What's new
What's new

1950 Colchester Triumph Lathe

Mikalee

Plastic
Joined
May 20, 2019
G'day all, from Australia,

Wondering if anyone might be able to provide directions to remove the back plate from a 1950 Colchester Triumph Lathe. It looks like an externally threaded spindle bore. I have assumed that it is a right hand thread. I have obtained manuals from England however they do not go back to 1950 or show external threads that I could at least use as a reference guide, they all show internal Morse tapered spindles. I would like to fit a four jaw chuck and to do this will have to make a new back plate to suit. But not if I can't get the existing back plate removed. All advice appreciated.

Cheer's Mate's


Mike.
 

Attachments

  • IMG_0091.jpg Small.jpg
    IMG_0091.jpg Small.jpg
    52.8 KB · Views: 1,026
  • IMG_0522.jpg Small.jpg
    IMG_0522.jpg Small.jpg
    55.1 KB · Views: 244
  • IMG_0525.jpg Small.jpg
    IMG_0525.jpg Small.jpg
    28.6 KB · Views: 239
  • IMG_0523.jpg Small.jpg
    IMG_0523.jpg Small.jpg
    28 KB · Views: 363
Sorry, Richard, the OP's lathe is an older generation than the manual you suggested. I once owned a 1953 vintage 15" Colchester Dominion that was same vintage as the manual. I suspect the OP's lathe is 1940's or earlier and if correct, it was a right hand thread spindle.

L7
 
It's threaded.
Attach a stud to the faceplate and "bump" it (in the correct direction) against a block resting against the bed.
Don't use the backgear to lock it up.

If particularly difficult, gentle tapping and a little heat (heatgun) will help matters.

I'd beleive 1950 if thats what the serial number dates it to- I had a 1949 model that was cone head. Colchester was very conservative and there was a strong export drive to the colonies after WW2.
 
I had to get a faceplate off a heavy ten that some numbnuts had spun on at high speed (well high speed for a heavy ten). I had to use a brass drift in the dog drive slot and hit the crap out of it to get it off. This is to say it might take a fair amount of force to get it off if it has been on there awhile.
 
Got a propane or MAPP gas torch?

Apply some penetrant or light oil to the spindle nose threads. Let sit overnight. Or don't.

Apply some heat around the spindle nose, to the face plate. Reasonable levels, like shouldn't sizzle if you touch with a wet finger. The heat will expand it some, but mainly, it's in aid of getting the dried oil goo to soften a wee bit.

Should be able to spin the plate off. If really on there, a rap with a mallet on the end of a hardwood block to get it broke free.

Watch that you don't resort to using the gears to lock the spindle in aid of this work. Been lots of gears buggered up that way.

Would suggest a strap type wrench to hold the spindle on the boss behind the face plate. I have used old vee belts or serpentine belts cut to length, and gripped with a locking pliers.
 
Hi all, thank you very much for your respective advice, time and assistance, very much appreciated.

You have improved my confidence level regarding the removal of the back plate. Yes the serial number indicates a 1950 build date for the lathe. It looks to me like it just pre-dates the introduction of the tapered spindle models.

What I did prior to my post was fit a bolt to the face plate and held the opposite end of the spindle with a “C” spanner and tapped the bolt. It felt very solid so I did not continue for fear of the possibility of damaging the gears.

Where on the faceplate end do you think I should I hold to try again using penetrating oil and heat this time as you have advised. In the second photo on the oiler end there is a collar with a recess on either side, might this be part of the spindle and the part to hold to try again. I cannot make out where the face plate separates from the spindle.


Thanks and cheers Mike.
 
Threaded ,for sure......looks like chuck mounting plate there now......do you have a chuck to fit the three bolt pattern?..............I think you will have to make a holder ,a flat plate with the three holes,and a handle of say 3/8x2" steel(10x50mm).If you dont have any other threaded mounts,maybe consider leaving the one thats there..........Ive seen too many lathes wrecked trying to get off a plate,when it was the only one,and there was no reason to take it off.......As a last resort ,you can machine it off,using the lathe under power.......whereabouts in Aus are you?
 
No one has mentioned it has a plain bearing spindle ,not rollers ,and lubrication must be seen to......If you look ,there is a fair bit on plain bearing Student/Masters on this forum and online.,very little about the larger models.
 
Hi all, thank you very much for your respective advice, time and assistance, very much appreciated.

You have improved my confidence level regarding the removal of the back plate. Yes the serial number indicates a 1950 build date for the lathe. It looks to me like it just pre-dates the introduction of the tapered spindle models.

What I did prior to my post was fit a bolt to the face plate and held the opposite end of the spindle with a “C” spanner and tapped the bolt. It felt very solid so I did not continue for fear of the possibility of damaging the gears.

Where on the faceplate end do you think I should I hold to try again using penetrating oil and heat this time as you have advised. In the second photo on the oiler end there is a collar with a recess on either side, might this be part of the spindle and the part to hold to try again. I cannot make out where the face plate separates from the spindle.


Thanks and cheers Mike.

Heat the section of the backplate that covers the thread and feed penetrating oil in at the exposed thread end. Not too hot, just uncomfortable to touch is about right. Tapping the backplate all over with a mallet and block of hardwood helps too.

Rolling a stud or bolt into a block using the inerta of the spindle is the most controlled way of delivering a shock- which is what it needs to break the seal. Be patient.

IIRC the gearbox models also lube from inside the headstock by chance, mine had wick cups in place of the snap oilers and ran fine on 30 wt with a little graphite.
 
Possibly the kindest way of holding the spindle really static is via an alloy plug drawn securely into the spindle taper by a threaded drawbar. 1/2 or 3/4" allthread will do fine for a drawbar. Alloy reduces chance of damaging the spindle taper and holds better than steel on steel at moderate draw in force. Just don't hammer it in or removal will be a pain. Drawbar thread needs to go right through so you can arrange an extractor.

Plug needs to extend a far enough from the headstock for the backplate to pretty much unscrew. Bolt a solid bar to the plug and strap it to the bed with a scrap of alloy underneath as a protector. If necessary shape things so as to have a decent contact ares.

With it all held solid all the force or shock on the backplate goes direct to undoing it. None wasted in taking up the slack in the spindle restraint.

She'll move.

Agreed this is over elaborate by most folks normal standards and takes half an afternoon or so to make and set-up. But the usual approach of steadily escalating force methods can take a fair while too and risks damage. Especially as frustration mounts. Having wasted far too much of my life going more and more postal on stuff that doesn't wanna move I now just go one step up from the normal way of removal for maybe five minutes at most then jump straight to a custom lock down solid device.

Clive
 
Hi John, thanks, the lathe is on the Sunshine Coast QLD. I am working in Chinchilla QLD about 350 kilometres away. I go home once a month for the weekend. I do have a three jaw chuck that fits the faceplate and agree I would like to avoid damaging the faceplate. Cheers Mike.
 
Hi all, thanks very much for all of your very insightful and helpful contributions. Given me a number of ideas and options to work with. I work away from where the lathe is so it will be some time before I get home for a weekend again, will investigate the faceplate removal and keep trying with the ideas you have all provided, . very grateful, cheers Mike.
 
Im in Brisbane,south side........one point,the early roundtop lathes have a different tooth form on the feed gears than the later roundtops,and bits dont interchange.However ,any Triumph stuff is so uncommon,probably not an issue.
 








 
Back
Top