Good news is I am finally getting some cutting done.. bad news is that my bit is getting too hot and it is burning the foam and foam is sticking and charring to the bit. What suggestions would you have to prevent this? This was at feed rate 900 cutting full 2 inches at a time. Also tried 1222 feed rate with 1 inch per pass… still burned. I guess I’ll try 1 inch per pass at 400 and see how that goes. Thanks for any suggestions.
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Hi!
Did you try lowering the router/spindle speed? Depending on the foam density you might not need a high spindle speed. Lowering it could prevent melting the material.
Lasse
Wes wrote:
Good news is I am finally getting some cutting done.. bad news is that my bit
is getting too hot and it is burning the foam and foam is sticking and
charring to the bit. What suggestions would you have to prevent this? This was
at feed rate 900 cutting full 2 inches at a time. Also tried 1222 feed rate
with 1 inch per pass… still burned. I guess I’ll try 1 inch per pass at 400
and see how that goes. Thanks for any suggestions.
the bit getting hot is almost always caused by rubbing against the material you
are not cutting, not from the cutting itself (especially true with easy to cut
materials like foam)
to reduce heat, you want to reduce rubbing
use a bit with fewer flutes (single flute would be good for foam)
spin the router slower
move the router faster
(at some point, spinning the router slower and moving it faster will not be able
to cut your material, so this is a matter of experimentation and possibly
breaking some bits and messing up some cuts)
David Lang
Hi ,
You might want to try a specialized foam cutting bit. I found this one that could help with your overheating issue:
The 2 flutes are designed to reduce friction and should help prevent the foam from melting and charring on the bit. Worth trying alongside the speed and feed rate adjustments.
compote
Thank you very much for your input. I’m currently using a double flute 2-in bit. Here’s the link to it:
It was $23 instead of the $75 single flute version.
I’ll try slowing down bitspeed and speeding up the feed rate.
I was able to tell when it was getting hot and burning so I would pause it and wait a few moments…. I could hear the material building up on the bit and then getting cleaned off, after I could hear it was cleaned of and move a few inches… repeated this process to get through my cut.
I echo everything the other have said, but I’d also almost be tempted to take the router out and do some manual testing on waste material (assuming you have a proper plunge base for it) - get a feel for whether much force at all is needed to move, can you run the router on the lowest speed and how that affects it, etc etc.
I’d also ask what you’re doing for dust extraction (apologies if you put it in another thread). Making sure it’s clearing everything well might help with stopping the gunk building up - tape to make the top opening smaller can help make sure you’re getting the best out of a shop vac
Wes wrote:
Thank you very much for your input. I’m currently using a double flute 2-in bit. Here’s the link to it:
This one is only 1.5" deep cutting edge, so it wouldn’t be able to do it in one
pass, but it’s cheap ($12)
https://www.homedepot.com/p/DIABLO-1-4-in-Single-Flute-Straight-Bit-DR03140/204073483
David Lang
Sweet… I just added some tape; hopefully that will improve debris removal. Good suggestion.
Good idea to test the router manually to find right speed combo… too bad I don’t have a spare.
I set router speed to 2.5 and feed rate to 1222 and that did the trick. Nice clean edges; 2 inches on a single pass. I’ll keep on kicking up feed rate slowly to test the limits!