Colchester Master 2500 Lathe

 After the grinder re-build i came across a Colchester Lathe on eBay, I already have a Chinese Mill Lathe with a tolerance quickly approaching +- 1cm, for those not in the know that's pretty crap.

I did my apprenticeship some years ago and remember the names Boxford, Enfield, Colchester etc and thought having a larger machine at work would be a good move and possibly dump the Chinese's thing.  

This time no mistakes in the transport and it comes out the van in one piece without damage to the van.

First thing lets get the top off and have a peek

I like to think i have a good eye when it comes to bargains, but with machinery you need to know your onions, well i obviously don't eat onions as this one turned into a monster that has badly bitten me.

Now I have never striped a lathe but even I know that's not good!

Looking further into the depths of this thing indicated someone didn't know their oil cap from the window washer bottle. There's at least 2 litres of water mixed with the oil and after a little research it looks like spindle bearings are at risk from this type of contamination.

Mega clean-up required and it looks like the spindle bearings will need replacing with a new set.

Ive had a few other jobs on and coming back to this i have decided to go the who hog. Im going to refit all the layshafts and clutch assembly with new bearings. 

There's no cleaning these, water and having the machine sitting around not running is the big issue here, Im also wondering if this machine was washed down using a jet wash, as some of the other items that have been stripped are showing similar contamination.

Casting was cleaned up and re-painted

Re-assembly of the drum is strait forward, the lay-shafts on the other hand were a pig. requiring special tools and a few attempts. 

These bearings are like rocking horse crap, and you will need a mortgage when you find them, super duper clean and keep them clean, this is where the casting cleaning must be spot on.

The headstock has taken me about a year to get this far as im on and off with the project. I have the shaft back in, and I can see the complex issues coming up here. I have seen that Colchester's are not cheep and parts are even more expensive, hardly anyone has detailed info and machine shops seem to think you have an open cheque book when you turn up. 

If all goes well im going to put together an in depth manual, one that I wish I had at the beginning. 

Re paint of the headstock and assembled, I rigged up a VHD to test the head bearings etc, only to find the motor bearings rumble too. Another job on the list.

 

Motor out and a quick clean, looks strait forward enough and is a standard fitting to the machine.

Careful use of the puller, after noticing the lock screw in the depths of the Vee groves.

Once the end plates are off, a quick check of the winding's and an insulation check i also replaced the rotor bearings.

I run up the main spindle with the VHD and after a bit of clutch adjustment and I'm back in business. The oil in the head stock (what was left) was badly contaminated. So a guess of what's in the gearbox is not going to be a shot in the dark. so lets have that apart to see what's there.

Hmm that looks pretty much what I expected, gearboxes can be a little intimidating although I have done a few car boxes but man there a some gears in here. 

I have already started to strip down the box and got the lower shaft out, again tricky but do able. 

Good all items out with a super clean up.

And gears back in, simples ! well this is a fast paced blog but believe me this is taking plenty of time.

 and identifying all the bearings (especially the ones not in the Colchester Book) is a slow process

Lick of paint with new oil window, this thing looks nearly new !

Saddle next, Again really mucky and the missus is giving me grief about the smelly gloves in the washing machine. Examining the oil ways shows the saddle is wearing down, i decided to re-cut the oilways to give a little more oil to the Vee slides.

Plenty of cleaning and a good etching paint to stop it coming off

Back On with new Cross Slide bearings, the nut assembly seems quite good so shouldn't need to much adjustment once its back together.

The top slide is a simple assembly, clean-up, re-paint and stone down the top surface. The jibs can take a bit of adjustment, to find that sweet spot without over doing it.

Check the spigot is clean, new swivel nuts and its back on

Tailstock

This parts seems really easy so i left it out of the way as an unimportant lump of metal. But after thinking more about lathes, without the tailstock the lathe is pretty useless. 

So strip down, new bearings and a good clean up and a little paint. For those doing the same, watch out for the cam lock mechanism, its a pig first time.

Time for the cleaned up screw threads and control linkage.

Apron

Be warned if the lathe is old then the smell is pretty awful, oil floats on water and the use of suds for cooling will find its way into the apron assembly. water and precision gears do not mix so do not be surprised the gear surfaces have corroded. 

Good cleanup, do not be tempted to add a Seal into the oil ho;r mating surface, they are purposely larger to allow for miss alignment.

Dials

Tooling

Slide hammer. You really need one of these, otherwise you will be damaging surfaces and creating burrs.

The rebuild is now finished, i ended up with a few more lathes (as if one is not enough) and slowly worked on a full strip/build manual. If you want a really detailed book on how the 2500 or the 1800 comes apart and put back together with tip bits, gotchas and part codes then head over to LatheWorkShop where i have a tone of parts and tooling. 

Derek :)