CNC alternatives to PyCAM

[Stuart Livings]

I write (again) asking for help... thanks in advance if you even get to
the bottom of this mail :)

I'm trying to machine a part on my CNC (hence the failed water pump post
earlier) and am suffering frustrations with the CAM tools I've
discovered so far. Please don't get me wrong, I appreciate that these
tools are all developed for free by people dedicating their time, but
they don't seem to work for me for a number of reasons.

Specifically I'm trying to solve the problem of converting a part
designed in OpenSCAD into gcode for the machine. Simple parts aren't a
problem, the actual 'real' part is causing issues. For reference the
part is 2.5D milled from 6mm nylon sheet and comprises a couple of holes
plus two pockets. One pocket is square, the other is circular so has
curved edges.

- HeeksCAD/HeeksCNC: The learning curve on this app is steep and seems
to be missing an intuitive interface, for example to pocket a part you
must define a sketch (even though I have the stock defined as a cuboid
and the part imported as an STL) but the sketch system doesn't appear to
automatically close shapes, I can't find out how to close shapes and the
app crashes repeatedly. I think some of my problems with HeeksCNC might
be solved by finding a stable build instead of the development build,
but the stable builds I've found are very old, still crash (albeit less
frequently) and the tutorials seem to use development builds. All that
said I *have* managed to use HeeksCNC to create a toolpath to level the
bed which is more than can be said for some of the other tools.

- PyCAM: This is great, the UI works the same way my mind does and I
believe I understand most of its features. I am having two problems
with it, though: 1) I can't get the contour feature to work, it seems to
do some zig-zagging rather than follow the curves of the part, resulting
in messy holes, uneven edges etc. 2) When I enable the contour feature
the processing is ridiculously slow. On my quad core hyperthreaded i7
with full multiprocessing enabled PyCAM takes over two hours to
calculate just the contour pass, plus another 30 minutes to complete the
other passes. Since I'm still trying to get a decent toolpath waiting
2-3 hours for each test is very frustrating. I believe, had I tried
PyCAM first, I would have been able to get it to level the bed very easily.

- FreeMill on VisualCAD/CAM (free): Exceedingly limited, though does at
least seem to have a decent UI. Cannot find a way to get it to follow
the curved upright portions of my part making the result look like some
1980s rasterisation of my design.

- FreeMill on Solidworks (I have an old licence for this): Crashes. And
crashes. And crashes. In most cases Solidworks won't even start up.
Had to uninstall FreeMill to get Solidworks stable. I don't know where
the fault lies here, I'm not blaming either product, but together
they're unusable.

There's a very large number of commercial products out there, each
claiming to be amazing. I don't mind shelling out a small amount if
that's necessary to get decent CAM but this is 'for fun' so budget is
limited based upon what it would cost for me to get the parts made
elsewhere.

Ideally I just want something which I can feed an STL and it'll do three
things:

1) Rough cut it with a large tool.

2) Use a finishing tool to follow the faces (rather than rasterising it)
to flatten the flat surfaces and curve the curved surfaces. At the
moment I can't find any app which does this, commercial or free.

3) Finish by cutting the part from the stock.

Does anyone have any experience of CNC software and can make
recommendations? Matt D?

Thanks in advance for any help anyone can offer...

Stuart

[Stuart Livings]

Update - I've just found BobCAD/CAM which does appear (at least) to
behave in both a way that's intuitive and generate tool paths in the way
I expect. It is, of course, commercial though the price tag of $400 (if
I understand their website correctly) is a number that's scary rather
than terrifying...

*considers demo*

[James]

Maybe check out Vectric software - http://www.vectric.com

I currently use an old version of vcut pro and aspire and found them to be excellent.

cut2d sounds like to would meet your needs and only(!) £95.
http://www.vectric.com/products/cut2d.html

James

[M P]

I've reached exactly the same conclusion as Stuart; all CAM tools are
just lame. After tinkering with Slicer's for 3d printing, I would have
assumed the same sort of software to work for CNC, but nope, they all
are next to useless. All the free ones at the very least.

I've had to also BUY a tool, I also picked VCarve pro. It's windoze
only, it's expensive, but it's the only one that even remotely allows
me to cut stuff the way I want. It's not even perfect, but it works.

I started by designing a part that I thought would be easy to cut:
https://github.com/buserror/buserror-reprap/blob/master/stl/buserror-spindle-cnc-mount-cnc-lazor.stl
And at that point, the nigthmare began, as it's actually very hard for
most of the software I tried to do that, let alone do it
'automatically'.. I thought the half-cylinders would be a doodle to
cut, but nope, most of the tools 'suggest' I cut square paths instead.

For pure 2D, there's a new one that looks interesting tho (web based):
http://millcrum.com/

M

> --
> You received this message because you are subscribed to the Google Groups "Reading Hackspace" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to reading-hacksp...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.

[James]

Nice looking part :) 

Was your issue because you needed a toolchange? i.e. 2 jobs, 1 using a standard square endmill to complete most of the job and a "ballnose" endmill for the half-cylinders?

If you just had just the one square endmill specified as the tool for the entire part then the resulting part would have the half-cylinders cut square?

James

On Wednesday, 29 July 2015 10:59:34 UTC+1, buserror wrote:

I started by designing a part that I thought would be easy to cut:
https://github.com/buserror/buserror-reprap/blob/master/stl/buserror-spindle-cnc-mount-cnc-lazor.stl
And at that point, the nigthmare began, as it's actually very hard for
most of the software I tried to do that, let alone do it
'automatically'.. I thought the half-cylinders would be a doodle to
cut, but nope, most of the tools 'suggest' I cut square paths instead.

 

[Andy Noyes]

If you don't have a tool-changer you can still save the toolpath in VCarve as eg Mach2/3 ATC and then edit the gcode file replacing the M06 commands with M00 to pause the machine and then manually change the tool.

[James]

Good point - in the past I have just exported multitool jobs as separate gcode files and run them one by one (changing the tool in between).

[Stuart Livings]

I've now been using Vectric Aspire for a few days.  It has Quirks (most notably the inability to parametrically modify drawings after development) but it holds the unique position of being the first package I've been able to use to export viable gcode for my part.

Aspire is not good at developing gcode from STLs, but it was VERY good at being able to redraw the part and develop the gcode from a 'machining' point of view.

There is definitely a BIG gap in the market for STL->gcode development, there don't appear to be any viable pieces of software at the moment.

Thanks for the pointer, James!

Stuart

[Foad S Farimani]

Now this is a super old post, but if there is still interest, I have listed all the Free and Open Source CAM/CNC software here in this Reddit post. 

F.