G2 Arc problems

[CharlesM479]

Im just getting started with a Dynapath 20 mill. I am having trouble with G2 arc command. I get an error "21 start radius <> end radius" I am using BobCad to make the program. The first thing I did was to make sure the I & J was correct. I checked this in AutoCad and it checked out. The next thing I did was to make sure the signs of I & J were correct. I did this by just changing the sign and trying it. The program is small just 3 arcs so it doesn't take long just to check it this way. The next I did was just to change it to a linear move between the points and it worked fine. I just wanted to make sure the end points were correct. Then I started thinking it was setup with polar cord. I found another G code that would take it out of polar and put it in the line before the G2. Same problem. Im not sure what else I can try. The numbers all look good, I think im putting them in correctly. Any ideas

[MetLHead]

The Dynapath wants the I and J coordinates in absolute coordinates instead of incremental. I don't know what the setting is in BobCAD, but I'm pretty sure it can be configured to output this way.

Scott

[mulcher]

if the tolarances are not super tight on the radius you can try to change the r value +or- a little and this may help i have run a puma 350 and some time the computrer will not like the values even if they are perfectly corect

[tobyaxis]

Originally Posted by CharlesM479 Im just getting started with a Dynapath 20 mill. I am having trouble with G2 arc command. I get an error "21 start radius <> end radius" I am using BobCad to make the program. The first thing I did was to make sure the I & J was correct. I checked this in AutoCad and it checked out. The next thing I did was to make sure the signs of I & J were correct. I did this by just changing the sign and trying it. The program is small just 3 arcs so it doesn't take long just to check it this way. The next I did was just to change it to a linear move between the points and it worked fine. I just wanted to make sure the end points were correct. Then I started thinking it was setup with polar cord. I found another G code that would take it out of polar and put it in the line before the G2. Same problem. Im not sure what else I can try. The numbers all look good, I think im putting them in correctly. Any ideas

Are you using TNRC G41/G42 (Tool Nose Radius Compensation)?
Can you post your G-Code for us to look at?

Hard to say with out a Part or Program to look at. I have BCC V21 and NC Plot. Post a File if you are allowed.

[CharlesM479]

Here is what I have. I was having trouble getting bobcad to download to the mill. I got that working today but I still get the error when it starts the first radius.

We are reworking this cam. We have built up the cam surface and now we need to mill it back to spec. So I dont have to do the hole thing just the cam surface.

[tobyaxis]

Here is your file back. I used a 1/2 diameter end mill and Cutter Compensation Left Climb Milling so you could program direct geometry. I also changed your X0Y0 Origin so you could do a quick pickup on the hole with an indicator.

Oh, it's color coded too and the Program is saved on the part drawing.

If you like this and it works for you I'll explain how I did this. If not, tell me how you want it done.

Cheers!!!

[CharlesM479]

MetLHead was correct about the i & j being ABS. Now I just have to make Bobcad do it for me.

tobyaxis I will take a look and see what you have.

thanks for the help

[CharlesM479]

The Dynapath wants the I and J coordinates in absolute coordinates instead of incremental. I don't know what the setting is in BobCAD, but I'm pretty sure it can be configured to output this way.

I just got this from the BobCad forum

open the NC Editor, click on setup>driver

Looks like it will work

[tobyaxis]

Originally Posted by CharlesM479 I just got this from the BobCad forum open the NC Editor, click on setup>driver Looks like it will work

Yes it will. That is exactly what you want.