View Full Version : Need Help! slots same width as bit

11-03-2011, 07:19 PM
I'm using VCarve Pro and I'm cutting slotted parts. The slots are .375" and so is the tool bit. Vcarve doesn't like this and when generating the toolpaths often skips the slots or doesn't cut the whole slot. I think that this is probably some intentional limitation preventing the program from attempting to cut a feature that is smaller than the bit?

So in order to get the tool path I had to tell V carve that my bit was a full .01" smaller than it really is (.365"). Problem is that this makes the slots too big. Is there a way around this?

11-03-2011, 07:47 PM
Draw a single vector down the center of your slot and do a profile cut on the vector.

11-03-2011, 08:27 PM
Hi Gerry.
Thanks a lot for the reply. I think that would work but I have an 18 sheet project with about 150 parts set up and the slots are already part of the profile cuts. I guess I was hoping for an easier way - like forcing VCarve to program the cuts into the slots despite the fact that they are the same size as the tool. Save me from re-nesting and redoing all of the tool paths.

Is there like, a tolerance setting that controls what the minimum difference between the slot width and the tool? Right now if my assumption is correct VCarve requires .005" on each side of the tool before it consistently programs the tool path into the slot. (it's funny how it isn't consistent with this too. Sometimes it does the slot, sometimes part of the slot, sometimes not at all). If I could reduce that minimum to like .0005" and use .374" instead of .365" as the tool width then the slots would be more or less perfect.

11-03-2011, 09:03 PM
What version are you using? In Aspire, I can cut a .375 slot with a .3745 tool using an Inside Profile cut.

11-03-2011, 09:06 PM
I just tried it with VCP 4.6, and it works in that too. Perhaps it's how your slots are drawn??

11-03-2011, 11:59 PM
I'm using VCP6. Let me have a closer look now. I just tried it again using .375 and it didn't work but it just worked with .374 - Maybe I was just mixed up. Wouldn't be a first.
Thanks for your time and sorry if it was wasted.

11-04-2011, 11:47 AM
Hi Gerry,
I had another look and the problem still persists for me but again, it isn't consistent. I tried once with just one of the parts that had the error, by itself and it worked with the .374 bit. When I tried with some of the other parts, the same toolpath just with more profiles selected the error occured in that same part again (and some of the others). Can you read VCP6 crv's in your VCP versions?

11-09-2011, 09:09 AM
I would draw a line down the center and cut on the line

11-09-2011, 09:22 AM
I agree,
draw your center line for the slot. Then do an online profile/pocket cut. You you might have to give it it's own layer, which should stop the machine after the cut for a bit change. If you're using the same.375 through out the part....just hit the start button again.


11-09-2011, 09:39 AM
He sent me the file to look at, and the problem was his slot was "pinched" in the middle, making it smaller than the tool.

11-09-2011, 10:21 AM
Thanks for the help on this everyone. I should have posted the outcome that Gerry mentioned. Sorry about that. I made the tool paths from a DXF generated from a Pro/E drawing. I always have to use the 'join vectors' in Vcarve, then I have to replace the faceted vectors with continious bezier curves. I think the minute error in the slot widths must happen in that operation.

I create the toolpath as a profile around the outside of the parts, including the slots. Once this project is nested there are alot of parts/profiles so it's difficult to change that approach - I would have to redo all of the tool paths and that would take a long time because I had to refine the tool paths alot to avoid hold down issues. If I started over I would definitely consider using the on line open vector approach you suggested - or go back in pro/e and widen the slots to .376" and make sure the profiles lines of the slots are straight!

Right now I have to edit my tool to tell V carve that the tool is .001" smaller than it is so that the tool path will go in to the slots. I do a lot of slotted designs and I don't like having so many weird tools defined - it's a recipe for mistakes!