Myford ML10 chuck not revolving.

[pothole50Participant @pothole50]

I would like to install my late father in laws Myford ML10 lathe into my garage, it is still in his workshop and I don’t want to disturb it until I can get it working. My problem is the motor works and it revolves the pulley but there is no drive to the other side that revolves the chuck. I have searched the internet for photos of the ML10 but none look like my father in laws which seems to have a clutch fitted as there is a 5 inch hole in the quard to accommodate it.  I have found numerous clutches the same as the one fitted to the ml10 and they look like the friction plates on a car clutch. Does anyone know if it is this clutch preventing the chuck from revolving. I do have a photo but not sure if this is allowed.

[David George 1Participant @davidgeorge1]

Hi Pothole 50 welcome to the forum.  This picture may help. There is a lever on the clutch which engages disengages by pulling forwards and backwards radially the ball ended piece which slides the clutch shaft in and out.

David

 

[Martin of WickParticipant @martinofwick]

OP refers to ML10.

Unless a custom built addition the ML10 has no clutch.

Check belts are fitted on lathe and are  in good condition / correct tension.

If OP means actually means an ML7, check that the belt drive  is engaged by moving belt cam lever to rear position (just out of view to right on Davids post).

Then check clutch lever is pushed to left position (if fitted).

OP should send picture so we can see what we are dealing with.

[halfnutParticipant @halfnut]

Yes photos would be most helpful.

The Myford ML7 Users Manual is comminly available for free download if you Google it. The ML10 differs in detail but general principles are the same.

As already said above, could be the clutch lever and or belt tension lever need a nudge. Both are located at the right hand end of the overhead countershaft, pretty much straight in front of the operator’s nose when standing at the lathe.

Another possibility is the back gear dog is not engaged. Symptom here is that the stepped pulley on the main headstock spindle behind the chuck is spinning, but the spindle itself is not, therefore the chuck is not spinning . See the manual for how to engage the back gear dog at the large end of the stepped pulley. And make sure the back gear lever is disengaged, or it will lock the spindle.

[JasonBModerator @jasonb]

Check that the belt tension lever is in the right position to tension the belt otherwise it will just slip (green Arrow)

if the 5″ hole is in the teardrop shaped cover and where circled in red then likely a retrofit clutch

You can just click the image icon which is the last in the line and drag a jpg file there.

 

[BazyleParticipant @bazyle]

Also try turning the chuck by hand and looking at the drive train to see where the motion stops. If the pulley on the spindle is not revolving (that is the pulley on the same shaft as the chuck) then it is the bacj gear as mentioned above.

https://www.lathes.co.uk/myfordml10/

 

[pothole50Participant @pothole50]

Thank you all for the help, it looks like the machine has been modified, I have found the gallery section and uploaded a few photos, hopefully someone will be able to identify the clutch and how to engage it to make the chuck revolve.

 

 

 

[Graham MeekParticipant @grahammeek88282]

It looks to me to be an Electro-magnetic clutch. There must be another switch which engages the clutch.

Regards

Gray,

[David JuppParticipant @davidjupp51506]

I noticed wires exiting the clutch unit – it could be something along the lines of the electrically activated clutch used on car air-con compressors.  Try following the wires, see if there is a switch, and some source of power (my guess would be 12V operation, but could be different depending in the source of the clutch).

[halfnutParticipant @halfnut]

Hard to tell from pics  but that rusty bolt on the outer clutch housing near the apparent wires looks very much like an anchor.  So it might be a combined clutch and brake unit like those used on industrial sewing machines etc.

Definitely follow those wires and find the actuating switch to see if the clutch can be made to engage.

 

[pothole50]

On pothole50 Said:

Thank you all for the help, it looks like the machine has been modified, I have found the gallery section and uploaded a few photos, hopefully someone will be able to identify the clutch and how to engage it to make the chuck revolve.

 

 

 

Please could you also post the photos here?

[John Haine]

On John Haine Said:

On pothole50 Said:

Thank you all for the help, it looks like the machine has been modified, I have found the gallery section and uploaded a few photos, hopefully someone will be able to identify the clutch and how to engage it to make the chuck revolve.

 

 

 

Please could you also post the photos here?

They are in his gallery, accessed by clicking on his user name at top of his post.

[John HaineParticipant @johnhaine32865]

Yes I know that but not needing to find the gallery makes it more likely that people will reply.

If it is an electromagnetic clutch it would make sense for it to need energising to engage,more fail safe.

[noel shelleyParticipant @noelshelley55608]

Looks like an electro magnetic clutch. Follow the wiring and see what you find, a low voltage supply ? And a switch ?If there is no 12v or 24v transformer Try putting 12V  DC across the 2 wires, Does it go clunk or move, may be only 25 thou. Now start the lathe motor and see what happens. Good Luck Noel.

[SillyOldDufferModerator @sillyoldduffer]

Can’t help with the clutch, here’s the photos:

Dave

[pothole50Participant @pothole50]

On further investigation on the bottom of the clutch there is a label which reads, Warner Brake and Clutch and is rated at 90 volts 10 watts.
My father in law was an electrician by trade so the wires disappeared into the shed wall, but I followed it to a light switch then further on to a big green ac/dc voltage meter under that was a Rotary Regavolt dial, and isolated by a fuse switch.
By then I thought  I had cracked it so I switched on the isolated fuse switch there was a pop inside the green voltage meter and a puff of white smoke, so I quickly isolated it again, whilst watching for any flames.

So at least I know why it was not revolving but can I fix it, I know the wires coming out of the green ac/dc were connected to the DC plug.

Why was this clutch in place, surely the Myford is safe enough without it, and how easy would it be to reverse the process.

Anyway thanks again for all the help, I have posted what I found in the gallery.

[pothole50]

On pothole50 Said:

Why was this clutch in place, surely the Myford is safe enough without it, and how easy would it be to reverse the process.

 

If you are doing repetitive work on the lathe where the spindle has to be stopped and started many times,  it is kinder on your motor to use a clutch to do the stopping and starting rather than switch the motor on and off.   On my ML10 and my Cowells,  I don’t have clutches fitted,  but use the belt tensioning lever as a “cheap and cheerful” clutch when doing such repetitive work.

 

Jim.

[John HaineParticipant @johnhaine32865]

The Myford 7 series lathes do have a clutch so I guess this was to provide the same function on the 10.

[noel shelleyParticipant @noelshelley55608]

Hey pothole, All is not lost, so long as the coil is not cooked, you know what the regavolt is and how to use it – it could have been set way to high hence the voltage meter and why it popped. It would be worth keeping, a clutch is a very useful extra and whilst your father in law used what he had but there are simple ways to get 90V and 10W is nothing. Do you know if it was DC ? Noel.

[halfnutParticipant @halfnut]

Clutch is not needed for general work. If the electrics are beyond use/repair, your easiest option may be to revert to the original fixed pulley, locked to the shaft with a woodruff key and or grub screw.

[halfnutParticipant @halfnut]

If you can get the electrics working, it’s possible the voltage regulator was used for gentle starts and stops rather than slamming full voltage on or off by the switch.

Be cautious of slamming the brake on hard, the threaded chuck could possibly unscrew off the spindle.

 

[SillyOldDufferModerator @sillyoldduffer]

May be hard to fix: the clutch looks DIY, so the design intent, wiring and operation are all uncertain.  I’d be inclined to remove it because it’s a specialised add-on, an unnecessary complication rather than essential.   May be easier to change the internals so the clutch is permanently engaged than dismantle it.

Clutches are valuable on single-phase lathes required to do lots of repetitive start/stop work, as in production.  Single-phase motors aren’t good at stop/start compared with other types, and a clutch overcomes the shortcoming by allowing them to run continuously.

I guess pothole is a hobbyist, and therefore probably has little need of a clutch.  As sold by Myford, the ML10 didn’t have one.

Does not having a clutch worry other ML10 owners?

Dave

 

[Graham MeekParticipant @grahammeek88282]

The Pulley on the motor is a “Picador” make and the one on the countershaft is not standard. I would suggest doing a search of the workshop for the original pulleys. It would make the solution to the problem a lot easier.

Regards

Gray,

[john fletcher 1Participant @johnfletcher1]

The Regavolt is a variable voltage transformer taking in 240 from the mains and giving out by use of the rotary knob on the top, any voltage up to the mains 240, in your case 90 . You do have to be careful not to overload the Regavolt, inside of which is a small carbon brush, it sweeps the top of the coil inside, the do get damaged, RS components used to sell spare brushes. You would much safer using a 240/90 volt isolating transformer, fitted with a bridge rectifier to obtain the 90 volt DC. Don’t bother with a smoothing capacitor, as the DC from a car wasn’t smooth. Mount things in an earthed ventilated metal box. If that cloud of smoke was damage to the Regavolt, with care it can be repaired. John

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