Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Peeps on July 02, 2012, 08:51:13 PM

Title: Why do my inside cuts look this way?
Post by: Peeps on July 02, 2012, 08:51:13 PM

Anytime I cut a square inside profile, two of the inside corners have a long radius......anyone know what could be causing this?

I looks right in Aspire, but cuts out like this.......see picture below.
(http://oi45.tinypic.com/zm1slu.jpg)

Title: Re: Why do my inside cuts look this way?
Post by: Banduramaker on July 02, 2012, 09:21:04 PM

Does the tool path look correct in Mach 3?

If it does and you're using CV mode and your accel could be too slow on one axis (but not the other) to keep up with your feed rate, Mach 3 will round the corners as it's trying to pick up speed to change directions while maintaining your feed rate.  If this is indeed what's causing your troubles, you could try the "exact stop on angles greater than" setting and set it to perhaps 89 degrees and see if that fixes it.

Title: Re: Why do my inside cuts look this way?
Post by: Hood on July 03, 2012, 03:05:01 AM

I would take a guess at it being backlash..
Hood

Title: Re: Why do my inside cuts look this way?
Post by: Peeps on July 03, 2012, 06:13:12 AM

I'll check the things you guys mentioned, but the odd thing is it's always on inside profiles.......I can cut a outside profile and it works fine.

Title: Re: Why do my inside cuts look this way?
Post by: RICH on July 03, 2012, 06:53:24 AM

It could be what Hood and Peep's posted but also make sure that the radius of the of the tool is smaller or equal to the radius of the corner your trying to cut, else the program may round the corner to suite the cutter.

RICH

Title: Re: Why do my inside cuts look this way?
Post by: Banduramaker on July 03, 2012, 11:31:00 AM

Quote from: Peeps on July 03, 2012, 06:13:12 AM

I'll check the things you guys mentioned, but the odd thing is it's always on inside profiles.......I can cut a outside profile and it works fine.

When going around an outside corner, CAM software usually uses an arc in the tool path, even with a square corner leading to a gentler acceleration.  What's the accell settings for your X & Y axes?