Bobcad-Turn and "Crop Circles"

I posted this over at Machsupport, but I thought I would post it here as well. I'm trying to get Bobncad-turn working with Mach3 on my G0602. The most basic of shapes results in insane output. Bobcad support made a lot of suggestions, and even ran my machine though showmypc.com, but can't get things working. They are saying it's a problem with Mach, which makes no sense to me.

Here's the Bobcad geometry complete with tool path. They drew this on my machine remotely.

Attachment 131074

And here's what it looks like in Mach.

Attachment 131075

And here's the output file Attachment 131076. Anyone have any idea what's wrong??

What version of BC are you using? Same of Mach 3? Have you read this thread?http://www.cnczone.com/forums/bobcad...p_circles.html or this 1?
BobCAD-CAM Help Desk - What are crop circles and how can I get rid of them? You said BobCads Turn?

I saw those a while ago, but read them again in case there was something I missed. Bobcad's page says they are due to non-matching endpoints between two entities, except I can cause them with a single arc drawn right in Bobcad. The other thread at least confirms that I'm not the only one with the problem.

I'm using the latest Bobcad V24 build 208 with the turn module. Honestly, if these crop circle thingies follow me into the mill portion of the software, I want my money back. They don't show up until you load the output into Mach, and depending on how Mach decides to display the part, they may be completely undetectable until the tool tries to crash into the spindle.

Bobcad support just sent me a new post file and an example. It seems to work on the example, but they are hard to see on the simple arcs I was using before. I need to load it in Mach tomorrow to see where it sends the tool...

I definitely still get crop circles on the part I was originally trying to make which is nothing but a cone with a blunt nose. I extracted the profile from an iges file which results in a couple of arcs connected together. If there are gaps anywhere, I can't detect them.

In Mach3, go to the General Config dialogue. Change the arc IJ mode from absolute to incremental (or the other way round if it is already on incremental, I can't remember). This may be the cause of your problem, I've seen it before when importing milling files to Mach when the previously-run program had switched the arc mode.

go into mach3 configuration, ports and pins, then to turn options. make sure that reversed arcs in front post is unchecked and that should fix it

Unchecking reversed arcs did the trick. Thanks, those circles were driving me crazy! I'll let the Bobcad support folks know about it as well.

Jeff

MasterCAM has a similar option "Lead In/Out". I have no idea what use it serves other than to mess up my tool paths.

Front tool post is the way to fix it. Then it works.
Big machines have the tool post behind and that makes it all back the front.
The code is fine.
It is all in the Mach3 manual.:eek: 7.5.1 and 7.6.
ReadTheFriendly($%^*)Manual:withstupi