rounded corners

[lunaj76]

Hi,

I am having some difficulty with my cv settings.  I have cv on and stop cv on 90 angles.  I am getting square corners if I cut clockwise but rounded corners cutting counterclockwise.  What am I missing?

Thanks

Justin

[Tweakie.CNC]

Sounds silly but are you looking at the tool radius as being your rounded corners ?

Tweakie.

[stirling]

What version of Mach are you using? - This was a problem I reported back in 2007, but it was then fixed and I havn't seen it again since.

[lunaj76]

Tweakie,

The corners look like the machine is trying to skip out on cutting all the way to the end of the line.

Stirling,

It is version R3.042.020

My machine is a gantry type router, I am trying to cut cabinets with a 5 mm bit in .75 material,  3 passes climb cut and 1 pass conventional to realease the part.  Corners look great for the 3 clockwise passes but on the final pass counterclockwise the corners get misshaped or rounded.

Thanks for your help

[stirling]

OK - I just tested R3.042.020 and it appears to be fine - no signs of the "old" CW/CCW CV trouble.

I have cv on and stop cv on 90 angles.  I am getting square corners if I cut clockwise but rounded corners cutting counterclockwise.

I guess you mean you have it set to "Stop CV on angles > 90" i.e. "greater than" - not "on" so to stop CV (if that's what you want) and you're cutting right angles you'd need to set this value to 89 degrees or so - i.e. NOT 90 degrees.

That however does not explain why CW passes are different to CCW passes - unless of course the feedrates are different.

[lunaj76]

I just retested and here are the results.

CV turned on,  stop CV on angles >89 on, CV distance tolerance .005 on,

clockwise 3 passes, I get square corners, 1 pass counter clockwise great corners,

Here is the problem,

I cut and oval and a square, the oval cuts really choppy but the square is good.

So I changed the settings to this

CV turned on, stop CV on angles>89 on, CV distance tolerance 5 on.

3 cw passes on the square great corners, oval cuts smooth, 1 pass ccw pass on the square rounded corners.

Strange!

[lunaj76]

Upgraded and it works now. Yeah!

[stirling]

Upgraded and it works now. Yeah!

That's good but what's REALLY strange is it all works fine in MY R3.042.020. This is EXACTLY the problem that used to happen a few years back.

Everything in your testing/results makes perfect sense and is what SHOULD happen EXCEPT for the very last bit "1 pass ccw pass on the square rounded corners." which was your original problem. Don't suppose you could post your test gcode (square and oval) just for interest.

Ian