Reducing the Speed of a Wood Turning Lathe : Suggestions Req

[SteveW]

Guys,

A mate of mine living in France is looking for advice on slowing down the turning revs on his wood turning lathe. For the sort of turning he's doing he's finding a bit too exciting.

He describes the thing as "a proper job not cheapo Chineesium lathe with single phase motor with two drive pulley options".

My first thoughts are that it's going to cost money. Maybe loads.

My thoughts:

An inverter could be the nice solution, just plug it in, but not sure if they work for single phase motors. This could mean an inverter AND new motor.

The alternate would be a new and smaller motor drive pulley subject to current size to his current two step motor pulley. Chances are standard motor shaft diameter hence standard parts so maybe cheapest and easy but subject to belt tensioner range.

If the motor pulley is already small it'll have to be the head stock pulley and proprietary parts and maybe subject to available gap for a bigger pulley.

All subject to what's available in France and the rest of Europe.

So, any better ideas or suggestions?

Edit: prompted by Johan's question: Just been beam an image of the lathe's little plaque. Difficult to read the manufacturer other than "???RUNET TOOL CO. DERBY. ENGLAND". The model appears to be " THE MAJOR".

Edit 2: "???RUNET TOOL CO" could be '"???RONET TOOL CO" as bit of the plaque are missing.

[johan]

It might help if we knew the brand or had a photo.

[andyhigham]

I would be wary of slowing a wood turning lathe down, it could lead to snatching and the chisel digging in

[Neale]

Sounds as if it could be a Coronet Major, if that helps at all.

[simplyloco]

Mar 8, 2024 22:04:43 GMT Neale said:

Sounds as if it could be a Coronet Major, if that helps at all.

AGREED. TRY THIS 'ERE.

www.lathes.co.uk/coronet-precision/

[ettingtonliam]

Its certainly a Coronet Major, a very popular wood turning lathe in ts day, with lots of different attachments available, Should be plenty of info available on the net, almost certainly covered by Tony Griffiths.

[SteveW]

Mar 8, 2024 21:37:37 GMT andyhigham said:

I would be wary of slowing a wood turning lathe down, it could lead to snatching and the chisel digging in

My mate's making bowls, I guess larger ones.

[jasonb]

Indeed, I used to do quite a bit of wood turning with rather odd shaped pieces of wood to start with which makes the work very out of balance and if the lathe were not fixed down it would jump along the workshop so you need them relatively slow particularly to start with and if leaving some live edge they will never be balanced unless weight is added. I often roughed out when the wood was still green (wet) so weighs a lot more than when dried which makes the balance problem worse.

Think of it as a large irregular shaped casting in a 4-jaw or on the faceplate you would all be reaching for slowest backgear on a Myford and woodlathe in this situation is no different, it's cutting speed at the diameter being cut and reduced until the thing is not jumping about. Not the same as turning a spindle between ctrs.

VFD and motor change would be the bolt on solution. Smaller pully may be limited buy how small the existing one is as you can't always go smaller than the minimum for the belt.

[uuu]

I'm a big fan of three-phase motors and inverters. Yes, this could mean more expense, but I've had success sourcing these on ebay. My current lathe has a lovely Siemens motor - new-old-stock - and a fine Mitsubishi inverter, second hand, but fully working. I've had half a dozen of the same inverter - all off ebay. Patience is needed - there are many listings at silly money, but wait a bit and the right one will come up cheap.

Wilf

[johan]

What about making an intermediate shaft, would that be an option? You can get those multi-pulley wheels like used on those cheap pillar drills for different speeds. Or it could be an option to put it on the motor which is maybe easier to work on. You should plan to make it that way you can adjust the tension of the belt of course.

Something like this would give you a lot of options: www.fruugo.be/25mm-bore-aluminum-wheel-a-type-5-step-pulley-wheel-for-v-belt-timing-belt/p-109493093-231219853?language=en&ac=ProductCasterAPI&asc=pmax&gad_source=1&gclid=EAIaIQobChMIpMOP-N3mhAMV1aODBx2WXgD-EAQYBSABEgIoePD_BwE

[ettingtonliam]

www.lathes section on Coronet lathes mentions a number of ways of speed reduction. Apparently they were originally fitted with 2800rpm motors, which can easily be changed for a 1425 motor. What motor does your friends lathe have on it?

[SteveW]

Mar 9, 2024 8:51:02 GMT ettingtonliam said:

www.lathes section on Coronet lathes mentions a number of ways of speed reduction. Apparently they were originally fitted with 2800rpm motors, which can easily be changed for a 1425 motor. What motor does your friends lathe have on it?

Just looked at the image he sent of the motor label. Its a 2850 rpm motor so scope there for a newer motor.

I suggested that an inverter/motor solution, although expensive, would be the best way to go. Certainly for turning bowls.

Edit: on reflection and given the faster motor the associated pulley could well be a smaller one or perhaps the smallest pulley is already fitted.

[jem]

I made my own wood lathe, and used a washing machine motor with a with a variable speed thingy to adjust the speed, cost next to nothing.

Jem

[SteveW]

My man in France sends his thanks for the good input he's seen here.

Thanks.

Edit: My last idea(s) shared with him follow, copied here for your approval:

Looking again at your motor label image, you have a two pole 1hp (750 watts) motor. The 2 poles gets you the nominal 3000 rpm which given the slip turns out at an actual 2850 rpm per the label.

One solution is a four pole 1 hp motor which should run at half the speed of a two pole motor. It's likely the shaft diameter (metric) will be different, so you'll need a new pulley with a compatible belt section.

Just looked in Machine Mart and they want £143.98 for one. Yes, I know, OUCH! Again think pre-loved.

If you can get a wide range multi-step pulley you might still get your current speeds subject to fiddling with the motor mounting arrangements plus your target low speed using a similar sized drive pulley as your current motor.

Another way would be an intermediate lay shaft with a suitable stepped pulley that lines up with everything else and two new, shorter, belts. If you go this route don't forget the extra safety guards you'll need.

[uuu]

When fitting motors with a different shaft diameter, I have managed to bore out the existing pulley, or make a bush. Also be aware the foot or flange holes may be spaced differently.

The lathe at the club has a horrible conversion (not done by me) - the whole motor is physically bigger than standard, so the shaft is further away from the foot. This meant enlarging the hole into the belt casing to stop it rubbing - and it doesn't hinge as easily for belt tension adjustment.

Wilf