Lubrication service on a small lathe

[ceejaydee]

I daresay that as the classic backgeared headstock design of lathe would have been driven by a flat belt which could be joined so stripping the headstock for belt replacement was not an original consideration.
I have a Drummond 4" Round Bed that has had it's flat belt replaced with a V belt although this has been cut and joined so again negating the requirement to strip the headstock for a belt change.

 

[Pete_S]

Finally I soaked the gearbox cover in the kitchen sink, in a very hot solution of washing powder. This softened/loosened a great deal of the caked-on dirt, and also dissolved the writing printed on the maker's plate. Oh dear!

Do either of these fit?

www.ebay.co.uk/itm/265085814035 :—


www.ebay.co.uk/itm/265043023084 :—

 

[RichardG]

Do either of these fit?

Yes the second design is just right! I did a search for "cowells lathe rating plate" and found them on eBay this morning. I guess I'm not the first to wash the ink off the original, and someone has found a market.


The Cowells uses a pair of sewing machine belts, so really easy to buy and cheap as chips. The part number is MB-410, which seems to mean “machine belt, 410 mm”. If only all part numbers were so simple!


When I started the motor, the machine duly flung drops of oil right down my shirt. As if to tell me, "all done!"


This exercise began when the motor kept on stalling. I looked at the the motor pulley and saw the belt was running on the boss of the pulley, not in the groove. The last person who changed the belts fitted the wrong length, and used the larger diameter of the boss to make the bottom belt fit. So the ratio of the gearing was higher than it should be, and everything was running faster than I thought it was.


I wonder, is this the original motor or a replacement? If it is the original, surely it hasn’t got much life left?

I have read about people putting a 3-phase motor into these machines to give continuously-variable control of the speed of the motor. So fewer belt moves. I need to sit and wait, see how the machine behaves itself. I haven’t persuaded it to stall yet, and it is clearly running at its proper speeds. The new speed plate will finish the job when it arrives.

 

[RichardG]

I have a Drummond 4" Round Bed that has had it's flat belt replaced with a V belt although this has been cut and joined so again negating the requirement to strip the headstock for a belt change.

Reassembling the headstock on the Cowells wasn't desperately difficult.

I tightened the Allen screw in the triple pulley a tad more than finger tight, then used a rubber mallet to tap the spindle left and right until the assembly spun freely without any end float. Then tightened down the bearings until they were catching, backed them off and then put everything else back. So I can grasp the chuck and see the spindle turns freely, but however hard I push and pull I cannot feel any play.

The Allen screw in the triple pulley can now be released and tightened at will, to use the back gear or direct drive.

 

[Nigel Cliffe]

I wonder, is this the original motor or a replacement? If it is the original, surely it hasn’t got much life left?

I have read about people putting a 3-phase motor into these machines to give continuously-variable control of the speed of the motor. So fewer belt moves. I need to sit and wait, see how the machine behaves itself. I haven’t persuaded it to stall yet, and it is clearly running at its proper speeds. The new speed plate will finish the job when it arrives.

I'd expect the motor to last absolutely ages. If the machine has been used every day for the last 40+ years, maybe the motor is tired, but for typical use of "now and then", its not likely to be on its last legs.

Continuous variable speed could be nice, but I find that the three top-belt options nearly all my needs - I've had a 12 speed Cowell for over 30 years.

Nigel

 

[RichardG]

I'd expect the motor to last absolutely ages.

Well, I started this excercise because the motor kept on stalling, and the machine would not produce enough torque to turn a diameter much bigger than 6 mm. I could see the primary drive belt was worn, and so I renewed both belts so I would know everything was as good as it could be before investigating a replacement motor. I had no idea the primary reduction ratio was wrong because the wrong length of belt had been installed incorrectly.

This morning I have turned some aluminium 25 mm diameter down to 23 mm in three passes, and the swarf is continuous. The improvement could not be greater. So for the time being, I am hoping the motor is still good.


The machine has a few signs of wear and tear on the bed right next to the headstock. Of course, I don't know whether this means it was used a great deal by a careful owner who made a couple of slips; or was used quite rarely by an owner who was a bit slap dash. Such is the joy of owning what is probably a fourth- or fifth-hand machine. Still, I reckon it will see me out.

 

[simond]

I am reminded of the craze in the late 70’s of “jacking up“ the rear of your Capri or Cortina, and fitting big wheels “so it looks like a dragster”.

the big wheels effectively put the car in second when still in first, the overdrive effect gave fantastic mpg on the motorway, but ensured the one thing the car could not do was compete in a drag race.

 

[RichardG]

I gave this post its heading "lubrication service" because I wasn't sure where it would take me, but really the task was a belt swap plus cleaning up.

The instructions for changing the belt on the Cowells ME90 are here (scroll down the page):
Cowells Lathe – Woody's Workshop
in case they are useful to someone else one day.

The machine now smells of engine oil, something I never noticed before I started but hopefully this will fade away before it impregnates the rest of the hobby room.

This excercise is now complete except for adding the new label whenever it arrives.

 

[paulc]

I am reminded of the craze in the late 70’s of “jacking up“ the rear of your Capri or Cortina, and fitting big wheels “so it looks like a dragster”.

the big wheels effectively put the car in second when still in first, the overdrive effect gave fantastic mpg on the motorway, but ensured the one thing the car could not do was compete in a drag race.

Or go around corners at more than a sedate pace .