# Variable Speed conversion



## BrianL (27 Jan 2009)

Can anyone advise me where and what to obtain to make my Sheppach dms 1100 lathe electrical variable speed


----------



## wizer (27 Jan 2009)

Welcome to the forum Brian. Hopefully one of our kind moderators will move this to the Lathe section where you will get a better answer.


----------



## CHJ (27 Jan 2009)

*Brian,* although it is possible to add electronic variable speed to your lathe I personally would advise that it is not a cost effective modification to fit.

The only way it can be achieved is to fit a 3PH motor and an electronic invertor which will cost you more than the original lathe.

The advantages gained over the existing mechanical variable speed are marginal given the mechanical limitations of the lathe. (I had a very similar spec. lathe for 2 yrs)


----------



## paulm (27 Jan 2009)

When I had my Record CL3 a few years ago I splashed around £150 on a single phase variable speed box that you just plugged straight into.

It was not as effective as a proper dedicated 3 phase motor and invertor and therefore you lost torque at low speeds, but was still worthwhile having in my view, it enabled matching speed to the workpiece to minimise vibration and allowed slowing down for sanding, all without the need to change pulleys all the time.

So I wouldn't dismiss the idea given the cost (if thats still a valid indication these days), it's not perfect/ideal, and has limitations, but can still be worthwhile as an upgrade rather than buying more expensive kit.

Cheers, Paul


----------



## boysie39 (27 Jan 2009)

I checked out a system with a company who advertise on the Woodturning Mag. and prices vary according to HP. My lathe is 1 1/2 hp and it would cost me upto £400 to change. Bearing in mind I live in 
Ireland and would have to get the motor over to UK and Back it would not be a viable exercise. I thought you could just buy the kit and Bob's your uncle. I have looked elswhere but they seem to be all the same. REgards Boysie


----------



## OldWood (28 Jan 2009)

I cannot pass comment on the value of adding this to this particular make of lathe, but I'm a retired electronics engineer and am aware of the value of variable speed control, even with limited wood turning experience.

A friend bought a school displenished Graduate recently (£50 - eat your heart out!!). Three phase motor - so the options were to look for a single phase one or create the three phases. I bought a suitable box off Ebay for him ( Ebay shop so new item) for around £70, but then found that this produces the 3 phase at 240 v not 440v so the motor required to be connected in delta rather than star; modern 3 ph motor have connection plates to do this - old ones don't, so it was either a new motor or dismantle the existing and rewire - the latter was easier for me as it would not involve new pulleys, mounting plates, etc.

There is then the problem that the 3 ph box needs new control buttons (latching rather than momentary push button), and how to wire in an emergency off switch, etc. So a new control box is required with the speed control in it too.

By now anyone thinking of this modification will get the message I hope that it's no mean task if taking it on yourself. There is no magic bullet as I'd hoped of just connecting the 3 ph box to the mains and then to the 3 ph input of the lathe; that just does not / cannot work I've learnt.

Suitable small 3 ph motors do come up on Ebay for a tenner or so. Having done my mate's machine, I'm going on the convert my Myford.

If anyone is wanting to take advantage of the learning curve (now at least 3 months long) I've gone up, please contact me.

OW


----------



## dickm (28 Jan 2009)

I've done a conversion on a small Record lathe, now sold, and it's not too difficult if you can get a 240v 3-phase motor (or know what to do with one that is convertible 240/415). Inverters are relatively easy to obtain (try Gavin Oseman via the homeworkshop site - he's very knowledgeable and helpful). Expect to pay of the order of £100 for the inverter; anything from nil to ?? for a new motor. But remember there are both foot mounting (easy) motors or a whole range of flange mounting ones. Flange ones are a pain, because there doesn't seem to be a standard way to describe them. I had to turn an adapter for the Record, even though the nominal size was correct.
The only problem I've not solved is dustproofing the inverter. Bigger ones have fan cooling, and it's a pain trying to set up a dustproof but not airtight enclosure.


----------



## BrianL (28 Jan 2009)

Thanks everbody for the advice and tips,
Would it be possible to reduce the speed mechanically. The reason I ask is that I have damaged the spindle on my lathe which i will have to replace.


----------



## CHJ (28 Jan 2009)

BrianL":2zoacn14 said:


> ....Would it be possible to reduce the speed mechanically. .....



Short answer is Yes, but the common sense answer is that it would not be very practical and be very expensive to achieve.

To do it you would have to have an intermediate spindle made and its associated mountings to take the existing motor driven spring driven VEE pulleys and a set of reduction pulleys. Then you would have to find a method of mounting the motor fitted with a corresponding set of pulleys to drive it.

Not over complicated if you forgo the ability to swing the headstock but very difficult to achieve if you still want to swing the headstock.


----------



## robo hippy (29 Jan 2009)

There are DC (direct current) motors as well. This is what is on most of the mini lathes that are VS. The older Nova lathes had this as an option as well. I believe that they come factory set, but can be fine tuned as well. The only other way to get a variable speed lathe I saw on a video by Del Stubbs. He had his motor on a levered plate that he could raise and lower, allowing the belt to slip. I do love the VS on my lathe. You can do a lot with the inverters, but you need an electrical engineer to help you program them. I had mine set so I could slow down the spindle speed to about 10 to 20 rpm. I use this speed for power sanding my warped bowls. 
robo hippy


----------



## turnerbc (2 Feb 2009)

Brian, I have a Record CL3 which I converted to variable speed drive about 3 years ago using a kit from Speed Genie ( Haydock Convertors) which included a phase invertor,control box with forward and reverse and 1hp 3phase motor. Whilst it was not cheap it was less than buying the same kit from Record and I have been very pleased with the result.The only draw back is that you dont have a direct visual rpm readout. I wouldnt go back to shifting belts at any price.
Regards,Barry.


----------

