Wheels for Peckett B2 conversion (and others)

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Wheels for Peckett B2 conversion (and others)

Postby Venturer » Wed Jan 15, 2020 11:40 am

This is the first thread I have started on the Forum - 3 posts in 6 years otherwise. Embarrassingly, I have to start with a public apology to Mark Tatlow and David Knight. Gents, I am sorry for missing your questions on the Scalefour News 215 thread as I very rarely login. I get almost everything as a 'lurking guest' thanks to the admirably enlightened policy of making our deliberations, advice and encouragement available to all. I believe it reflects well on us that we can be seen to embrace others currently outside the Society in this way.

On to practicalities - I have posted this as a 'technique' as it is non-specific in terms of prototype.
The Hornby wheel centres are nicely moulded, but are obviously wider than we require.The bit I failed to take photos of was the reduction of the wheel thickness from the back until it was fractionally less than the tyre width (to avoid fouling pickups), whilst leaving the hub at the full depth for about 3mm from the centre. Think in terms of the moulded-in bushes on Ultrascale conversion wheels.
Yes, the axle ends no longer reach the front face of the wheel, but by using the original full thickness of the bush to grip the splines, I am fairly confident this is secure enough for small locos.
I would certainly not advocate this technique for 6'+ driving wheels.

Please ask more questions so that I can improve the original writing in future!

Best,
Bernie
Nihil sine labore - school motto
The more I practice, the luckier I get - Gary Player et al

David Knight
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Re: Wheels for Peckett B2 conversion (and others)

Postby David Knight » Wed Jan 15, 2020 2:26 pm

Hi Bernie,

No apology needed, the Peckett is just one of a long queue of projects on my “To Do Eventually” list so there was no rush for an answer. I do have a few questions though. First off, did you recess the Hornby wheel to accept the rim of the Gibson tyre as they do have the extra bit on the outside face that the Gibson wheel centre sits against. Secondly, the Hornby wheel has a metal insert that the crankpins screws into, did you remove this before turning the back or leave it as part of the hub?

Cheers,

David

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Re: Wheels for Peckett B2 conversion (and others)

Postby Venturer » Wed Jan 15, 2020 3:15 pm

Q1. No, I didn't. Yes, I should have. I almost certainly will in future.

Q2. No, I didn't. I think the over-simplified description came about as I thought I had achieved the objectives of avoiding pickups whilst leaving enough plastic 'meat'. I seem to have subconsciously forgotten to mention the middle bit which wasn't getting in the way!

Thanks for the questions. As I said, just the sort of thing to improve future writing.

Bernie

Philip Hall
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Re: Wheels for Peckett B2 conversion (and others)

Postby Philip Hall » Wed Jan 15, 2020 4:37 pm

The Gibson wheel driving wheel mouldings don’t have a recess to accept the rim of the tyre, at least all of those I have had here don’t. The thin rim of the tyre just butts up against the centre. If a recess was turned the face of the tyre would be virtually flush with the spokes which wouldn’t look right.

Philip

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Re: Wheels for Peckett B2 conversion (and others)

Postby Venturer » Wed Jan 15, 2020 5:26 pm

That was my initial thought, Philip, but they look a bit thick in some of the photos in the original article.
Slight chamfer, perhaps?

Bernie

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Re: Wheels for Peckett B2 conversion (and others)

Postby Philip Hall » Wed Jan 15, 2020 10:44 pm

Hi Bernie,

Yes, a chamfer is a good idea. When I skim a wheel centre I always take the sharp edge off the front of the moulding, and clean out the inside of the tyre in case there is any swarf in there. The thinking is that possibly the inside of the tyre might be a fraction less than a sharp right angle, and coupled with a sharp edge on the moulding might prevent a proper seating. It also provides a (admittedly tiny) space for the epoxy I use to secure the tyre (5 minute Devcon).

Philip

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Re: Wheels for Peckett B2 conversion (and others)

Postby David Knight » Thu Jan 16, 2020 12:13 am

Thanks Bernie and Philip for the added insight. A question, now that the quality of Gibson wheels has gone up the tyres are more reluctant to let go of their centres. Any suggestion for how to pop them off with minimal risk of damage?

Cheers,

David

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Re: Wheels for Peckett B2 conversion (and others)

Postby Philip Hall » Thu Jan 16, 2020 12:43 am

I have some old tyres from wrecked wheels, so I choose a diameter slightly bigger than the moulded centre I want to remove. I then place the wheel face up on top of the old tyre and tap sharply with a small hammer and a punch, usually a pin punch used upside down. This spreads the load over the wheel centre more easily. A half inch bolt would do the same.

This is quite brutal, and is either easy or a bit of a job, depending on the fit of course. It might be worth trying Colin at Alan Gibson to see if he would be able to supply tyres (I don’t think so, but worth asking).

The alternative is to order the tyres from Ultrascale, who will supply virtually any diameter to order, as well as allowing you to specify the tyre width - very useful if there is limited clearance behind slide bars. The Ultrascale tyres do not have the recess that the Gibson ones do, so care will be needed when gluing or forcing them on to make sure they are true and in the right place on the centre, but that’s not insurmountable.

Philip

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Re: Wheels for Peckett B2 conversion (and others)

Postby Mark Tatlow » Thu Jan 16, 2020 10:49 am

Bernie, thanks for this I will ponder it and probably have a go at some point! I have a few similar looking wheels already discarded, so I will have a go on these.

David, Colin Seymour (aka Gibson) does sell his tyres independent from his full wheels. You need them to use his cast brass wheels (which incidentally, I do really like). I assume his full range is available thus, but you would need to speak to him in order to confirm.
Mark Tatlow

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Re: Wheels for Peckett B2 conversion (and others)

Postby David Knight » Thu Jan 16, 2020 9:12 pm

Mark, Philip, thanks for the advice on the tyres.

Bernie, can you give a bit more detail on the Hatton’s Barclay conversion, please? Are the wheels mounted on splined axles like the Hornby ones, can they be removed with a fine drift punch or are other methods needed and did you use the same technique on the cylinders of splitting and spreading?

Cheers,

David

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Re: Wheels for Peckett B2 conversion (and others)

Postby Venturer » Fri Jan 17, 2020 3:12 pm

Slight delay due to checking facts rather than posting rubbish!
Dismantled for photos I failed to take at the time.
The wheels are all metal with hub insulation (like Romford C&W), so need quartering. They are easily removed. When the total wheel thickness is reduced below about 2.3mm, all detail is wiped out. The appearance is unimpressive, but they work well as the proverbial "temporary measure until a better product appears".
The cylinders were split in the same way as the Peckett.
The decoder is a Zimo MX617. It is intentionally tilted upwards for an easier fit in the smokebox. The chassis block is a tight fit in the body. First removal will probably be difficult, so its a good idea to smooth the sides before re-insertion.

Bernie
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David Knight
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Re: Wheels for Peckett B2 conversion (and others)

Postby David Knight » Fri Jan 17, 2020 5:55 pm

Thank you Bernie, very useful. It would appear that the pickups are a bit more amenable to bending than the Hornby ones.

Cheers,

David

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Re: Wheels for Peckett B2 conversion (and others)

Postby davebradwell » Sat Jan 18, 2020 5:55 pm

I've always thought the Barclay a missed opportunity due to the lack of daylight under the boiler but looking at you pictures do you think it might it be possible for me to cut through and correct this if I bought one or are there vital organs contained therein? I see there could be an odd gear near the firebox but this may not be terminal. Considering Bachmann introduced their fully see-through tiny WD 4-6-0T the same month you'll understand my disappointment. Your wheels look fine and far better than inappropriate replacements.

DaveB

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Re: Wheels for Peckett B2 conversion (and others)

Postby Venturer » Sun Jan 19, 2020 5:27 pm

LRM_20200119_130343.jpg

The rather poor photo shows the redismantled model balancing upside down on a torch! Daylight can be seen just to the right of dead centre, i.e no hidden gears.
Hattons seem to be quick learners and quite possibly regret the compromise.
The wheels look better for the roughly pencillled shadow "tyres".
It's convinced me to redo a better pencil job and improve the centres.
Thanks for the supportive comments, Dave.
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Re: Wheels for Peckett B2 conversion (and others)

Postby hughesp87 » Fri Jul 17, 2020 10:54 pm

Like many, I fell for the charms of the Hornby Peckett W4 even before it hit the shops. I nurtured dreams of converting it to P4, but for many months avoided the inevitable. The announcement of Gordon Ashton’s etched chassis seemed to make things more achievable, but somehow I was reluctant to throw away what appeared to be an excellent slow running mechanism, and in any case the Hornby model had captured the profile of the unique 11-spoke wheels very well and trade sources could not offer a suitable P4 alternative.

To the rescue came an article in Scalefour News from Bernie Baker, who had converted both the W4 and the later B2 to P4 by removing the tyres and replacing them with P4 versions from Alan Gibson. So I carefully dismantled the loco and determined that other aspects of the conversion would be straightforward. With two colleagues in our regular Friday night group purchasing their own Pecketts, we resolved to pursue the same methods and three sets of the appropriate tyres were ordered from Ultrascale, which arrived three weeks later. The wheels then passed to my good friend Alex Duckworth, who skimmed the centres down at the rims and on the back, leaving the large axle centre bush to maintain a suitable grip on the axle. The wheels were then reassembled with Loctite and then remounted on the original axles. These have splined ends to improve grip, which also aided quartering. On the Hornby wheels, the axles fit in blind holes, so small plasticard packing pieces were superglued to the ends of the axles to help locate the wheels at the correct back to back.

As is usual with small tank locos that have outside valve gear, the clearance between the back of the crosshead and the front crankpin is critical – in this case zero! The cylinder unit was therefore separated from the chassis and cut along the centreline of the chassis, allowing the cylinders to be spaced out by 1mm either side. The motion bracket also received similar treatment.

Finally, the cosmetic bits. New frames were cut from 20thou black plasticard, spaced out from the cast chassis to increase the dimension over frames from 12mm to 16mm. Brake gear and pull rods were made up from a mix of the original Hornby and etched items from the spares box. New safety valves and whistle were turned up from brass, the Hornby transfers removed with Mek-Pak and replaced with Fox lettering, weathering with the airbrush and a crew added from Alan Buttler’s excellent Modelu range.

Thanks are due to Alex for turning the wheels, to Ultrascale for a speedy response to my order for tyres, to Philip Hall for converting me to the idea of cosmetic plasticard frames some time ago, and of course to Bernie Baker for the inspiration from the original article. Proof indeed, if you needed it, that the Snooze can spur you on to greater things!

The Peckett is destined for my new Cromford & High Peak layout, which includes the Derbyshire Silica Firebrick works at Friden. Sadly the company's internal rolling stock was limited to various 2 foot gauge internal combustion contraptions which never got to the CHP yard, so the loco and the livery here is entirely fictitious. Now to build some opens and Palbricks for it to shunt!
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Geraint Hughes
Cromford & High Peak in P4
Danish Railways in P87

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Re: Wheels for Peckett B2 conversion (and others)

Postby Andy W » Sat Jul 18, 2020 1:04 pm

Rather lovely!
Make Worcestershire great again.
Build a wall along the Herefordshire border and make them pay for it.

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Re: Wheels for Peckett B2 conversion (and others)

Postby Philip Hall » Sat Jul 18, 2020 2:58 pm

Geraint, a lovely little engine.

I am interested in how the wheels were assembled with Loctite, as I had a problem recently when reassembling some Alan Gibson wheels after skimming the centres. I used cyano, but for some reason it just didn’t stick properly and so I took them all apart again and used my normal 5 minute Devcon. That might have been the difference between Hornby’s plastic and Alan Gibson’s of course.

Was the tyre just slid on to the centre and then a thin bead of cyano run around the tyre/centre joint? Or adhesive applied before sliding the tyre on? In the latter case I guess it would have had to be very quick! I know that the bore of the Ultrascale tyres goes right through without the outer lip that there is on an AG wheel, so am also interested in how the tyre was set without wobble on the centre without a lip to set it in place. When I do this (possibly on a Hornby unrebuilt Merchant Navy, also 2mm axles) I am thinking of using Devcon to give me time to adjust the tyre.

Finally, did you use standard 2mm wide tyres or something narrower to give more clearance?

Philip

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Re: Wheels for Peckett B2 conversion (and others)

Postby hughesp87 » Sat Jul 18, 2020 5:04 pm

Philip,

Thanks for the nice comments.

The tyres ordered from Ultrascale were 2.00mm wide. From memory they were 10.64mm internal diameter, and Alex then turned down the wheel centres to give an interference fit. The tyres were laid face down on a piece of tufnol and the wheels pressed in from the back, using a piece of hardwood with a hole greater than the boss circumference to apply equal pressure across the circumference of the wheel. Loctite was applied with the wheel centre 'half-in' and the rest of the centre then pressed home. Seemed to work well, with no wobbles. I do think that the Hornby wheels use a different plastic from Gibson wheels, which is why I may have had more success with this method.

I didn't mention that when applying the cosmetic frames I cut back the Hornby mazak frames to make them less obvious in the normal front or rear three quarter view, as the attached photo shows. Of course this is one problem that you don't get with Gordon Ashton's excellent etched chassis, but at least I have the additional weight to improve its running qualities.

20200413_112231.jpg


I also had to add packing pieces to the top of the chassis, as in my opinion the Hornby model sits about 1mm too low. Rather obvious when you place it next to a wagon as the buffer heights don't match. It's odd that Hornby made this mistake, given that the wheel diameters are correct and the rest of the model is one of the best off the shelf products I have ever seen. I think it's really improved by conversion to P4 and now looks a sturdy little beast when it sits on the track.

Good luck with the Merchant Navy. I'd be interested to hear how you get on.

Regards,

Geraint
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Geraint Hughes
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Re: Wheels for Peckett B2 conversion (and others)

Postby barrowroad » Sat Jul 18, 2020 7:25 pm

Geraint,

You've mad a really great job of the Hornby Peckett, it will look good on Friden, well done. No surprise but I have a soft spot for Pecketts coming from Bristol.

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Re: Wheels for Peckett B2 conversion (and others)

Postby Philip Hall » Sat Jul 18, 2020 10:38 pm

Thanks Geraint, I will bear all that in mind on the MN. It will be a fair while; I ordered the engine (the BR Blue one) about a year ago now and delivery is still delayed...

Philip


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