Author Topic: This is not a Cowells lathe!!!  (Read 8004 times)

Offline John Hill

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This is not a Cowells lathe!!!
« on: November 24, 2013, 07:11:29 AM »
This is the Flexispeed lathe the postie dropped off at our house this week..






Somewhat like the curate's egg....

The chuck jaws are so tight it makes me wonder it has ever been used as there is no sign of anyone having done whatever one would do to make them tight,  I have gingerly rubbed the jaws on 120 grit paper but I am really scared of going too far!

The bigger back gear on the spindle has a worn centre so that the the gear does not lie true when the locking screw is tightened,  fixing that will require careful boring and a bush put in.

The little brass gears on the worm drive(s) that drive the lead screw are almost totally worn away.

But worst of all the saddle does not slide smoothly along the bed instead it tend to 'cock' sideways and lock up, no doubt this is what led to the premature demise of the feed gears.

The tail stock is threaded to take a small Jacobs chuck and has no taper, is that to be expected on a small lathe like this?

The spindle bearings are snug and there is no wear on the bed that I can detect without instruments.


What is the relationship with these lathes and Cowells which seem to have the same bed casting?  Are Cowells 'tea tray' lathes like this one?

What should I do with it?  Wipe it over with an oily rag and put it on a shelf or should I by a slow process fit change gears,  feed screw dog clutch, put a taper in the tail stock, etc etc and turn it into a 'real lathe'.
« Last Edit: November 24, 2013, 07:28:07 AM by John Hill »

Offline Jo

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Re: This is not a Cowells lathe!!!
« Reply #1 on: November 24, 2013, 08:03:39 AM »
The Flexispeed was the original lathe design and over the years improvements were made through successive owners, until you finally reach today's Cowells.

The bed is slightly different as the Cowells has a Tee slot down its length, which means that the tail stock and accessories fit differently. And they modified the headstock as overly enthusiastic tightening on the earlier Cowells was known to sometimes break the headstock clamps.

Looking at what you have there, once set up, I would think that is a useful addition to the workshop  8).

Jo
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Offline John Hill

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Re: This is not a Cowells lathe!!!
« Reply #2 on: November 24, 2013, 09:25:07 AM »
Thanks Jo,  I am thinking about setting it up for change gears but I also need to know how to fix the saddle jamming.


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Re: This is not a Cowells lathe!!!
« Reply #3 on: November 24, 2013, 09:49:20 AM »
John

Does the saddle jam in the same spot every time, or can it jam anywhere along the bed?

When it jams, is it under feed or are you moving the saddle otherwise?

Dave

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Offline John Hill

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Re: This is not a Cowells lathe!!!
« Reply #4 on: November 24, 2013, 10:19:15 AM »
Dave, it seems to jam just wherever it takes a fancy to do so.  I first noticed it jamming when under feed as it stalled the little motor  so  I removed the feed screw and tried pushing it by hand and found the same problem.  The saddle cocks to one side which may be a consequence of it being a very narrow saddle and it certainly does not have the 'wings' common on larger lathes.   Of course the entire machine is rather grimy and perhaps a good rub over with a scotchbrite pad and some solvent would be a place to start.

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Re: This is not a Cowells lathe!!!
« Reply #5 on: November 24, 2013, 10:41:15 AM »
Probably wouldn't hurt John.  The saddle looks narrower than the bed width, which is a bad state of affairs.   It would seem to be right on the edge of the old " 2 to 1 ratio" that causes "window locking"

As it occurs anywhere, I don't think it a bed imperfection.      Clean it up, and adjust the gibs carefully, your goal to get as low a friction as you can.   Cleanliness is the only option short of making a change.

Is there a separate gib?...and does it show signs of being "shortened"....?

Dave
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Offline Ian S C

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Re: This is not a Cowells lathe!!!
« Reply #6 on: November 24, 2013, 11:47:26 AM »
John, I'd almost expect to find a counter shaft between the motor and the lathe, as I have on my little Super Adept, don't know the lathe of course, so only guessing.  Maybe the saddle just needs cleaning, and the gib adjusted so that it bares on the ways evenly, you might have to check that the side of the bed is straight, without dents to catch on the saddle when it's adjusted to minimum clearance.    Ian S C

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Re: This is not a Cowells lathe!!!
« Reply #7 on: November 24, 2013, 11:56:16 AM »
Hi Ian,

I'm concerned that the saddle is worn "hourglass" shape from lots of use.  That would offer one possible  cause for the lock up.   First thing though is to clean and adjust and take some measurements.

Dave
 
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Offline BillTodd

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Re: This is not a Cowells lathe!!!
« Reply #8 on: November 24, 2013, 04:45:35 PM »
Quote
But worst of all the saddle does not slide smoothly along the bed instead it tend to 'cock' sideways and lock up, no doubt this is what led to the premature demise of the feed gears

I've had this problem with a Cadet.  It is very important to check the fixed dovetail fits well and is not worn in a curve.  If it is,  you'll need to scrap or file to make it a good square fit to the bed.  Also,  make sure the gib strip is flat and restrained by the screws, it should not move (relative to the saddle)  when the carriage is moved.  Chek the screws have the correct shape to fit the indents in the gib.

don't over tighten the gib screws - it should slide freely with minimal,but some, clearance.

https://docs.google.com/file/d/0BwXDcXKx2KzlZDQ1bTR2UUF0bUk/edit?usp=docslist_api

Bill

Edit: as someone has already mmentioned,  it should really have a coutershaft reduction pulley to drop the spindle speed to say 300 to 600 rpm, with perhaps a second hispeed range upto 1200 max.


« Last Edit: November 24, 2013, 05:00:44 PM by BillTodd »

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Re: This is not a Cowells lathe!!!
« Reply #9 on: November 24, 2013, 04:49:34 PM »
Hey Bill....couldn't agree more........That's exactly what I'm concerned is going on here
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Offline John Hill

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Re: This is not a Cowells lathe!!!
« Reply #10 on: November 24, 2013, 06:29:14 PM »
Thanks everyone,  wear on the fixed dovetail is a good point and somewhere for me to check.  As far as I can see the saddle has not been modified in any way.  The gib (which is on the back of the saddle)  fits neatly and has little divots for the adjusting screws to locate it, I am confident it is the original part as it has the same little '3' stamped on it as shows on the bed.

Ian, it came with a countershaft which will get fitted at some time, I suppose it is fortunate it has not been fitted as that would have given even more torque to strain things  when the saddle locked up.

Offline John Hill

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Re: This is not a Cowells lathe!!!
« Reply #11 on: November 24, 2013, 06:39:10 PM »
Hmmmmm,  maybe this saddle will prove to be a job for 'Sally Shaper'...



...I hope the dovetail is not worn bad enough to require this.
« Last Edit: November 24, 2013, 06:42:43 PM by John Hill »

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Re: This is not a Cowells lathe!!!
« Reply #12 on: November 24, 2013, 06:48:27 PM »
That'd do it.....provided it runs like it looks.....it's not particularly difficult cut to make....just tedious!...and not something to rush.


Dave
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Damned ijjit!

Offline John Hill

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Re: This is not a Cowells lathe!!!
« Reply #13 on: November 24, 2013, 07:48:09 PM »
I will hesitate before letting the little shaper loose on the job as there are more than 711 ways of things going wrong!

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Re: This is not a Cowells lathe!!!
« Reply #14 on: November 24, 2013, 08:43:47 PM »
yup.....Chasing down the 711 ways and eliminating them before you cut is the tedious part..... 8)
"Mister M'Andrew, don't you think steam spoils romance at sea?"
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