Wainwright H Class P4 conversion

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Horsetan
Posts: 893
Joined: Tue Jul 29, 2008 9:24 am

Re: Wainwright H Class P4 conversion

Postby Horsetan » Sat Apr 13, 2019 6:51 pm

grovenor-2685 wrote:
I found them near-impossible to disassemble if you get the quartering a bit wrong, as the boss will not let go of the axle...
. The original P4(Studiolith) ones have a taper fit between bush and axle, like the flywheel on a Mini or Morse drills in a lathe, the come apart very easily with a sharp tap on the axle end, .....


Some of mine refused to budge, so the whole boss and axle shifted, resulting in a ruined wheel.
That would be an ecumenical matter.

Crepello
Posts: 93
Joined: Thu Jan 31, 2013 11:32 am

Re: Wainwright H Class P4 conversion

Postby Crepello » Sat Apr 13, 2019 8:21 pm

grovenor-2685 wrote:
I found them near-impossible to disassemble if you get the quartering a bit wrong, as the boss will not let go of the axle...
. The original P4(Studiolith) ones have a taper fit between bush and axle, like the flywheel on a Mini or Morse drills in a lathe, the come apart very easily with a sharp tap on the axle end, some of mine have been on and off many times. This should apply to any taper fit. The taper fit did, however, require extreme accuracy in manufacture so maybe AG changed to a parallel fit when he took them over.


I suspect my own trial purchase 4F set also dished under compression from the tyre, thus being impossible to seat to gauge at the correct point on the axle taper.

Clive Impey
Posts: 34
Joined: Sat Aug 15, 2009 9:09 am

Re: Wainwright H Class P4 conversion

Postby Clive Impey » Sun Apr 14, 2019 10:28 am

FCA
You say that converting Studiolith wheels for split frames is difficult but are you aware of Barry Luck's article in MRJ 19 ? His method is to use a 1/8 reamer in the wheel socket hole until a i/8 axle will go in half way. The axle can then be pushed the rest of the way in and is a firm fit in the wheel. I have not used this method with Studiolith wheels but have done so with the Alan Gibson brass centred ones and found it works well.

To separate socket fitted wheels and axles I use a punch and hammer like Keith, but support the wheel in a steel plate, with a 1/8 slot, laid across the jaws of a vice. Keith - I too have put wheels on and off tapered axles but found that after a time the fit no longer held at he correct back to back. Hence my use of Barry's method on AG wheels.

Clive Impey

FCA
Posts: 51
Joined: Wed Jul 23, 2008 2:49 pm

Re: Wainwright H Class P4 conversion

Postby FCA » Sun Apr 14, 2019 1:09 pm

Given the less than friendly relations between the P4 and S4 tribes in the early days I doubt that AG had any access to the former's products. Past history best left undisturbed.

I also have some early AG wheels (for a Mallard Brighton K) which use almost the same axle/boss design as Studiolith. One day I'll get round to building the K!

Richard

Philip Hall
Posts: 1239
Joined: Mon Aug 10, 2009 7:49 pm

Re: Wainwright H Class P4 conversion

Postby Philip Hall » Sun Apr 14, 2019 1:45 pm

As far as I can recall Alan Gibson did indeed take over the former Studiolith wheels. The remnants of this are in the current range where some wheels are not drilled for a crankpin but merely have a dimple. Some very early AG wheels had the brass centre, but gradually the purely moulded centre superseded this.

One other thing. I am a bit wary these days of very old wheels (apart from Ultrascale, which had, and have, a different brew of plastic). I have recently exhumed an old set of Sharmans from a box, and found that what was once quite concentric is now very decidedly eccentric, beyond turning true. So it’s a good idea to check. Maybe it’s the age of the plastic, and I have seen comments about this before.


Philip
Last edited by Philip Hall on Sun Apr 14, 2019 5:20 pm, edited 1 time in total.

FCA
Posts: 51
Joined: Wed Jul 23, 2008 2:49 pm

Re: Wainwright H Class P4 conversion

Postby FCA » Sun Apr 14, 2019 5:54 pm

You say that converting Studiolith wheels for split frames is difficult but are you aware of Barry Luck's article in MRJ 19 ? His method is to use a 1/8 reamer in the wheel socket hole until a i/8 axle will go in half way. The axle can then be pushed the rest of the way in and is a firm fit in the wheel. I have not used this method with Studiolith wheels but have done so with the Alan Gibson brass centred ones and found it works well.


Barry's MRJ articles were, for me, seminal; I have never used any other method since. And yes, I have successfully used the reamer trick.

Rather than cutting the axle in half and then trying to cobble it back together straight and true I like to bore it out, epoxy in an HSS core (broken drill) and then cut the gap(s) with a piercing saw. This way the axle remains straight and you don't need any jigs (though you do need a lathe)

The trouble with the Studiolith axles is that they seem to be made of very hard steel indeed as they consumed quite a few drill bits before I was able to get sufficient depth for the core. Once they are done though they are completely trouble free.

Richard


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