qcad/cam post processors

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Solo318i
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Posts: 29
Joined: Tue Apr 13, 2021 2:54 pm

qcad/cam post processors

Post by Solo318i » Thu Apr 15, 2021 3:21 pm

Before I pony up for the whole package, can someone chime in on the Cam side of things? I specifically want to run this with the Langmuir Crossfire Pro plasma table. The offer the post processor for sheetcam, but I was wondering if I could save a step by using the Qcad/cam to do both part design and G-code generation.

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andrew
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Re: qcad/cam post processors

Post by andrew » Thu Apr 15, 2021 6:10 pm

There is no post processor out of the box for this controller (FireControl). However, it looks like standard G-Code, probably with some extra codes. If you can provide an example file that works on your machine, we can tell you more.

Solo318i
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Re: qcad/cam post processors

Post by Solo318i » Fri Apr 16, 2021 3:08 am

Thanks, I won't get my machine until June. I will update this thread at that time.

neffk
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Posts: 7
Joined: Mon Sep 03, 2007 3:38 pm
Location: Rochester, MN

Re: qcad/cam post processors

Post by neffk » Sun Apr 18, 2021 7:26 pm

Here's the same part with fusion post and QCAD. The difference is fairly simple... I have an automatic height module so there is a block of code before each cut which basically is torch-height adjustment and the pierce process.


If you can get post set up, I'll post about this on the Langmuir forums and make sure people know they can use QCAD seamlessly with the CrossFire Pro. I think there's an upside for your efforts.

Is there any documentation/guidance/examples for writing postprocessing code? If you can't provide a postprocessor, perhaps I could build it for you.



Here's a simple part with fusion360 + Langmuir post

[quote](v1.6-af)
(top and bottom, 2pc)
(Machine)
( vendor: Langmuire Systems)
( model: Pro)
( description: CrossFire Pro)
G90 G94
G17
G20
H0

(2D Profile6)
G0 X-1.5108 Y-0.0625
G92 Z0.
G38.2 Z-5. F100.
G38.4 Z0.5 F20.
G92 Z0.
G0 Z0.04 (IHS Springback + Backlash)
G92 Z0.
G0 Z0.15 (Pierce Height)
M3
G4 P0.6
G0 Z0.063 (Cut Height)
H1
G1 X-1.4025 Y0. F20.
G3 X-1.5975 I-0.0975 J0. F20.
G3 X-1.4025 I0.0975 J0.
G1 X-1.5108 Y0.0625
H0
M5
G0 Z1.

G0 X-1.3941 Y-0.4036
G92 Z0.
G38.2 Z-5. F100.
G38.4 Z0.5 F20.
G92 Z0.
G0 Z0.04 (IHS Springback + Backlash)
G92 Z0.
G0 Z0.15 (Pierce Height)
M3
G4 P0.6
G0 Z0.063 (Cut Height)
H1
G1 X-1.4415 Y-0.288 F20.
G1 X-1.5373 Y-0.275
G2 Y0.275 I0.0373 J0.275
G1 X1.2463 Y0.6523
G1 X1.25 Y0.6525
G1 X1.75
G2 X1.7775 Y0.625 I0. J-0.0275
G1 Y-0.625
G2 X1.75 Y-0.6525 I-0.0275 J0.
G1 X1.25
G1 X1.2463 Y-0.6523
G1 X-1.4415 Y-0.288
G1 X-1.518 Y-0.3868
H0
M5
G0 Z1.

M30
(PS20)[/quote]



Here's what I got from QCAD



[quote]G0 Z1
G0 X0.0884 Y-0.0884
T1 M6
S100 M03
G0 Z2
G1 Z-4 F20
G3 X-0.0884 Y0.0884 I-0.0884 J0.0884
G3 X0.0884 Y-0.0884 I0.0884 J-0.0884
G1 Z2
G0 X3 Y0
G1 Z-4
G1 Y-0.625
G1 X2.75
G1 X-0.0336 Y-0.2477
G2 Y0.2477 I0.0336 J0.2477
G1 X2.75 Y0.625
G1 X3
G1 Y0
G1 Z2
G0 Z1
M30[/quote]

CVH
Premier Member
Posts: 1368
Joined: Wed Sep 27, 2017 4:17 pm

Re: qcad/cam post processors

Post by CVH » Sun Apr 18, 2021 8:29 pm

Hi,
Seems that 'Pluge' =

Code: Select all

G92 Z0.
G38.2 Z-5. F100.
G38.4 Z0.5 F20.
G92 Z0.
G0 Z0.04 (IHS Springback + Backlash)
G92 Z0.
G0 Z0.15 (Pierce Height)
M3
G4 P0.6
G0 Z0.063 (Cut Height)
H1
and 'Retract' =

Code: Select all

H0
M5
G0 Z1.
Should be easy, any main header too.
For the plunge section the 'Post' itself needs a few extra parameter fields.
Not that big of a deal.

Apart from that I can't make out on the fly if the travelled paths are equal. :roll:

Regards,
CVH

neffk
Newbie Member
Posts: 7
Joined: Mon Sep 03, 2007 3:38 pm
Location: Rochester, MN

Re: qcad/cam post processors

Post by neffk » Sun Apr 25, 2021 7:10 pm

So I've hacked together a postprocessor in perl. It does static, wiggle, ramp, and spiral pierce. Hops over slag, if you want, etc. It detects the beginning and end of profiles and puts in pierce, retract, and feed settings. Wrote a bunch of test patterns for the Razorweld Cut45 by hand and post-processed with no problem.

Now, I'm trying to use CAM output from QCAD for a non-test piece. There's a stupid G41 in the output. Stupid because it doesn't make sense and a real problem because the FireControl doesn't know what to do with G41. I moved the part so the corner of the part is on the origin---still have a G41 command. I move the start point of the polyline to the origin. Now the G41 offset is 0.00

Does anyone know how to suppress this G41 output? I want to generate several tool paths but they can't all start on the origin. Also, on a simple part, I didn't find G41 in the output.

Also, why is G41 being used? Tool compensation would have 1/2 the kerf so I would expect to see something like "G41 X0.035" but instead it's "G41 Y12.1304". Had to move the start of the cut to (0,0) to get G41 under control. I doesn't seem to be for tool compensation. Seems like it's being used like G92, the position shift command.

I found this (below) web page, which may be a clue about how G41 is used in postprocessing. I don't understand how the create-profile dialog box corresponds to this. If what I read here is accurate, the kerf of the tool should appear in the arguments for the G41 command---but it doesn't.

https://qcad.org/en/qcad-cam-postprocessor

Looking for any and all input...

CVH
Premier Member
Posts: 1368
Joined: Wed Sep 27, 2017 4:17 pm

Re: qcad/cam post processors

Post by CVH » Mon Apr 26, 2021 12:47 am

neffk wrote:
Sun Apr 25, 2021 7:10 pm
Now, I'm trying to use CAM output from QCAD for a non-test piece.
What QCAM post did you use?

Regards,
CVH

neffk
Newbie Member
Posts: 7
Joined: Mon Sep 03, 2007 3:38 pm
Location: Rochester, MN

Re: qcad/cam post processors

Post by neffk » Mon Apr 26, 2021 2:47 pm

I'm an idiot.

I switched to "G-Code (fofset) [in]" and everything seems to work.

I think the problem was that I changed the settings on the file but not the application preferences.

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