Sprial cutter question

[paul60]

a sprial cutter with a 7/8 flute would it be ok for
cutting through 3/4 ply?
what would be better 2 flute or 4 flute.
have anyone used cutters from www.american- carbide.com
just wonder how they stand up
thanks paul

[jhicks]

Paul, I'm sure you will hear there are many solutions but lately we have been cutting prefinished ply and have excellent results with a 3/8" diameter 2 flute compression bit in a single pass with feed about 180IPM or 3IPS at 16000rpm.
Crisp top and bottom edges no problem running with ascension control box.
I think bit suppliers would tell you 2 flute will clear chips better but check with onsrud. They have great tech suppport and recommendations
Probably could move faster but this works for now.

[patricktoomey]

Paul, I would go with 2 flute because to get a good chipload with 4 flutes would require very low RPM or very high feedrates. I cut with rates similar to Jerry although I run a little lower on the RPM but I'm doing 2 passes. My bits have a 1" cutting edge length, I don't see why 7/8" wouldn't work though. My cutters come from Amana Tool and I usually get 40-50 sheets of cabinet parts out of one, I haven't tried American-Carbide.

[paul60]

thanks for the information. what cnc do you both have i own a prtstandard with a milwaukie router
cant see a prt standard cutting in one pass.
i do 3 passes on 3/4 ply patrick 40-50 sheet thats great what is the part number of the bit you use?
thans paul

[patricktoomey]

Paul, I have a PRT standard but I'm running the Ascension 1000 controller. I can cut in one pass but I have better results with my vacuum hold down system by doing it in two passes. I can cut up to 10 inches per second in thinner material but cut quality starts to suffer in 3/4 sheets so I usually run 3 to 6 ips depending on what kind of shapes I'm cutting. I have a 5hp Colombo spindle which also helps with fast cutting.

[jhicks]

Paul, I have a PRT120 with 2 shop vacs on valves over trupan bleeder board and multiple zones running on the Ascension control box, 5HP spindle, and Mach software.
3/4" in single pass on prefinished 2 sided maple or birch with the 3/8" compression bit seems to run best for full depth cuts with ramp into stock on flat sides rather than corners.

I double checked and we were running at 180IPM but found on the 7 ply prefinished 160IPM was the sweet spot.
Different that 13 ply so each material has its own best cutting range.
Nice large and warm chips but probably could run it up a bit, just no reason to fix it if it isn't broken right now