I am a newb at all this and just a hobbysit trying to understand all this. I have a job that I cut with a 1/8" end mill. I comes out great. At the end I need to drill 4 2.5mm holes in it. I swap the end mill holder, and put on my chuck and my 2.5mm bit, and start my machine and it slams down into my work. I pretty it has something to do with the machine/CAM software does not know the bit is 2" longer. How do I do this correctly? Should the CAM software compensate for it, or should mach 3. Not sure on how all this works.

Sorry for the stupid question, but just trying to learn.

you specify tool lengths in your CAM software so that's where you need to look. Look at the tools and "shorten" the 2.5mm bit by 2". And that's it!

hope this helps! :D

If the drill bit is hitting my work surface before it gets to 0(top of work surface) shouldn't it be lengthened 2"?

erm yes, sorry, lenghten it by 2" :D

Ok, thanks.

As for as the added lenght of the Chuck how do I account for it over the end mill holder? Is this in the tool setup screen as well?

If the drill bit is hitting my work surface before it gets to 0(top of work surface) shouldn't it be lengthened 2"?

Doesn't the machine software have a tool library that you can set each tool off the top of the material?

I would look in tool offsets or some other location of the control to define each tools attributes. Cam packages can take the diameter into account to follow a path, but more than likely the length of the tool must be set at the control on the machine in reference to the Z-axis. AKA tool1, tool2, toolxx. This will relate Z zero to the end of each tool and the top of your material.

DC

I am using Mach 3 demo, and using MCX and VM5 at school to do this. Considering buying OneCNC but the price really has me put off. I would like a full 4 axis setup for my sherline, but .....WOW

The best thing would be to do some measurements. Take out the chuck and put back the end mill holder. Lower the Z axis so your router touches the work surface. Set Z to 0. Then lift the Z axis, put the chuck on, put the drill bit in the chuck, and then lower the Z axis and see what number you get at the point where the drill touches the work surface. The number you get should be input as your tool length. And you're done! :)

Thanks guys, I will give this a shot and see what happens.