# Carbide 3D - you cunning foxes?

(Luke) #1

Morning all

I might have made an exciting discovery in carbide motion, at-least I think I have…

I’ve been using lots of odd sizes end mills - metric in the UK and I’ve been getting really frustrated having to use a 6.35 mill if I wanted to probe. I want to use metric mills and this was one of the reasons I changed my spindle, but not bing able to probe with different diameters was a drawback.

This morning I wanted to probe a corner and just a 8mm bit. I tried using an positive offset of 1.65mm and it cut 1.65 positively, I then used a 1.65 negative offset and it too was off in a negative fashion. Both positive and negatives were wrong but I had probed with a 6.35 mill and using a 8mm bit.

Scratching my head I thought what if I probed with the 8mm bit and use the original code… boom right where it was meant to be. Now thats rather strange as I’m using a 8mm end to probe, this should have an offset on it.

If I’m right this mean that Carbide Motion is not just calculating the Datum, but it’s calculating the end mill diameter! Now for me this is a huge benefit! It opens my a raft of possibilities.

Now I am using the beta of CM 4.11 (where I have found a few niggles) and the official CM probe but can anyone else verify this? @WillAdams @RichCournoyer do you have some odd size end mills they can have a go with?

(Richard Cournoyer) #2

I remember testing 1/32" end mills (also not on the list) and thinking that the end mill selection is ONLY for the amount of Z travel (below the top of the probe, so as to not touch the 1/8 shank). So now you got me thinking.

I do have 6mm end mills and will give that a go next week (and report back), when I attempt to calibrate my machine to 0.0001" (Yes I got a nice new set of Gauge (Joe) Blocks for Xmas. I wonder how close I can get it…I will do a post on my efforts.

(Luke) #3

I’d love to have you come and sort mine out

I’ve had another quick look at this and I can’t figure it out. I used a 10mm bit and it was well off. I did the 8mm bit and it looks spot on.

The more I think about it the more I think the actual offset in CM might be wrong - I had some issues with a 1/8 bit which seemed to be off by around 1mm - this might be giving me the issue.