Coll Ace Precision Grinder

While clearing out the garage I came across one of these in a pretty disgusting state.. Motor, frame and 2 spindles, one for bores and another for external.

It states model M2 plus the voltage and little else.

Does anyone know anything about them ? I could ideally do with some idea of motor power and rpm

Doh - I thought I had clicked on workshop equipment. Maybe a mod could move it there ?? Pretty please.

John

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Edited By Ajohnw on 14/05/2016 21:06:34

Just in case anyone has one and the name is different or has worn off there is another one on ebay at the moment. Not mine and less rust

**LINK**

John

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That old Lorenz motor might do nicely, John

MichaelG.

Looks like the rest of it will do nicely to Michael. I had completely forgotten that I had acquired it and was thinking about making another but light high speed motors with reasonable power levels are a bit of a stumbling block. Hard to find or rather expensive.

It should also do for titivating tools.

John

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Can't you get motor power by looking at some other make? They are all going to be the same. Then operating speed is just a matter of pulley size which will depend on stone size.

See a lot of TPGs on ebay and wonder what if anything makes them different from say a Potts spindle. Do the bearings have special dust shields? Obviously you want low runout and high speed capability but you'd want that ideally in any spindle.

I suppose I was hoping some one had a manual for it. The motor looks to be a similar size to the Wolf one but without actually seeing one it's hard to be sure. That one does mention current draw 2.2 amps but no mention of power. 8000 rpm. These things come with all sorts though. I can measure the rpm but feel that I had better dismantle and clean it all before running it. Spindles too.

Other than that the bearings all need to be accurately aligned even in the motor there isn't really any difference. It all needs to be well balanced to avoid vibration. There seems to be 3 screws locating the front bearing on the motor positioned in a way that they could be used to centralise it to the rear. Or maybe they just clamp without distorting the bearing.

It looks like the spindle bearings run in oil going on the oil caps fitted to them. Some universal grinders use a labyrinth to keep the oil in - sort of "cooling fins" on the spindle and on the bore ahead of the bearings. In terms of making one I intended to bore and maybe ream all the way through, add 2 circlip grooves to position the bearings and then add preload with disk springs. That way all machining is in one setting so will be accurate and the disk springs will smooth out the slight run out in bearings and maintain a decent pre load with temperature changes.

Easy but as I mentioned a suitable motor has proved a stumbling block. Turns out I have one. I hope. The alternative was phone up Parvalux and order one but what power? I probably wouldn't like the price and there is also the point of just how smoothly the lathe needs to run to make these things useful.

John

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John,

This ebay listing has a much better photo of the motor rating plate.

MichaelG.

John, reading this post prompted me. I have a tool post grinder forgotten about for years, it lives in a box behind the Bridgeport mill so rarely seen. I will dig it out and look for a motor plate/makers name. It remains unused in over 30 years.

Thanks Michael. Mmmm. Looks to be the same or a very similar motor and if it's 1/4hp more than enough power going on some cylindrical grinders Pulta produced based around their micro lathes.

Mine just has the motor voltage where that one has power and the model where it has the volts.

A speed controller and different pulley arrangement might mean that they could make a decent tool post spindle as well. Not sure but I suspect the speed is obtained using a shunt series arrangement and am not sure if these are suitable for speed control. On the other hand it might just be done with windings and the commutator. I've had no interest in universal motors for a long time.

Thanks for the offer Chris. Any info is useful. True it may lay around and get no use as a tool post grinder. In some ways it's lust caused by a toolroom background - if I wanted to grind something I just went and used a grinder so the lack bugs me.

John

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Edited By Ajohnw on 29/05/2016 17:03:55

Hi John,

Seeing your post on the spindle construction i had come to
the same conclusion to through bore to obtain the bearing
alignment.

Seen here in the universal grinder album three spindles
under construction ,the spindle bodies are turned and honed
to get a close bearing fit, the spacers are turned to closely fit the
bore and as such the diameter and bearing face can be turned
at the same setting.The front one is eventually loctited into position
and the rear floats in the bore ,three springs provide the preload
similar to the Quorn grinder spindle design ,in this way it is possible to
adjust the bearing preload.These spindles also have a labyrinth
sealing , like the spindle body bore care in the design allows the
parts to be made in a single turning setting in total about 5 parts
which all fit together and eventually loctited in place.A departure
from the Quorn spindle design is a screwed fitting at both ends
on the shaft allows for an easier construction for the shafts as
there is no need for a central sleeve between the bearings ,perhaps
the biggest advantage is the shaft is larger in the centre.
The three shafts one has a Quorn nose to use existing grinding
wheels ,one has a turned morse 1 taper which will be eventually
ground in situ and the other a plain protruding shaft of about 3 inches.
Bearings are 17x35 x10 angular contact high temperature rating.

The workhead seen here assembled uses a similar through bore
construction and preload arrangement and uses just ordinary
deep groove ball bearings ,displays no detectable runout which
says something for the bearings and also having them in alignment.

Hope you find this of interest.

John