Tuesday, September 22, 2009

Another post without a mention of guards vans

Yes, I'm managing to hold back for yet another post. This ones a bit late today but I though I would let discussion from the previous post run its course. Thanks to all those who replied for keeping the debate positive, hopefully the Guild will take some of the comments on board.

Tonight's ramble is on a currently vexing problem, wheels. More accurately axles. The main problem is one of length. Back whenever Peco made its first N scale wagons, some rocket scientist made one of those typically British decisions similar to those that have systematically destroyed every sensible scale/gauge relationship they have been involved in. Namely deciding that 15mm axles were a good idea regardless of the actual scale implications (for all you S scale readers, this scales to a 28mm axle) . To get round the overly long axle lengths the pin point bearing bits were buried way out in the axleboxes.

The unhappy sequel to all is that our merry band of modelers who are now looking to make underframes and bogies of a more scale appearance face having to do something similar with brass pin point bearings, which is a pain in the ass. Thus the search is on to find a replacement source of wheels. So far Markits (no answer) and Parkside Dundas ('how many do you want, we need to make then specially', which is a small production run killer ) have been tried, but if you only want 2 dozen wheelsets to check if your idea will actually work, you're 9maybe should read we're) screwed.

I'm now mulling over the pros and cons of actually joining the 2mm association just to get my hands on some wagon wheels (regauged) that are sort of correct, and the possibly trackwork implications that finescale wheels entail. The alternative is to try to locate someone locally who would turn axles up locally, and just import the wheel disc. North Yard is out, primarily because we are to small a market, but I'd be interested to hear of any others.

10 comments:

gfg said...

If you would like to provide me with a drawing showing the necessary dimensions, I will pass to an engineer friend who may be able to help .....

ben scaro said...

Issues regarding wheels:

1 Farish are similarly vexed by this . . . now that they want to make more accurate models. Their answer - start reducing axle lengths. As I posted on NZ120.org, their new 6-45-6.5mm wheels come on 14mm axles. Maybe they’ll standardise on that, but who knows ? It means keeping more spares in stock, and Farish don’t like doing that. They’ve also used 14.8mm axle lengths on one model (a new open wagon), and 15mm axles will not fit.

So . . . be careful before laying down your hard earned, and know that most dealers are pig-ignorant about these issues and few have the time/inclination to check.

2. I was happily assuming I could use old Coastal Engineering TT bogies, in order to avoid casting my own bogies and have all the attendant problems in casting something so small. So I bought the remaining stock from a TT dealer, about 25 pairs!

Nice idea, but . . . even 15mm axles from PD and Farish slop around in these trucks, which are designed for an odd 7.5mm plastic TT wheel on a brass tube axle. The 1.5mm dia axles on these TT wheels extend 1.5-2mm beyond the wheel face, and only then start to go to a point. A PD or Farish N axle, which starts going to a point straight off the wheel face, just slops around in the axlebox, and looks rubbish when sitting on the track- the truck sideframe hangs too low as it sits on the axlepoints, almost rubbing the track.

Bearings do not particularly help, and in one way make it worse, as they force the truck sideframe out too wide. Apart from being an absolute bitch to glue in place, and impossible to adjust if you get one placed slightly wrong.

As the Farish wheels I want to use can be slid off their axles, I’m wondering whether a better option might be to dispense with this whole pointed axle/bearing nonsense that N seems obsessed with, and do what 1950s TT did - use blunt axles. No issue of the truck sitting too low, no bother with gluing bearings. I have pairs of blunt axle Allen trucks from the early 1950s and they roll superbly (and have a finer wheel profile than any N wheel.) Oldtime TT knew what it was doing, mechanically at least.

3. Remember that the standard 2mm Association axle is 1mm diameter. If you are a member, they can be ordered cheaply in various lengths from 12.25mm to 15.2mm. I’m worried though, that you might have the same problem I did in trying to use N wheels in TT trucks, the thin axle may slop around in the roomier axlebox and sit badly. Also, I found already with Farish underframes that their stock 1.5mm axle comes to a sharper point than the 2mm Ass'n axle, so the Ass'n axle may not roll well in a Farish 4-wheel wagon. Fun times.

Ben

Motorised Dandruff said...

Cheers for this Ben. the aim currently is to get correct length axles and then either modify the Trackgang bogies or get new ones made, so they will be designed for the axle length.

ben scaro said...

Buying 2mm Association bits need not entail going to finescale 2mm standards.

http://www.2mm.org.uk/products/shops.php?shop_num=2

This is the 2mm Ass'n shop for freight bits. You want 2-220 for 6mm wagon wheels and 2-221 for 7mm coach wheels. Both are regular N gauge profile, NOT 2mm standard, though with fairly fine flanges. They are on a 12.25mm long, 1mm dia axle. Scroll up a bit for their range of axles, if you want to swap for longer ones.

BTW, another reason for belonging to the 2mm Ass'n . . . they do 1.5mm loco axle steel in 75mm lengths, for 25p each. Guess I better not tell them I want it for TT . . .

Motorised Dandruff said...

Sorry to burst your bubble Ben, but you actually need to be a member of the association to buy bits from the shop.
thanks for pointing those wheelsets out, though I really like the spoked ones as they really add something to an old style wagon. NZR only requires the 6mm wheelsets as all the wagon and coach wheels were 2'6" as standard.

ben scaro said...

Yeah, I know, that's why I said 'another reason for belonging to the 2mm Ass'n'.

It really is worth it, if you are modelling in any small scale, they have so many things that are hard to get elsewhere . . . three types of code 40 rail, axles, wheels, bogies, motors etc.

Motorised Dandruff said...

Sorry ben, didn't read youre comment properly. i must be getting old.
the strong NZ dollar is starting to make it worthwhile to join possibly. will have to see what the domestic environment is like.

woodsworks said...

Just thinking aloud here; Would it be too difficult to cut the axles in half, taking a reasonable chunk out at the time with, say, a decent sized cutting disc, tap the wheel discs along their axles a smidgen then rejoin the halves with a piece of brass tube? NorthYard have metric tube sizes that will be neat fit on 1mm and 1.5mm axles, and most hobby shops stock imperial tube to fit 1.6mm axles, so I can't see why they shouldn't run true after such butchery. This would seem to be no more effort than making entirely new axles and pressing wheels on.

This is only a stop-gap measure, obviously, because it will add to the cost of a wheelset but it would allow us to standardise on a particular axle length until such time as we get enough dosh together to order batches from the likes of Parkside-Dundas.

How many wheelsets did they want as a minimum order, by the way?

Motorised Dandruff said...

Its an interesting though paul, I'll have to see if it will work.

Minimum order was 1000. a few too many to check if an idea will work.

ben scaro said...

Hi, that's a good idea Paul. I tried a 15mm blunt axle before I went off on holiday to New York (where I am now) and it looks a lot better. I suspect that 14mm axles would look better.