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rustydog
11-04-2012, 06:35 PM
I've been working on a small run of special wood plane cutters. Iíve successfully made many in the past using O1 steel. In order to get the profile I need I was using a fly cutter. I hogged out about .175 x .800 with a standard 4 flute cutter (multiple passes) with no problem. This left .025 to be removed on 1 edge and about.090 on the other. I started taking about .010 on both surfaces and the soft O1 steel ate the cutter. The cutter was a high speed 5/16 lathe bit sharpened with shallow relief angles and honed down to about 1000 on the diamond stone. It worked beautifully on two mild steel tests, Since I was planning on taking .010 cuts I was running at about 800 rpm with a 1.25" diameter cutter diameter.

I'm surprised that I ruined the HHS cutter so fast since Iíve had no problems running standard mill cutters in O1 taking much bigger cuts.

I'd appreciate any critique or thoughts since I'm relatively new to fly cutting..

MaxxLagg
11-04-2012, 06:47 PM
Too fast a RPM by almost a factor of 4.

As a general rule, I use a cutting speed for O1 of 70.

Cutting Speed x 4/diameter=
70x4/1.25=224 RPM

Jaakko Fagerlund
11-05-2012, 01:23 PM
Yup, too much speed and also probably lack of cooling also (didn't mention flooding it).

I would say around 150 - 200 RPM (it is tool steel you are working, so slower than mild steel is preferred) with that 1.25" cutter.