Variable speed motor

[abunaitoo]

I have a brush AC 110v motor, from an air compressor.
Trying to make it variable speed.
I tried my router control and it did almost nothing.
Tried a light dimmer switch, and it did bring it down, but not as much as I need.
Doind this as cheap as possible.
Any ideas???

[Jake McCracken]

Safest way to avoid motor damage is one of these...

a VFD (variable frequency Drive)

Sent from my SM-G960U using Tapatalk

[KCSO]

Remember the slower you go the less torque you get. If you need torque for something better to gear it down with pulley and belt.

[redneck1]

Single phase brushed motors can be controlled by a variac ( variable voltage transformer )
But be certain it is a brushed motor. A brushless motor will burn up rather quickly if it isn't run fast enough to kick out the start windings .

The router control won't work because it is for a dc motor .

I went out and took a picture of a variac I have kicking around for visual stimulation.

I can't say they don't make them , but I have never seen a vfd for a single phase motor
Vfd's are for three phase motor in general .
For smaller motors of less then 5hp there are plenty of vfd's out there that convert single phase into three phase making them really easy to use .

225111

[NyFirefighter357]

What are you powering with it? I'm a member of Vintage machinery & Old wood Working Machines http://www.owwm.org/search.php?keywords=treadmill+motor Besides VFD's & Variacs the easiest speed controlled motors can be found for free in basements and bulk pickup piles. Treadmill motors are being used to power drill presses, lathes ect.

[abunaitoo]

He wants to get one of those .223 case trimmers like a Trim-it, or something like it.
Thinks a hand drill will not be fast enough.
He wants something spinning around 3000rpm.
He saw it on utube.
I don't think it needs much torque spinning that fast.

[NyFirefighter357]

Dewalt 3/8" electric hand drill 2,500RPM

[Adam20]

I tried putting one in a wood router, DO NOT TRY at full speed, it ripped it out and bent the shaft and flung it across the room. (Ruined it) I put variable speed router control on it and that works
Electric drill is best option

[Jake McCracken]

I can't say they don't make them , but I have never seen a vfd for a single phase motor
Vfd's are for three phase motor in general ..



They do make them, not the cheapest option for what he wants tho.

Just google "115v single phase VFD"

[abunaitoo]

I'm thinking 3000rpm is way to fast and dangerous.
But for some reason he's stuck on that number.
I've suggested to him many times, if he dead set on getting a trimmer like that, to get it and try different ways to spin it.
I'm sure a power drill is way fast enough.
He a newby to reloading, so he want the best.
Just trying to help him out.

[redneck1]

I use the Lee trimmer with a hand drill quite often , it works much better at lower speeds then it does running the drill wide open .

[JimB..]

Easy to get pulleys to get to 3000 if he is hell bent on trying it. You could probably do it with a bicycle mounted on a stationary trainer. The goal should be to show him that he’s wrong at the lowest possible cost and risk, rather than try to build something durable but useless.

If he wants the best, just have him buy the Giraud, it is a great tool!

[varmintpopper]

Perhaps the motor from a commercial sewing machine with the speed controlled with a resistive foot controller, That is what I use.

Good Shooting

Lindy

[popper]

At that speed he will burn out the cutter. Even at handheld drill high speed you have to keep the cutter lubed (cooled).

[pete501]

You can find used treadmills often for free. Electric motor is variable speed and comes with the controller.

[JonB_in_Glencoe]

At that speed he will burn out the cutter. Even at handheld drill high speed you have to keep the cutter lubed (cooled).
I agree...I use a battery drill with Lee tools for case trimming large quantities of cases...I think it works real well, I use the slow speed of the drill.


Perhaps the motor from a commercial sewing machine with the speed controlled with a resistive foot controller, That is what I use.
Good Shooting
Lindy
I have read about others using a sewing machine motor and foot control for a trimmer station...If I were to make a trimmer station, that is the route I'd try first, because you can find old sewing machines for cheap or free
...and If I thought I needed 3000rpm :shock: ...I'd use a belt and pulley system...you could probably just reverse the pulleys from the sewing machine and use that belt.
That's my 2¢

[fast ronnie]

3000 is WAY too fast even for a carbide cutter. I use a high speed counterbore for a case trimmer and run it 4 to 5 hundred rpm. 3000 rpm will burn up a high speed cutter very quickly. (in just a few parts)

[country gent]

Look for a DC motor and controller they don't loose power when reducing rpms as bad as AC motors do. He may have the set up to power the cutter already in a table top drill press. A standard 1/4 hp motor and set of step pulleys will do the job and allow for some speed adjustment to experiment with. As will the drill press. run the tool there and see where it needs to run speed wise to maintain smooth cut with no grabing, chatter or stalling.

[NyFirefighter357]

You can find used treadmills often for free. Electric motor is variable speed and comes with the controller.

I got one today. Was all taken apart to be removed out of a bedroom. Just took all the electronics.

[Mr_Sheesh]

I use treadmill motors as generators sometimes - 100V output at full speed on the one I used for that. I have found that for PC Board drilling, I can use a carbide drill at more like 4 RPS so 240 RPMs and it's plenty fast for my needs, doesn't have as many problems that way as a faster speed one. Doing something unusual in what I do though.

[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.