Author Topic: Cowells Query  (Read 461 times)

Offline JimG

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Cowells Query
« on: September 12, 2017, 06:23:33 PM »
I've just been doing some back gear work on my Cowells 90ME for the first time and I'm just about to change back onto direct drive.  But a question arises.   Is there a flat or a dimple on the Cowells spindle to accept the grubscrew?   I've peered down the grubscrew hole and can't see anything obvious when turning the spindle.  I can't put my hands on my Cowells manual at the moment and I don't want to tighten down on to the spindle and raise a burr.

Jim.   

Online b.lindsey

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Re: Cowells Query
« Reply #1 on: September 12, 2017, 08:58:41 PM »
Jim, I haven't had an occasion to use the back gear yet but I know right where the manual is. I will have a look at it tonight and see if it sheds any light on the matter. As I recall it doesn't say specifically but one would sure hope there is a dimple for the reason you state.

Bill

Online b.lindsey

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Re: Cowells Query
« Reply #2 on: September 13, 2017, 12:22:09 AM »
Jim, there is nothing in the printed instructions as to a dimple on the spindle, but I did fine the attached pictorial image in the accompanying book by Andrew Smith,  "The Cowells 90 Lathe, A Handbook."  This would seem to show that there is a v groove machined into the spindle for this purpose. There may even be a brass "V" pin just below the grub screw though it doesn't show that. That is the case in the connection between the compound rest and the crossfeed, an angled groove in the hub of the compound that fits into a hole in the crossfeed whereby rotation is achieved by loosening and then tightening the two grubscrews which push on two angled pins that engage the groove in the hob withoug any damage.

Hope this helps. If not a quick email to Collin at Cowells, and I feel sure he can advise if the above is correct. Given the engineering on this lathe I can't even imagine that some provision such as I am assuming from the picture, isn't made into the spindle.

Bill

Offline Chipswitheverything

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Re: Cowells Query
« Reply #3 on: September 13, 2017, 10:03:15 AM »
"Given the engineering on this lathe I can't even imagine that some provision such as I am assuming from the picture, isn't made into the spindle."

Don't like to rain on the parade, Bill, but I've just taken the grub screw out of my own Cowell pulley, it's just a conical point socket grubscrew with serrations that goes down into a vee groove, there is no push piece...    Could always make such a thing if you felt inclined, but where the screw graunches in is at least not on the surface of the spindle.  It does make an effectively tight lock.

  Though I like the little Cowell lathe ( it came from Cowell's of Norwich in the early 1980's, so this is going back a way, )  and use it for small jobs, when I got it, there were things that needed some sorting out.  The tailstock, despite the manufacturer's check chart that claimed otherwise, , was unacceptable, it had side play in the ways, and the barrel bore was o/s, wouldn't lock up the barrel.   I returned it, and was sent another complete tailstock, but I wasn't very impressed with the new one, for the same reasons.   In the end, I refitted the tongue myself, and bored out the front end  of the half inch bore in the casting, and inserted and bored a closely fitting ( split ) bush that fits the moving barrel closely.   I also fitted slide locking levers, dowelled the gib strips, and put extra gib screws on the cross slide.   As I haven't fitted any digital or dial readouts ( yet!), it's a pity that the lathe hadn't featured adjustable index dials, essentials really.
  Realistically, it is a nice step above the small Far Eastern type of lathe, and everyone clucks over it when they see it, because it does look like a proper miniature lathe.   For real engineering quality, one might look at German and Swiss watch and instrument lathes..    I have got a Lorch watchmakers' lathe with its accessories that came from Germany immediately before the IIWW closed trade ( my father did some watch restoration ):   the quality of engineering in every aspect of it is simply astonishing, it's as much art as engineering!    Dave

Offline JimG

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Re: Cowells Query
« Reply #4 on: September 13, 2017, 10:14:03 AM »
Many thanks for the responses.

I've poked  the back end of a small drill down the grubscrew hole and can find no evidence of a "V" groove or even a rectangular section groove.  There are a few millimetres of longitudinal play on the pulleys and I can't find an edge to a rectangular groove if there is one.  However,  I poked the depth gauge end of my calipers down the hole with reference to the diameter of the largest pulley then checked to the spindle in front of the large pulley and there would appear to be a difference of around 1mm.  So it looks as though there is a rectangular groove about 1mm deep which is wide enough to encompass the end play of the pulley.

But I've dropped an email to Colin at Cowells just to double check before I tighten it down.  :)

Jim.

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Re: Cowells Query
« Reply #5 on: September 13, 2017, 11:43:53 AM »
Jim, I would be interested to know what Collin says when he replies.

Bill

Offline JimG

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Re: Cowells Query
« Reply #6 on: September 13, 2017, 12:29:47 PM »
Jim, I would be interested to know what Collin says when he replies.

Bill,

I've just checked my email and Colin has already responded.    The spindle is relieved under the grub screw in the pulley.  He also notes that the spindles have been hardened for the past twelve years.

Jim.

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Re: Cowells Query
« Reply #7 on: September 13, 2017, 12:36:32 PM »
Dave, thanks for taking a look at that. I would think the serrated set screw in a "V" groove for the spindle would be an effective lock as you say. A softer metal push pin (like brass) as used on the compound wouldn't be as secure most likely on the spindle where more forces are encountered. My reference to some engineered solution was more along the lines of just such a "V" groove as shown in the diagram...anything other than a set screw digging into the actual surface of the spindle.

Interesting story as to the tailstock also. I have not encountered any such issues yet at least and have used the tailstock with both the center and drill chuck on several occasions now.

Do you have any pictures of your Lorch? I would enjoy seeing it.

Bill

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Re: Cowells Query
« Reply #8 on: September 13, 2017, 12:38:51 PM »
Thanks for the info Jim. The relief part we had assumed already, the hardening is not something I was aware of though, but nice to know.

Bill

Online sco

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Re: Cowells Query
« Reply #9 on: September 13, 2017, 01:22:19 PM »

  Though I like the little Cowell lathe ( it came from Cowell's of Norwich in the early 1980's, so this is going back a way, )  and use it for small jobs, when I got it, there were things that needed some sorting out.  The tailstock, despite the manufacturer's check chart that claimed otherwise, , was unacceptable, it had side play in the ways, and the barrel bore was o/s, wouldn't lock up the barrel.   I returned it, and was sent another complete tailstock, but I wasn't very impressed with the new one, for the same reasons.   In the end, I refitted the tongue myself, and bored out the front end  of the half inch bore in the casting, and inserted and bored a closely fitting ( split ) bush that fits the moving barrel closely.   I also fitted slide locking levers, dowelled the gib strips, and put extra gib screws on the cross slide.   As I haven't fitted any digital or dial readouts ( yet!), it's a pity that the lathe hadn't featured adjustable index dials, essentials really.
  Realistically, it is a nice step above the small Far Eastern type of lathe, and everyone clucks over it when they see it, because it does look like a proper miniature lathe.   For real engineering quality, one might look at German and Swiss watch and instrument lathes..    I have got a Lorch watchmakers' lathe with its accessories that came from Germany immediately before the IIWW closed trade ( my father did some watch restoration ):   the quality of engineering in every aspect of it is simply astonishing, it's as much art as engineering!    Dave

Dave,

I had the same problem with the tailstock on my Cowells - spent ages trying to get it aligned and eventually realised the bore was on the scunt so alignment depended on how far the barrel was extended.  Gave up with it and replaced it with a Boley #2 and haven't missed it one bit.

Simon.
Ars longa, vita brevis.

Offline tangler

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Re: Cowells Query
« Reply #10 on: September 13, 2017, 01:31:19 PM »
Jim,

Here's a picture of what is left of my original Flexispeed spindle, which, as you know, was the ancestor of the Cowells.



As you can see, the indent for the pulley locking screw is a  flat bottomed groove rather than a V, so can be tightened anywhere.  The back gear lock just goes onto a flat as this is only used if removing the spindle.  I imagine that Cowells retained this system.

HTH,

Rod


Offline tangler

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Re: Cowells Query
« Reply #11 on: September 13, 2017, 01:39:16 PM »

.. eventually realised the bore was "on the scunt" ...

Simon.

Now there's a phrase I've only ever heard my wife use and she caught it off a boss from the Black Country.  It's a favourite in our house in the effite south.

Cheers,

Rod

Online sco

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Re: Cowells Query
« Reply #12 on: September 13, 2017, 02:12:16 PM »

.. eventually realised the bore was "on the scunt" ...

Simon.

Now there's a phrase I've only ever heard my wife use and she caught it off a boss from the Black Country.  It's a favourite in our house in the effite south.

Cheers,

Rod

Yes I learn't it off my wife too - think it's a Staffordshire term - she always used it to describe pictures that weren't hanging straight!
Ars longa, vita brevis.

Offline Chipswitheverything

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Re: Cowells Query
« Reply #13 on: September 18, 2017, 09:47:47 PM »
Just to say, in respect of Bill's interest in seeing some pictures of the Lorch lathe, that I'm taking some photos and will put them on in just a little while, bit more sorting out to do there. 

As for THAT word!, it be a good idea to know your companions around the dinner table well before dropping it casually into polite conversation...      Dave