Mineral wagon poll

Details and announcements about our expanding range of specially designed and produced kits of resin wagons, transfers and etched parts
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MIKEWILLIAMS
Posts: 587
Joined: Mon Aug 20, 2012 5:12 pm

Mineral wagon poll

Post by MIKEWILLIAMS »

I, too like Tony B am back from les vacances. It was quite amusing to watch the Tour de France going through Holmfirth on TF1. Anyway, I'm making good progress on patterns for a Diagram 46 mineral and its predecessor the Diagram 22. Before I go any further with the latter, would you prefer the solid buffer version or the later sprung buffer rebuild? The upgrading started in 1905, but only really got under way in 1912/13. Whichever one you vote for, the other will follow later.

Best

Mike
dumb buffer
Posts: 552
Joined: Tue Aug 14, 2012 11:13 pm

Re: Mineral wagon poll

Post by dumb buffer »

Mike

I could use a lot of dia 22's with dead buffers!

Allan F
David Blevins
Posts: 310
Joined: Fri Nov 16, 2012 8:26 pm

Re: Mineral wagon poll

Post by David Blevins »

I too would be Interested in the Dumb Buffered Wagon.

David Blevins.
Dave Lochrie
Posts: 457
Joined: Mon Aug 20, 2012 9:38 pm

Re: Mineral wagon poll

Post by Dave Lochrie »

Both D.46 and D.22 for me Mike but with a bias in favour of the dumb-buffered D.22 variety first.

Dave L
MIKEWILLIAMS
Posts: 587
Joined: Mon Aug 20, 2012 5:12 pm

Re: Mineral wagon poll

Post by MIKEWILLIAMS »

Looks like solid buffers then - unless we have a late rush the other way. I'll leave the poll open for a while.

Best

Mike
tony brenchley
Posts: 348
Joined: Sun Aug 26, 2012 10:36 am

Re: Mineral wagon poll

Post by tony brenchley »

I would go with this. With a bit of care it should be possible to convert a dead buffer wagon to sprung by removing the buffers and replacing them with a headstock and sprung buffers. To convert a sprung buffer wagon to dead buffers is not so easy!

The only downside of a dead buffer wagon is that this probably requires more effort to remove from the mould and this may be reflected in CMA's price. The dead buffer wagons they did for Burntisland were much more expensive than those they have done for us and this is the only reason I can come up with. Perhaps 'Dumb Buffer' would like to comment.

Tony B
dumb buffer
Posts: 552
Joined: Tue Aug 14, 2012 11:13 pm

Re: Mineral wagon poll

Post by dumb buffer »

Dumb Buffer could make some remarks.......! You may recall that I had expressed an interest in mastering some outside framed dumb buffered wagons. Well, I built the first master, and it wasn't bad. I then made a rubber mould. Then I made another rubber mould. Then another. And another.... The problem is partly the buffers, which mean the mould has to be split horizontally at the top or bottom of the buffers. But it also needed to be split horizontally at the top of the sides so that the plug for the inside could be fitted. Then when pouring the resin there was a problem of bubbles getting trapped in the buffers, so I fitted risers to the end of each buffer. But I then found that the mould material I was using tended to tear when being extracted from the narrow recesses between some of the frame members, and I felt that I would need to make the sides and ends separate to enable the mould to be lifted vertically off the casting. In fact I managed to make three usable resin castings before the mould began to break up and I decided this was a mugs game. Even these castings suffered quite badly from bubbles. So I can see why CMA charge extra!

Two other factors then appeared. Firstly, my standard of modelling is nowhere near as good as Mike Williams :cry: While acceptable to me, I wouldn't offer it to anyone else. Secondly there is quite a lot of ironwork to be fashioned, and added to the model (end door hinges, side door hinges, vertical tie bolts, outside W irons with axleboxes and springs, brake gear, drawhooks). I felt that this was more than would be acceptable to many modellers. (Incidentally I have devised and trialled two different methods of arranging suspension or springing.)

So I'm now trying to finish off the three I've got and going back to thinking again about the whole thing.

Incidentally with the Burntisland wagons we found the maximum weight we could achieve with lead under the solebar (i.e. empty wagons) was about 30 gms, not really enough. What we did with them was to fashion a false floor of lead sheet, scribed to represent planking; this raised the weight to about 45 gms, just about acceptable.

Allan F
MIKEWILLIAMS
Posts: 587
Joined: Mon Aug 20, 2012 5:12 pm

Re: Mineral wagon poll

Post by MIKEWILLIAMS »

I could make the solebars separate if that would help. They would be located easily enough by the headstocks. Would it be worth asking CMA about this?

Best

Mike
dumb buffer
Posts: 552
Joined: Tue Aug 14, 2012 11:13 pm

Re: Mineral wagon poll

Post by dumb buffer »

One of the lines of thought had been to go back to the way the MWC did the whitemetal wagon, i.e. 2 sides, each with solebars and buffers, and 2 ends. No floor, though.

Allan F
MIKEWILLIAMS
Posts: 587
Joined: Mon Aug 20, 2012 5:12 pm

Mineral wagon poll

Post by MIKEWILLIAMS »

I should have mentioned that Diagram 22 was also used for trader's wagons - see the section on thirled wagons in the Wagon Book. Any further comments, Ed McK?

Best

Mike
tony brenchley
Posts: 348
Joined: Sun Aug 26, 2012 10:36 am

Re: Mineral wagon poll

Post by tony brenchley »

Thank you Allan for your time spent on the experiments on the outside framed mineral wagons and explaining it to us. These are a must have (eventually) and your work on the body moulding and underframes is very welcome. You have suggested that the way forward might be for a kit of cast resin parts as for the cattle wagon (and MWC kits). This does open up the possibility of moulding the axleguards and springs integrally with the solebar/floor unit.

Do we need to apply the same consideration to the diagram 22 wagon body (not the underframe bits)? I remember you told me that CMA charged £11 for each of the Burntisland wagons. If that is the case then I expect that this is the sort of price that might be asked for the diagram 22 wagons as a single moulding. It depends whether the moulding problem is with the dead buffers or heavy framing or it might be both!

I will contact CMA to seek their advice before we go any further.

Tony B
John Duffy
Posts: 155
Joined: Tue Nov 05, 2013 11:02 pm

Re: Mineral wagon poll

Post by John Duffy »

Tony the moulding of axle guards and springs integrally then restricts the options for springing or compensating the vehicle and is in my view a retrograde step. I personally would much prefer to have some options around how I did that and would prefer it did not waste parts in the process.

John
tony brenchley
Posts: 348
Joined: Sun Aug 26, 2012 10:36 am

Re: Mineral wagon poll

Post by tony brenchley »

John - my comments about integral axleguards and springs referred to the outside framed mineral wagons. These have axleguards or w-irons fixed to the outside of the solebars with the springs located behind them. There is not a lot of option but to have model compensation system or springing independent of these. We have been trying to devise a means of doing this whilst retaining pin point bearings for some time. The jury is not back with a unanimous verdict on this yet! Most but not all Caley wagons from the pre-Drummond era had this feature.

For the post-Drummond wagons with w-irons fixed inside the solebars there is no reason to move away from model compensation or springing with etched w-irons or fixed axleguards depending on your standards and preferences.

Tony B
John Duffy
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Joined: Tue Nov 05, 2013 11:02 pm

Re: Mineral wagon poll

Post by John Duffy »

Gotcha!
dumb buffer
Posts: 552
Joined: Tue Aug 14, 2012 11:13 pm

Re: Mineral wagon poll

Post by dumb buffer »

Tony

When I looked back at my records I find we paid £10.50 each for the Burntisland wagons; I presume this is what was paid to CMA, but it may be our group subsidised them to some extent.

As regards suspension, I measured the Bedford sprung units at 24.78mm width; the space between the solebars on my mouldings is 24.78mm! The solebars are 20thou thick; the prototype distance over the outside of the solebars is 26mm. So there isn't much to play with -- the springs need to be considerably pruned to fit behind the cosmetic external W irons and the functional internal W irons. Internal bearings are of course possible. I was worried whether solebars that thin would work, but they moulded satisfactorily and have shown no sign of distortion.

The difficulty for me of moulding separate sides and ends is that the solebars are vertical, while the sides are sloped, and the vertical frame members, of course, fit against both.

Everything is soluble, eventually!

Regards

Allan F
Dave Lochrie
Posts: 457
Joined: Mon Aug 20, 2012 9:38 pm

Re: Mineral wagon poll

Post by Dave Lochrie »

I would usually favour the option giving me the least work an obvious benefit of this is the ease of sale of a one piece body moulding).
The technical aspects differ between the D.22 which should be relatively simple in either sprung or dumb versions. The only plus in favour of seperate body solebar sections will be the use of common masters, but I feel this will be outweighed by the benfits of a sinnle piece moulding.

Any outside framed body is going to be more complex due to release issues, but if single piece bodies were done for Burntisland then I feel that is still th best route especially given the sloping sides above the solebar which Allan mentioned. It kind of goes without saying that any compromise on solebar width which has been proven on the exhibition circuit with Burntisland is going to work for the rest of us.

Any CRA members travelling down to Wells with the layout in August?

Dave L
lindsay_g
Posts: 488
Joined: Mon Aug 13, 2012 9:43 pm

Re: Mineral wagon poll

Post by lindsay_g »

Hi Dave,

There will be a couple of Caley types down to Wells with Burntisland in August, myself and Jim Summers. We'll be more than happy to let you examine them in depth. Look forward to seeing you there.

Lindsay

P.S. Full details of the Wells show are at http://www.railwells.com/railway_show/
tony brenchley
Posts: 348
Joined: Sun Aug 26, 2012 10:36 am

Re: Mineral wagon poll

Post by tony brenchley »

Allan, Dave - I made some attempts at outside framed mineral wagons many years ago and made up a jig to file the angle on the bottom of the side frame pieces to give the sides the correct angle to the solebars. I would think that if we resolve the other problems with the suspension we would make the patterns with sides, solebars and buffers combined. Obviously Ian Middleditch worked this out as the best way many years ago and presumably didn't have problems releasing the castings from the moulds. I will have a chat with him at Perth to see how good his memory is!

I think a minimum thickness solebar to suit the Bill Bedford sprung units negates the option of fitting integral axleguards, bearing boxes and springs. I envisaged using a scale thickness spring to support the axle guard at its potentially weakest point and maybe with some strengthening on the back of the lower part of the axleguard legs. I would think a resin casting should be strong enough to cope with normal handling.The price to pay is having to use inside bearings. The current Exactoscale wagon bearings I think use cylindrical bearings on plain axles. Have they resolved the problem of greater rolling resistance?

Jim Summers has built a number of MWC kits with one rocking iron with inside bearings and squeezed in pin pinpoint bearings at the other end. I am not proposing we go with this but it is another way of reducing the rolling resistance.

How well did the prototype wagons roll on a cold winter's morning with a coating of snow and frozen grease!

Tony B
MIKEWILLIAMS
Posts: 587
Joined: Mon Aug 20, 2012 5:12 pm

Re: Mineral wagon poll

Post by MIKEWILLIAMS »

Tony tells me that CMA Moldform are happy with the Diagram 22 wagon as a one piece casting - so that's easy to progress.

Best

Mike
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