Colchester student round head

[Jacktegla]

Hoping someone could provide me with some advise, after a long period of looking i finally found myself a cheap lathe, colchester student roundhead. However I have two issues. First being I am unsure what a couple of the levers do if anyone could help, on the face.


Secondly I can turn the lathe on by the isolator and it runs However the lever with the red nob which I presume to be the start stop, isn't working. Any suggestions.

 

[minimutly]

The lever under the Gamet bearing badge is the ratio levers indicated by the chart above “lever at front”.
The small one to its left is the auto feed reverse neutral forward. The long lever with the red knob is the clutch/brake, my Triumph doesn’t have a clutch, so the lever starts the motor and applies the brake. The little black knobbed lever centred with the red knobbed one could be forward reverse on the main motor - mine has been wired up to the light.
Further down, you have English off metric for the lead screw, and clunky selector for tpi. And to the left speed selectors for the auto feed (which from memory might also affect the tpi on the leadscrew?? Not sure about this).
All this is off my Triumph, but they are very similar. Be careful you don’t engage the thread cutting half nuts together with the auto feed.

 

[carbon]

Here is a manual for a student lathe.

As the control circuit has been modified by adding a dol starter to the outside of the original switch panel it would seem like when this was done the wiring was drastically modified. If the original switches still work then it should be possible to reinstate them to there correct functions.

The little black knobbed lever centred with the red knobbed one could be forward reverse on the main motor

Yes it should be motor direction change

 

[Screwdriver]

The lever under the Gamet bearing badge is the ratio levers indicated by the chart above “lever at front”.
The small one to its left is the auto feed reverse neutral forward. The long lever with the red knob is the clutch/brake, my Triumph doesn’t have a clutch, so the lever starts the motor and applies the brake. The little black knobbed lever centred with the red knobbed one could be forward reverse on the main motor - mine has been wired up to the light.
Further down, you have English off metric for the lead screw, and clunky selector for tpi. And to the left speed selectors for the auto feed (which from memory might also affect the tpi on the leadscrew?? Not sure about this).
All this is off my Triumph, but they are very similar. Be careful you don’t engage the thread cutting half nuts together with the auto feed.

You sure about that? "The ratio levers" you refer to only engages or disengages the headstock drive on mine. The badge refers to the two gear selector levers on top of the machine.

 

[Pete.]

Hoping someone could provide me with some advise, after a long period of looking i finally found myself a cheap lathe, colchester student roundhead. However I have two issues. First being I am unsure what a couple of the levers do if anyone could help, on the face.


Secondly I can turn the lathe on by the isolator and it runs However the lever with the red nob which I presume to be the start stop, isn't working. Any suggestions.

That's a 3 phase machine. I'm guessing yours has been converted with a single phase motor?

The two small levers on top and the long one on the front with a black knob do the spindle speed changes as per the chart.
The small lever to the lower left is the gearbox reversing control.

The long lever with the red knob is the start lever. The little lever built into it is the motor reverser. You can reverse 3 phase motors instantly when running so they put in a handy switch.

What the red lever does depends on how the machine was specified. If it must be pulled outwards before it will lift it's a 3 phase motor starter. If it will lift without being pulled outwards then it's a clutch lever (or the safety lock has been defeated). If it can be pushed down against a spring then it has a brake fitted also.

 

[Screwdriver]

Zoiks! After all these years...

On mine the large lever "disengages" the drive to the headstock.

Methinks there could be a problem here!

<edit> Nope. Ignore that. I'm having a senior moment. I think it does switch gear ratios but I also commonly use it in the mid position to put the headstock in neutral.

 

[Jacktegla]

You sure about that? "The ratio levers" you refer to only engages or disengages the headstock drive on mine. The badge refers to the two gear selector levers on top of the machine.

I had the top off and that lever is also most like another gear change for speed I wouldhave said

 

[Jacktegla]

That's a 3 phase machine. I'm guessing yours has been converted with a single phase motor?

The two small levers on top and the long one on the front with a black knob do the spindle speed changes as per the chart.
The small lever to the lower left is the gearbox reversing control.

The long lever with the red knob is the start lever. The little lever built into it is the motor reverser. You can reverse 3 phase motors instantly when running so they put in a handy switch.

What the red lever does depends on how the machine was specified. If it must be pulled outwards before it will lift it's a 3 phase motor starter. If it will lift without being pulled outwards then it's a clutch lever (or the safety lock has been defeated). If it can be pushed down against a spring then it has a brake fitted also.

Ok thanks, yes been converted to single phase by last owner I believe.

From trying thr red lever and be pressed down as a brake and pulled up

So if its a clutch lever presumably that's a mechanical clutch and would need adjusting in my instance which could be why it doesn't work only when pressing controll box pn bottom on

 

[Pete.]

Ok thanks, yes been converted to single phase by last owner I believe.

From trying thr red lever and be pressed down as a brake and pulled up

So if its a clutch lever presumably that's a mechanical clutch and would need adjusting in my instance which could be why it doesn't work only when pressing controll box pn bottom on

If it can be pressed down as a brake then it won't be a clutch lever as the matrix clutches were clutch and brake combined (some certainly were not sure if all). It's an on/off switch and brake IMO.

 

[minimutly]

I had the top off and that lever is also most like another gear change for speed I wouldhave said View attachment 407221

It’s not hard - the spindle speed chart shows the speeds selected by the lever at the front.
Edit -and the two at the top..

 

[Jacktegla]

So just taken back cover off and had a look at back, so I can see the reverse switch definitely cannot be used as no wires going to it, however I've also had a look at the lever with the red nob and the linkage at the back, presumably when lever is pressed down pushes linkage up applying brake but what happens with linkage when lever pulled up. I know it's missing a nut but have tried it and not sure what it'd supposed to do as I though it was through to switch for on and off.

 

[Pete.]

Look further in you should see a plunger switch under that bar. Looks like you can just see it in the pic above.

 

[minimutly]

Ooo, has the brake band snapped?

 

[carbon]

Ooo, has the brake band snapped?

I believe it should be an internal brake with shoes

 

[Jacktegla]

Is anyone able to take a picture of the back of their lathe is this area to see if theirs any differences as I presume that the lever must do something with the switch

 

[Pete.]

There should be one of these

If you want something that will do the job instead I can sort that out for you.

 

[Jacktegla]

There should be one of these

View attachment 407322

If you want something that will do the job instead I can sort that out for you.

Yeah I've just been looking at numerous videos, I would love something that can sort this out. What do you have in mind ?

 

[Pete.]

Something like this would do it. How are you going to wire it up though? You could cut in to the DOL starter you have and use it only for stopping the spindle (whilst applying the brake).

 

[Jacktegla]

Something like this would do it. How are you going to wire it up though? You could cut in to the DOL starter you have and use it only for stopping the spindle (whilst applying the brake).

View attachment 407323

I though something like that would work, again unsure on wiring found this video on someone wiring everything origional up to a vfd.

Shame its not a tad better video but get the idea, from this does it go from vfd to foward reverse switch, to on off switch. To motor. I struggled a bit not getting to see whole wiring

 

[Pete.]

You could very easily wire that red lever to start-stop a VFD, keep the brake (or not) and use the small lever for fwd/reverse. If you decide to go that route then the wiring is very simple and there are plenty of people here to advise.