Look for Jack sewing machine motors on Amazon etc

You could use a modern electronic (thyristor) foot controller for sewing machines (instead of the old graphite pile types), which at least is unlikely to boil your foot. Or purchase a cheap (£5 to £25) generic ac motor controller from the usual on line markets and wire in

There is no plug and play brushless unit available that I am aware of unless you want to get one of the far east 500w to 1000w servo motor and control packages (circa £100+ and probably too much for a watch lathe). Some are now adapted for lathe use rather than sewing machines. As usual, no backup.

If you scan about on the net,  sometimes you can locate small (but not toy)30 to 60v 100 to 400w brushless motors that run at a reasonable speed, but you are on your own as far as sourcing and rigging up power supply, drivers and controllers. Some claim to not require a hall effect controller, but as usual with Chinacarp, they provide no useful information.

Brushless CNC spindle packages are available, but are likely too high RPM for lathe use.

There are some nice 1/6 Hp 3P induction motors on ebay for £30 delivered at the moment, but you will have to get a a VFD for £40 and wire it up yourself.

On 25 August 2024 at 20:06 not done it yet Said:

Most brushless motors are multi-phase (rather more than just 3).  Most 3 phase motors are induction motors where variable speed is often controlled via a VFD.

Maybe wear something over your stockinged feet?  The controller is likely operating near its maximum rating.

Could you not use one of those motors from a larger heli or quadcopter?  Maybe use a common driver/drill as a power source?  There are loads of alternatives out there.

 

Really? All the Brushless DC motors I’ve seen were 3 phase. That runs from tiny ones for fans (low power) and models (high power) to large industrial ones used including servo systems and even linear versions. The only options over 3 phases are 4 and 5. A 4 phase has all the disadvantages of a 2 pole. A 5 pole does not divide into 360 degrees very well and I can’t see the advantage. Six phase is same as 3 Phase with more poles. Six phase motors do exist but mainly in high power variable speed applications so you can use two sets of inverter output devices (or 2 inverters) to get the power but modern high power semiconductors have reduced the need for that.

Can you give an common example of a small non 3 phase BLDC motor?  I’m aware of 5 phase, as compared to normal 4 phase, stepper motors but that is a different application and rare. Vexta seem to be the biggest maker of 5 phase steppers.

Robert.

I use the same sewing machine motor as you do, but use a cheap thyristor speed control like this with an on/off foot switch.

One switch is wired as on/off, one is wired as foot/continuous and speed is controlled by the knob. Stop/start with the foot switch always returns to the same speed.

Link below is as close to a £30 ebay motor as I can find

‘Spares no longer available’ is unlikely to bother anyone here!

I’m tempted to get one just I ever want to power a smallish machine.

https://www.ebay.co.uk/itm/325889161484?

Ian P

Oops, I replied earlier but forgot to submit

This thread is worth a read.

https://www.model-engineer.co.uk/forums/topic/brushless-dc-motor-for-mini-lathe/

I run a Perris (Cowells predecessor) lathe using the Vevor brushless sewing machine motor I mentioned in that thread. I re-boxed the controller in an aluminium enclosure and used a 10-turn potentiometer for speed control (electrically isolated since the potentiometer ends up at high voltage). The torque is only limited by belt friction at any speed.

Andrew.

You can now get those brushless motorising units configured for use as power unit for general rotary equipment, with a generic machine control pendant rather than sewing machine specific. £140 on the bay half that from aliexcess.

550W- 2.2KW Brushless Servo Motor & Controller Driver For Belt Sander CNC Lathe

I would take the power ratings with a pinch of salt, but one would certainly be a contender. I have the sewing machine version, not put into use pending conversion to VR control. Somewhat surprised to learn that it gets mains voltage down to the VR. I thought the hall sensor control side was 0.5 to 5 volt. I did have some notes from my previous fiddlings, but cant find them now.

Question, what problem is Icon trying to fix. The heat from the old fashioned resistive controller or a specific need for a more powerful motor?

As I read the OP the issue is the controller not the motor. Sewing machine (universal) motors are easily controlled by modern thyristor units – sold as lighting or fan controllers.

If he is happy with the power of the existing motor, then the simplest solution is a cheap thyristor controller to replace the one he currently has.

A very interesting post, Clive !!

… a few more details of the motors you are using would be much appreciated.

MichaelG.

Hi Martin,

I have not worked the lathe hard so I don’t know how hot it can get, I’ll do a test with something like 1″ steel and will get back to you, probably the end of the weekend.

Andrew.

Whilst brushless are the best of all possible motors, I’d be inclined to go for a brushed e-scooter motor.   120W is a common size, plenty of power and torque for a watchmakers lathe, bigger if needed.   Also required, a power supply and PWM controller.

Duffers patent list of motors for machine tools, worst to best:

• Universal motor, common on old sewing machines and small lathes.  Chief advantage speed control, otherwise poor torque and low power.  (Though speed control is technically easy, it’s done with a rheostat, liable to give the operator a hot foot!)
• Single-phase motors.  Chief advantage they work off ordinary AC mains.   Otherwise no speed control, low starting torque, unwelcome vibration and relatively poor reliability.   But being able to deliver conveniently up to several HP covers up a multitude of sins.
• DC Brushed.   Low vibration, speed control, high starting torque, and good power.   Disadvantages, brushes reduce efficiency and reliability.  Bit of a pain even though brushes are consumables.  DC supply required.
• Three-phase AC.  Highly Reliable and efficient with good power and torque plus low vibration.  Significantly enhanced by powering them with a VFD, which provides speed control and other goodies such as soft start.
• DC Brushless.  More like a 3-phase motor than brushed DC.  Markedly more efficient than 3-phase, plus somewhat better power and torque characteristics.  Good speed control.  Main disadvantage is a special controller is required, but these aren’t expensive or rocket science.   Closest yet I think to the ideal machine tool motor.

In practice, Universal and Single-phase motors work ‘well enough’ for many purposes.   But no-one who has had reason to upgrade to one of the better types has ever complained.

Dave