# My Cowells Lathe



## Dr Jo (Feb 2, 2012)

Hi Guys,

I have just acquired, after twisting the previous owner's arm for many years, a very well equiped early Cowells lathe:







A question: she comes with the full set of screw cutting gears for which I have the thread cutting chart, but she also came with an additional 40 and 16 tooth wheel and idler. Does anyone have the chart for the extra threads that this enables?






I plan to restore her over the next few weeks, if you are interested I could post photos of progress.

Jo


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## tel (Feb 2, 2012)

Go for it Jo - I'm interested, for one. Been lusting after one of those for years!


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## steamer (Feb 2, 2012)

Hey Jo,

Wat Tel said!  lot's of photo's ect.

Marv Klotz has a nice program that will determine the result of pretty much any gear combination on a change gear lathe.

40/16 is 2.5.  That could be to change the range of threads, or even a very rough approximation of 2.54, which for short threads might work as a metric transposition set.....but I would have to do some math to confirm that and I don't have enough coffee in me at the moment. ;D

Dave


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## raggle (Feb 2, 2012)

You must have twisted that arm quite severely, Jo. That's a nice grab.

It looks just like this one

www.lathes.co.uk/cowells/page3.html

An extra idler stud is required on lathes not equipped with the perceived luxury of a tumbler reverse in order to produced LH threads, as in pre-ML7 Myfords and my 2-1/2" Exe lathe.

As for the extra gears it would be interesting to know the full list of what gears as supplied and the leadscrew pitch then someone with a spreadsheet will be along soon with an answer  

I won't be me

Ray


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## steamer (Feb 2, 2012)

raggle  said:
			
		

> You must have twisted that arm quite severely, Jo. That's a nice grab.
> 
> It looks just like this one
> 
> ...


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## Dr Jo (Feb 2, 2012)

What a lovely man, thankyou Ray :-*, extra idler = left hand threads so obvious once someone mentions it!

If anyone is a wiss with a spread sheet:

Leadscrew pitch = 1mm,
My extended gear set is = 64, 40 (2 off), 35, 32, 30 (2 off), 25, 20, & 16 . 

Jo


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## Jasonb (Feb 2, 2012)

I've got an old Cowells Accessories sheet in front of me and they don't list anything for L/H threads, the only item that looks to have small change wheels is the "Auto- Traverse kit" which would have allowed teh lead screw to act as a feed screw.

The standard set of change gears was 50, 40, 35, 32, 30 (x2) & 25

PM me your e-mail if you want a scan.

J


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## Dr Jo (Feb 2, 2012)

Thanks, I have got various copies of the Cowells acessory sheets as well as the Model 90 Lathe book. None mention the extra two gears or the idler but I have noticed them turn up on Fleabay so they must be a well known mod.

The 64 tooth and the 20 tooth wheels are standard parts of the auto-traverser which supplement the available wheels for threading. (Sorry I missed off the 25 tooth wheel on my earlier list :wall: )

Jo


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