6” Single Angle Milling Cutter on R8 Stub Arbor

[erikmannie]

I bought the tool below, & I have not yet figured out the feeds & speeds to make it work.

This is a 6”, 45° single angle cutter on an R8 stub arbor. My machine is a 220V, 3 phase, 3HP knee mill.

The first time I used it, I was trying to put a bevel on 1” mild steel plate. I had thought to try cuts of about .025”, but the tool set up could not handle it. I was barely able to make cuts of about .007”.

The cutting tool would stall in the work & the mill was not happy about it. It was about this time that the drive V-belt in the head of the knee mill was damaged, & my attempt to use this tool may have contributed to the damage of this belt.





The cutting tool is HSS & made in USA. The stub arbor is a Bison. Both were quite expensive.

 

[erikmannie]

As far as beveling plate, we are now going to tilt the head of the mill & use a face mill. The 45° angle of the cutting tool above is not even the bevel angle that I use (which happens to be 37 1/2°).

It would appear that this tool in my mill is limited to soft metals & plastic, neither of which I machine very often.

Does anybody know how I could use this tool on mild steel in my mill?

I don’t remember what spindle RPM I used, but it was probably somewhere around 400 RPM. The feed rate was somewhere between 5-12 ipm.

Like I said, this setup could barely handle a .005” DOC with the feeds & speeds above.

 

[mmcmdl]

Wrong tool for the job .

 

[erikmannie]

Wrong tool for the job .

Have you ever seen what job(s) people use this cutter for? I don’t even have a guess.

 

[mmcmdl]

Those types of cutters are used on large boring mills etc where the rpms go down very slow . Need flood coolant also . This is not a high speed (rpm) cutter by any means and your mill doesn't have the HP to run it . The tool itself will machine dovetails after roughing out , but not with the arbor you are using .

 

[erikmannie]

Those types of cutters are used on large boring mills etc where the rpms go down very slow . Need flood coolant also . This is not a high speed (rpm) cutter by any means and your mill doesn't have the HP to run it . The tool itself will machine dovetails after roughing out , but not with the arbor you are using .

That response does correspond to the limited experience that I have with this tool on my mill.

**So what can I ever do with this tool on my mill?** The minimum RPM available to me is 60. I would go for the “manual flood coolant” which is aerosolized WD-40.

A 6” diameter cutting tool on an R8 arbor is not good! I won’t even buy a 3” face mill. I think that a cutting tool of diameter of 2” to 2-1/2” is the upper limit for an R8 taper (fly cutting & boring excluded), depending on the material of the workpiece, of course.

I calculate that a spindle speed of 25 would be recommended for using a 6” diameter cutter on mild steel, assuming a (non-aggressive, home shop) value of 40 for SFM.



[40 X (12 divided by pi)]/6 = 25.4

 

[benmychree]

I can't imagine that the tool is even usable after running at that speed; 400 rpm is over 600 FPM cutting speed, on steel the RPM should be only 50 - 60 RPM, for 80 - 100 FPM. A cutting speed of 40 FPM is a bit slow for HSS, although a lightly built machine could possibly not allow such speed as I suggested.

 

[Parlo]

Have you ever seen what job(s) people use this cutter for? I don’t even have a guess.

Here is a use for the cutter.

 

[erikmannie]

I can't imagine that the tool is even usable after running at that speed; 400 rpm is over 600 FPM cutting speed, on steel the RPM should be only 50 - 60 RPM, for 80 - 100 FPM. A cutting speed of 40 FPM is a bit slow for HSS, although a lightly built machine could possibly not allow such speed as I suggested.

I wish I remembered what speed I ran it at. I would have calculated RPM as above. Maybe I used 120 RPM; I am disappointed in myself that I don’t remember.

If it is the case that this cutter is abused/spoiled/unusable, I would be able to tell by looking at the edges?

I almost always use carbide. I should make sure to always keep RPMs much lower when I do use HSS.

 

[benmychree]

I did not think that it looked too bad in your picture, but to be usable, the teeth should be sharp, not having a worn or radiused look, they can be resharpened if necessary, 120 RPM would be in the realm of possibility.