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Author Topic: Velocity control problem on complex surfaces  (Read 1638 times)

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Velocity control problem on complex surfaces
« on: May 03, 2011, 08:58:13 PM »
Colleagues,

I can cut polygons with no problem.
I have a serious problem with Mach3 lookahead, CV ignore, and complex surfaces.

We cut stencils in plastic, such as the numbers shown in the picture below
http://store.parkinglotplanet.com/components/com_virtuemart/shop_image/product/12inNUMBERx400.gif
The problem is with paths like the number 3, where the curved path moves in one direction, steps to the side, and then moves in the opposite direction.
Mach3 does not decelerate when approaching these pseudo-corners, and causes one of the steppers to abruptly stop.  This makes the CNC tool shake, and creates waviness in a flat edge.

It doesn't matter if the lookahead steps number is set from 5 to 50.
With Ignore CV if angle >89, cutting curved segments, like in the 3, 5, 8, where it goes from curves to a straight segment, it doesn't decelerate properly.
 
Does anyone have any ideas?
Thanks in advance,
Craig

Offline BR549

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Re: Velocity control problem on complex surfaces
« Reply #1 on: May 03, 2011, 09:11:13 PM »
Try turning off ALL the cv settings and let it run with the internal  settings. Also turn on CV in the Gcode.

Then set the look ahead to 200.

The shaking may be your machine not being rigid enough and not the code or Mach. IF so then slow down the acceleration settings and try again

Just a thought, (;-) TP