Author Topic: Colchester Student question (Read 16347 times)

jonny neate · « **on:** March 09, 2011, 05:18:05 PM »

Hello, just wondering if anyone on here, has any experiance on stripping a Colcster Student lathe. I need to remove the leedscrew half nut. can the apron be stripped in situ or do i need to remove the leedscrew and the power drive shaft and slide the whole lot of the bed.

I hpoe this makes sense, Thanks,Jonny

joegib · « **Reply #1 on:** March 10, 2011, 08:16:02 AM »

Hi,

Well, for a start you'll need to identify which Colchester lathe model you have. Suggest you have a look on this site to identify which of the models there matches your machine:

http://www.lathes.co.uk/colchester/index.html

Then post the model name here and maybe someone with experience of that model will be able to help.

If no one can help here you could try the 'Practical Machinist' forum (post in the 'General' section):

http://www.practicalmachinist.com/vb/index.php

There are plenty of people who have knowledge of Colchester machines there. Make sure you post the model name (or a photo of your machine, at least) or you'll get a rough ride!

Joe

mike os · « **Reply #2 on:** March 10, 2011, 12:51:58 PM »

I tried to get the apron off mine, but gave up because as far as I can make out the leadscrew and driveshaft have to come out & I dont have the spanners fot teh leadscrew.....

if you work it out please let me know as there are a few minor repairs needed on mine, mainly wear related.

Jonny · « **Reply #3 on:** March 10, 2011, 03:19:28 PM »

Old Student or Newer?

Newer is similar to M300 both use same cross slide. Whip the top off the half nuts are accessable, worst case just wind carriage back half off the bed.

jonny neate · « **Reply #4 on:** March 10, 2011, 03:24:06 PM »

Thanks Mike, you may have comfirmd watt i expected but didn,t want to hear. I belive taking the leedscrew out is a big job. Ive got someone who may be able to have a look and be should be able to give me some advice on how it comes a part,but i wont see him for a week or two.

Jonny its a 1970 mk2 square head Student.
Mike iff i find any thing out i will let you know

Jonny Neate

mike os · « **Reply #5 on:** March 11, 2011, 12:16:00 PM »

on mine you take the cover off the gearbox & there are 2 lock nuts... i dont have the c spanners for them yet....( rh student)

jonny neate · « **Reply #6 on:** March 11, 2011, 01:10:46 PM »

From watt ive been told you can take the cross slide of and unbolt the top part of the carrige leaving the top of the apron open.
Thats watt it lookes like in my user manual but not sure if i could remove the half nut without taking the apron right off.

Watt work do you need to do to yours Mike ?

Jonny

mike os · « **Reply #7 on:** March 11, 2011, 03:46:04 PM »

couple of c spanners...... cant remember the size tho 45mm -1 1/2"? rings a bell

I found I could not seperate teh carage & apron while the shafts were in... removing teh feed shaft made things more moveable but still caught up on the leadscrew...

It all works so not a big issue, but ...... one day when I get some enthusiasm back I will go play.... at the moment work is driving me insane, I hate my job, but work for myself

jonny neate · « **Reply #8 on:** March 11, 2011, 05:25:32 PM »

Mike do you think I could get to the half nut from inside the apron after taking the top off.

Jonny Neate

Jonny · « **Reply #9 on:** March 12, 2011, 06:06:33 PM »

Should be like the M300 then but havent actually had the half nuts out.

Whip top off the half nuts are in between the back of the carriage and the bed. Remove the bracket holding the lead screw, fwd/reverse etc three cap hd screws and two nuts on end of the shafts complete with bearings, easy.
Theres 7 or 8 cap hd bolts, leave the slotted adjusters in for gib strips. http://i1140.photobucket.com/albums/n563/Jonhareng/Jons%20machining/DROCrossslideinstalled.jpg
Take tailstock off and push the saddle half off end of bed, the half nuts will be visible then. The leadscrew and two others may want to move with the saddle, just keep pushing back in to gearbox.

Wouldnt want to get the leadscrew out looks a right bitch on all Harrisons, 600 Group, Colchesters etc.

jonny neate · « **Reply #10 on:** March 12, 2011, 11:46:39 PM »

Thanks Jonny im going to have a look when i get time, but the half nut in mine is on the left side of the apron,so i cant see how sliding the back of the carrige of the bed will help,but i will take tghe top off and have a look.
Jonny Neate

mike os · « **Reply #11 on:** March 13, 2011, 10:46:50 AM »

Quote from: jonny neate on March 11, 2011, 05:25:32 PM

Mike do you think I could get to the half nut from inside the apron after taking the top off.

Jonny Neate

did not seem to be able to remove the top with the apron still attached...... looks like there is a fixing/rubbing strip onto the front of the carrage

jonny neate · « **Reply #12 on:** March 13, 2011, 11:33:16 AM »

Hello Mike I think the top comes off leaving the apron behind. When I get the chance to see one of the engineers at work I will ask him he,s sure to know.

Jonny

mike os · « **Reply #13 on:** March 13, 2011, 04:15:25 PM »

Quote from: jonny neate on March 13, 2011, 11:33:16 AM

Hello Mike I think the top comes off leaving the apron behind. When I get the chance to see one of the engineers at work I will ask him he,s sure to know.

Jonny

thanks... that would be great

removed the rear guide, & all the bolts through the carrage, feedscrew etc.... everything that I could find, they would move apart, but could not lift off the carrage & apron was hung up on lead/feed.... looked like there was an anti-lift/ gib/ alignment fitting attached to teh carrage "inside" the apron that I could not see how to access without remofing the leadscrew first..

jonny neate · « **Reply #14 on:** March 15, 2011, 02:42:03 PM »

Mike , had a go at it today and you are completely right in watt you say. The right way to do it is to remove the feed shaft and leedscrew and wind the whole carrige of the end of the bed after removing the tailstock.

I did speek to someone today who managed to remove the top without taking out the feed shaft and leed screw but his way was far to brutal for me to try.

He levered a gap about an inch wide between the top and apron by flexing the leedscrew and wound the apon along the bed leeving the other part behind ,he said that there were gib strips as you said there might be on the front side.

Like I say far to brutal.

Reguads Jonny

mike os · « **Reply #15 on:** March 15, 2011, 03:27:14 PM »

Thanks Jonny... thats a real help, at least I know I am not loosing my marbles

One day I'll have another go at it

jonny neate · « **Reply #16 on:** March 15, 2011, 03:54:32 PM »

Some day with some help im going to have a go at taking the leedscrew and feed shaft out,I really need to replace my half nut. I know its going to be a big job but it wont need doing again ,not in my lifetime.
Jonny

mike os · « **Reply #17 on:** March 15, 2011, 04:41:59 PM »

thats the thing with these monsters... get them sorted & thats it... unless you are on them every day

jonny neate · « **Reply #18 on:** March 18, 2011, 02:52:57 PM »

Mike watt model is your student, a mates got a mk1 roundhead and he say to get the leedscrew out you have to strip out a load of geers. I looked at mine a mk2 square head and like you say mine has 2 C spanner type nuts on the geerbox end of the leedscrew and in my user manual it shows the leedscrew with splines on the end. I wonder if they just pull out after removing the C nuts.
Jonny

mike os · « **Reply #19 on:** March 18, 2011, 03:06:17 PM »

early roundhead...

jonny neate · « **Reply #20 on:** March 21, 2011, 03:53:42 PM »

Mike , spoke to the engineer at work today and he says that the geerbox where the feed shaft and leedscrew go into can be un bolted and pulled away with the feed shaft and leedscrew still atatched,ive not tried it myself but ive never known this bloke to be wrong and will be having a go when i get time.

Jonny

mike os · « **Reply #21 on:** March 22, 2011, 04:03:04 PM »

I'll have a look when I get a minute

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Author Topic: Colchester Student question (Read 16347 times)