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Re-motoring Unimat SL


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Hi, 

 

I fitted my unimat 3 with a 24V 150W scooter motor a couple of months ago. I use a 24V 200W supply.

Using the orange or green polyurethane belts I find that the belts slip before the motor 

stalls.

 

As mentioned by others there is a lot of extra information available through the yahoo unimat sl and unimat 3 groups.

 

John 

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Aww the unimat 3... Fantastic Toy and Hobby Shop in Sydney had one in the window when I had my first job in Sydney back in 1982... I used to spend many a lunch time gazing at it.

 

A question on the polyurethane belts if I may. I intend to give them a go, especially since I bought several standard black rubber replacement belts a couple of years ago, but they are all showing signs of cracking, even the ones I haven't used yet. With the polyurethene belts though, there seems to be from what I've read, two kinds of people - those who can join them successfully and swear by them, and those that can't and have given up on them. I've read many techniques both successful and unsuccessful, so I was wondering what you use?

Edited by monkeysarefun
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I bought a couple of sets, ready jointed, from Ebay for my SL and Uni 3, expecting them to be a bit rubbish, but they have turned out to be great. They show no sign of wear and don't leave the rubber dust all over the place. I did try joining the polyurethane belt on our Club turntable, but for the price of a ready made set it didn't seem worth the bother.

 

Peter

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Joining is simple, use heat to melt the ends without burning them and press together. I use the body of a soldering iron as it heats up, testing a scrap bit till it reacts and mushrooms the end, leaving a sticky dome. then do it to the bets ends in the same way.

You will always get a bump over the joint that must be trimmed with a very sharp knife or scalpel.

The main thing is practice and trying it out on scrap. Wait too long on the heat and you get carbon burning soot that can weaken the joint, too little heat and it will not stick together.

A gas flame can be used, even a lighter flame, or better an object like a steel plate heated in the flame. Special soldering iron tips are made to fit temperature controlled irons and act as a hot spatula to join the ends.

With Practice the bulge in the joint can be minimised, but it will still need attention with the knife to some extent.

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Thank you both  for the information, just one more thing if I may kind sirs - is 5mm diameter the one to get for the SL?

 

(I like the idea of the pre-made ones, but not sure what the postage to the land downunder would be, so I  will try to source the poly lengths from somewhere here.)

Edited by monkeysarefun
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Thank you both  for the information, just one more thing if I may kind sirs - is 5mm diameter the one to get for the SL?

 

(I like the idea of the pre-made ones, but not sure what the postage to the land downunder would be, so I  will try to source the poly lengths from somewhere here.)

I didn't mention that when I tried to join the belt for a turntable it seemed fine using a soldering iron, though it was less stressed than on a lathe.

 

The orange pre-made ones I have are 5mm, with the small auto feed one on the Unimat 3 being 3.5mm

 

Peter.

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  • 1 month later...

Hi, I'm new to this forum and this is the tread that took me here. I have almost gathered all parts except the 8mm motor pulley - could some kind soul give a link to where I can get two of these as I'm making the motor conversion on two Emco SL 1000 lathes. I am also wondering about if someone is still making the "top hat" bush? I could use two of them - maybe... I'll know when I've got that thetered pulley off the shaft.

 

FYI I gathered these:

 

Speed control: http://www.ebay.com/itm/10V-60V-20A-Pulse-Width-Modulator-PWM-DC-Motor-Speed-Controller-Control-Switch/121733845515?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

Motor: http://www.ebay.com/itm/Small-Electric-E-Scooter-Bike-MOTOR-24-Volt-DC-150-Watt-24v-150w-Belt-Drive/172731697838?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

PSU: http://www.ebay.com/itm/AC-DC-1A-5A-10A-30A-50A-70A-Switching-Power-Supply-Driver-5V-12V-24V-F-LED-Strip/222288584678?ssPageName=STRK%3AMEBIDX%3AIT&var=521153636254&_trksid=p2057872.m2749.l2649

I bought the 20A 24V model.

 

Struggling with the belt drive pulley - as said it is glued very well...

 

Regards

Edited by Turbon
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Ok, I can confirm that I'll need the top-hat bushings.

Regards

Hi,

 

The top hat bush (and the 8mm bore pulley) were not commercial items, mine were made by a friend - I afraid you'll have to find a friendly model engineer with a lathe to turn them up for you.

 

Best wishes

 

Richard

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In the spirit of lathes building themselves, would it be possible to rig up a hand crank to turn the lathe spindle, make rough temporary bushings/pulleys to temporarily fit a motor to one of the lathes and then use this to make proper bushings/pulleys for both machines?

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The "top hat bush" was just a more elegant way to give sufficient material for the fixing bolt to screw into - a suitable nut glued inside the motor would achieve the same purpose, and once it is tightened up, wouldn't be going anywhere even if the glue failed

Just a thought

There's always more than one way to skin a cat........

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ps RDG tools list unimat pulleys as spares - it shouldn't be too difficult to bore one of these out to 8mm

Cheers

Richard

I did this but it is wobbling a bit now as I had to do it by free hand with a hand held drillingmachine. But it will do as a starter :). Thanks a lot.

 

Regards

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The "top hat bush" was just a more elegant way to give sufficient material for the fixing bolt to screw into - a suitable nut glued inside the motor would achieve the same purpose, and once it is tightened up, wouldn't be going anywhere even if the glue failed

Just a thought

There's always more than one way to skin a cat........

That's an excellent idea. Simple enough.

 

Regards

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In the spirit of lathes building themselves, would it be possible to rig up a hand crank to turn the lathe spindle, make rough temporary bushings/pulleys to temporarily fit a motor to one of the lathes and then use this to make proper bushings/pulleys for both machines?

Thank you Pat but I prefer Richards idea as there would be need of making more difficult parts to achieve this. It would probably work.

 

Regards

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Hi again.

 

Right, I managed to duplicate your ideas. I hope I can attach photos but they are almost the same as Richards photos.

 

Now on to taking care of the other Unimat that will be setup as a lathe :).

 

Regards

post-32308-0-38196000-1501765555_thumb.jpg

post-32308-0-85938200-1501765580_thumb.jpg

post-32308-0-95713300-1501765592_thumb.jpg

Edited by Turbon
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  • 2 years later...

Hello Richard Jones, I found this topic on RMweb whilst searching for solutions to repair or replace my Emco Unimat SL lathe motor. I found the items you used to replace your motor with a 24 volt scooter motor and ordered them (they are a little bit more expensive now but still reasonable) however there are no instructions included on how to wire them up. The switch mode power supply is straight forward enough (mains in one end a 24 volts +- out the other) but the pulse width speed controller was supplied with the three way switch separate, and no wiring instructions. Of the other connections, I assume the +- on one side is from the switch mode power supply and the M1 M2 are to the motor. I just can't figure out the way the four wires (two black two red) from the DPTT switch connect to the four connectors which are labelled out, out, in in respectively. I've tried contacting the seller on Ebay but his English is very poor and I don't speak mandarin so we are at an impasse. would appreciate your help.

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On 03/12/2014 at 23:00, Richard Jones said:

Hi,

 

The  original motor on my Unimat SL recently gave up the ghost, and via the Unimat Yahoo group, it was suggested that a 24v electric scooter motor was an economic replacment.

 

Here is said motor (£12.99 of ebay) + another £13.20 for the switch mode power supply and £2.79 for the Pulse width speed controller fitted and working on my Unimat (and a lot quieter that the original motor)

 

Many thanks to Keith of the Unimat Yahoo group for the original idea, and Peter Boorman for making me the new (8mm bore) pulley on one of his other lathes...post-12271-0-13170700-1417647265_thumb.j

post-12271-0-63959200-1417647614_thumb.jpg

 

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  • 1 month later...

As the owner of a Unimat SL which lacks a motor I was delighted to find this discussion.  I found on eBay what seems to be the exact motor used by Richard Jones available from a UK seller, but the PSUs I've seen all appear to come from suppliers in China.  I've no objection to buying from there beyond the long delivery times, but if anyone can point me to a UK source, I'd be very grateful.  Many thanks.

 

Edited by Bert Coules
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I’m afraid I can’t find the e-bay link of the one I bought some years back now, which may not work anyway, but if you search 24v LED power supply it brings up lots of UK based ads. I got a 24v/15amp/360w with an auto fan which works well although I did put it into a homemade acrylic box for safety and protection. I see enclosed waterproof ones are now available, which might be an alternative.

 

Izzy

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Huh, seems like I stumbled upon this site at the same time, I am currently looking at this motor https://www.ebay.ca/itm/150W-24V-ZY6812-Electric-Motor-150-GM150115-w-Chain-Sprocket-f-scooter-Razor/161768380023?epid=10038355915&hash=item25aa259677:g:YsEAAOSwImRYk-at however my issue is I don't have any tools besides a unimat DB without a motor so I cant machine and tap the front. Do you know of any motors that fit out of the box? I was looking at the U-100 however its still a 90W motor with brushes so that will probably be consumable if I get it (not to menton pricy)

 

(I'm in canada)

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2 hours ago, Izzy said:

I got a 24v/15amp/360w with an auto fan which works well although I did put it into a homemade acrylic box for safety and protection.

 

 

Thanks for that.  I found this unit on eBay which seems to fit the bill.  I like the idea of enclosing it (with ventilation) though, not just for protection but also perhaps to arrange a proper socket for the incoming mains connection.

 

PSU.jpg

Edited by Bert Coules
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Don't know if that has a fan, but I would look for one that has to aid in heat prevention, trouble is many of the cases look identical, and are, just the specs change. There are quite a few UK sellers so it's a case (ouch!) of trawling through the listings and the individual specs they give via the drop-downs.

 

I made my case from 1.5mm acrylic sheet sold to glaze pictures. It can be glued with poly type liquid glue and I fitted a removable end piece to fit/remove the PSU. There's plently of holes drilled to match the ventilation holes in the PSU case. Here's a couple of shots that might help. I used a 2-pin plug on the 24v lead to connect to my Sieg lathe, but a 3-pin one would be better as it's 24v DC and so the polarity must be correct or the PWM controller could get blown (!). Cable ties stop the leads getting pulled out. Obviously it sits on the floor and well away from the lathe, another safely aspect, keeping the 240v AC as far away from me as possible.

 

1904060371_RMweb07.jpg.0f51a4e4652a0cf79b9824a2947792a6.jpg

 

1940665254_RMweb04.jpg.1b72a9d8058ddeea96d2bbea11b344ff.jpg

 

cheers,

 

Izzy

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