[dwb]

I have decided to fit some tender pickups to my new Ivatt class 2 2-6-0. I have chosen this locomotive for three reasons:-

1) The six coupled wheels have a short wheelbase which is quite rigid so any discrepancies in my track laying can lead to one wheel being lifted in mid air.

2) The wired connection to the DCC plug in the tender means that is one connection I don't have to make

3) I plan to put an SWD sound chip in, so major surgery is inevitable to fit the speaker.

The plan I have in mind is to solder some phosphor bronze spring strip to some copper coated board. The phosphor bronze spring strip will rub against the inside rims of the wheels. The copper coated board will be attached to the underside of the tender chassis by UHU or similar adhesive.

Before I go any further, I have two questions:-

1) Is this a good plan or are there significantly better ways of doing this?

2) What type and size of phosphor bronze should I buy? Mainly Trains do such a wide range, I am confused by the choice available.

David

 

[34C]

That would be my usual choice, phosphor-bronze wipers soldered onto a piece of copperclad. I have an ancient piece (bought goodness knows when) that is about 5 thou thick. I always bung a self tapper through the copper clad, in addition to some contact adhesive, just to make sure it stays put. Also, never bother with wipers for the centre wheelset, as these typically carry no load and will often be braked by wipers. I always polish the the wiping face of the phosphor bronze with a little brasso before installation; because Mr Henry (schoolmaster of my youth) who first showed me this technique always did so.

A simple alternative is to form and solder up two loops about 25mm apart in a length of 0.5mm dia nickel silver wire. Two self tappers through the loops to secure to the vehicle, arrange the free ends beyond the loops against the wheel backs.

 

[Richard Johnson]

A couple of alternatives that work well
** If the wheelsets in the tender are not one wheel live/one wheel insualted, then use wheelsets from Markits which are (They are a really nice wheelset anyway).

Wind fine phosphor bronze wire into a "spring" about 1/2 an axle long using a slowly turning battery drill and a former that is appx the same size as the axle. Leave a tail of a few MM on the spring. (Clamp one end of PB wire+ axle diameter former in drill, keep tight as it turns.)

Slip this spring onto the axle and it will give almost no friction but always keep contact. Solder a wire to the short tail and route it up through the tender for connection to the motor circuit or decoder.

** Consider soldering a short bit of gold wire to "wiper" pickups - a 2mm bit off a gold earring (one of the simple round s"sleepers) will actually cost very little per pickup and do the job well. Gold never corrodes or tarnishes so gives better pickup, and it is soft enough to wear to mate perfectly with the wheel back and will give less "rollling resistance" than the end of a bit of Phosphor bronze wire.

** If you use wiper style pickups on non-driven wheels, then then Keep the PB wire fine as possible - 0.25mm or less is more then enough as long as it is positioned carefully. I've found that a simple wiper will actually give better pickup if it is made to rub on the very edge of the flange with the end actually slightly past the flange lip.

It is 100% invisible as long as its only a whisker past the flange, seems to give lower friction and to be very much better at "self cleaning" when in that position.

Richard
DCCconcepts

 

[dwb]

There are some helpful suggestions there - thank you. The idea of the gold wire looks worth following up, perfect running is my Holy Grail.

David

 

[dwb]

Well I have now fitted some pickups to the tender of my Bachmann 2MT. The design has been through several iterations and this is what I have ended up with:-

I really wanted to use Richard's idea of wrapping phosphor bronze around a live axle but I baulked at the idea of switching the snub nose Bachmann wheel set for something pointy which would require brass inserts. I'm not terribly good at that just yet as my Parkside wagons can attest.

I secured the copper strip (the stuff used for sleepers) using 12BA screws rather than glue. This turned out to be a wise move as I had the strips in and out and in and out rather a lot.

I also tried a traditional horizontal wiper across the wheel backs as you find on locomotives but it turned out to be virtually impossible to install once built. So in the end I've gone for the simple arrangement above. It mostly works. I suspect that sometimes only 4 or 5 wheels are collecting at any one time but now the locomotive and tender can crawl through a lot my pointwork. It certainly manages better than my Hornby Fowler 2-6-4. I think that if I put together one of those Zimo capacitor thingies and actually wire up the frogs in my pointwork, I'll have a very nice little runner.

The next tenders due to retro fitting are the Bachmann 9F and A1

David

 

[Makemineadouble]

you might want to replace the wire between loco and tender, I find the fine wire 0.75mm (black) from all components to be excellent for this, and it's cheap.
If Bachmann would only fit tender pick ups, they have an excellent reliable drive mechanism. Baxhmann seem to be caught in the target price trap, rather than producing a truly outstanding model, which the punters would buy anyway.

 

[Sol]

MMAD, I too have used fine wire for the pickups I fitted - not quite as neat as DWB but they work OK.

yes Bachmann Blue Riband for good mechs & pickup - Bachmann Branchline for the older units - & no tender pickup.
Hornby Railroad for older mechs & pickup with Hornby Railways for first class mechs & pickups . In both manufacturers, for both diesel & steam ( though Bachmann diesel is pretty good as it is in most cases & Hornby should put the older mechs, etc back into the railroad range).

 

[34C]

QUOTE (dwb @ 14 Nov 2007, 22:57) <{POST_SNAPBACK}>The next tenders due to retro fitting are the Bachmann 9F and A1
If you can accept the inaccurate number of spokes, a really easy, no adjustment required, low friction pick up is possible on BR standards like 9F's. All you need are some of Bach's split axle spoked wagon wheels, and a thin strip of metal with axle holes attached to both of the frames. You may even have the wheels to hand under some of your wagon fleet...

QUOTE (Makemineadouble @ 15 Nov 2007, 08:37) <{POST_SNAPBACK}>If Bachmann would only fit tender pick ups, they have an excellent reliable drive mechanism. Bachmann seem to be caught in the target price trap, rather than producing a truly outstanding model, which the punters would buy anyway.
Particularly when they have the split axle technique in use on their Pullmans, and on much of the older product, so have plenty of experience of a very suitable cheap and low friction method. I find it a little puzzling that they don't do it from the competitive side as well, since it is established as a Hornby feature. Often with 'draggy' consequences, which a better technique would eliminate.

 

[dwb]

Thanks for the tip 34C, I'll bear it in mind.

David

 

[Makemineadouble]

Three of the new Hornby loco's I worked on in the last week didn't have effective tender pickups as none of them were in contact with the wheel backs. It's an easy job of course to adjust them. But I make the point that there's no point in fitting them if they don't function. So this is a quality control issue. Oh I also found a DCC plug that produced a dead short, and one of those connector thingies that when it moved it produce a dead short.

 

[neil_s_wood]

QUOTE (Makemineadouble @ 18 Nov 2007, 19:24) <{POST_SNAPBACK}>Three of the new Hornby loco's I worked on in the last week didn't have effective tender pickups as none of them were in contact with the wheel backs. It's an easy job of course to adjust them. But I make the point that there's no point in fitting them if they don't function. So this is a quality control issue. Oh I also found a DCC plug that produced a dead short, and one of those connector thingies that when it moved it produce a dead short.

Hornby doesn't seem to have any quality control anymore. I had the same pick up problems with the pendolino. Half of them had to be adjusted to get them to pick up power. It's still a struggle to get the thing to work as a normal loco should.