Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Mogal on June 06, 2015, 07:09:44 PM

Title: Exact Stop - kinda working?
Post by: Mogal on June 06, 2015, 07:09:44 PM

Hi Guys, I've been struggling with a new one :)
I built a plotter attachment for the CNC and am trying to plot a blueprint.

I turned off CV and enabled exact stop (anything else need to be done?)
It doesn't seem to be a rhyme or reason for what corner it misses.
but it is the same each time it is printed.

I know its not the gcode. It was generated with VCarve pro, and the corners are clean.
I've attached a few pics and the dxf file of the print.

Thanks,
Chris

Title: Re: Exact Stop - kinda working?
Post by: Mogal on June 06, 2015, 07:22:38 PM

My settings:

Title: Re: Exact Stop - kinda working?
Post by: ger21 on June 06, 2015, 07:53:10 PM

Does the gcode have a G64 in it?

Title: Re: Exact Stop - kinda working?
Post by: Mogal on June 06, 2015, 08:19:33 PM

No there is not any G64, nor is there any G61.
It almost seems there is a distinct line at the corner, its not rounded.

Title: Re: Exact Stop - kinda working?
Post by: BR549 on June 06, 2015, 11:16:29 PM

That looks like the pen flexing in the holder to me. Try slowing the feedrate down real slow and see IF it still does it.

Also as Gerry mention you need to include a G61 in the  safety block to force Mach3 to run in exact stop mode

I like your plotter I have an old HP pen plotter and LOVE to watch it work.

(;-) TP

Title: Re: Exact Stop - kinda working?
Post by: Mogal on June 06, 2015, 11:39:21 PM

There is a mild amount of pen flex, but there is distinctly an extra movement in the corners.
I don't have time to try again tonight, but will slow the machine right down later on.

I'll also look a little further into the G61(I don't recall having to use it before)

Thanks!