Colchester Student. Surfacing

[Hamish McNabParticipant @hamishmcnab62554]

I have a 6" Student which I am finding my way around. When I engage Surfacing I can get the cross slide to move back and forward OK and can adjust its speed my moving the collar to give me low, off or high on the feedshaft. This works OK but the saddle is not secured and if I engage the saddle lock this engages the lead screw resulting in the saddle moving. Is it possible to disengage the lead screw? I assumed the collar I move to vary speed of feed shaft would have provided that and perhaps its all just out of adjustment or am I looking for something that is not there. Any help appreciated.

Edited By Hamish McNab on 07/01/2015 10:47:20

[Hamish McNabParticipant @hamishmcnab62554]

How to disengage leads crew?

[Hamish McNabParticipant @hamishmcnab62554]

Had another look and a closer look at the manual and it does not appear as if what I want is possible. Will find a clamp to lock saddle as an alternative. Any suggestions?

[Ian ParkinParticipant @ianparkin39383]

What model student do you have? mk1 1.5 or 2 ?

The clamp to lock the saddle is on the top on the right hand side with a square head

No way engaging that should also engage lead screw

Not sure which collar you are adjusting to give you a different speed

you can disengage lead screw by putting imp/metric lever into neutral

you cant disengage lead shaft unless you remove gears

[Hamish McNabParticipant @hamishmcnab62554]

Thank Ian.

It is a Mk 1 Student non gearbox as shown on the "Lathes" site

There is no lever to lock on the right hand side only on the left hand side which engages saddle to allow thread cutting and locks saddle when doing manual surfacing feed.

On the lead screw at the far left there is a collar which you can slide to give the three positions of low, off and high. This engages gearwheels from the lead screw shaft to the feed shaft.

I can disengage the lead screw shaft by the lever you suggest but then this also means the feed shaft is disengaged so no cross feed available.

Gears can be removed as you suggest but then we are back to the previous mentioned situation.

I think I am asking for something that is not there but will keep looking.

Thanks again

[JasonBModerator @jasonb]

The lock is the square headed bolt on the top right of the carrage in teh middle of teh photo. Sounds like you have been "locking" the saddle by engaging the screwcutting half nuts on the stationary lead screw

[Hamish McNabParticipant @hamishmcnab62554]

Thanks Jason, the mystery has been solved. I had noted that hole but that is all as the part has been removed. Will see if I can manufacture a locking device. Is it possible to provide a close up photo?

[Ian ParkinParticipant @ianparkin39383]

Heres a pic of the locking mech

Its ( on my lathe a mk1.5 )

The nut is 15mm dia where it slides into the saddle 28mm long

the big end is 35mm dia 10mm thick with one side cut flush with the 15mm dia bit

the opposite side overhangs by 6mm which engages on the bed slideway

the 2 pins are to stop it rotating

The bolt is 58mm long under the washer

obviously all dimensions would be imperial

Is there a pic on lathes of a non gearbox student?

[Ian ParkinParticipant @ianparkin39383]

one more pic

[Hamish McNabParticipant @hamishmcnab62554]

Really grateful for all this information. Another task ahead but in the end I think I will be delighted with this old lathe as all these repairs/ improvements are giving me much pleasure in doing as well as prolonging the life of the machine.

Again many thanks to all.

[mark costello 1Participant @markcostello1]

The more You do, the more You learn. It's a vicious circle that leads to needing more machinery. Don't ask………..

[Hamish McNabParticipant @hamishmcnab62554]

Hopefully this link will work.http://www.lathes.co.uk/colchester/page5.html

[Ian ParkinParticipant @ianparkin39383]

Still no picture of a non gearbox student ?

[Hamish McNabParticipant @hamishmcnab62554]

Yes the link shows the carriage only and not the complete lathe. Need to try harder in future

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