Machsupport Forum
G-Code, CAD, and CAM => G-Code, CAD, and CAM discussions => Topic started by: sceliaso on August 05, 2015, 10:52:18 AM
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I have a plotter table with tangential knife and scoring tools, which I have been trying to run via the tangential settings in Mach3, however tangential control in mach3 is apparently completely broken and the only way to get around these problems is to include the rotational commands in the G-Code. This is not a difficult thing to do, but many of the profiles I need to cut are complex and re-coding them by hand would be labor and time intensive. I am currently using CAMBam, which is important because I have to be able to load a DXF and assign individual lines to toolpaths/tools, I have looked at some other software (sheetcam for instance has settings seemingly set up for my specific situation) But they group lines from my DXF files oddly and I can't seem to get any of them to work. My CAD Software (Rules by AlphaCorr) generates a DXF with line colors to show what is a score and what is not, but this does not show up as layers or anything else in any CAM programs I have tried.
So, my question is: Does anyone know of a good CAM program that will generate the A Axis inputs for a tangential toolpath (including lifts between angle adjustments) and still allow me to assign individial lines from a single layer DXF to their own toolpaths?
Specifics on my setup: I am running a 90"x50" Alpha Merics cutter/plotter table, recently the electronics fried themselves and we replaced everything but the rails and the frame. It is going to be used to prototype folding cartons (paperboard boxes) Performing both cutting and scoring. It works well (I'm still fixing some backlash and motor tuning issues), but the goal is to be able to train someone who is not an experienced CNC programmer to use it.
This is my first post, though I hope to become a regular.
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Are you running a DEMO version of Mach3 ? Last I checked the Tang control worked ok.
SHEETCAM has a Tang cutting plugin that does what you want.
(;-) TP
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It functions in a very limited sense. When if a G01 follows a G02 or G03 the tangential control will rotate the head to the arc angle as it moves along the G01. Also the lift angle does not function. While this could be specific to my build, the following was provided to me by Mach3 support and mimics the behavior of my machine exactly. Their solution was to hand code in all of my tangential moves.
http://www.machsupport.com/wp-content/uploads/2013/02/Mach3_Tangential.pdf
http://youtu.be/4XnM3MX_H7w
Are you running a DEMO version of Mach3 ? Last I checked the Tang control worked ok.
(;-) TP
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What version are you running ?? I understand the need to simpify this for the OPs and having to RECAM everything to make it work is well just wrong. THere ARE other control options that the Tang control does work correctly.
(;-) TP
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Sorry, its R3.043.066
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So, my question is: Does anyone know of a good CAM program that will generate the A Axis inputs for a tangential toolpath (including lifts between angle adjustments) and still allow me to assign individial lines from a single layer DXF to their own toolpaths?
Vectric Aspire (v. 4.0 onwards) has the 'drag knife' equivalent of a tangential toolpath Gcode generator which basically overcomes the problems you mention but it costs $$. :'(
Tweakie.
addition...
Its a 'plug-in' so should be usable with other Vectric products.
Edit - Correction made to my description, in the light of experience :)
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First I would back up a few versions and retest. V.066 is NOT a stable version it has its problems.
Sheetcam is very cost effective . But the Tang plugin IS an extra cost with it as well.
I remember tang working OK in older versions ???? Could be wrong but I do believe that Art would have fixed that in his day if it was broken back then.
Just a thought, (;-) TP
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Where might I be able to get a copy of the older version? I found some links in old threads, but they don't work anymore.
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Where might I be able to get a copy of the older version? I found some links in old threads, but they don't work anymore.
If you look in FTP Downloads / FTP Server - Main Menu / Mach3 you can find all the available versions. http://www.machsupport.com/software/downloads-updates/
Tweakie.
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Any recommendations for which previous version? I would just go for the build before this, but I'm not sure when the instability was introduced.
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I think everybody each has their own preference.
If it's any help, I use R3.043.056
Tweakie.
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So, I rolled all the way back to R3.034.022 (Via process of trial and error) Now the tangential works, all except for the lift angle, which it does not do. Instead it will rotate to the angle of the next line even if it has to lift to reach the next line. If anyone has any suggestions?
Interesting notes on the journey - The scale on my axes has changes (I haven't recalibrated to find out how much yet), and my Angle coordinates rotated by 90 deg.
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I read online that the Tangential knife does still work in mach3.
You need to set the z lift value to greater than the depth of the cut plus a distance above the work piece. I have
not tried this myself so if someone can confirm this please post it for everyone.
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These may help.
http://www.machsupport.com/wp-content/uploads/2013/02/Mach3_Tangential.pdf
https://www.youtube.com/watch?v=4XnM3MX_H7w&feature=youtu.be
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I have had some success playing around with the raise height, however it seems to have inconsistent behavior. This could however be due to my cam software (CamBam).
In mach3's most recent versions the tangential control is completely broken, and all they will tell you to do is write all your own tangential commands, which is very frustrating when your cam software doesn't have that ability (that's why I bought mach3, which advertises tangential control) and you have several thousand lines of code to modify (including new lift commands) by hand.
Ver. R3.034.022
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My answer may be slightly late :D. I was facing the same problem a few days ago, so I started looking for answers on this forum. Later I found very simple solution to work around this bug of mach3 (A axis rotates even in linear move after a g2/g3 arc). What I noticed is this only appears when the specific linear move is perfectly parallel with X or Y. So I started rotating my sketches. It turns out even an angle 0.01 degree is enough to avoid the problem :). Just make sure your Gcode cordinates have enough decimals for this rotation to become visible (I use 3 decimal)
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Also you should check out a free software called ECAM. It's great for 2D CAD too, and it also has very simple post processor editor, so with a few tweaks you can get the Gcode you want without having to manually overwrite it.
Take a look: https://postimg.org/image/wcaz5ur2x/ (https://postimg.org/image/wcaz5ur2x/)
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Excellent information FeketeB, thanks for sharing.
Tweakie.