Controlling Speed of Motor

[Peakoverload]

I'm looking to build my own cresting jig, this is a device used in the making of arrows for archery and simply spins the arrow around, a bit like a lathe, so you can paint the arrow.

As arrows are very light the motor doesn't need to be very powerful and really you only need one capable of around 150-200rpm. A lot of people who build these use a sewing machine motor but I'm reading a lot of conflicting advice on how to control the speed of it.

The motor I'm currently looking at is a AC Sewing Machine motor:

Rated power: 180 (W)
Rated voltage: 220 (V) AC 50HZ
Rated speed: 5000 (rpm)
Rated current: 0.9 (A)

This one or very much like it http://www.ebay.co.uk/itm/220V-180W...671175?hash=item4402bc4d87:g:K8YAAOSwR29ZCE4O

This comes with a footpedal to control the motor but I'd rather not use a foot pedal and instead want some kind of rotary pot so that I can set it to a particular speed and then leave it.

My initial thought was to just use a lighting dimmer switch as these are rated to 400W but I've read conflicting information with some saying that this is exactly how the foot pedal works and so perfectly safe and others saying that I'd actually need a fan dimmer switch. Others still say that you should use a dedicated motor speed controller saying that adjusting the voltage will harm the motor and that you need to change the frequency to adjust the speed.

Does anyone know which is the correct/safe method to use?

 

[Minder]

The 'old' style sewing machine motors were Universal motors, which this appears to be, if so they were often used with a variable resistance footpedal control.
If it IS a Universal motor, i.e. has brushes and is ran off of AC then it probably is.
If so you can use a dimmer style controller.
First you need to establish the motor type.
M.

 

[Alec_t]

Could you use the turntable drive from an old microwave? Or would that be too slow?

 

[kellys_eye]

The KISS principle holds good here.

There are dozens of 12V motors and equally there are dozens of PWM motor speed controllers for them. It's also a lot safer messing with low voltage systems than AC mains motors - more so if your knowledge/understanding of electrics/electronics is minimal.

 

[Minder]

You can use a power tool dimmer style, or just buy one of the ceiling fan Dimmer style, if necessary you could beef up the Triac, but I don't think that will be necessary.
The ceiling fan type usually come with the noise suppression choke in them.
M.

 

[Bluejets]

As Kellyseye says, plenty of low voltage dc motor gearbox units on Ebay along with 2,3 and 10amp pwm controllers. Even with a power supply, a much lower cost than what you have shown and safer into the bargain. A varity of full speed ranges also available.