Copper strip for pickups.

SquiddlyDiddly said the following on 13/07/2006 13:17:

You would be better off using phosphor-bronze strip for pickups, as copper is too soft. You can get this from Mainly Trains at

in various widths and thicknesses. If you really want to use this horrible method of collecting current, don't just have the flat face wiping the wheel. You will get better reliability if you fold one end corner down so that the corner is "scratching" (for want of a better word) the tread or the back of the tyre. You can also use Alan Gibson's hard brass wire for this, but that can wander about the wheel.

Actually, you would be *much* better off using split-frame chassis, but that's another whole ball-game :-)

Paul Boyd wrote: snipped

I'll agree that split-frames may be a reasonable solution for a simple sprung or compensated 0-6-0 with inside (and unmodelled!) valve-gear, but IMO once you start to model more sophisticated prototypes the complications rapidly cease to be worth-while.

Even in finescale 2mm, where the use of split-frames is almost an article of faith, I note that the little coalyard on Copenhagen Fields actually uses locos with skates bearing directly on the track. Now that really is an efficient way of picking up current!

(But you're right that ph/b is far better than copper!)

John in Sunny West Wales

Andy,

I think you would probably want something like phosphor bronze strip rather than copper. Copper is a bit to soft and ductile to maintain any contact pressure against the wheels. Eileens Emporium is probably your best bet for this since they carry a wide range of small section metals.

The problem with Eileens is that they don't have a web presence and you can only really deal with them by phone, mail, or from their stand at exhibitions. They do attend a lot of exhibitions so you might find them at an exhibitions near you. Otherwise, you could give them a ring and probably order over the phone. You could get their catalogue, but that costs £2.00 so you may not want to add that overhead to the purchase of some PB strip.

Eileen's Emporium details can be found on supplier.txt from the CLAG web site

It's a large document so use search on "eileen" to make things easier.

Jim.

snipped-for-privacy@aol.com said the following on 13/07/2006 14:16:

The 2mm boys tend to use the skates as a supplement to split-frame pickup, rather than as the sole means, although I'm sure some have just used the skates. Seems a bit of a cheat to me, but the locos can be so light that they need all the help they can get.

I just hate doing pickups - I've got a little line of locos virtually finished, but they've all come to a grinding halt waiting for me to install pickups. With the split-frame locos, they are suddenly a running chassis!

I like the American way - locomotives and tenders insulated on opposite sides. No pickups at all. Just an insulated drawbar. Of course this can't be done with tender engines.

How do these work? In 2mm I would have thought sprung skates would have tended to lift an already light engine.

John,

I might argue with you on that score :-)

With complex outside motion, you could use insulated frames. Everything on each side of the loco will be at one potential, therefore no shorts to motion, brake gear, etc. All you have to ensure is that there is no bridge across the frames which means that a metal body has to be insulated from the frames, and it is usually advisable to make sure that metal couplers and buffers are insulated as well.

Otherwise you can use the insulated axlebox method which means that the frames are insulated from the wheels and the pickup is from the axleboxes. This can be the easiest way of doing locos with no outside motion and the possibility of shorts to brake gear, etc., is minimised since, with the insulated frames, it requires wheels on both sides of the frames to short at the same time to cause a short across the track supply.

With inside motion, you can construct a driving axle which allows you to accommodate cranks and still provide insulation.

It might take a bit more work than slapping a bit of PCB with some PB wire onto the underside of a chassis, but it does work so much better than wire scraper pickups and there is no drag on the wheels. I've built split axle/frame pickup in S scale (like the 2mm Assoc, is the recommended method in UK) and 7mm and have had no problems - especially when compensation or springing makes sure all the wheels are in contact with the rails all the time.

Jim.

OK, now you've got an American reader (me) curious. Are you saying that the way you just described is not used on UK models? Even if from American manufacturers? If that is the case, is there a reason other than "that's the way we've always done it"?

That should have read "...can't be done for tank engines".

No, it's not common in the UK. They used to use one-sided insulation. Now the most common is both sides insulated, using sprung plunger pickups against the wheel.

The rationale is that you can get shorting if two engines are coupled together, or in similar situations..

On 13/07/2006 18:06, Larry Blanchard said,

This method is not commonly used in the UK, but some people do use it.

Are there any American manufacturers of steam locos? I'm not being funny, just that I've only ever seen American diesel models, and European models of US steam such as Rivarossi.

I think that about sums it up! Every method has it's advantages and disadvantages. I must admit that the American method seems attractive for some locos.

Bachmann, Broadway Limited and a few others. Also the Japanese, Korean and now Chinese brass.

As much as anything it depends what's available.

In 7mm the biggest supplier of wheels (Slaters) only makes them insulated. The smaller manufacturers like Home of O Gauge, Alan Harris, Walsall etc make both.

Masters of Epsom do them on Mail Order

tel 01737 356867 or 356373 Fax 379238 Don't bother with the web site!!

Peter A Montarlot

We're probably in basic agreement - I have locos which have split frames which work well enough (though I've sometimes also added skates to them in 4mm scale just to be sure, and this does have a positive effect) and locos which use good-old edge-of-wheel scrapers in ph/b, and frankly I can see no difference in their performance, though I'd agree that there *ought* to be better running from the split-frames. (Incidentally, the weight even of 2mm locos seems to be enough to allow the use of skates without lifting the loco, though I've never modelled in that scale myself.)

I just don't think that any theoretical gain is worth all the extra hassle you've described with a complex loco! Incidentally I've also got a few locos which use the 'American' system of picking up on different sides of the loco and tender, and although it has the merit of being uncomplicated it also has the disadvantage of ignoring all those lovely potential pick-up points - so I've added contacts to the insulated sides of both the locos and tenders, and skates on both sides as well.

Do I ever have to clean the track? Not likely!

John in Suny West Wales

Well, I'm modelling around 1900 and have steam from Bachmann, IHC, and = MDC (now defunct). A Heisler, a couple of Moguls (2-6-0), a Consolidation (2-8-0) and an 0-6-0 tank engine. I still want a 4-6-0 and a 4-4-0 as = the budget allows and both are available.

I'm talking pretty good running engines, not the toy-grade supersonic runners :-).

--=20 It's turtles, all the way down

Look at my website, the URL is in my sig.

All the steam is North American, Bachmann Spectrum with four Athearn steam.

I also have the Spectrum 4-6-0, waiting to be modernised and Spectrum and Athearn have announced a 4-4-0.

-- Cheers

Roger T.

Home of the Great Eastern Railway

Hi The metal is not copper but phospher bronze. You can purchase it in small amounts as strip, sheet or wire from Eileens emporium who are to be found at most major exhibitions in UK or at Mainly Trains who advertise in the Railway Modeller Hope the info has bee of some help

Hi The metal is not copper but phospher bronze. You can purchase it in small amounts as strip, sheet or wire from Eileens emporium who are to be found at most major exhibitions in UK or at Mainly Trains who advertise in the Railway Modeller Hope the info has bee of some help