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Project Logs / A little 3D project
« Last post by AdeV on Today at 06:03:55 PM »
In my master bedroom, I have a built-in wardrobe with four mahoosive sliding mirror doors. They are phenomenally expensive, yet they are the cheapest nastiest construction I could imagine; basically, some bent metal to make the frames, relying on some weird clips and a folded metal piece to tie everything together. Really nasty....

The wheels at the bottom, although rudimentary and not pretty, do function:



The holder simply has a nylon "pulley" (which runs on an aluminium inverted "V", much like a lathe way). The holder slides (rather stiffly) into the other part, which is screwed and clipped to the frame. The long bolt sticking out the top allows one to adjust the wheel height. Gravity keeps the whole shebang in place. As I said, at the moment these run on an aluminum V-shaped track; but they do have a tendancy to fall off at the slightest provocation (e.g. if you open or close the doors...  :scratch:), so I'm going to change the track for a simple slot routed into some plywood, which the wheels will run inside. This should reduce their tendency to go wonky.

The topside of the doors currently has a dreadful "blade" arrangement, glued on with what I can only describe as "hard snot", which run inside a slot in some more V-track aluminium. Unfortunately, because the slots aren't quite completely straight in at least 2 dimensions (and possibly all four), the "blades" have a tendency to bind, jamming the door and lifting one of the wheels off its track...  Here's where my 3D-printer comes to the rescue!

I'd already designed this up with the idea of making it in folded metal; but the 3D printer allows me to play around a bit, and this is what I came up with:



From left-to-right: The wheel's pretty self explanatory. I am not yet sure if I'll use printed plastic, or nylon around a bearing. I guess we'll see how it works out with the printed versions, although I do actually have the nylon already! Then the simple shaft (I'll use metal if I use a bearing, for a nice press fit), then the equivalent of the wheel holder. Unseen in the photo, this has a ~6mm hole up its back end. Not shown ('cos I don't have one!) is a fairly strong spring that'll be in there; this will be trying to push the wheel out of the next part, the "box" for want of a better name. This is the bit that screws to the frame. Atop that is a "handle", and the bolt which goes into the wheel carrier & stops the whole thing from flying out.This could be replaced by a wood screw if a better "bite" in the plastic carrier is required to hold the spring back.

The next two photos show how it's supposed to work:



Imagine it upside down, the wheel is in the upper track, the spring holds it up. To fit the door, or to remove it for any reason, simply pull down on the handle, which pulls the wheel into the holder, out of the track, and away we go!



The height can be adjusted by simply screwing/unscrewing the bolt somewhat. So long as there's enough thread in the hole to keep the spring in check, it should be good; and why the complicated spring/handle arrangement? Well... apart from a) it's cool, and b) ease of installation; it also means I don't need to worry too much about height variations in the upper track. So long as the wheel is sufficiently engaged not to drop out of the track at it's highest point, it should automagically adjust at the low points without binding or other unpleasantness... At least... that's the theory  :lol:

There's a couple of tweaks I need to make to the design to overcome a couple of minor issues I've found; and I need to find some suitable length bolts with a smooth shank at the top (I reckon a cap-head bolt will be better than a hex nut), find some suitable springs, and I'm good to go!

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Still no parts but at least today I ran the cabling from the digital output, across three cabinets within the existing trunking, bored a 20 mm hole for the cable gland and terminated the cable on the other side of the gland  in an illuminated DIN 43650 solenoid socket ready for when bits arrive.

I even bored a hole in the lid of the coolant tank to take the output hose from the currently non existent de-pressurising solenoid valve.


 . . . . . so back to thumb twiddling . . . . .I don't do the patience thing very well  :lol:

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The Water Cooler / Re: Masham Steam Fair this weekend
« Last post by howsitwork? on July 21, 2019, 02:51:43 PM »
please ignore the nerds bit of the post  a combination of operator incompetence ,autocorrect and big fingers on ipad. Itís been a good day. Weather fine but cloudy. Displays were good and loads to see.
Traffic que getting out as the traction engines left ( some under their own power returning home) was as bad as expected but most drivers seemed to take it in good spirit. Hopefully Double boost will ave video up on his website shortly.

Ian
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CNC / Re: Cetus3D 3D Printer
« Last post by AdeV on July 21, 2019, 01:03:34 PM »
100 mm x 70 mm by about 65 tall

For scale the hole in the middle is 42 mm (To take a VDI 40 spigot)

The Cetus 3D table build size is 180 mm x 180 mm

Ahhh, they're quite a bit bigger than they seem in the photos then. Fairy nuff!

TBH, the reason for printing multiples wasn't so much to save time, as to save faff: Set off a 16hr print, go off and do 16hrs of Other Things. Obviously, yes, you need to be confident that your printer won't foul up mid-way through!
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CNC / Re: Cetus3D 3D Printer
« Last post by awemawson on July 21, 2019, 07:27:35 AM »
And those inserts are only printed at 20% fill rate so inside is just a fairly open honeycomb. Surprisingly this was more than adequate for the application.



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CNC / Re: Cetus3D 3D Printer
« Last post by Muzzerboy on July 21, 2019, 07:17:57 AM »
Crumbs - how big ARE they? It looks like you should easily be able to get 4 or even 6 on the bed at once... unless my sense of scale is completely out of kilter?
As Andrew says, the print time isn't improved by clustering several together. You still have to extrude the same amount of material per part and there is also the additional moves from part to part within each printed layer. Although the process seems to have gone well here, if there had been a problem with the filament etc, it could have led to more than one part being scrapped.

The biggest time savings come from choosing the lowest resolution (thickest layer) that makes sense for the application. I've found that even fairly coarse settings can result in very reasonable looking parts.
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CNC / Re: Cetus3D 3D Printer
« Last post by awemawson on July 21, 2019, 06:53:12 AM »
100 mm x 70 mm by about 65 tall

For scale the hole in the middle is 42 mm (To take a VDI 40 spigot)

The Cetus 3D table build size is 180 mm x 180 mm
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by awemawson on July 21, 2019, 06:48:39 AM »
The Grippex gripper works on a large range of diameters and also will grip hex. I think mine covers 2 mm to 60 mm without adjustment.

There are parting tool holders that incorporate a push fit forked gripper that grabs the bar by pushing in the X direction rather than Z - their concept is quite clever in that usually you want to bar pull after parting off so this avoids an extra tool change and associated move to a safe place, but like your tube the range of sizes is severely limited.
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by AdeV on July 21, 2019, 05:23:24 AM »
A friend of mine is a CNC machinist by profession, I was talking about bar feeders to him one day, he said - don't bother... just turn up a piece of tube to be a 1 thou interference fit. Put a shallow taper in the front end just larger than your bar stock, so the end slips over. Now mount it in a toolholder. When you want to pull the bar; simply drive the tool onto the bar; release the chuck; pull the tool back the desired distance, close the chuck, then pull the tool off the bar... job done!

Obviously, you have to make one for every size of bar you want to pull; and it's no good if you need to pull something that's not plain bar; but it struck me as an elegant solution to the problem: Simple, cheap and reliable.

On the other hand... those grippers look cool!  :thumbup:
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CNC / Re: Cetus3D 3D Printer
« Last post by AdeV on July 21, 2019, 05:13:26 AM »
Crumbs - how big ARE they? It looks like you should easily be able to get 4 or even 6 on the bed at once... unless my sense of scale is completely out of kilter?
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