How to cutt 3/4 Baltic Birch wit a 3/8 compretion cutter

[steve4460]

Hi Guys
I have these 3/8 compretion cutters and I have to cut up 15 sheets of baltic birch.What would be the best feed speed / passes and RPM to use .
The reason I am asking is That I don't have the time to play with it to figure out these numbers . Any help would be greatly welcome .
Thanks

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[Brady Watson]

PRT or Alpha?
Spindle or Router?
Vacuum system specs or other holdown method?

Search this site via Google for Compression Spiral (http://tinyurl.com/2h4jr9)

[elcruisr]

Also, single edge or double? I run lots of my jobs with 3/8 compression single edge tools. If I was cutting on my setup which is a 5 hp spindle with vacuum hold down, a PRT Alpha and medium to large parts. Then I'd be turning 18,000 rpm and feeding at 6"/ sec. doing a single pass through cut. Normally I'd feed at 8 but baltic birch is a little tougher to cut and I get better results with a smaller chip load. If an even better cut is needed than I'd do a single roughing pass with a .04 offset and a finish pass.

[steve4460]

Hi Brady

It's an PRT ALPHA ,PC router 6.5 Hp shopvac for the holdown and Jet2 Hp dust collector. 2 flute 3/8 compession cutter.
Thanks
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[Brady Watson]

You are going to have a tough time holding parts down with a shopvac using a compression spiral, unless you make a custom setup like the BradyVac II. You may still have to tab parts to keep things from moving. I would try running at 2 IPS initially and see where that gets you. Ramped plunges are a MUST when using a comp. spiral.

-B

[steve4460]

Thanks Guys
As it turns out I have to run some datos in there too and that compression bit chips the baltic bad . so I went back to my tryed and tested 1/4" downspiral that one I can run at 8" ips wit 0.25 stepdown . By doing that it takes a little longer but I have less cleanup to do .Eventualy I will have to find something I can cut with thos 3/8 compession cutter , or put them back out on ebay .Thanks again

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[srwtlc]

Stephen,

Try a mortising bit like Onsruds 60-123 (3/8"). They have less of a upcut portion on them. I think it has something like a 0.188" upcut.

[knight_toolworks]

I was cutting the workstation out of 3/4" birch plywood (not baltic) and I could not do it in a single pass because the toolpath was written for two passes. so I was worried about what would cut clean on both sides. I had this 1/4" bit I got off ebay a onsrud https://www.onsrud.com/xpost 52-624 TWO FLUTE and it cut perfectly on both sides. since it only has a light spiral I was pretty impressed. I was doing 1/2 the thickness at 6ips