Hi Guys

I am trying to make a plastic pump impeller and the vanes are shown in the attached drawing, i will be cutting 5mm deep in 10mm stock so the shapes are effectively bulges when its finished.I have been trying to create the tool path using offset. I have read the LC manual and watched the videos and have been trying for ages to get a tool path that leaves the bulge( even one at a time doing 5 complete machinings would suffice) all i get are weird shapes that are nothing like the drawn part. The nearest i can get is a complete circle that follows one outer curve but cuts completely through where the other vanes would be. What am i doing wrong? I imported the shapes sample and was able to generate the correct tool path for cutting them as bulges so i think i understand the basics. I have read on this forum that some badly drawn dxf files can cause problems so what i did was draw the vanes in LT2011 using the clipping command so everything should be joined , i then tried filleting every intersection and when that didn,t work i exploded the drawing just for the hell of it , still no joy. Help please!

I just draw a circle to enclose the vanes (red), then do a POCKET w/islands and it will leave the vanes proud.

Russ

A nice drawing and a nice reply .......
RICH

Thanks for the quick reply Russ i appreciate it , will try this out tomorrow.
I take it i just draw the circle in LT or am i missing something again.
Would i always need to leave bulges as islands in a pocket regardless of shape or it is just the odd shape of the vanes that caused the problem?

Thanks again.

Yes, just draw the circle in CAD and export the whole thing.
If someone told you to remove the material around the vanes, how would you know how much?
Needs some limit to process what you want to do. Some cam programs would ask you how big the stock is. LC only imports drawings.
RICH

OK thanks

OK , i tried it and after a while i managed to get what your attached picture showed , i outputed to mach3 and ran it.
It machined the vanes in the right place but as pockets where they should have been islands so when the code finished i ended up with a very large pocket with absolutely nothing left inside . I tried running it through with a 6mm cutter in stead of the 10mm tool i used when creating the code but same result.
I then tried selecting only some of the chains around the vanes hoping that it would leave at least something  but i keep getting bad lines in the code when i load it into mach3.
Any ideas?

Have a look at the attached doc file. You need to unenable the lproifle of the vanes.
RICH