What's the best way to cut thick foam. I have 1.5 inch foam insulation foam from Lowes and a 1" bit. Multipass maybe?

Eric

 

Eric,

I'd like to hear how it goes for you -- I am cutting 2" foam, and I have using 2 passes. I've had to slow the feed rate down to 25ipm, and the biggest challenge is to reduce/eliminate the foam sheet from skewing; so that the second pass actually coincides with the first one.

 

Cool guys, Ill give it a shot, maybe Mark's new guides will help Neil.


Eric

 

My roller side rails are on their way -- I'm getting four of these:

http://www.surpluscenter.com/item.asp?item=1-2940


And I'll use some aluminum angles to get a rail on each side front and back of the sheet. I try it as I have my pressure rollers, and if it still moves, I'll take the grit tape *off* of the pressure rollers so the rails won't have to "fight" the drift.

[Fixed link -- thanks for catching it.]

 

Looks like you got the last ones, Neil. That site says that they are discontinued or is not offered on the web. :girl_cray2:

 

I think the link was supposed to be:
http://www.surpluscenter.com/item.asp?item=1-2940

 

Yep, those are the ones I am getting.

 

I have been cutting a lot of 3/4" Dow blue core. I have yet to find the perfect speed and feed but I am getting close. So far, 70 ipm and about 9000 rpm seems to be the closest I can find for a usable setting making a single pass. I have gone as low as 50 IPM but found it was to slow causing the tip of the bit will melt the foam even on the slowest setting on using a Bosch pony router. Much faster than 70 ipm and the board will slip around causing inaccurate cuts. I have been trying out several different bits. The Bosch root zip bits with the loose spiral designed for cutting plastic seem to work the best. The drywall rotozip bits work well also but if your doing any pockets or face milling, the pointed tips leave too large of a groove. Tool chatter is also a problem. With a low RPM and higher federate, the tool doesn't chatter but it causes a greater load that increases board skew.
Eventually I will nail it down and find the perfect speed and feed rate.

 

Are you using the triangular "knurled" bit (that came with my PhlatPrinter 3) or a different type? I'm hoping to cut 1" foam in one pass at ~50ipm. Does the stock Chicago rotary tool spin at 15K RPM?

 

The maximum rpm for the Chicago rotary tool is 15K RPM's.

Hope this helps.
GHB

 

I don't use the diamond tooth bit.Its a good bit but I like the finish and the price of these two bits:

The rotozip standard point bit, pack of 8 for $8.

If I am doing any pocket work, I like the Saberpoint bits better because they have a flat (ish) tip. They come in packs of four for $8.

I advise getting a router if your wanting to do a single pass, that way you can slow both your speeds and feeds.