Scattergun Bogies !

[Railwaymaniac]

I bought a diesel loco recently, and have been looking at it.

Particularly the bogies. This is the power bogie


I have already done some remedial work on this bogie. For example, have run a reamer through the bushes, just to make sure that there is no obstruction in that area.

And I have now fitted the motor the right way around ! ! !
No, it doesn't help the running at all, but it does mean that it' a lot easier to solder wires to it.

Less obviously, I have also removed any lingering 'cusps' around the motor area, this has had the effect of lifting the motor slightly, I think that the motor worms were intermeshing too tightly with the gear wheels on the axles.

Ian

 

[Railwaymaniac]

Here's the second photo of the bogie, the other side


And now we reach the real point of this discussion. Pick-ups.

The previous user had fitted the (rather whiskery) pickups that you can see in the picture. These are tinned copper wire, I think.
And these are the *second* generation of pick-ups on this bogie, the original pick-ups were fitted in the holes just visible behind the whiskers and 'above and to one side' of the axle bushes. these have disappeared into the mists of time and antiquity.

Given that I am NOT EVER going to fit insulated hornblocks to this bogie (and hence use split axles), and having a need to do *something* to the pick-ups here, I'm left with the choice of plungers or wipers.

The obvious choices for plungers are Slaters and/or PFS pick-ups. I understand that some folks on here don't like plunger pick-ups - is this due to bad experiences?

Wipers. Phosphor-bronze, I guess. Wire or thin strip? And should they wipe on the working face of the tyre, or on the back of the tyre? ? ? ?

Your thoughts, experiences and suggestions are requested and required . . .

Ian

 

[mickoo]

Have a look at page 19 and post 374 for my use of wipers, thus far have not failed at all across any S7 point work, granted they haven't run a million miles but I see little difference between these or plungers, the trick being to get them to run partially on the rim which does not come into contact with the rail and thus (in theory) pick up dirt.

My wipers are on top...because I can and they're hidden on the real thing, but if visual then side wipers on the rear of the wheel rim might be a better solution.

Plungers tend to be problematical due to the spring pressure, which creates a fair bit of drag, I've seen solutions where the springs are cut in half to reduce the pressure and increase reliability.

 

[Railwaymaniac]

Thanks Mick

The original pick-ups on here were P-bronze backscratchers, fairly long pick up, so low down on the wheel (and so easy-ish to clean fluff off).

I've had a look (in the past) at Slaters plunger pick-ups, and heard of VERY mixed results with them. However, there's a page on Big Jim's website which shows all the tips and tricks for them, and I think that if you follow these, then you get a good result.

Right now, I'm just canvassing opinion on the matter. I could go either way here - I've used all the types mentioned and I'm still not very sure.

Anyone?

 

[dltaylor]

Wiper pickups every time for me, and I use nickel-silver wire which is far more springy (and therefore adjustable) than copper, which usually has very little springiness. I've found 15thou wire to be about the optimum thickness, and my supply came from Eileens Emporium.

I've used phos-bronze strip backscratchers before, but only because I couldn't fit my usual wipers. I've tried plungers and don't like them, the main problem is that you have to install them before you fit the wheels, and once installed you can't adjust them.
I prefer to achieve a running chassis before I fit the pickups. I've had locos passed to me with the words "Help, it won't run" and the problem was plungers so tight it was like having the brakes seized on.
I prefer wipers to bear on the backs of the wheels where they dont pick up so much dirt, but it really depends what is achievable. On your motor-bogie the treads my be preferable.

If you look at my Workbench thread, Dave's SR Locos, my pickup methods are shown on there.

All the best,
Dave.

 

[Steph Dale]

Dave, Ian,

I wouldn't recommend using nickel-silver wire for pickups. Yes, it is more springy to start with, but work hardens very quickly. To be honest, although I have used phosphor-bronze wire, I'd probably suggest nothing any more sophisticated than a length of 0.45-0.5mm diameter half-hard brass 'handrail wire' carefully bent to rest on top of the wheels.

Much as Mickoo describes, in fact.

Steph

 

[dltaylor]

Dave, Ian,

I wouldn't recommend using nickel-silver wire for pickups. Yes, it is more springy to start with, but work hardens very quickly. To be honest, although I have used phosphor-bronze wire, I'd probably suggest nothing any more sophisticated than a length of 0.45-0.5mm diameter half-hard brass 'handrail wire' carefully bent to rest on top of the wheels. Steph

That's interesting Steph, in that its totally opposite to my experience!
Brass handrail wire has relatively little springiness, and a quick experiment showed that it hardened and broke very quickly when bending and straightening it. In contrast the nickel silver wire didn't harden at all and took a lot of bending and straightening without any noticeable change in its behaviour.

The trick with pickups is to use springy wire and gentle curve it avoiding sharp bends. Nickel-silver is perfect in this respect.
Any metal will harden and break eventually. Phos bronze strip, while springy, is particularly delicate and will break very quickly if bent sharply.

Some of my own locos are over thirty years old and running just as well as the day they were built (better in some cases!) with their original nickel-silver pickups still in place. Often when cleaning the wheels I've accidentally caught and bent a pickup well out of shape, but its always bent back easily. In fact, when locos have been passed to me for repair or refining, one of the usual jobs is replacing the pickups with nickel silver wire.

Cheers, Dave.

 

[Railwaymaniac]

Many thanks for all the posts and suggestions here.

Eventually, I decided to go with p-bronze back-scratchers on this bogie, not unsuccessfully.

Not the neatest work in the world, but there you go.

Here's the other side.

And when the wheels are fitted, then the thing actually runs!
In fact, it runs with a lot less sparking and general upset than the it originally did


To be honest, I am not entirely convinced about this arrangement.
The power wires that come around the side of the bogie to solder to the copper-clad strip seem to go horribly close to the other working parts of the loco.
It hasn't failed yet, we shall have to see what happens here.

Ian

 

[Railwaymaniac]

Moving right along here, let's go have a look at the bogie at the other end of this loco . .


And in perhaps slightly better focus, here's another view . . .


And in better focus, several interesting points raise their ugly heads.
- Firstly, I happen to know that this is supposed to be a POWER bogie. So where's the motor, john????
- Secondly, the gubbery surrounding the thing is soldered on. Not bolted on. So how is anyone supposed to do any maintainance on this thing????
- And thirdly. . . Thirdly, well it just becomes apparent that *somebody* has put together a bogie made out of thin bits of brass . . .

Ian

 

[Railwaymaniac]

Oh, and before anyone asks . . .

'Yes!'

That's a 3/16" (Slaters?) brass axle bearing slightly soldered onto the top.

It is supposed to be an 8mm diameter threaded bush . . .

Ian