Since Mark has announced that we might need to lower our feedrates in order to eliminate skew (because our router only spins at 15000 RPM), I thought it might be a good idea to start a thread were we can all gather feedrates that work well on different materials and bit sizes.

I have cut 3 mm depron (snowflakes) with a 1/16" bit at 50 ipm with no skew. the edges were a little melted, though.

I just cut some 3 mm depron (sea horses) with the 1/16" bit at 75 ipm with no skew. the edges should have been cleaner but i cant say for sure because my bit was all gunked up after cutting foamboard with the paper on

<EDIT>
Data Entry Form
https://spreadsheets.google.com/viewfor ... c6MQ#gid=0

Collective Data Sheet
</EDIT>
https://spreadsheets.google.com/ccc?key ... rJoJ#gid=0

- Jeff

 

"We're sorry.
That is not a valid spreadsheet URL. "

OHHH! This link goes straight to the spreadsheet, so I bookmarked it directly: https://spreadsheets.google.com/viewform?formkey=dDlvbV9ISVc0UWx3Sjl3M1RnVTllRGc6MQ#gid=0
I'll see what I can do to get this data incorporated into the CNC Simulator also, if you don't mind. I have a 3-year license to it also, but it doesn't have much foam-related data yet. http://www.cncsimulator.com/index.php

Excellent spreadsheet! :mrgreen:

 

Added the data for cutting 1/4" light ply with a 1/16" grout removal bit. However, there wasn't a place to say that I'm taking multi-passes at .050"

 

For those interested in trying different bits, here is a website where I get mine....

http://bitsbits.com

 

Thanks for the link, Flash! I'm going to be doing some business with these guys soon.

 

A couple weeks ago I tried cutting some 5 mm coroplast. That is some thick, tough stuff! 10 ipm on the stock 1/8" bit made a nice clean cut; however, I suspect the multipass tool may do a better job at a higher feedrate because some spots melted slightly while others were clean.

- Jeff

 

I have been cutting a lot of 9mm 1.9lb density EPP over the last couple of evenings. I tried several feed rates and bit types. I achieved a very good edge finish with the 1/8" Dremel Tile Cut bit feeding at 35ipm on the stock Phlatprinter 3. The edges are slightly skinned over, which in my opinion is perfect for foamy airplanes.

I also tried feed rates of 25, 30, and 50 with combinations of the 1/8" Roto Zip Tile Cut, Roto Zip Saber and finally the Dremel Tile Cut bit. I don't know if there is a real or percieved difference in the Dremel and Roto Zip Tile Cut bits but I ended up with the Dremel bit. The Roto Zip bits seem to produce less than expected results.

Feed rates faster than 35ipm resulted in tearing small pieces of the edge from the material. Of course slower speeds showed more melting. I didn't get any noticeable melting of material onto the bit at any of the speeeds I tried.

 

I got a new shipment 9mm 1.3lb density EPP last week. All I can say is what a pain! I killed several sheets trying different parts nesting orientations and part counts per sheet sequences. I kept getting way too much material stretch and squish to achieve a repeatable cut. I didn't have much luck correcting the issue until late last night when I tried using a FFF spolier on the bottom to drive the material. I still saw some squish and misalignment from the pressure rollers but, nothing like what I was seeing with the EPP alone. I'm going to try a FFF sandwich of the EPP tonight, time was running out last evening. Hopefully I can find a suitable mix of spoilers and roller pressure for this lighter density foam.