Messages

21

General Mach Discussion / Re: Pocketing and Island avoidance issue, need help

« on: April 19, 2009, 04:47:11 PM »

With so many files and trials going back and forth, that may have been the gcode tech support sent me to try, just in case, I regen'd the gcode from my file, like yours a 1" hole with a .175" center.

I'm afraid I'm really new and green at this and just starting to read and understand the gcode, but I have noticed there have been a couple differences in how I've seen 'circles' handled from a friend of mine (green like me) and tech support and the software itself.  Octagons doesn't sound right, but I couldn't tell why it is.

I ran your gcode and ended up with .165-.168 measuring around the island, the outside of the pocket came in at .999

Thanks for looking at this,
Mark

22

General Mach Discussion / Re: Pocketing and Island avoidance issue, need help

« on: April 19, 2009, 10:19:04 AM »

Gcode file attached.  Thanks

I should mention that I have tried this cutting with climb and conventional cutting and a finish pass with no difference in the outcome.

23

General Mach Discussion / Re: Routing Acrylic!!! Please Help!

« on: April 18, 2009, 11:46:01 PM »

I'm new here and just a hobbyist with this, but I spent weeks on this as 95% of what I'm currently working with is Acrylics.  I found as someone else said, you need CAST Acrylic and be careful, even some vendors or their employees don't realize the difference or it's not real clear what they are selling.  TAP sells only cast, a little pricey, but it will be cast.  I'm using 2 flute carbide bits I purchased from Precise Bits and I'm generally using bits 3mm and under.  For example, I run a .1181 2 flute end mill at around 8-12 ipm with the router speed around 25k with .04 passes and I get gorgeous chips with a nice clean edge.  I'm using no lubrication and having zero issues, sorry I can't help with extruded, I gave up on it as I couldn't come up with the right combination and using cast is so much easier. 

24

General Mach Discussion / Pocketing and Island avoidance issue, need help

« on: April 18, 2009, 09:56:53 PM »

Newbie using a home 'desktop' cnc.  I've been at it hard for close to 2 months now and have been getting more advanced with some projects.  This led me to my current problem and the software vendor says it's not their problem.  I can cut Left, Right, on the line of circles, squares, whatever without issue and within a .002 tolerance all day long except for Pocketing with Island avoidance.  In fact, take a simple 1" circle, put a .175 circle in the middle of that and tell it to pocket it and avoid the inner circle and I end up with .150 - .155, yet the outside of the pocket is 1.003  I can separately cut a .175 circle and be within .003

I have calibrated the system on X and Y it's within .001 - .002 (dialed in a 4" block measured at 4.279" and got 4.278"), backlash is the same, I can cut a 1" circle and measure all the way around and get 1.006 - 1.007.  I've replaced the router with a better one and verified I do not have a runout issue with either the router or the bit.  Again, this only happens on islands within pockets.  My current workaround is to cut the raised island first with a slightly larger toolpath around it, then pocket specifying the larger toolpath for island avoidance to prevent it from getting whacked.  If I do this same procedure without the larger toolpath, it will get cut down.

Anybody know why this is happening?  Is it some configuration issue between the post processor and Mach3, or some setting in Mach 3?  I'm new at gcode, but the simulation looks correct and the gcode looks correct, yet, it will eat into the island.

Appreciate any help on this.
Thanks,
Mark