Milling Machine Question
 

A simple and quick question. How much tork does it take to stall a milling machine?

Re: Milling Machine Question
 

The torque limits vary machine to machine, but it's usually quite a lot (i.e. significantly more than it should experience under proper working conditions).

Re: Milling Machine Question
 

Specs for a Fadal VMC 4020

SPINDLE DRIVE MOTOR AC, VECTOR Drive
HORSEPOWER* 15 HP / 22.5 HPA , 30 HPB
TORQUE* 160 ft.-lbs. / 220 ft.-lbs.A / 270 ft.-lbs.B
AXIS DRIVE MOTOR (X/Y/Z) AC, 3,800 lbs.* thrust

Re: Milling Machine Question
 

It varies quite a bit from one machine to another. If you have your mill stalling out, there could be a few different issues. The most likely one is you're taking too big of a cut based on what the machine is rated for. The easy solution is to take a smaller cut.

You could also using cutting oil or some other type of approved lubricant to maintain the material at a cooler temperature which prevents chips from being welded to the part it was just cut from. It will also extend the life of your end mills.

Your end mills may be dull. If they're used heavily, then you probably should be replacing them every other year.

A little more complicated may be if the belts inside the mill are worn out so they don't have as much friction to turn the spindle.

Re: Milling Machine Question
 

My experience your removing to much material with each pass, causing it to stall, or the bit is not sharp, or plugged up, what type of material are you milling?

Re: Milling Machine Question
 

I guess the question in reply is: Why? Are you stalling out a mill? If so, what make, model, and motor size is involved, as well as the specifics of the cut? There is noting that I can think of that a FRC team should be doing that could stall out a standard vertical mill (mini-mills etc are a different story).

Re: Milling Machine Question
 

Excess chip loading:
1) number of teeth engaged with the cut to large.
2) volume of metal per chip too large (excess depth per pass & feed per tooth)
3) strength of metal per # of simultaneous flutes cutting to great.
4) diameter of cutter too large for spindle motor torque
5) cutter teeth too dull or damaged
6) profile of cutter giving too much linear contact with teeth

Other:
7) if a variable speed spindle motor, running at too low of an RPM

Re: Milling Machine Question
 

8) If you are running a manual mill on a static phase converter it loses 1/3 of the hourse power.