Colhester chipmaster bearings

[Steenkamp]

Hi All
I have recently acquired a Colchester Chipmaster as my primary lathe by trading in my ML7 and related rooling. I have had this niggle for some time now of not getting a decent finish using negative rake carbide, positive rake carbide or even with a tangential cutter or super sharp hss. I started playing around with tipes of material im cutting too. Known stock that used to give a mirror finish on the Myford doesnt even come close to shiny on the chippy. So i started checking all the gibbs and other adjustments that can have an effect. Still same old. Even locking cross and topslides makes no difference.

I then tested a 0,01mm finger guage against the spindle bore and i get no movement on the guage whatsoever. But if i slowly rotate the spindle by hand i can feel little rough spots while turning, and the rough spots are at random places, ie not repeating on the same place.

Can someone who know these machines perhaps give me a pointer as to what direction to go in now?

Could it be the bearings in the counter shaft that the clutch and brake system utilizes that makes such an impact on finish?

I have already contacted Nobilla tools in Uk and they quoted me £420 excluding shipping to SD!
If i convert that to our currency its more than what i paid for the whole machine! In fact i can buy a similar new asian machine for the price of second hand bearings.

Sorry , rant over.

Can somebody please direct me to an alternative make of bearings as nobody in SD  or SA can even find these Gamet bearings.

[awemawson]

When I was rebuilding a Round Head Colchester Student twenty years ago to my horror I found that one of the hollow rollers in the front spindle bearing had collapsed and knocked a hole in the outer race. Like the Chipmaster the Student uses Gamet, and even then I could find no equivalent or any at a sensible price. In the end I found a used but ok one.

Have you had the bearing out yet for inspection? If yours has a similar issue but hasn't gone too far you may get away just changing the rollers.

[Steenkamp]

I haven't removed anything at all yet, bit scared of what i might find. there is no noise or heat buildup around the spindle bearings. I used a screwdriver " stethoscope" to try and hear anything and the only place i think i could hear anything was on the drive-shaft containing the clutch and brake. I guess i will have to dismantle the headstock and take dimensions so our bearing suppliers can look for an alternative. Will a bad spindle bearing still make no movement on the spindle taper when testing with a finger guage?

[awemawson]

Certainly with mine there was no unusual play apparent, but there was a graunchy bit at one point in the revolution.

[loply]

If you're getting random tough spots are you rotate the spindle, is it possible there's some swarf or suchlike in the bearings?

I would inspect them and see if you can wash out all the grease fully then regrease them. It should be clear what the problem is once you've cleared the bearings out.

If it is the bearings, I'd be hopeful you could find a sensibly priced alternative without too much difficulty.

[awemawson]

(Unusually) there are four Gamet bearings on ebay at the moment - one may be the one that you need:

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=gamet+bearing&_sacat=0

[vintageandclassicrepairs]

Hi,
Heres a link top a complete Colchester student spindle and bearings in NZ, looks like a bargain??
I wonder if the bearings would suit??

http://www.ebay.co.uk/itm/Lathe-Genuine-Colchester-Student-Spindle-Gamet-Bearings-/121211508255?hash=item1c38c4d61f:g:z1MAAMXQUmFSfpne

HTH
John

[Steenkamp]

Awemawson and Vintage, thanks for the links. Will keep an eye on the bearings. How will i be able to cross reference the bearings between a student and chipmaster?

[awemawson]

Parts lists are around on the net with part numbers, but the Colchester parts were 're-numbered' several times in their lifetime which makes things confusing

[awemawson]

G&M in Ashington are breaking a Chipmaster at the moment, and have a complete headstock on eBay

Give them a call. Tim and Digger are both great blokes, had lots from them over the years.

[Steenkamp]

Hi Awemawson, im in a different part of the world so calling is not something easily done. Will try contact them.
I got hold of a stethoscope and had a good listen to the various bearings while running. The rough sounds come from the shaft carrying the clutch and brake. I really hope that it is those bearings causing the issue. Will try and dismantle that over the weekend

[lordedmond]

Pop your location on the big ball in your profile so we know where you are

Like Andrew and myself have done then the help can be more helpful

Hope you get it sorted without to much pain in the wallet

Stuart

[awemawson]

OK Steenkamp - from your ip address you are showing as Swaziland, so no I understand not quite so easy.

As Stuart says - put you location in your profile so we know where you are. If you also include your location in your 'personal text' it shows on your posts.

[Steenkamp]

Will do, thanks guys