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Lester
06-16-2016, 06:43 AM
Hello to all.
I have been a lurker on this list for a considerable time and have learnt a lot about many different aspects of machining. I do however have what I consider to be a fairly major problem which I am hoping someone may have the answer to. This relates to quite a heavy chatter when turning using even light cuts and feeds.
The machine is a 1952ish Colchester Master 6" I have clocked the end float and find this to be .002" which I am sure is greater than it should be. I have not clocked for vertical play yet as I was keen to resolve this issue first. My question is: can I adjust the end float and if so, how? Is this job likely to require any specialist tools?

I would appreciate any help you may be able to provide.

Best wishes to all.
Lester

Carm
06-16-2016, 08:15 AM
Generally speaking only.
There is likely a nut at the back end of the spindle to preload the bearing sets, if rolling element bearings.
A plane bearing spindle can use tapered take ups as well, sometimes having a rolling element thrust bearing, again using a nut to preload.

Careful examination of the spindle and bearings in situ should reveal the arrangement, or, verify the bearing styles via parts list.

Likely to involve special spanners which can be made in the shop. A fine resolution test indicator and means of determining temperature are required.
Given the age of the machine (era, not usage) the temperatures might be verified by tactile testing.

Read up on thermal runaway and proceed with caution.

Bryce.R
06-16-2016, 08:21 AM
Should be a big nut with slots in it to suit a c spanner. Usually located at the opposite end of the spindle from the chuck. Tighten the nut untill the end play dissapears.
Run the spindle at full rpm for 10 or so minutes, the bearing housing should be warm to the touch but not hot. If your chatter doesn't dissapear tighten the nut another 1/8th of a turn and moniter how hot the bearings get. Keep doing that untill your satisfied with the chatter.

I don't know your machine exactly so this is purely a rough guide

Richard P Wilson
06-18-2016, 09:48 AM
Hello to all.
I have been a lurker on this list for a considerable time and have learnt a lot about many different aspects of machining. I do however have what I consider to be a fairly major problem which I am hoping someone may have the answer to. This relates to quite a heavy chatter when turning using even light cuts and feeds.
The machine is a 1952ish Colchester Master 6" I have clocked the end float and find this to be .002" which I am sure is greater than it should be. I have not clocked for vertical play yet as I was keen to resolve this issue first. My question is: can I adjust the end float and if so, how? Is this job likely to require any specialist tools?

I would appreciate any help you may be able to provide.

Best wishes to all.
Lester

Photos would help. Wartime Colchester Masters had plain bearings, later ones taper rollers, but when the changeover took place, I can't recall.

Lester
06-23-2016, 04:04 AM
Thanks for the reply. I have some photos but have not yet figured out how to upload/download them. Will persevere!

Lester

pinstripe
06-23-2016, 04:55 AM
Have you seen the sticky?
http://bbs.homeshopmachinist.net/threads/62262-Posting-Photos

It's a little fiddly, but not hard.

Lester
10-27-2016, 06:52 AM
Hi all,
Sorry it has taken so long to respond to my initial problem, and the useful replies, but I have been out of action due to a complication following a broken wrist. This has however enabled me to get to grips with pasting links to photos as requested. Hopefully this will work!
The photos are of a spare headstock from a slightly earlier machine but they are similar in all respects apart from having a clutch.
Please let me know if the link works.

Best wishes to all

Lester

https://goo.gl/photos/yTf6WHiM7eFZqbYHA