Curve Quality in plasma

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Alwis
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Joined: Wed Feb 21, 2018 10:31 am

Curve Quality in plasma

Post by Alwis »

I'm having issues with my curves.
My Setup is DIY plasma table pinion gear driven, Masso controller, using solid works, AutoCad, and inkspace SVG.
The circles and radius areas of my drawings come out jagged and lack resolution but look good on screen. I have used auto cad, solid works, and inkscape. I have converted polylines, max'd out the resolution on my stepper drivers. Not sure where i am going wrong. Is there a steeing in SheetCam that may help. Text cuts are even worse.
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Les Newell
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Re: Curve Quality in plasma

Post by Les Newell »

Could you post a copy of the job file here (File->save job) with the cuts all set up ready to run.
mancavedweller
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Re: Curve Quality in plasma

Post by mancavedweller »

Are you sure the problem is not with the plasma table itself.

Bit confusing when you say:

The circles and radius areas of my drawings come out jagged and lack resolution but look good on screen.

Are you saying the circles and radius areas CUT jagged, despite looking good on the cnc controller screen when you open the file. If so it may be an issue with the plasma table. I generally find what is on the screen is representative of the gcode.
Alwis
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Joined: Wed Feb 21, 2018 10:31 am

Re: Curve Quality in plasma

Post by Alwis »

Attached are a couple of pictures of the cuts and the TNG file. It seems that large radius areas cut ok
When i looked closer at the screen on the controller i think you can see the cut areas dont look right but its a little hard to tell. The masso controller does handle the Aspect ration of my screen well so the view is a little distorted.
Attachments
IMG_1.jpg
IMG_1.jpg (602.54 KiB) Viewed 2321 times
IMG_2.jpg
IMG_2.jpg (324.02 KiB) Viewed 2321 times
Travel Trailer Key Hanger.job
(71.32 KiB) Downloaded 77 times
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Les Newell
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Re: Curve Quality in plasma

Post by Les Newell »

The job file looks reasonable. Does your Masso controller have a graphical preview? If so, does it look clean in the preview?
Do you have constant velocity enabled in your controller? I'm not sure about the exact terminology used by Masso so it could be called something like smoothing.
A lot of that looks like mechanical issues. Check if you have any backlash. With the drives enabled try moving the gantry with your hand. If you feel any backlash or spring you will have to track it down and fix it.
Alwis
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Joined: Wed Feb 21, 2018 10:31 am

Re: Curve Quality in plasma

Post by Alwis »

I changed the screen so i can get a better view and it looks like it cuts. It seems to mostly affect the text. And it cuts some good and others not. The drives are pinion gear x and y, spring tentioned with very very little back lash. And again, some curves and circles/arches cut good. I have changed my stepper driver resolution up and down from min to max and stops in between with no real differance. Slowed my travel speed and reduced the acceleration. I converted the text in solidworks, unconverted, Exploded and unexploded in autocad, and converted objects to paths in inkscape. They are consistantly the same. I will have to email Masso, but dont believe constant Velocity is setable
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Les Newell
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Re: Curve Quality in plasma

Post by Les Newell »

So in the Masso controller you see the arcs as sequences of straight lines? In that case it looks like the controller isn't recognising the arcs correctly. What post processor are you using?
Alwis
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Re: Curve Quality in plasma

Post by Alwis »

I also found if I use sheetcam’s Version marked stable, all my holes get converted to half circles. When I use the development version he are holes again.
Not sure if that helps ?
Alwis
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Joined: Wed Feb 21, 2018 10:31 am

Re: Curve Quality in plasma

Post by Alwis »

i use an edited version of what Masso posted
attached is the unedited version
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MASSO Plasma (with THC1).scpost
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Les Newell
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Re: Curve Quality in plasma

Post by Les Newell »

Near the middle of the file is a function called function OnArc(). Replace everything up to the next function with this version:
function OnArc()
post.ArcAsMoves(0.1)
end
Alwis
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Joined: Wed Feb 21, 2018 10:31 am

Re: Curve Quality in plasma

Post by Alwis »

my appoligies and thanks for all the help

The edited file i am using says

function OnArc()
post.ArcAsMoves(0.1);
end

Does the ; make a differance

attached is the file being used
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MASSO Plasma (with THC) Edited.scpost
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Les Newell
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Re: Curve Quality in plasma

Post by Les Newell »

The semi colon makes no difference. Try changing from 0.1 to 0.01
Alwis
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Joined: Wed Feb 21, 2018 10:31 am

Re: Curve Quality in plasma

Post by Alwis »

Thank you ever so much. That little 0 was the missing link. It cuts perfectly. Cant sing your praise enough !
Alwis
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Joined: Wed Feb 21, 2018 10:31 am

Re: Curve Quality in plasma

Post by Alwis »

Thanks again Les
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improved angle view.JPG
improved angle view.JPG (132.41 KiB) Viewed 2296 times
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