Colchester student 1800 carriage handwheel issues?

[bruce edwards 1Participant @bruceedwards1]

[bruce edwards 1Participant @bruceedwards1]

Has anyone on here had an issue with the push pull handwheel on the carriage not engaging securely , if you keep some inward pressure on the wheel it drives ok but it still likes to jump .

There is a detent but its like its not strong enough to keep the wheel engaged.

Ive just got the machine up and running and the hand wheel and other levers were removed for transit before I got it so I think there may be a link also the wheel dial is just free wheeling on the shaft so it looks like the small key has gone awol

[David George 1Participant @davidgeorge1]

Hi Bruce on the Colchester lathes I used in the past the disconect feature was never used. I was told that It could be used when screw cutting and because the handle on the handwheel could cause the carriage to be uneven it should be disconnected but never did. If the key has got lost it is a simple job to make a new one. key steel is readily available or if it is a woodruff key, a half round type,they are a standard item. The detent may need cleaning and maybe the spring is weak and needs replacing. Where in the country are you as there nay be someone local to you who may be able to help.

David

[bruce edwards 1Participant @bruceedwards1]

ok thanks ill check that out , yes the key will be straightforward to make replace, based in central scotland

[Nick HughesParticipant @nickhughes97026]

The detent pressure on Colchester Triumphs is adjustable, but don't know if the students are the same. Have a close look at the handwheel collar for a grub screw.

If you find a grub screw but can't tighten it, take it out, as it may be just locking the adjusting screw beneath.

Nick.

[Nigel McBurney 1Participant @nigelmcburney1]

Just had the top slide index ring slipping on my master ,the friction device is three balls and three compression springs,these had lost their spring due to a build up of old soluble oil and dirt,the saddle handwheel detent may just be stuck with dirt.

[bruce edwards 1Participant @bruceedwards1]

latest update , I stripped the entire handwheel assembly ,the dial driver gears were both seized , the friction pegs only had 2 springs , I assembled the handwheel without any of the dial parts and tried the push pull action which was perfect ! spent a couple of hours cleaning and lubricating the dial gears etc and re assembled to find that the engagement was intermittent again! its like the shaft isn't going in far enough ? I made up a small spacer for behind the handwheel and this seems to have cured the issue ?

Anyway ive searched all the parts lists and I dont seem to be missing any spacers nor should it have any spacers behind the handwheel retaining screw .

Next disaster is the tailstock , it wont lock to the bed with the over centre cam handle, AFAIK its never been removed , theres an adjusting bolt underneath which sets the preload but ive tried various settings but it wont clamp it solid to the bed , any ideas?

[Howard LewisParticipant @howardlewis46836]

Most camlock Tailstocks have a nut underneath which allows you to adjust the clamp load applied to the Tailstock

Essentially, the handle rotates an eccentric which pulls up a rod carrying the clamp plate. So tightening the nut will move the clamp plate closer to the underside of the bed, meaning that the handle clamps the Tailstock earlier in its rotation.

Unless you can easily access the adjuster, remove the Tailstock and take a look. You may have to experiment a little until you get things to your satisfaction, ranging from "Still can't clamp it " – too loose, tighten some more, to "Can't refit the Tailstock "- Clamp plate too high = too tight, slacken of a little.

If the bed is worn, you may have to compromise between what happens at the far end compared with what happens close to the chuck.

May be time for a strip and examine prior to make / replace parts?

The clamp plate is still there?

Howard

Edited By Howard Lewis on 22/03/2020 18:03:30

[bruce edwards 1Participant @bruceedwards1]

turns out the saddle clamp retained by the bolt up to the cam was reversed so only clamping to one side of the bed underneath ,all sorted now thanks

[Howard LewisParticipant @howardlewis46836]

Glad that you are now up and running, having sorted the problems.

Go for it!

Howard

[mark costello 1Participant @markcostello1]

I have a Colchester Triumph and the tailstock clamp kept coming loose. I put a stack of washers under the clamp and found the optimum position then ground a washer to the correct thickness and solved the problem. A stack of washers has too much slack in it and kept working loose.

[bruce edwards 1Participant @bruceedwards1]

Mine was entirely down to the plate underneath being 180 deg out , theres an offset slotted hole for the clamp bolt , because mine was away to the side it was only clamping at the side of the bed rather than seating properly in the track under the bed , very easily clamped solid now the correct way round

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