cutting a slot with a t-slot cutter

[cncuser1]

I want to cut a slot with a T-slot cutter.
I'm using a 2d contour toolpath

I can't get MC X2 to start cutting at the top of the slot. It always starts below the top of the slot by a distance equal to the depth of cuts.

How do I force MCX2 to start cutting at the depth I want.

[AbsoluteZero]

Are you cutting a t slot or just using a t slot cutter?

[cncuser1]

Originally Posted by AbsoluteZero Are you cutting a t slot or just using a t slot cutter?

Cutting a slot
The cutter is about .100" high, my slot needs to be about .15".
So I have to do a pass at a given Z, then move dow .05" to a final depth.

I get the final depth, but the start Z off by my depth of cut.

[Matt Berube]

If you wanted to do it in 2 passes it may be simpler to make 2 operations out of it.

Otherwise, you could change the height of the first pass by adjusting the "top of stock" value. This was not my first choice only because I *think* it could be slightly unpredictable where the first pass lands with depth cuts activated but I am away from my hasp right now and can't test this theory...

Either way, if you play around with it I am sure you can get it to do what you want.

[AbsoluteZero]

Two operations would solve all your problems. I dont see why it wont work for you I just ran that through with false numbers and with a final z set I told it depth cuts value of .05 and it generated a two pass slot. Also you could try to lie to the software and tell it its a normal end mill it wont look right on verify but the fact that its compensating for a slot cutter might be messing it up. Any case fastest way tell it a contour pass with a final z and then copy the contour and change final z by .05.

[cncuser1]

Originally Posted by cncuser1 I want to cut a slot with a T-slot cutter. I'm using a 2d contour toolpath I can't get MC X2 to start cutting at the top of the slot. It always starts below the top of the slot by a distance equal to the depth of cuts. How do I force MCX2 to start cutting at the depth I want.

Thanks Guys it looks like it will work, a little bass akwards, but it seems to work, I'll try it on some metal tomorrow

[cadcam]

I know it can be done properly even with a custom keycutter like this one used in thread re leafs for valve body's. here is one I just did on a project I just finished programming.
http://www.mastercam-cadcam.com/keycutter.wmv

[cncuser1]

Originally Posted by cadcam I know it can be done properly even with a custom keycutter like this one used in thread re leafs for valve body's. here is one I just did on a project I just finished programming. http://www.mastercam-cadcam.com/keycutter.wmv

Thanks Cadcam, as far as I can tell I did what your video shows ( no sound?) but like I said the first cut is below where I want by an amout equal to the depth of cut.

I think all the countouur 2D cuts start at a depth below top of stock equal to cut depths? No?

I am using MCX2, maybe they have different algorithm for X3.

I think I solved the problem by doing a new, separate toolpath at each depth I want.

[cadcam]

CNC user want to share your file so I can see what you are doing? you can email it to me if you want.

[weirdharold]

Good video by the way. Please see if I am understanding this correctly. Top of part is 2.4855, bottom is 2.4255, a differance of .060, plus a stepdown of .025 for a total width of groove, or relief, is .085. Is this correct ? Thank's . Harold C

But after watching video again, the differance of .060 is total width of relief & cutter is .035 with .025 stepdown ???

[weirdharold]

I finally figured this one out. Made my own model & custom t-slot cutter & played with it for a short while, & got it. Work's like a charm. We don't do many internal / external grooves , but we do them from time to time. Very helpful. Thank's. Harold C.

[cadcam]

I guess now I need to make a short video showing a keycutter doing and undercut surface path.