Zeroing dials - setting amount of friction 'hold'

Hi My small bench lathe (an Axminster BV20) has zeroing dials on the feeds. Most are Ok, except the one on the compound which was always
very stiff. On examination, it looks fairly standard construction - a steel 'hub' with a outer aluminium graduated sleeve and a gap between the two. In this gap was a flat piece of bowed springsteel that contacted the outer sleeve - giving the necessary friction. No matter how much fiddling with this I did, including replacing with thinner ,better spring steel I cannot seem to get a nice even & consistent 'feel' to this. Its either still far to tight or to sloppy. I tried replacing the spring with a thick rubber grommet & grease, it is generally better but still doesn't seem 'right' at times - tends to stick quite a bit. Anyone got any tips where they have had similar problems and got around them?
Thanks Mike
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Why is a barmaid hot in the middle?
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Sorry Mike- was fooling with this. Suggest that you add a little curve in the spring and see where you get. Had a 9180 once- and that cured it. However,I suspect that your spindle and the dial are not concentric. This may account for sticking.
OK Norman
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ravensworth2674 wrote:

Never mind that - why is a barmaid hot in the middle?
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On Wed, 20 Feb 2008 02:09:28 -0800 (PST), jontom snipped-for-privacy@hotmail.com wrote:

You appear to have mis-spelt Omphaloskepsis <G>
Peter
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Well spotted Peter, should of course have been "Erudition for Lotus Eaters" still won't sell though :-))
Keith
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In article

Shouldn't this be taken to avizandum?
--
A T (Sandy) Morton
on the Bicycle Island
  Click to see the full signature.
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wrote:

Do they still switch the electric off at midnight there?
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Thanks for all the useful replies folks, one or two ideas that I'll look into. David, your suggestion about the George Thomas book sounds promising - I've got a number of 'standard' workshop books, but not just that one. I completely lost the plot in the thread joking about the 'bar-made' though I'm afraid.
All the best Mike
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Mike, Oh dear! Why is a bar made hot in the middle? So that you can bend it!
As for George Thomas, the Divine, there are two books- or three but you want the Model Engineers Workshop Manual and you also want 'Workshop Techniques' which is the joining of his earlier Dividing and Graduating and the Universal Pillar Tool. I have most of the Pillar Tool built and have to add the sensitive drilling attachment and the small dividing head described there. Our kind Chris Edwards passed on his kit for something called the Headstock Dividing Attachment- free gratis- and my thanks. In the Workshop Techniques book information is given on the dials described in the Manual.
Again, I have quite a few other GHT items such as a rotary table and rear tool post.
Others will agree that they have also followed 'the words and music'
I am now going off at a tangent- which GHT explains- and concentrating on a fabricated Stent tool and cutter grinder- which mysteriously arrived in my shed.
I am too old for 'barmaids' and now concentrate on frothy dialogue!
Cheers
Norman
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Unfortunately no.
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On Tue, 19 Feb 2008 02:43:59 -0800 (PST), MikeH_QB wrote:

If you have room, three steel balls set into holes 120 degrees apart in the main shaft with small springs behind them, running in an internal groove on the collar feels quite nice.
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Spring steel sliding on aluminium doesn't sound good. Can you try to arrange it so that the spring is locked to the aluminium and slides against the steel ?
-adrian
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In article

Mike,
You seem to have got a lot of froth in reply, with one or two useful suggestions.
I don't know whether you have a copy of The Model Engineer's Workshop Manual, by George Thomas - if not, get one, every ME of any pretensions should have a copy. Chapter 15 has a lengthy discussion of cross slide micrometer collars, with various methods of achieving smooth zeroing dials, from simple spring plungers to incredibly sophisticated designs with locks on both feedscrew and collar.
The designs themselves are specifically for ML7 and S7 lathes, but the principles used should be fairly easily transferable to most medium-sized lathes. The ideas can also be used on other feedscrews, such as vertical slides.
David
--
David Littlewood

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On several occoasions used O-rings and sometimes phosphor-bronze hollowed disks for this purpose. On my nice Herbert Junior surface grinder the heavy indicator dials are friction coupled by an axial adjusting bolt forcing a small steel wedge outward. Dirk
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