Author Topic: What CAM?  (Read 23895 times)

Offline AdeV

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What CAM?
« on: January 08, 2013, 07:44:19 AM »
OK, so I've finally started to get the hang of SolidWorks. I've now got a wheel designed, with cutouts to make spokes, nicely filleted edges, yada yada. Now I need to turn it into something the Bridgeport will understand...

So... what CAM software?

I reckon either MeshCAM or BobCAM for S/W (not that I can find any prices - if it's more than about £100 for a licence then it's not going to happen). BobCAM has a Heidenhain post-processor, which is great, it means I can feed the controller with the same language I've already been programming it in. MeshCAM looks to be a G-code only system, which is OK (my controller will do G-codes), and makes quite a song and dance about how simple it is to use - which is great for a numpty like me.

Any recommendations gratefully sought.
Cheers!
Ade.
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Offline Swarfing

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Re: What CAM?
« Reply #1 on: January 08, 2013, 07:59:19 AM »
I use CamBam and like it a lot
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Offline AdeV

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Re: What CAM?
« Reply #2 on: January 08, 2013, 08:45:29 AM »
Cool - CamBam is somewhat closer to the right price (significantly cheaper than the other two...). My first effort with it would appear to be an epic fail however....


OK, so I've used SolidWorks to knock up my spoked wheel, and got to the attached drawing. I've exported that as a .STL file, which is the only common one between CamBam & SolidWorks.

So, now I have a picture of the wheel in CamBam - what do I do to turn it into machining instructions?
Cheers!
Ade.
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Offline Swarfing

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Re: What CAM?
« Reply #3 on: January 08, 2013, 09:00:04 AM »
That will now need to be turned into polylines at least so that you can plot the machining lines. Then it is a case of creating a MOP from then on. Have a look at the Vids on their website, will get you going very quickly. I've not tried creating anything from a STL
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Offline Swarfing

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Re: What CAM?
« Reply #4 on: January 08, 2013, 09:02:28 AM »
http://www.cambam.info/doc/plus/cad/DrawSurface.htm

This is what a STL is normally used for
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Offline Swarfing

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Re: What CAM?
« Reply #5 on: January 08, 2013, 09:07:04 AM »
can you post the pic in 3ds or dxf format?
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Offline AdeV

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Re: What CAM?
« Reply #6 on: January 08, 2013, 09:26:13 AM »
Apparently not.... these are the formats available to me (see pic).
Cheers!
Ade.
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Offline Swarfing

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Re: What CAM?
« Reply #7 on: January 08, 2013, 09:32:46 AM »
Problem i see with the mesh fille (stl) is that the object does not always come out exactly as what you want (perfectly round etc). Attach the stl file so i can have a look in cambam
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Offline AdeV

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Re: What CAM?
« Reply #8 on: January 08, 2013, 09:53:42 AM »
No prob - although I think I'm getting somewhere now; at least, I seem to have got some toolpaths which aren't crazy...

STL is in the attached Zip
Cheers!
Ade.
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Offline Swarfing

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Re: What CAM?
« Reply #9 on: January 08, 2013, 10:38:01 AM »
This pic does not look like the first one you showed with the mesh? have you changed it so that the regions where filled in?
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Offline Lew_Merrick_PE

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Re: What CAM?
« Reply #10 on: January 08, 2013, 11:09:20 AM »
The STL format was developed for STereoLithography.  There are a number of settings that will determine the fineness of the resulting output that easily become either too coarse or too large a file for the intended recipient.  The resulting output is dumb (or blob) geometry.  I most normally deal with this (mess) for actual stereolithography operations and I quick discussion with the owner of the STL machine usually gets my file settings reasonably close to optimum.

I most normally work with fairly high-end CAM systems, so I am unfamiliar with the ones under discussion here.  Do these systems not import STEP, ACIS or Parasolid file formats?  Any of them would provide actual, mathematically founded geometry for processing.

Offline AdeV

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Re: What CAM?
« Reply #11 on: January 08, 2013, 11:25:42 AM »
Lew,

CamBam is (as far as I can tell) aimed at the low volume/possibly amateur market(?), its import options appear limited.

Oddly, SolidWorks (2008) output options also appear limited, such that there is no decent crossover; SW will output STEP and parasolid files. Then again, SW costs many thousands of pounds, if purchased properly...

On the other hand, I have now managed to generate some "sensible" toolpaths, as far as I can tell at least. I fancy re-writing the post-processor to produce Heidenhain conversational rather than G-codes, because I've got a bit of a handle on Heidenhain, and it saves me the trouble of hunting through the manual to work out how to switch it to G-code mode and back again. But more to the point, if it's in Heidenhain, I can work out in my head that it's OK, which since I'm in the office a couple of miles away from the machines, is a good thing...

Or, if the post-processor looks like it's too hard to reconfigure, then I'll just try it out tonight in some wax :)


Paul,

This pic does not look like the first one you showed with the mesh? have you changed it so that the regions where filled in?

Erm, I may have accidentally posted the Extrude1 object without the rest of the cuts, etc.... Let me try again...

Cheers!
Ade.
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Offline Swarfing

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Re: What CAM?
« Reply #12 on: January 08, 2013, 11:35:39 AM »
That one looks a bit better.

 Being as this is a simple 2d object i would have done this as a dxf i think and in the MOP set it use a radius tool for those inner edges of the cutouts. This would have been a lot less code for it to produce and given a quicker cut job.
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Offline AdeV

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Re: What CAM?
« Reply #13 on: January 08, 2013, 12:41:57 PM »
I can take the fillets off easily enough, can't do a DXF though, unless SolidWorks will output a sketch in DXF format....

So much for the day job today, I've been playing with CAD/CAM all day  :Doh:
Cheers!
Ade.
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Offline Swarfing

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Re: What CAM?
« Reply #14 on: January 08, 2013, 12:57:40 PM »
It does DWG though i believe?
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Offline AdeV

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Re: What CAM?
« Reply #15 on: January 08, 2013, 01:09:23 PM »
DWG isn't on the list of "save as" options.

Interesting, I notice on the STL file, CamBam doesn't recognise the central hole...
Cheers!
Ade.
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Rob.Wilson

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Re: What CAM?
« Reply #16 on: January 08, 2013, 01:56:09 PM »
Hi Ade

If your going to machine the part as a 2d  part , you will need to do make a drawing of the part in SW , un check the display sheet format box , insert the correct view ,set drawing scale to 1:1 , then you can save as  DFX ,DWG.


Rob

PS remove/delete  other SW auto generated features from the drawing , like centre marks.

Offline John Stevenson

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Re: What CAM?
« Reply #17 on: January 08, 2013, 02:20:31 PM »
You have paid 5 grand for Solid Works but only prepared to pay £100 for a 3D CAM program ?
John Stevenson

Offline philf

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Re: What CAM?
« Reply #18 on: January 08, 2013, 03:21:08 PM »
Hi Ade,

Your wheel could easily be done on a 2d system using a radius tool to put on the fillets. I use Vectric Cut2d for all my 2 1/2d stuff.

Some time ago I cut a steam loco wheel in mdf to see whether it would be viable to cut the wheels in steel rather than buy castings. The result was very pleasing but extrapolating the depth of cut and feed speed for steel I decided that life was too short to stand over the machine applying coolant with a brush and vacuuming up swarf for something like 12 hours per wheel.

I did a few posts at the time http://madmodder.net/index.php/topic,6995.0.html

I tried code from a few 3d cam packages. I got superb results from MeshCam and wish I'd bought a copy at the time because it was then around £100 - it's $250 now! The results from Vectric Cut3d looked promising (John S supplied me with the G Code). I've more recently downloaded several 3d Cam trials and have uninstalled most within a few minutes (inc. CamBam). The one which looks to have the greatest number of cutting strategies was DeskProto. You can get a 30? day trial with no limitations - unfortunately my laptop backlight died and I couldn't get a replacement quickly so for most of my trial period I couldn't do anything with it. It's priced at 248Euro.

Phil.
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Offline AdeV

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Re: What CAM?
« Reply #19 on: January 08, 2013, 05:24:58 PM »
You have paid 5 grand for Solid Works but only prepared to pay £100 for a 3D CAM program ?

Monopoly money is great, isn't it?
Cheers!
Ade.
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Offline AdeV

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Re: What CAM?
« Reply #20 on: January 08, 2013, 05:32:06 PM »
OK, a word about 2d vs 3d.... yes, I'm sure I can do this wheel in 2d very easily. However, that rather defeats the point of the exercise, which is to find a good 3d partner to SW. Today a wheel, tomorrow a sump, the day after that around 2500 £2 coins to pay for a certain piece of software.

So, yes, I _could_ probably re-draw the wheel as a 2d drawing, but then I'm going to run into the same problems when I do my first complex 3d shape that isn't the same shape along the Z axis.

ANYWAY.... by removing the fillets, I got CamBam to produce some nice sensible tool paths and a relatively short program ( ~ 600 lines), unfortunately, the mill won't switch to ISO mode, it ignores my demands to change user parameters, mutter grumble.

Control is a Heidenhain TNC151. Press MOD -> up arrow -> up arrow (to get to User Parameters) -> ENT - nothing happens.

Everything else appears to be tickkety-boo, so I assume it's somehow locked (one of the machine params)? If anyone knows which one, I'd love to know... meanwhile, I will go googling.

Edit: I cheated & set the machine parameter, so now it's in ISO mode. Unfortunately, the CamBam output crashed the controller..... back to the drawing board...
« Last Edit: January 08, 2013, 06:07:55 PM by AdeV »
Cheers!
Ade.
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Offline John Stevenson

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Re: What CAM?
« Reply #21 on: January 08, 2013, 06:09:12 PM »
Ade,

Long short is you need a program that has a dedicated Heidenhain post processor as it's a totally different lanuage.
I program various shapes [ as opposed to parts ] for a local one man band who doesn't have any CAM software, these are all simple 2D shapes which he then types in and adds repeat commands etc.

He understands Heidenhain language, I don't, even though I can do the programming the code is in a foreign language to me.

Dolphin is a decent program but only 2D, Bobcad is now OK but only from V24 on, Sprutcam again OK, last two are all 3D but anywhere from £500 to £1500.

After that, well you need to talk to the bank manager.
John Stevenson

Offline AdeV

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Re: What CAM?
« Reply #22 on: January 08, 2013, 07:24:29 PM »
I've got a reasonable handle on the Heidenhain langauge - parts of it at least, I now know what I did wrong with my manually-written wheel program, and could probably fix that more easily than getting CamBam talking Heidenhain.

CamBam does have a HH TNC151 postprocessor, but it appears to be broken. MeshCam has one, but it's "untested on a real machine" and I can already see errors in the output. Both of those are producing "Heidenhain friendly G-code". Bobcam claims to do native, but at $1500 is currently out of reach. Maybe next month.

CamBam seems to have a pretty configurable postprocessor, I might try to get that writing HH.
Cheers!
Ade.
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Offline Swarfing

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Re: What CAM?
« Reply #23 on: January 08, 2013, 07:36:25 PM »
Adev

Send Andy (10bulls) a mail as he will let you know the limits for HH, if there are any and if you find issue he will correct them very quickly.
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Offline AdeV

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Re: What CAM?
« Reply #24 on: January 12, 2013, 05:11:07 PM »
Woohoo!

Spent a few hours farting around with CamBam's postprocessor macros, and now I have a PP which writes Heidenhain conversational  :beer: It needs a few post-process steps to make it "just so", a handy VBS script does most of the grunt work.

So, now I can cut out my spoked chair wheels! Hurrah! No more sitting in the office at a 20 degree list...
Cheers!
Ade.
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Location: Wallasey, Merseyside. A long way from anywhere.
Occasionally: Zhengzhou, China. An even longer way from anywhere...