in my final CNC router build I opted for welded Steel (Cheaper and stronger).

The last lot of S/S threaded rod I bought looked too good to be rolled and I was under the opinion it must have been cut? I can't really comment on processes used. In general S/S rod just seem to present much cleaner threads and by virtue gives a lot less issues. You could opt for ballscrew but really a bit over the top for a small 3D printer unless you want that extra perfection?

At some point I will build another for myself and again I would go for the birch ply approach. My friend is very pleased with the results he is getting. It is the 13 Laminate variety I used so is very stable especially with a coat of lacquer. I wish I had a pic which I'm sure would speak a thousand words. The overal advice I would give is to keep it simple and don't complicate it too much. With a working machine he has already remade some of the plastic parts to a much beafier spec.

Hope that helps
Title: Re: 3D printing
Post by: tom osselton on August 06, 2015, 02:20:30 AM
Have you checked out your area for a makerspace or hackerspace for laser cutting?
Title: Re: 3D printing
Post by: nrml on August 06, 2015, 01:13:21 PM
Maplin have an offer on a bundle of parts and plans to build a complete printer for 399 at the moment http://www.maplin.co.uk/p/velleman-k8200-3d-printer-kit-n82qg. From what I have researched so far, it is gives decent performance for the price and lends itself well to improvement mods and upgrades. I would love to get one just to build and improve even though I know nothing about electronics or CAD / 3D modelling. Money is a bit tight at the moment, but it is definitely on the cards at some point.
Title: Re: 3D printing
Post by: picclock on August 06, 2015, 03:33:47 PM
@nmrl

I mentioned the vellman kit about 5 posts previous. It appears to have some issues in that the head is a (relatively) low temperature one unsuitable for nylon or other exotic plastics - but its OK for PLA / ABS. The other issue is that the z axis only has one motor. This will lead to head droop on the X axis, and although it can be sort of compensated for by aligning the bed. I don't think it has a heated print bed either, which could lead to adhesion issues.

I think it depends what you want to do with one of these machines. I want to make working mechanical parts out of nylon or other loaded materials so they will have to be hard and hard wearing, and hopefully accurate  :lol: ,  but if you just want to make decorative parts or parts with low use requirements this may suit. The Velleman model @ 400 (-1p :-) ) is a more expensive - see http://semiu.co.uk/product/prusa-i3-complete-kit/ for the prusa I3 (metal frame). I would buy without Power supply for 330 as I can get a 12v 30A psu for 15 on flea bay rather than modify a PC psu (no hot resisters).

Best Regards

picclock
Title: Re: 3D printing
Post by: nrml on August 07, 2015, 05:18:24 PM
Thanks for pointing out the issues with that one. It will make it easier for me to save my pennies and do a bit more research before taking the plunge. I've been sorely tempted by it ever since the advertising catalogue came in the post.
Title: Re: 3D printing
Post by: picclock on August 10, 2015, 02:42:49 AM
@nmrl
If you want to compare different styles of repraps there is an excellent page with over 50 links to designs and variations here :-

http://reprap.org/wiki/RepRap_Options#Models

There is even one with a welded steel frame that someone here was interested in called an eventorbot.

Best Regards

picclock
Title: Re: 3D printing
Post by: PeterE on August 10, 2015, 05:07:46 PM
Throwing myself into this thread ...

This is an interesting read! I have also started to look for a potential 3D printer for my other hobby (Model Railroading in 1:87 -H0 scale). A fair bit of items lend themselves to be made using this kind of printer.

I have found that the setup I am most appealed by is closest to a Prusa i3 Rework version with a plywood box frame.

The box frame is very stable in Y-direction and fairly stable in X-direction. This can be seen from this image where a plate is used:
http://reprap.org/wiki/File:Prusa_Box.jpg (http://reprap.org/wiki/File:Prusa_Box.jpg)

The original Prusa up till i2 (iteration 2) was set up like a triangular frame in which the moving axes are fitted:
http://www.emakershop.com/browse/listing?l=717 (http://www.emakershop.com/browse/listing?l=717)
This frame is more stable in X than in Y direction.

What I would like to do is to make a Prusa i3 Reworked (latest version) using a plywood box frame and brace it with diagonal bars front and back. I think that would make for a very stable setup in all directions. Then, if the whole thing is secured to a base plate of something like 25 mm ply, that would be as stable as it can get and still be possible to make in a modest home shop.

In all other parts the base i3 stuff works nicely as a start.

What are your opinions on these thoughts?

BR

/Peter
Title: Re: 3D printing
Post by: picclock on August 11, 2015, 07:07:56 AM
Hi PeterF

These are my thoughts on the Prusa i3 so far.

For me plywood is not stiff enough, nor dimensionally stable (humidity and heat are the worst offenders), hence my choice of a metal frame. The weak point in the i3 mechanical design is maintaining the right angle/positioning between the X/Z axis and the Y axis. I have a 600mm square granite kitchen worktop which I will use as a base. By mounting the Y frame directly to the base and using side supports for the gantry, also mounted to the base (as per the plywood version),  the stiffness and precision in all three axis will be maximised. 

By using a direct filament feed to the hot end the loads on the x axis are varied with the need to unwind filament from the spool, additionally the mass of the x axis is increased by having a stepper motor attached. So my choice will be to use a bowden feeder system. This may be iffy for very flexible filaments but for Nylon/abs/polycarbonate it will give better results.

The X axis tensioner is either not implemented or pulls against the vertical smooth rod. I will alter this to place the tensioning load on the two horizontal X axis parallel rods. 

Will initially assemble mine with M5 stainless studding for Z axis and test the results. If accuracy is nbg will replace with better system. Am also not happy with running two stepper motors in parallel from one driver chip so may well make an adapter to use two driver boards, one for each z motor.

Any mechanical mods I make will be probably machined out of aluminium to preserve accuracy - plastic has too high a temperature coefficient for precision stuff.

Future thoughts :-
Stepper motors, the Ramps board uses A4988 chips which are rated up to 35V. Unlike most things, turning up the voltage on a stepper driver results in a decrease in average current consumption and allows a much higher stepper speed - so this is something I may investigate. Likewise an increase in heated bed voltage will allow speedier warmup. Much better Ramps Heater FET needed for this trick. Obviously, plus side of heater bed just goes to higher voltage supply.

Hope to order my kit in the next week or so  :ddb:

Best Regards

picclock

Title: Re: 3D printing
Post by: PeterE on August 11, 2015, 12:08:14 PM
Hi picclock,

Thanks for feedback! Much appreciated!

About the plywood. The box version of the i3 suggests 12 mm furniture (multilayer) ply and that I agree with, but I would double the thickness on the upright frame for both stability and better meat for screws.

Also, to improve the X-Z vs Y stiffness, I will add a diagonal bar from the table surface to the top of the frame. This of course requires a sort of table surface and I have a suitable old piece of 40 mm chipboard countertop. Cutting that in suitable dimensions and then sealing the edges will make for a good enough humidity-resistant base for the whole thing to begin with.

I think it will be sufficent to stabilize the printer and maintain accuracy in print.

The vertical Z axis studding will use stainless for me too. 5mm seems to be standard so that it will be. No ball-screws yet. I will still keep the combined drive for two stepper motors from one output to begin with.

Then when it comes to filament feed and other things, they will be dealt with as the build goes and usage experience tells. Your future thoughts sounds very interesting so I will keep looking in to this thread.

A friend is currently printing the plastic parts on his machine as we speak.

BR

/Peter
Title: Re: 3D printing
Post by: picclock on August 12, 2015, 01:48:32 AM
Hi PeterE

After some further investigation yesterday, I have decided to build from scratch rather that a kit. The kits are more expensive and still don't have the parts or support the configuration I would prefer to use. So I have started to order parts from ebay and will do a build thread in the project logs when I get started.

One of the changes I think is fairly important for a good machine is to change the stepper driver chip to the DRV8825 flavour. I have designed pcb's with the a4988 and I know from experience how ratty they can be at 1/16th step. The DRV chip will microstep to 1/32, but more importantly is a smoother driver, with a higher current rating. I ordered 6 assembled, Ramps compatible boards from ebay at 1.32 each last night.

Does your plastic printing friend take orders ? A lot of the frame parts/bearing holders I will make from Aluminium, but there are some bits like the extruder and the motor holders I will struggle with. I can get a complete set for 36 but will probably not need half of them.

Good luck with your printer project. It sounds like you have the right ideas re stiffness.

Best Regards

picclock
Title: Re: 3D printing
Post by: PeterE on August 12, 2015, 11:56:08 AM
Your suggestion on using DRV8825 stepper drivers sounds like a good choice. I will though stick with the currently common a4988 ones at the moment as I have a fairly steep learning curve to do before getting fluant here.

What was the name of the RAMPS compatible boards, they sound as if they are good valy?

I can check with my friend if he can provide some prints, but don't wait as this is done within the company I work for if you know what I mean.

Sounds like I too should make some photos too when I get started.

BR

/Peter
Title: Re: 3D printing
Post by: picclock on August 12, 2015, 12:37:53 PM
Hi PeterF

The printer has 3 main types of board and an LCD display/sdcard interface. The Arduino card I got from http://www.ebay.co.uk/itm/171827024551 for 7-99 (you could possibly do better on this). This then has a Ramps 1.4 card which I got from http://www.ebay.co.uk/itm/151768808587 for 3.78. The Ramps 4 card has 5 plug in Stepper drivers which I got from  http://www.ebay.co.uk/itm/141672347924 @ 1.32 each (I ordered 6). It also has the thermistor inputs and the head/bed heater control outputs. The Arduino board is also attached to the graphic display and SD card adapter which I got from http://www.ebay.co.uk/itm/141679594646 for 6.48. I also ordered some thermistors and optical end stops for a few pounds.

So far I don't think I have spent much for what I have ordered. Time will tell when it eventually arrives. Am more concerned about drilling the granite countertop than the electronics.

Best Regards

picclock
 
Title: Re: 3D printing
Post by: awemawson on August 12, 2015, 12:58:46 PM
It's amazing what you can buy for remarkably little money in the way of pre-assembled electronics these days. At those prices you couldn't buy the components !
Title: Re: 3D printing
Post by: PeterE on August 13, 2015, 12:05:38 PM
Hi picclock,

Some very nice links there, thanks a lot. Have to investigate a bit closer but I don't think I can get so much better deals than those.

When it comes to drill the granite.
I had to get rid of a very slightly broken corner on one of the benchtop granite "boards" in our kitchen. What worked the best was my diamond file with which a gentle hand quickly fixed the problems.

That said, I guess that diamond-coated drill bits might be a good way forward. As an example of types and prices, the link below lists some easily available ones at reasonable cost.

http://www.arceurotrade.co.uk/Catalogue/Diamond-Tools/Diamond-Drills (http://www.arceurotrade.co.uk/Catalogue/Diamond-Tools/Diamond-Drills)

Slow going (light pressure) and maybe water cooling should do the trick.

BR

/Peter
Title: Re: 3D printing
Post by: picclock on August 13, 2015, 02:10:11 PM
Hi PeterE

I have ordered a couple of 6mm diamond drills from flea bay. I figure I will have to drill about a dozen or so holes hence the spare. I plan to do the drilling on my mill so that all is controllable with minimal lateral forces. Its just something I've never done before - hence the trepidation. I will make aluminium holders for the y rails and do away with the studding altogether. The gantry will be mounted with side plated directly to the granite so the relationship between the two will be v good. I have ordered up a cheapy set of ABS printed plastic parts for $20 (around 13), so that will be enough to get me started to print the final pieces for the machine. Am also getting on well with designspark - done cones now  :med:. Will have to cheat on text though and import it from sketchup when needed. Looking forward to when all the parts arrive and I can do a build. Will start a thread with piccys in Project logs, though there are a lot of build threads for this type of machine on the internet, so I'm not sure how useful it will be.

Best Regards

picclock
Title: Re: 3D printing
Post by: PeterE on August 13, 2015, 03:37:18 PM
Hi picclock,

Will be interesting to hear/read about the granite drilling exercise when time comes.

Your thoughts and mental sketches for the "frame" sound very ridgid and it will be interesting to see the build.

One thing that occurred to me today was that the four printed corner pieces making up the Y axis have no means to secure them to a bed surface. No "ears" or any other means to fit a screw. Think I am going to make some add-on ears from a couple of alu bits. Just haven't worked out the final solution yet. But that should give even more rigidity and stability to the whole setup.


BR

/Peter
Title: Re: 3D printing
Post by: picclock on August 14, 2015, 02:54:07 AM
Hi PeterE

The whole issue with the base in this design is a major one. As you so rightly point out, the y frame and gantry are all supposed to rest on a flat surface in order to achieve any sort of accuracy. Fixing them to something flat is the only way to consistency and rigidity. Once that is sorted the only other thing is the flexing of the gantry in the y plane which can be sorted by two side plates. These can also be used to ensure a true 90 degree angle for the gantry. As to the rest I will find out soon  :scratch:

Best Regards

picclock
Title: Re: 3D printing
Post by: Swarfing on August 14, 2015, 05:21:56 AM
I did not find the base to be a real problem. The longitudinal threaded roads fix to the cross member by aposing bolts which is very rigid. Also if you look at pics of the machine the back cross threaded rod fixes into slots on the side bracing pieces. words of thought here as I found the measurements did not compute for me and the rods ended up being short so measure this bit carefully before cutting. I screwed from the bottom of the base up through to the cross member and side braces. I managed to get him to send me a pic to show you more detail. Hope that helps.
Title: Re: 3D printing
Post by: efrench on August 15, 2015, 03:26:03 AM
I used masonry bits to drill through a 3" thick granite surface plate.  I did it outside with a hand drill and the garden hose keeping it wet.  You definitely don't want to be breathing the dust.

I made through holes, but the best way to do it is to epoxy steel inserts into the holes and keep them level with the top using magnets.

IIRC, the Prusa i3 attaches the print bed at four points.  If this is so, it should be modified to use only three points similar to the way a surface plate is supported.
Title: Re: 3D printing
Post by: picclock on August 15, 2015, 02:35:39 PM
Hi EFrench

I thought to do it much the way you said, except I was going to drill 15mm deep holes,  fit a nylon bolt into a steel M6 spacer with a nut and washer on top. Then epoxy spacer into hole using washer as depth stop. Loosen nut and washer before finally set off and remove any partially set epoxy, then finally remove nylon bolt. I figured it would be a lot easier that drilling 30mm of granite.

Print bed is not nice in the original design. Problem is that its not stiff and flexes with temperature as it warms up. Will try it with the original, cos its dead cheap and quick, but will likely replace with glass and heater pad, shame the cost is so high atm..

I seem to remember at one time you could get stick on heating elements for rear windscreens - something like that on a printer bed glass would resolve the issues of warping altogether (100C on a windscreen is a bit much I suppose  :lol: ).

Best Regards

picclock
Title: Re: 3D printing
Post by: PeterE on August 15, 2015, 04:32:01 PM
Swarfing,
The picture attached shows a lot but not all of your setup.

   I notice that you placed the bracing triangles in line with the central opening and not in line with the outer sides of the upright. Any particular reason why?

   The Y axis motion parts are as you say connected to the upright using the two Y axis all-threads and nuts, and I can also see that you have made the upright with double thickness compared with the drawings I have seen - much along my thoughts as well, but did that create the "too short allthread problem"? Menaning that it affected the length for housing the Arduino below the allthreads at the back?

   You mention that you have secured the upright to the base plate using screws from below, but have you also secured the Y axis motion end parts as well or is the only connection through the pinching in the upright slots?


efrench,
Yes you remeber correctly. The design is to have the print bed secured at the four corners and I guess that the clipped-on glass plate is used to prevent/minimize the warping.

   How would a three-point securing improve on warping, that is less warping,  in comparison? Would the glass plate make a better work of stabilizing the whole thing?


picclock,
Using glued in thread spares into the granite bed would work beautifully.

/Peter
Title: Re: 3D printing
Post by: efrench on August 16, 2015, 04:03:23 AM
A good analogy would be a three legged stool compared to a four legged stool. It's easy to get three legs all touching the ground at the same time, but it's rather difficult to do the same with four. 

Four points are over constrained and will cause stress in the plate which may lead to the plate being warped. 

I think it's more likely the glass will take on the shape of the plate rather than straightening it.

Title: Re: 3D printing
Post by: picclock on August 16, 2015, 04:11:05 AM
@EFrench

The bed levelling issue is mad. The bed is levelled by adjusting a heater board which buckles under heating due to differential expansion and is attached  via the screws and springs which is dubious at best. Much better (IMHO) to fix the glass and level it, then clip the heater board to the glass and let it go where it will.

I think some edge connection clamps for the glass, rigidly mounted to the y carriage with space underneath for the heater to attach would be a significant improvement, and once leveled should not need an readjustment.

Best regards

picclock
Title: Re: 3D printing
Post by: efrench on August 16, 2015, 12:40:30 PM
In that case I'd attach the heater to an aluminum diffusion plate. If you're going to be printing multiple items, then you will want to remove one glass plate to cool while printing on the next. 

My diffusion plate is 8mm thick (400mm diameter) Mic6 aluminum and is attached at three points.  The bolt holes are oversized to allow for expansion.  Initially the heater will be held against the bottom of the diffusion plate with springs.  If this isn't satisfactory, then I'll use a silicon glue. 
Title: Re: 3D printing
Post by: Swarfing on August 17, 2015, 06:26:04 PM
Peter the ramps unit is fixed to the left triangle you see in the picture. unfortunately that is the only pic i have supplied by the owner. I only built him the basic unit and left him to finish all the wiring etc but I did have it running smoothly before handing it over. it leaves plenty of room for the electronics and the z axis is no problem at all with height. In short you can make things as thick as you like without affecting anything at all. The opening is still as per the original so no problems there with bed movement etc. Don't forget the original design is to try and make it as cheap as possible in-line with the reprap philosophy.
Title: Re: 3D printing
Post by: PeterE on August 18, 2015, 12:49:41 PM
Swarfing,

Thank you very much for answering.  It verified what I needed to find.

Just trying to compile as much info as possible before attacking the wood with a saw.

My version will be a wooden box framed Prusa i3 Reworked or at least something close to that. Bits have been ordered and are on their way in.  :drool:

/Peter
Title: Re: 3D printing
Post by: picclock on August 21, 2015, 02:00:15 AM
Hi PeterE

Good luck with your build !!. Will you be doing a project log ? Will be interested to see what snags you encounter.

I have most of the parts for my I3 now. A couple of things worth mentioning. I have sourced some 16 tooth GT2 pulleys for the steppers. These will improve acceleration, especially on the heavy Y axis, though you may have to change the motor position to get a straight belt run. Also have the motors. Force produced by motor is directly proportional to magnetism produced by current. As all motors are inductive, current rises slowly, so speed of rise is controlled by voltage and Inductance of windings. Higher inductance results in more torque but slower operation, so there is a best compromise somewhere in there. I intend to run the drivers at 24V as this will halve the time for the motor to produce torque, also it is the design sweet spot for the drivers I am using, DRV8825's.  Have decided to alter bed design as shown in sketch below.

I found good youtube series of videos by a chap called Thomas Sanladerer, this one about pid tuning marlin :


Best Regards

picclock

Title: Re: 3D printing
Post by: PeterE on August 21, 2015, 10:32:53 AM
Hi picclock,

Have been thinking about a build log, but I have to be very clear that it will take time. I still work for a living which includes travelling at scheduled times so I think it would be very useful if I were not alone  :poke:

My log would be called "PeterE Builds a 3D printer". Perhaps you could make a similar one because I too think it will be nice to compare ways forward. But where to put it? In this folder or under Projects????

My pulleys are 20T as part of this kit I picked up from ebay:
http://www.ebay.com/itm/3d-printer-reprap-prusa-i3-movement-kit-GT2-belt-pulley-608zz-lm8uu-624zz-/181651872211?hash=item2a4b4b99d3 (http://www.ebay.com/itm/3d-printer-reprap-prusa-i3-movement-kit-GT2-belt-pulley-608zz-lm8uu-624zz-/181651872211?hash=item2a4b4b99d3)
Felt like a fair price to me and I got all the important bits in one go.

When it comes to first setup I will follow the "standard" to begin with. This is learning on my part so keeping with standard makes it easier to acquire. Then I may well do some of your tweaks to enhance the whole thing. This also means I am starting out with the A4988 drivers which are part of this electronic kit - Hope it will work as intended because I think it was a silly low price.
http://www.ebay.com/itm/3D-Printer-RAMPS-1-4-Kit-Mega-2560-5x-A4988-LCD-2004-Controller-For-RepRap-/191233668287?hash=item2c866a34bf (http://www.ebay.com/itm/3D-Printer-RAMPS-1-4-Kit-Mega-2560-5x-A4988-LCD-2004-Controller-For-RepRap-/191233668287?hash=item2c866a34bf)

When it comes to instructions I have found two which seems good, especially the one referenced below! This fellow also has an interesting idea of placing the Y axis motor opposite to standard - a thought to contemplate a bit but sounds interesting.
http://www.dragonflydiy.com/p/building-3d-printer.html (http://www.dragonflydiy.com/p/building-3d-printer.html)

I also have some ideas about a new bed design but it is not finished.

BR

/Peter
Title: Re: 3D printing
Post by: picclock on August 21, 2015, 01:17:08 PM
Hi peterE

That electronics kit was a steal. Only other thing you may want to add is the graphics display because that allows you to download a file to an sd card and print it standalone.

Having the y motor at the back and the home position at the rear also are both things I will try, then when it goes home at the end the model is pushed to the front ready to remove.

 I have just started looking at some of the parts and have run into an issue which I had encountered before. I pushed the linear bearings into the z axis plastic holders and found that the smooth motion degraded to lumps and bumps. I took one of the bearings out and the other one was still nbg. Then I remembered my previous experience where this happened. It was on an industrial pick and place robot where the hole for the bearing was out of round. Just pushing the bearing into the holder is enough to distort the case and destroy the smooth motion. should be OK with the tye wrapped ones but the z axis pairs will need the holders sorting if they are the same as mine. I was making new parts anyway so not a bodyblow, but a bit of a surprise. btw, the two z axis bearings can be replaced by one LM8LUU - still have to have a gentle holder though. 

I was thinking of putting my assembly attempts in project logs - cos thats the right place. Will probably call it picclocks attempt at an I3 3d printer. Should cause no confusion  :lol:

Will not start log or build proper until after I return from holiday on the 17th September.

Best regards

picclock

PS Just had a thought. You can program and check out the Arduino card just using the power from the usb lead. I did it to check for functionality but I was surprised at how long the compiler (Arduino 1.6.5) took to compile the marlin code ~4.5 mins. I thought it had crashed but it just takes a long time.  I7 64bit Windows 7. The other thing is that it recompiles to upload even if it has successfully compiled before.
Title: Re: 3D printing
Post by: PeterE on August 21, 2015, 04:58:20 PM
The graphics display was included! At the top in the picture!

/Peter
Title: Re: 3D printing
Post by: Brass_Machine on August 21, 2015, 09:09:09 PM
Peter & Picclock,

I will be watching your build threads. I plan on building a 3D printer sometime in the next year...

Eric
Title: Re: 3D printing
Post by: picclock on August 22, 2015, 03:13:10 AM
Hi PeterE

The display card you have is a 4 line text display - as is the one I incorrectly ordered. The display card I should have ordered is a graphic display - but I screwed up and ordered the wrong one  :bang: One of those late at night jobs .. . 

The difference is that the graphic display can show temperature plots and other non text stuff and its easier to navigate between menus. Not sure if the text display will do the run standalone bit.

Have ordered correct one for 8.39 - don't usually make that kind of mistake. Pictures below for reference .

Best Regards

picclock
Title: Re: 3D printing
Post by: PeterE on August 22, 2015, 08:56:56 AM
Aha, THAT was the difference  :palm: I just thought it gave more text rows ...
Title: Re: 3D printing
Post by: picclock on August 22, 2015, 05:21:32 PM
@ brass machine
typo error - should be years  :Doh:

hopefully you will learn a whole new lot of mistakes from the logs.

Best Regards

picclock
Title: Re: 3D printing
Post by: Arbalist on November 07, 2015, 06:27:21 AM
Good luck to all those building these machines but I'm still left wondering why. This article reinforces many of my thoughts. Even if I made plastic models the quality from many machines leaves a lot to be desired.

http://www.techrepublic.com/article/3d-printing-10-factors-still-holding-it-back/

Title: Re: 3D printing
Post by: RobWilson on November 07, 2015, 06:54:47 AM


http://www.techrepublic.com/article/3d-printing-10-factors-still-holding-it-back/

What a load of bollocks !


Rob
Title: Re: 3D printing
Post by: Arbalist on November 07, 2015, 07:22:37 AM
http://www.techrepublic.com/article/why-desktop-3d-printing-still-sucks/
Title: Re: 3D printing
Post by: S. Heslop on November 07, 2015, 07:27:35 AM
"Yes, 3D printing stands to completely transform the way we make, replace, and transport products and will disrupt nearly every major industry."

i'm really having a hard time writing anything about 3d printing without it becoming snarky. i think its almost useless on the hobby end, but i dont hold it against anyone that wants to play around with it. but there are so many... tech hipsters out there that get real self-aggrandizing about it, proudly proclaiming that their cnc hot glue guns are going to lead us into a utopian future of expensive and lumpy extruded plastic and pirated action figures

the things really hit all the right beats for those kinds of people; open source, arduino controlled, touching on piracy (or the promise of piracy), a continuation of the old cnc fad, and the whole self-important tech-fetishism thing

i think the only way i could see these things being used outside of rapid prototyping is as a marketing gimmick
Title: Re: 3D printing
Post by: PeterE on November 15, 2015, 01:20:25 PM
That was kind a harsh, I agree.

The reason for my venture into the 3D printer "world" is to investigate whether it is good enough to produce the base for 1:87 (H0) scale model accessories for those things that are difficult to create in more than one piece. Particularly double-curved surfaces like small boat hulls and other relatively complex details that are fiddly to make by hand.

Think  hulls, small phone booths, stacks of things, etc etc. The advantage with 3D printing is it requires a cad file as source nad the result will be as many bits as desired.

The thing about piracy may well be a risk, but there is also a community around the OpenSource projects that shar designs with the particular purpose of tweak a design to your own specific needs. That means that I can use a design  and by then upload it to the community page I can say "Thanks for letting me use it, here is my version".

If the printed result is supposed to be base for business it is of course handled in a completely different manner and the original CAD file will most certainly not be available on line.

The printed result is not very smooth, but that is not  a concern on my part as I anyway need to finalize the part and give it a surface finish that suits the use and purpose. I don't believe for a minute that I can get a completely smooth finished part of my slef-built thingy. I am building it to test my precision and abilities and get a working thing out of that exercise.

I think this also makes it clear that I am not a tech hpister - I am a eBusiness System Manager handling a major company's eShop activities as a proffession and daily work. At home I actually do enjoy all kinds of activities using hand and machine tools, wood or metal.

BR

/Peter
Title: Re: 3D printing
Post by: RobWilson on November 15, 2015, 01:55:24 PM
I for one think its a marvelous technology, it  brings Plastics an engineering material into the home shop , yes the 3DP  technology  is in its infancy , SO WHAT !  , I can remember when there were no home shop welders , NO STICK ,MIG and hell no TIG . Look now cheap as chips .

Plastics are fairly difficult to work with , yerh bar stock is easy but has anyone out there got a plastic injection moulding machine ?,,,,,,,,,,,,,,,,,,,,,,,,that will be a no then !  3DP means complex shapes can be made at home by anyone .

As the the argument about making toys , yoda's heads  and the likes is all they are  good for , well thats fine if that all your imagination can only come up with is making wee doodads  , me I can see all sorts of uses , pattern making for one , plastic  patterns are moisture resistant for one .


And what about the machine build , the learning involved   is that not part of the fun . To me if it gets kids off frigging with an xbox controller and making plastic gears its all good .

And the printing the  plastic gun  argument   :loco:,,,,,,,,,,,,,,,,,, WTF ! ,  get a grip


To me the 3DP haters are narrow minded and stuck in the past . At the end of the day its HERE TO STAY ,  :thumbup: to me its another tool/machine ,medium to be exploited .


Rob

Title: Re: 3D printing
Post by: Arbalist on November 15, 2015, 03:45:31 PM
Another good article from someone who uses 3D printers for a living.

http://gizmodo.com/why-3d-printing-is-overhyped-i-should-know-i-do-it-fo-508176750
Title: Re: 3D printing
Post by: Joules on November 15, 2015, 07:21:59 PM
 Ahhhhhh 3D printing, it be witchcraft I tell's ya....

As with any new skill, it takes time to learn the craft.  Those with maker skills fare much better, but it's not going to be for everyone, bit like whittling spoons.   :ddb:

Knocked the bedside lamp whilst fumbling for my glasses and thought I can do better than this.

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/IMG_0018_zpsep96fcyy.jpg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/IMG_0018_zpsep96fcyy.jpg.html)

My other half had picked up some usb flex LED lights.   Aldi had just had a Powerbank on offer, so why not combine the lot into something useful.  Sat down Friday morning with the bits and by Friday afternoon had the above.   His and Her reading lights that should be good for 60-90hrs continuos use between charges.  No wires, you can lift it out of the cradle and take to the bathroom if required, and its to hand but not in the way.

Since this turned out OK, print another one on Sunday to use as a desk lamp for craft work, macro photography or illuminating the microscope stage.

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/IMG_0023_zps0ppdgie1.jpg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/IMG_0023_zps0ppdgie1.jpg.html)

As I mention macro photography here's an example.

(http://i7.photobucket.com/albums/y253/joulesbee/3D%20Prints/IMG_0022_zpsyani6nrx.jpg) (http://s7.photobucket.com/user/joulesbee/media/3D%20Prints/IMG_0022_zpsyani6nrx.jpg.html)

3D printed on a cheap machine.  But why would anyone want to mould parts in silicon rubber.  Surely machining them out of cast iron has got to be a better idea....   :palm:

Guy's, it's a relatively new technology for the home user.  You do need some imagination to use it, but I think alot of people miss the point for how handy it is for prototyping, making parts to get you out of a fix quickly and complimenting other methods of making.   Think of it like the early home computer, people would ask me what the heck do you want one of them for, what can you do with it.  Well early on I had a hard time coming up with an answer, finally I got a job as a computer engineer and they stopped asking me what you do with it.

p.s
     Hi Rob   :wave:  I have an injection moulder in the corner of the workshop.

(http://i7.photobucket.com/albums/y253/joulesbee/Workshop/Front%20view_zpsftycizk5.jpg) (http://s7.photobucket.com/user/joulesbee/media/Workshop/Front%20view_zpsftycizk5.jpg.html)

Old Austin Allen Gnat.  It doesn't get any use now I have moved onto 3D printing.   No longer cost effective to do short runs, might as well farm out abroad  :( Once the prototype has been approved.

Right, my broomstick has printed so I'm off.............
Title: Re: 3D printing
Post by: Pete49 on November 15, 2015, 10:27:12 PM
The reason for my venture into the 3D printer "world" is to investigate whether it is good enough to produce the base for 1:87 (H0) scale model accessories for those things that are difficult to create in more than one piece. Particularly double-curved surfaces like small boat hulls and other relatively complex details that are fiddly to make by hand.
Think  hulls, small phone booths, stacks of things, etc etc. The advantage with 3D printing is it requires a cad file as source nad the result will be as many bits as desired.

/Peter
Peter this is what I am doing with what I find online as I'm crap at learning 3D cad as I seem to have trouble retaining what I learnt the day before. It prints nice and to smooth it I am looking at acetone smoothing. I have printed a sample to try it on (printed at0.01mm layer). Your printer should do what you want easily
Pete
Title: Re: 3D printing
Post by: RobWilson on November 16, 2015, 04:36:44 AM

p.s
     Hi Rob   :wave:  I have an injection moulder in the corner of the workshop.

(http://i7.photobucket.com/albums/y253/joulesbee/Workshop/Front%20view_zpsftycizk5.jpg) (http://s7.photobucket.com/user/joulesbee/media/Workshop/Front%20view_zpsftycizk5.jpg.html)

Old Austin Allen Gnat.  It doesn't get any use now I have moved onto 3D printing.   No longer cost effective to do short runs, might as well farm out abroad  :( Once the prototype has been approved.




 :lol: :lol: :lol: Nice one Joules  :Doh:   ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, something you don't  see often in the home shop  :dremel:


The Silicon mould looks interesting , did you print the part and take a mould from that  or just print the mould ? 



This I thought was an excellent example of how 3DP can be put to good use  ,    http://madmodder.net/index.php/topic,10491.msg120010.html#msg120010  .



Rob
Title: Re: 3D printing
Post by: RobWilson on November 16, 2015, 04:57:29 AM
Title: Re: 3D printing
Post by: Joules on November 16, 2015, 05:29:23 AM
Printed the mould Rob, as I wanted to see how it would come out.  The contact surfaces of the mould were polished, note the rounding of the corners.  The loop round the upper mould half slides down to locate the two parts, then I gently clamp them.  Small holes in the upper half allow silicon to ooze out under pressure, I needed to use a pin to get the silicon into the narrow part of the mould around the vertical insert.  With hindsight I would make this a push in part after the mould halves are joined.   On my CAD system is a partially drawn model for an injection moulder using printed parts for the scissor arms and other parts, the idea is to use a 3D printer extruder for a desktop automatic micromoulding machine.  Think 3D printer on its side with no X,Y.



This is my inspiration.


PPS, open to offers on the injection moulder if anyone fancies it.
Title: Re: 3D printing
Post by: Joules on November 16, 2015, 06:40:25 AM
I know, it's only a toy  :thumbup:

http://www.rcgroups.com/forums/showthread.php?t=2390401
Title: Re: 3D printing
Post by: RobWilson on November 27, 2015, 03:56:00 PM
NinjaFlex ( name is a bit sad )  looks interesting 


Title: Re: 3D printing
Post by: RobWilson on November 27, 2015, 04:03:38 PM
This just shows what can be 3DP 




I don't see the iron man suite  :borg:  , I see motorcycle fairings and seat units   :dremel:


Rob
Title: Re: 3D printing
Post by: bry1975 on November 28, 2015, 10:34:39 AM
Guys,

For pro 3D printing why not send the designs out to 3D p*i**tUk or S****ways etc.

IMO SLS printing is far superior to abs or pla filament printing!

Regs

Bry
Title: Re: 3D printing
Post by: AdeV on November 28, 2015, 10:37:48 AM
Guys,

For pro 3D printing why not send the designs out to 3D p*i**tUk or S****ways etc.

IMO SLS printing is far superior to abs or pla filament printing!


You ask this on a forum populated exclusively (?) with people who have home workshops....!?  :lol:

IMHO the biggest attraction of 3D printing is the immediacy of it. Sending out to have it made is no better than outsourcing your machining work while your mill stands idle IMHO...

Now... I might change my tune a bit if I ever raise the 100,000ish needed to buy a 3D titanium sintering machine....  :drool:
Title: Re: 3D printing
Post by: bry1975 on November 28, 2015, 10:53:24 AM
Sorry Ade. :D
Title: Re: 3D printing
Post by: Joules on November 28, 2015, 11:47:20 AM
Guys,

For pro 3D printing why not send the designs out to 3D p*i**tUk or S****ways etc.

IMO SLS printing is far superior to abs or pla filament printing!

Regs

Bry

Depends what you need, I had used one of those outfits for quite a while.  Once I got my machine dialled in and worked out how to get a good surface finish.  My turn around time on prints can be as little as 24 hrs rather than a week+.  Add, no hassle over confidentiality agreements when faced with sending work out over the net.  It takes a bit of elbow grease to polish a silk purse, but its still less hassle than working wood or metal that used to be the preferred prototype materials, not to overlook keeping it in house means the outsource fee's stay in house too.

I have to smile at times, when people compare SLA/SLS and FDM.  What isn't obvious to many is the blob size on each can be about the same in X,Y  Vibration is your worst enemy in 3D printing closely followed by getting all the settings for your chosen material nailed.   I admire the guys that work from polyurethane foam, carve and coat with epoxy to produce stunning work.  The 3D printer is just a better enabler, you get out what you put in.   Thats where it fits in the home workshop where you can spend the time, under no pressure to perfect your art and understand how it fits in with your other skills.
Title: Re: 3D printing
Post by: Will_D on January 15, 2016, 10:11:48 AM
What with the couple of threads about 3d printing ( Peters and the Quorn) and a requirement to have a STL file printed for an Arduino/Brewing project I am getting more interested in at least the design process

I may not need to buy a printer as there are plenty of d printers available even in Dublin.

Anyway my point is I intend to use Google sketchup as I know it, its free and I very much like user interface. There is a add-on to output STL files (and a lot of others.

Just updated to Sketchup 2016 and will see how I get on.

Anyone got any comments/suggestions/or "Don't do it Will"
Title: Re: 3D printing
Post by: Joules on January 15, 2016, 11:19:02 AM
Will, get it drawn up as an STL, if you want shoot it over to me (PM for address) and I can check it's watertight and ready to print.


                      Joules
Title: Re: 3D printing
Post by: efrench on January 15, 2016, 03:42:03 PM
I've seen a few complaints about STL creation in Sketchup.  It seems they leak a lot of water :bugeye:  I was never able to make a useful drawing in Sketchup, but you may have more success.  I like the Fusion 360 interface a lot better.  Its UI is a lot closer to other CAD programs than Sketchup. 

There are models for all of the Arduino boards online and importing them into Fusion 360 is a breeze.

Here's one I'm working on for an Arduino + 16x2 LCD + Stepper driver:
(http://img.photobucket.com/albums/v649/etfrench/Misc/CaseForArduinoAndLCD_Front_zps9wte1rs9.jpg)

(http://img.photobucket.com/albums/v649/etfrench/Misc/CaseForArduinoAndLCD_Back_zpsdsxoohwh.jpg)
Title: Re: 3D printing
Post by: PK on January 15, 2016, 03:59:46 PM
We've really looked hard at it for hobby/work applications. We even sent a few grand to Formlabs for a Form1 at one point, only to later get the money back.

Joules prints are excellent examples of what can be achieved with a "plastic puker" (apologies but it was someone else on this forum that came up with that one) printer. He clearly has a good grasp of what it takes to operate the equipment and his results reflect that, ie they all look half decent and at least good enough for fit up tests and prototypes.

A business peer of mine who does a lot of mechanical prototyping and very short run production reckon's his FDM printers are fantastic. Interestingly and OT, he does something I've not seen anyone else do. He runs the printers in an box at elevated temperatures. This speeds things up and reduces shrinkage induced stress in the part.

I want to make case prototypes for products and other things I can show customers. So plastic pukers are not for me. Even SLS (shapeways) needs lots of finishing before I could show it to someone and have them be impressed.

We may still buy an SLA printer, but we recently sent a complex part off to a prototyping company in china for 3d printing so we could check it before we got injection mould tooling made and they said that we should get them to machine it from ABS on their 5 axis machine instead. It came back absolutely perfect. In fact, the first two units we sold were the machined prototypes because the tooling wasn't ready.

So we'll probably go down the 5 axis path rather than 3d printing.
Title: Re: 3D printing
Post by: Will_D on January 16, 2016, 03:31:23 PM
Will, get it drawn up as an STL, if you want shoot it over to me (PM for address) and I can check it's watertight and ready to print.
Joules
#Many thanks for the offer Joules, but I downloaded SolidInspector^2 which claims to find the leaks and even fixes them. Also the 3d printers "tend" to verify the .stl files before printing.

Any ways "new year and new technology(free-software only)"

Wth: By the end of the year it will be "end of year and new hardware arriving" ( Black Friday deals on 50 micron printers  :bugeye:)

Tis a slippery slope us madmodders tread!

And as for the digital scopes/testers/sig gens threads: "Get behind me Satan"
Title: Re: 3D printing
Post by: Joules on January 16, 2016, 03:50:22 PM
Thanks PK, don't know if this would be of interest, maybe too small/expensive for what it is.

www.pocketnc.com/

Well Will, have to find something to offer you, still hankering after trying some of your Grain father produce.   :drool:
Title: Re: 3D printing
Post by: PK on January 16, 2016, 05:21:34 PM
I've seen that little 5 axis machine before. It looks surprisingly good!

I already have a 4 axis setup for my X3. It seems logical to add a trunnion table type of thing to that....

Anyhow, I promised pictures:
I've done it as a link to a large JPG here http://www.caswa.com/images/forums/proto.jpg so you can zoom in and see the detail. The black part is from the injection mould tool we went on to make after we were happy with the fit of the part on the left which was machined from ABS.

The finish on the ABS part is perfect...
Title: Re: 3D printing
Post by: PK on January 16, 2016, 05:32:10 PM
 :doh: Having hit the Post button I, of course, immediately find the other samples I was going to put pics up of!

First one is of two technologies, on the left is a black part made by my aforementioned buddy with the preheated machines. On the right is an SLA part we had made a few years ago. You can see (I hope) that it starts to loose detail on the threads...

Second is an example of what we have used 3d printing for.. The black bit was 3d printed by ShapeWays, sanded, filled, sanded, filled, sanded, sanded, sanded....... Textured.
We then made an RTV silicone mold and cast the blue part in 95 shore polyurethane. The blue bit has an inductive charger for the device potted inside...

Title: Re: 3D printing
Post by: Joules on January 16, 2016, 05:52:01 PM
I've seen that little 5 axis machine before. It looks surprisingly good!

I already have a 4 axis setup for my X3. It seems logical to add a trunnion table type of thing to that....

Anyhow, I promised pictures:
I've done it as a link to a large JPG here http://www.caswa.com/images/forums/proto.jpg so you can zoom in and see the detail. The black part is from the injection mould tool we went on to make after we were happy with the fit of the part on the left which was machined from ABS.

The finish on the ABS part is perfect...

Very nice design work on that part PK, can you give me a clue on dimensions. I look to breaking complex designs up into smaller parts then reweld them back to single parts.  I assume some nice internal moulded detail so maybe produce this as two shells, inner and outer to get best surface finish on both sides.  I would love one of those 5 axis desktop cnc's, on my wish list if someone pays me an obscene amount for one of my designs.
Title: Re: 3D printing
Post by: PK on January 16, 2016, 05:59:51 PM
Very nice design work on that part PK, can you give me a clue on dimensions. I look to breaking complex designs up into smaller parts then reweld them back to single parts.  I assume some nice internal moulded detail so maybe produce this as two shells, inner and outer to get best surface finish on both sides.  I would love one of those 5 axis desktop cnc's, on my wish list if someone pays me an obscene amount for one of my designs.

The black part was done on a commercial injection moulding machine using a tool made from tool steel. The tooling cost was about $AU2500 as I recall, which is pretty good, but still worth AU$100 to get the prototype machined first, just to be sure.

We've done two part tooling in silicone, you pretty much have to use a non gassing resin (ie anything cured with MDI is out of the question) unless your part geometry is very simple. 

Silicone molding is pretty easy to set up for. You can do it without any special tools, although a vacuum/pressure pot is really helpful.
Title: Re: 3D printing
Post by: Joules on January 16, 2016, 06:26:24 PM
Yikes, only AU$100 for the 5 axis machining.  Thats really good value compared to 3D printing, not much in the cost, but a world of difference in quality. 
Title: Re: 3D printing
Post by: PK on January 16, 2016, 08:34:03 PM
Sorry, I didn't answer your question.
One ISO standard beer bottle top for scale: