offset dimension for roundover tool

[Chris Flint Two Ft Pty Ltd]

Guy's,

I am having a problem I have a contour which is 20mm wide 6mm high and is 1800 mm long.

My first machining toolpath is to cut the above contour.

Now I want to radius both top sides ( it is a mould, for easier release).

The tool (in the pic, don't know how to add the darn pic nothing in FAQ) is a "roundover tool" with the following dimensions.

shank 12.73mm, width 16mm,2 flute flat plate like cutter which has 2 radius's X 5mm and the flat centre is 1/4inch 6.35mm wide effectivly the centre of the tool is in the middle of the 6.35 and then you get the 2 radius's then up to the flutes.

How much must I offset the contour and then use compensate either left or right to get this tool to trim radius. ( round over the top 2 sides, does not have to be full radius, just enough to smooth it).

Everytime I program it and then run verify it seems/looks wrong, and is driving me crazy, cause it should be simple.

I cannot afford to run the job and screw it up as it is a huge 2800 X 1800 mould.

Anyone care to assist.

thanks

chris f

[Randy Morton @ Clem Industrial]

I may not have the solution for your problem, but I can tell that to post pictures you need to have a web server to host them. I use www.photobucket.com It's free to register and put your pictures on, then it gives you a link that you directly place in the forum type box and it will link to your picture.

 

How that helps at least 1 of 2 problems.

[Psychomill]

I think you're describing a "Corner Rounder" ? If I understand your tool it sounds like a 5mm corner rounder with a 1/4" pilot?

 

For these types of tools, I usually program the tool as a 1/4" tool ( or whatever the pilot diameter is). To climb cut (provided its not a left handed tool), "Comp Left". For Z depth, you can set the tool at the back end (or 'top') of the 5mm radius and call that zero (therefore programming at Z0), or set it at the bottom of the tip and program Z to the top of the radius.

 

Just sneak up on it by keeping the Z a little short and running plus (+) comp at first until you like the result.

 

This is all provided we are talking about the same tool type.....

 

 

[Randy Morton @ Clem Industrial]

I don't know about Vamvany, but that is a much better sound way then how I have been doing it, Psychomill. I use those and always have issues, but your way sounds easy and accurate.

 

Thanks!

[Guest]

+ 1 Psychomill

 

Most reliable way I've found to do it too.

 

[ILv2Rk]

Same here Psychomill.

 

Best way I have found also.

 

[Chris Flint Two Ft Pty Ltd]

Psychomill,

you have delivered me from darkness.

Thanks a heap, I think your method is fantastic, and will end this for me issue for ever, and save a lot of extra drawing of offset contours.

thanks again

chris f

PS to Millingman thans for the pointer, but I think it odd that we cannot post JPEG images with our posts here? ( maybe again I just do not know how to do it).