Variable speed motor

[abunaitoo]

He sent he a link for the Giraud trimmer.
They say they trimmer spins at 3000.
I don't know.
It would seem to me if it's going that fast, with no lube, it will burn out.
I just don't see the reason in going that fast.
My RCBS Trim Pro 2 spins slow and it does OK..

[country gent]

Cutter speed is determined by surface feet per minute, material and cutter type. There are formulas and charts to give you this number. Size plays a big factor in speed. A 1/8" shaft at 3000 fpm is actually lower than a 18" dia at 100 rpm. OSG, Cleavland twist drills Morse may have this formula or charts on their web site. Case trimming is unique also since dia is not only small but is thin sectioned at .010-.012 thickness. A carbide cutter properly ground for brass 3000 is probably about a 3rd what a shop would be running it rpms. Chip load per tooth is also a consideration and hard to figure with a hand feed set up.

I do my neck turning in a drill press with a balanced cutter head. ( made it myself for this purpose as neck turning a 1000 cases for high power season was a pain by hand) I normally run the high speed cobalt cutter around 2000 rpm and feed slow on the spindle. I get a beautiful finish very accurate neck wall thickness and loaded round dia. At the upper end rpms tools need to be balanced as vibrations set up can also cause wear poor finishes and tools to walk.

When you look at the charts or use the formula use the biggest caliber your going to trim ( 45 50) as the dia. You might be a little on the slow side for smaller calibers but not much.

[David2011]

While just about any speed from a few hundred rpm up will trim a case (hand operated RCBS or Forster for example) I've been very successful with battery powered drills in the 1200-1800 rpm range for the Forster, Possum Hollow and World's Finest Trimmer. I have a Dillon Rapid Trim 1200 case trimmer. It uses a carbide cutter and spins at 5000 rpm. It's trimmed a bunch of 5.56 brass, numbering in the thousands on the same cutter that was in it when I bought it used. It still cuts fine shavings so I would say it is not burned up after only a few cuts.

The Dillon Rapid Trim is unbalanced with only a single triangular carbide cutter. It does have a high frequency, relatively low amplitude vibration but it leaves the case mouths clean and smooth but with a burr to the outside of the mouth. It cleans off easily with a deburring tool.

[abunaitoo]

I use a RCBS powered trimmer.
Clean it up the the RCBS case prep center.
Goes fast enough for me.
The RCBS hand turn trimmer is actually faster than the power trimmer, but it is tiring.