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Anonymous
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Hi Dave.
I used one of these Teco units for my speed conversion. Would work fine if your motor is labeled 240/450v, and needs to be wired in 'Delta' format. The instructions are fairly easy to follow. Only problem is the unit need to be dust prooffed. I enclosed mine in a steel box.
There is a similiar unit which is water/dust proof so don't need a enclosure, but is quite expensive.
I used one of these Teco units for my speed conversion. Would work fine if your motor is labeled 240/450v, and needs to be wired in 'Delta' format. The instructions are fairly easy to follow. Only problem is the unit need to be dust prooffed. I enclosed mine in a steel box.
There is a similiar unit which is water/dust proof so don't need a enclosure, but is quite expensive.
richburrow
Established Member
Hello Dave, glad you found a graduate at the right price 
Hopefully doug will be on in a while, he is the man in the know :wink:
Hopefully doug will be on in a while, he is the man in the know :wink:
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Anonymous
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Hi Tam,
the motor is supposedly dual rated. Does this mean the motor could be run from 240V without an inverter? Obviously if I could put a control box on fairly cheap then that is preferable but it would be good to see it spinning soon.
Rich, I paid a little more than I really wanted (actually quite a bit more) but I've actually been turning recently so I figured the purchase was necessary. It's as exciting as buying my first lathe. That feeling of 'oooh, look what I've bought' combined with swmbo's feeling of 'I'm not carrying that down the garden!'. Hmm, photos....photos.
Cheers,
Dave
the motor is supposedly dual rated. Does this mean the motor could be run from 240V without an inverter? Obviously if I could put a control box on fairly cheap then that is preferable but it would be good to see it spinning soon.
Rich, I paid a little more than I really wanted (actually quite a bit more) but I've actually been turning recently so I figured the purchase was necessary. It's as exciting as buying my first lathe. That feeling of 'oooh, look what I've bought' combined with swmbo's feeling of 'I'm not carrying that down the garden!'. Hmm, photos....photos.
Cheers,
Dave
This is what you need to change a 3 phase graduate to variable speed single phase...
A dual voltage motor it will still be 3 phase. ( but wired in delta rather than star)
A variable frequency drive ( commonly though erroneously called an inverter)
You can use your original switch gear with rewiring
you need to remove the contactor in the base ( you dont need this)
And find space for a speed control potentiometer
You can also easily fit a reverse switch too.
As most graduates are only 3/4 hp as standard its best to fit a new motor ( perhaps 1.5 hp) whilst you doing the job ( only about £100 or so) but then theres pulley bores to consider and new foot mounting holes..
I have converted 4 lathes in this way and have 2 in my workshop converted as such.
Its tight but if you buy new industrial switches you can fit start/stop reverse/ forward and speed in the original housing.
Ian
A dual voltage motor it will still be 3 phase. ( but wired in delta rather than star)
A variable frequency drive ( commonly though erroneously called an inverter)
You can use your original switch gear with rewiring
you need to remove the contactor in the base ( you dont need this)
And find space for a speed control potentiometer
You can also easily fit a reverse switch too.
As most graduates are only 3/4 hp as standard its best to fit a new motor ( perhaps 1.5 hp) whilst you doing the job ( only about £100 or so) but then theres pulley bores to consider and new foot mounting holes..
I have converted 4 lathes in this way and have 2 in my workshop converted as such.
Its tight but if you buy new industrial switches you can fit start/stop reverse/ forward and speed in the original housing.
Ian
Hi Dave.
DON'T try and run your dual voltage motor on household power. It WILL blow it. As Ian has said all this is wired as 3phase delta.
You would be better getting instructions from a better man than I, I'm no 'spark', but did manage mine myself by following the instructions in the book that came with the 'variable frequency drive' inverter.
IMO any competent DIY guy would be OK.
DON'T try and run your dual voltage motor on household power. It WILL blow it. As Ian has said all this is wired as 3phase delta.
You would be better getting instructions from a better man than I, I'm no 'spark', but did manage mine myself by following the instructions in the book that came with the 'variable frequency drive' inverter.
IMO any competent DIY guy would be OK.
If you can find a second 3-phase motor, and you really want to try out the beast, you <can> run the "spare" motor as a generator, feeding it with single phase, but taking 3 phases off it to the lathe. Lot's of problems (it won't be self starting for one thing) but I have done it as a trial. The generator motor needs to be slightly higher rating than the one on the lathe.
There is an article in one of the Fine Woodworking collections on this. If you are interested, PM me and I could scan it for you.
And if you do decide to go the "inverter" route, Gavin Oseman, who posts on the homeworkshop.org model engineering site supplies them, and advice, at a very reasonable cost. But be aware of the dust problem, as most of them have fan ventilation once you get above 1/2hp, and you'll need to find a way of stopping the dust getting in, but still cooling the electronics.
There is an article in one of the Fine Woodworking collections on this. If you are interested, PM me and I could scan it for you.
And if you do decide to go the "inverter" route, Gavin Oseman, who posts on the homeworkshop.org model engineering site supplies them, and advice, at a very reasonable cost. But be aware of the dust problem, as most of them have fan ventilation once you get above 1/2hp, and you'll need to find a way of stopping the dust getting in, but still cooling the electronics.
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Anonymous
Guest
Right, which bugger failed to tell me how heavy the headstock is? Firstly it nearly killed me getting it from the seller's workshop 20 yards to the van. Thankfully he was better at shifting heavy stuff than me. Then when I got home I tried sticking it in a wheelbarrow with swmbo. We had it about 20 yards before I dropped it on the floor. Once on the floor we slid it on lengths of wood 150 foot down the garden. Finally we tried getting it up the massive step into the workshop. First attempt had it sliding back out. Second attempt involved raising it on planks, a little at a time, then dropping it on the workshop floor.
Don't worry. When I talk about dropping it I really mean gently landing it on the floor.
Absolutely shattered now so will talk electrics tomorrow (I have seen it running though....through a rotary inverter).
Cheers,
Dave
Don't worry. When I talk about dropping it I really mean gently landing it on the floor.
Absolutely shattered now so will talk electrics tomorrow (I have seen it running though....through a rotary inverter).
Cheers,
Dave
DaveL
Established Member
Oh dear, no brownie points there.DustyDave":gfpk3bhm said:
You need to look at the techniques used by the Egyptians for moving heavy things, rollers under the headstock, best on it side to keep the centre of gravity low. With a couple of bits of ply you can even cut across the lawn. Steps are a problem but some 4x2's with cross bracing outriggers make then possible.
As you found out wheelbarrows are not good with large very heavy objects, I hope your back is OK?
Heres how I arrange the switchgear in a standard opening its a piece of perspex and 22mm diameter switches
[/img]
Ian
Ian
A
Anonymous
Guest
Here are a few photos, mainly from after the event:
This is how we ended up moving the headstock:
The rest of the parts in the van. It's a 'classic' rather than a bowlturner.
Finally made it into the workshop:
This is the plug for the lathe. When I was shown it working this was plugged directly into the rotary inverter (I think).
Some wires inside the lathe:
Upside down headstock:
Dave
This is how we ended up moving the headstock:
The rest of the parts in the van. It's a 'classic' rather than a bowlturner.
Finally made it into the workshop:
This is the plug for the lathe. When I was shown it working this was plugged directly into the rotary inverter (I think).
Some wires inside the lathe:
Upside down headstock:
Dave
A
Anonymous
Guest
OK, I've started reading about the eletronic inverters like the teco and the Lenze. I'll double check the motor tonight for suitability. I've got one question though. Do these run the lathe at 415v or 240v? The reason I ask is because of what I read here about types of phase converter:
http://stores.shop.ebay.co.uk/Drives-Direct-Inverters-LTD/OUR-GUIDE-TO-PHASE-CONVERTERS.html_
My other reason for asking is because these boxes require dual voltage motors rather than 415v motors.
I'm not too fussed about getting myself up and running but then upgrading everything in a year or two when I've got a little more money. A bigger motor is definitely a long term thought/project.
Cheers,
Dave
http://stores.shop.ebay.co.uk/Drives-Direct-Inverters-LTD/OUR-GUIDE-TO-PHASE-CONVERTERS.html_
My other reason for asking is because these boxes require dual voltage motors rather than 415v motors.
I'm not too fussed about getting myself up and running but then upgrading everything in a year or two when I've got a little more money. A bigger motor is definitely a long term thought/project.
Cheers,
Dave
stevebuk
Established Member
wizer":b3zwui34 said:
hi tom,
just in answer to your question, i have turned backwards with one of these when we went to Rich's house and made the mirrors, it is certainly different but not impossible, i found it strange but by the time i had finished the mirror i was ok, but i wouldn't like to turn this way all the time.
Tom
Turning on the outboard takes some getting used to everythings back to front.
I'm lucky having 2 graduates set up one for spindles and one for bowl work
Dave
Most drives that run on 240v single phase output 240v 3 phase some do lift the voltage up to 415v but these are less common.
Most industrial motors are 3 phase ..modern ones are dual voltage which means that you can change the wiring of the 3 coils inside to run on either of the 2 voltages..
Some of the older graduate motors are only wired for 415v (its a right job delving in the windings to get the neutral pole out to wire it as 240v)
Your motor will be marked on the ratings plate which it is
On 415 v you basically run the volage across one coil (star connection)
on 240 v you run it across 2 coils in series ( delta connection)
If you wired your motor to delta and connected your domestic single phase to 2 of the connections and on switching on the supply ,spun the lathe spindle it would run..
It would take a while to get up to speed and it would be noisy..
You could add a capacitor to provide a false 3 rd phase and it may then start in the correct direction..
BUT dont go down this route...
Either put a single phase motor on for now and run it with just the 4 speeds or
Do it properly with a bigger motor if you want to do bowls ( 1.5hp) or the standard one ( 3/4 hp) if you are happy with spindles
You then have a modern lathe with lots of power and speed control from 50rpm to say 3000 rpm and also easy reverse for sanding etc ( be careful of chucks undoing if you do this)
If you do this ,say £100 for motor £150 for the drive £ 50 ish for new switches and wiring your graduate is suddenly worth 1100-1200 ish on ebay ( its now a variturn)
Ian
Turning on the outboard takes some getting used to everythings back to front.
I'm lucky having 2 graduates set up one for spindles and one for bowl work
Dave
Most drives that run on 240v single phase output 240v 3 phase some do lift the voltage up to 415v but these are less common.
Most industrial motors are 3 phase ..modern ones are dual voltage which means that you can change the wiring of the 3 coils inside to run on either of the 2 voltages..
Some of the older graduate motors are only wired for 415v (its a right job delving in the windings to get the neutral pole out to wire it as 240v)
Your motor will be marked on the ratings plate which it is
On 415 v you basically run the volage across one coil (star connection)
on 240 v you run it across 2 coils in series ( delta connection)
If you wired your motor to delta and connected your domestic single phase to 2 of the connections and on switching on the supply ,spun the lathe spindle it would run..
It would take a while to get up to speed and it would be noisy..
You could add a capacitor to provide a false 3 rd phase and it may then start in the correct direction..
BUT dont go down this route...
Either put a single phase motor on for now and run it with just the 4 speeds or
Do it properly with a bigger motor if you want to do bowls ( 1.5hp) or the standard one ( 3/4 hp) if you are happy with spindles
You then have a modern lathe with lots of power and speed control from 50rpm to say 3000 rpm and also easy reverse for sanding etc ( be careful of chucks undoing if you do this)
If you do this ,say £100 for motor £150 for the drive £ 50 ish for new switches and wiring your graduate is suddenly worth 1100-1200 ish on ebay ( its now a variturn)
Ian
Bob Chapman
Established Member
Please don't take this the wrong way, it's a genuine question and not some sort of snide comment, but what is it about the Graduate lathe that makes it so popular with turners?
It always seems to me to be so limited over the bed as to make it almost not worth bothering with compared with other lathes that have a much bigger swing and go for similar prices. I know it's a solid lathe and that you can turn outboard, but that involves left hand threads and all sorts of fuss. Why not spend the money on something more useful?
Bob :?
It always seems to me to be so limited over the bed as to make it almost not worth bothering with compared with other lathes that have a much bigger swing and go for similar prices. I know it's a solid lathe and that you can turn outboard, but that involves left hand threads and all sorts of fuss. Why not spend the money on something more useful?
Bob :?
Bob
I agree that at new prices the graduate is very expensive for the capacity of it. But if you buy secondhand at say £400-500 which most seem to sell at on ebay spend say 300 making it variable speed and single phase and you have a very capable machine.
You can have centres of 30,40 or 50 inches
Centre height is 6 inches as standard but its so easy to drop the bed by 6 inches lift the tailstock up 6 inches and extension spindle on the rest and you have swing of 24 inches inboard.
Or buy a shortbed then you have 24 swing and 15 between centres.
Or for really big stuff remove the bed and use a floor steady for the rest.
The quality of the castings and ridigity of the whole thing makes it a delight to use. handles fall to hand and are quick to adjust everything you need to with cam locks ( tool rest and tailstock)
Ian
I agree that at new prices the graduate is very expensive for the capacity of it. But if you buy secondhand at say £400-500 which most seem to sell at on ebay spend say 300 making it variable speed and single phase and you have a very capable machine.
You can have centres of 30,40 or 50 inches
Centre height is 6 inches as standard but its so easy to drop the bed by 6 inches lift the tailstock up 6 inches and extension spindle on the rest and you have swing of 24 inches inboard.
Or buy a shortbed then you have 24 swing and 15 between centres.
Or for really big stuff remove the bed and use a floor steady for the rest.
The quality of the castings and ridigity of the whole thing makes it a delight to use. handles fall to hand and are quick to adjust everything you need to with cam locks ( tool rest and tailstock)
Ian
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Anonymous
Guest
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Dave
Almost certainly your lathe will be wired ***STAR***
dont connect this up to a VFD without changing it to delta
Unless its been run before on a VFD it will be wired for 415
Ian
Almost certainly your lathe will be wired ***STAR***
dont connect this up to a VFD without changing it to delta
Unless its been run before on a VFD it will be wired for 415
Ian
