Dapol Class 73 conversion to P4

[Stephan.wintner]

I appreciate that this is a non starter for those who don't own a lathe but here goes...

Google “2mm Association” and “Fonly Lathe”.

I haven’t tried it personally, but…

Best,
Paul

Oh! Very interesting. Many older North American hobby magazines suggested using a drill, held in a vise, and a file as a crude lathe, including for wheels (not to P4 precision, presumably). That assisted graver looks like a much more capable setup, thanks for sharing. I may need to try that.

Stephan

[Philip Hall]

Without a lathe and a means of holding the wheel true I would have reservations. I've only done this sort of thing on my very old Unimat SL because I don't touch the tyre surface, only the back and the flange depth. Provided the wheel is true in the first place (not always a given!) and close to the P4 profile in the appropriate places it seems to work.

Using the Society's form tool is obviously the best idea but that requires a mandrel of some sort which I am working on.

Philip

[Hardwicke]

Oh! Very interesting. Many older North American hobby magazines suggested using a drill, held in a vise, and a file as a crude lathe, including for wheels (not to P4 precision, presumably).

Stephan

Many years ago I turned some Dapol/Airfix/Kitmaster 04 wheels down and fitted P4 rims to them. 5 out of 6 worked a treat with no glue needed but the final one didn't and needed fixing on. A pair of Romford wagon wheels had been turned to P4 previously and this was my inspiration. The loco is still under construction and I have a lathe now, but if a teenager with a drill in a vice can produce this, anyone can.

[Terry Bendall]

Google “2mm Association” and “Fonly Lathe”.

An interesting idea and for turning small parts where great accuarcy and concentricity is not needed it could be useful. Others on here have done the same thing for example for loco detailing parts. I am doubtful about the success of the idea for re-profiling 4mm scale wheels.

Lathes are an expensive investment, especially a decent one. It is certainly possible to achieve a great deal without one, including scratch building of locos but dealing with re-profiling wheels is one area where it is not easy to achieve success without access to a lathe. Being in an area group or club means that you may know people who have a lathe and would be prepared to do the job for you which is of course one advanatge of group membership.

A long time ago, I achieved quite resonable success by turning down OO wheels and pressing on a P4 tyre. This meant that the wheel was true and the orginal axle was used. At that time Alan Gibson (the original) was willing to supply tyres if you asked nicely. It may be necessary to buy tender or trailing wheels of the correct size just to get the tyres needed. You need to make a mandrel to hold the wheels and it needs a bit of skill but if you don't feel up to making a mandrel, which is very basic lathe work, then the job may not be one for you until you have developed the skills.

Terry Bendall

[Porcy Mane]

I've had a bit of success thinning & turning RTR wheels down to fit on aftermarket tyres.

First up Heljan 05 wheels using tyres removed from Ultrascale class 24 economy wheelsets. This was done years ago and way before Ultrascale offered their "tyre only" service. When looking at the date of the photograph I shocked myself to find I did this almost 9 years ago.

Hlt05Medelling-163-(c)EditSm.jpg

Next up is a class 04 wheel using a Styrene centre from the Dapol/Airfix kit using a Gibson Tyre. Colin supplied me with a few tyres separately but understandably now chooses to supply only complete wheelsets. I wonder if the society might have a role to play here in negotiating a bulk purchase of some tyres of various sizes?

Pic shows the mandrel I turned up as per Mr. Pendletons MRJ article and a crankpin drilling jig.

B'mann-04-Md'ing-023-EditSm.jpg

Final pic shows some original brass Bachmann 101 DMU wheels thinned to 1.8 mm and re-profiled using the form tool. I found that I could only remove 0.3 mm from the rear face of the wheel whilst retaining sufficient material to form the P4 flange. Strangely the silver wheel (A Gibson 12 mm conducting wheel) looks to be a larger diameter but it isn't.

Cls101Modelling-035-editSM.jpg

Might be worthwhile keeping an eye out on MRJ over the coming issues as there just might be a useful article on re-tyring Hornby wheel-sets. Nowt to do with me.

P

[MFD1]

Talking of 2mm……
There was a successful system devised to deal with re-wheeling Dapol stub axles I wonder if it has any relevance?
Of course i mention it not having measured anything to see if it is actually viable !
Basically the stub axle was knocked out of the wheel and the dimensions corresponded to simply replacing the wheel with a 2mm one.
Had anybody tried this with the 4mm version, i wondered if a black beetle 12mm wheel could be used on the original stub axle?? Or anything else as a donor ???
Don’t have the offending items to hand but just wondered if it’s worth pursuing????
Best michael

[Horsetan]

I've had a bit of success thinning & turning RTR wheels down to fit on aftermarket tyres.....

....a class 04 wheel using a Styrene centre from the Dapol/Airfix kit using a Gibson Tyre.....

Pic shows the mandrel I turned up as per Mr. Pendleton's MRJ article and a crankpin drilling jig.

B'mann-04-Md'ing-023-EditSm.jpg

This is highly interesting. I've got a fair few leftover Airfix/Dapol centres which could be gainfully employed.

In the days when you could get Sharman wheels, I just bought the correct diameter for the 04 and chopped out the excess number of spokes - two either side of the crankpin - glued the bits together to form a solid spoke and reinserted them with superglue. The top half of the wheel centre was basically all balance weight so that was filled in with a Squadron Green filler/superglue mix. Looked like a Drewry wheel when done.

.... Strangely the silver wheel (A Gibson 12 mm conducting wheel) looks to be a larger diameter but it isn't....

That's only because the tyre face is thin.

[Porcy Mane]

I just bought the correct diameter for the 04 and chopped out the excess number of spokes - two either side of the crankpin - glued the bits together to form a solid spoke and reinserted them with superglue. The top half of the wheel centre was basically all balance weight so that was filled in with a Squadron Green filler/superglue mix. Looked like a Drewry wheel when done.

Sounds like you had a plan. Got any photos?

I tried something similar with a Sharman. That's why I decided to use the Dapol wheel centres. I also had to make some 0.8mm crankpins to replicate the prototypes. Still got to make the coupling rods with their distinctive oilers.

Bmann03-04Mdl-ing-099-EditSm.jpg

1MiscToSort58-EditSm.jpg

P

[Horsetan]

I just bought the correct diameter for the 04 and chopped out the excess number of spokes - two either side of the crankpin - glued the bits together to form a solid spoke and reinserted them with superglue. The top half of the wheel centre was basically all balance weight so that was filled in with a Squadron Green filler/superglue mix. Looked like a Drewry wheel when done.

Sounds like you had a plan. Got any photos?....

Here ye go....

[Porcy Mane]

Looks good Ivan.

On thing I forgot to mention about the Airfix wheels was, they nearly all had an air bubble in the rear boss that extended into the wheel centre.

I had to fill this with 24 hour araldite before drilling out the centre. If I do another set I might use Bi-carb and superglue to save time waiting for the araldite to cure.

P