Shapeoko3 2" depth HDPE

(chris) #1

my client wants me to cut 1.5-2" thick logo/letters for a prop, and I’m not clear on if my SH3 can handle this. There is enough z travel, but how much does the bit/tooling need to stick into the dewalt? I guess the biggest tool i can use is a 1/4" shank … so what is the maximum thickness that I can cut with my Shapeoko ?

(William Adams) #2

You should be able to cut 1.5" – 2" thick material, the problem is getting an endmill of a suitable length — there are long reach 1/8" endmills w/ 1" flutes, and 1/4" ones which are longer:

you’ll need to flip the workpiece if you can’t tolerate a bit of rubbing. If not, you’d want to work up a suitable toolpath which avoids that, say a series of stacked pockets with gradually increasing offsets from the geometry working your way down, then a final pass with really aggressive, and gradually decreasing depth of cut working your way down to the bottom.

(chris) #3

thanks Will.
What do you mean by ‘rubbing’?

(chris) #4

I’m looking at this and thinking it should work in my 1/4" collet.Seems like the cutting edge doesnt have to go the whole distance- if its already cvut -maybe that post-cut contact is what you mean about ‘rubbing’.?

(Phil Thien) #5

I have been known to cut to a depth of about .75” and then finish with a bandsaw/jigsaw and then long pattern bit in my router table. The problem is my pattern bit D is .5”, so corners can be a problem. Also not having a router table and jig saw could be a problem.

(Dan Nelson) #6

I did this at 2 1/4" using standard C3D 1/4" bits and a flip. I also have an additional 3/4" waste board on top of my waste board, so I had to lift the router up a little in the clamp:

It can be done, just have to do a little planning.


(William Adams) #7

Correct. Rubbing is the shaft of the endmill spinning against the material when you cut deeper than the flutes.

(Csaba Horváth) #8

It is possible to get that done on your S3. I am just in the middle of a HDPE project and found that it is a great material to work with. Plan for the tool stick out, run some test cuts in the air and than in XPS foam to be absolutely sure that you will not have collisions. You might not be able to use a dust shoe depending on your setup.

You can also cut out the letters from thinner material and than bond the layers with epoxy. It is possible to make the lines between layers almost invisible with a little attention to detail.

Think about the chip evacuation and try to prevent chips getting into the Z axis! I run the machine with f:1960; DOC:3; WOC:2,2; 22000 RPM; MRR 12.94 mc3/min; with a 2 flute carbide endmill. It is possible to almost triple the MRR sacrificing the surface finish.

Good luck!