dave flint Posted June 22, 2011 Share Posted June 22, 2011 Not having access to a mulitmeter (it's moved) I'm wondering if I can improve the pick-up performance of two tender drive loco's - the Thomas range Edward and James. They collect power through the loco wheels and have a contact between loco and tender, but going off the wiring in the tender, it seems that the tender wheels should collect power too. I can read/write cv's with just the tender attached, but the tenders only move a fraction on their own when power is applied. They both have a traction tyre on the two outer axles of the tender. Could I remove these to gain extra pick-ups ? What would be the reduction in haulage as a result ? They will only be hauling short trains, and thre seems to be lots of weight in the tenders anyway. Link to post Share on other sites More sharing options...
Charlie Posted June 22, 2011 Share Posted June 22, 2011 I don't know about the loco's you've mentioned but I know that without traction tires my old mainline class 45 does nothing! I would also suggest that the slow movement isn't down to lack of pick ups as the current etc will be the same no matter how many pickups you have. Link to post Share on other sites More sharing options...
dave flint Posted June 22, 2011 Author Share Posted June 22, 2011 Sorry, I've not been clear. It's stalling thats is the problem, not slow running. They're ok, but could be better. Link to post Share on other sites More sharing options...
James Posted June 22, 2011 Share Posted June 22, 2011 You can't just remove the traction tyres as their absence would leave a grove in the wheel tread. If you can source replacement wheels, through spares people like East Kent Models, or Ultrascale then to run with normal wheels is no problem. In the first instance it may be worth fitting replacement traction tyres. I don't know how old your models are or how much yuse they've seen but traction tyres can become worn and stretched with time which may affect the running of a model. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted June 22, 2011 Share Posted June 22, 2011 If these tender drives are to the same pattern as standard Hornby then you can reassign the wheelsets to get metal tyres onto the driven axles, and have the pick up you are looking for on both sides of the driven tender wheels. Basically; tender body off, unclip the motor from the chassis frame, the centre idle wheels fall off the stub axles. These idle wheels are usually complete with gear, and can be substituted for the traction tyred wheels. (If one or both idle wheels is lacking a gear, then knocking out the plain plastic wheelcentre and substituting the geared wheel centre will be necessary.) The grooved tyred wheels can go on the stub axles and will cause no problems there in my experience. Adding weight to the tender will help compensate for the lost traction tyres, but if loads are modest and there are no gradients these typically pull well enough as they stand. It is something of an irony that just as Hornby were reverting to loco drive, the China production of tender drive units moved to a five pole motor with performance not seen since the original tender/motor bogie motor design licenced from Fleischmann in the 1970s. This original unit was then subjected to several cost down cycles in the death spiral competition with Lima to see who could foist the worst mechanism on the OO buying public... Link to post Share on other sites More sharing options...
dave flint Posted June 22, 2011 Author Share Posted June 22, 2011 Will try.....yes idler axle has an identical gear to the others so it looks like its worth a try Link to post Share on other sites More sharing options...
dave flint Posted June 23, 2011 Author Share Posted June 23, 2011 Well I've had a go but am stumped on how to remove the motor. I can't see anything resembling a clip or a screw anywhere. Can anyone let me into the secret, please ? Link to post Share on other sites More sharing options...
steviesparx Posted June 23, 2011 Share Posted June 23, 2011 This original unit was then subjected to several cost down cycles in the death spiral competition with Lima to see who could foist the worst mechanism on the OO buying public... Ouch ! ....but with regard to removing the motor from it's chassis, it's clipped into the plastic frame by lugs on the front and rear of the metal motor casing. A screwdriver inserted into the front of the chassis, between plastic frame and metal motor casing should flex the plastic frame enough to release the lug, and motor casing... Link to post Share on other sites More sharing options...
Sam Moss Posted July 2, 2011 Share Posted July 2, 2011 Don't remove the traction tyres. Rewire the loco. At the moment Horny seem to have swictched the contact sides on these tender drives. Our club Edward kept having a problems and after a bit of investigation work we came to the conclusion that Hornby now seem to be using the top finger contacts for tranfering the oposite side power to the tender whereas before they use the lower contacts. The lower ones give alot better contact on the tender coupling pin and a simple rewire of the tender and loco to swap th contact feeds over should solve 99% of the problem. Link to post Share on other sites More sharing options...
Klink Posted July 2, 2011 Share Posted July 2, 2011 This is a fairly drastic way of fixing the problem but Hollywood Foundry here in Australia manufactures replacement modern drop in mech units for Hornby and Triang tender drives. (and some others like the Blue Pullman). Link to post Share on other sites More sharing options...
JeremyC Posted July 3, 2011 Share Posted July 3, 2011 I don't know the details of the OPs locomotives, but I have an old Hornby A4 with tender drive [the type with one side of the pick up on the loco and the other side on the tender]. The loco itself was quite light and I found adding weight to the loco body made an improvement in pick up performance at low speeds. In addition I hard wired the loco chassis to the tender contacts on the rear pony truck. [Permanently wiring the engine to the tender didn't show any real advantage over the latter and you couldn't separate the two]. I also found the loco middle axle had both wheels insulated so the collection was only on the outer two wheels. The insulation was broken on the relevant side by drilling the bush and screwing in a 12BA screw, [a piece of wire pressed in would probably do just as well]. Jeremy Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted July 6, 2011 RMweb Gold Share Posted July 6, 2011 I'd agree that the solution is to leave the tender alone but improve the pick up arrangement in the loco. It's relatively simple to add extra pickups to the rolling chassis, bearing on the side that doesn't "collect" in Hornby's arrangement, or even both sides. This can then be fed through to the tender using a permanent connection or a removable two-pin plug. I've done this with a Margate 9F and the improvement in slow running and non-stalling is terrific. Link to post Share on other sites More sharing options...
amdaley Posted July 6, 2011 Share Posted July 6, 2011 I'd agree that the solution is to leave the tender alone but improve the pick up arrangement in the loco. It's relatively simple to add extra pickups to the rolling chassis, bearing on the side that doesn't "collect" in Hornby's arrangement, or even both sides. This can then be fed through to the tender using a permanent connection or a removable two-pin plug. I've done this with a Margate 9F and the improvement in slow running and non-stalling is terrific. Did you fashion the pickups yourself or did you use a Hornby set ? Link to post Share on other sites More sharing options...
dave flint Posted July 6, 2011 Author Share Posted July 6, 2011 Don't remove the traction tyres. Rewire the loco. At the moment Horny seem to have swictched the contact sides on these tender drives. Our club Edward kept having a problems and after a bit of investigation work we came to the conclusion that Hornby now seem to be using the top finger contacts for tranfering the oposite side power to the tender whereas before they use the lower contacts. The lower ones give alot better contact on the tender coupling pin and a simple rewire of the tender and loco to swap th contact feeds over should solve 99% of the problem. Thanks to all - I've been on holiday for the last few days. I had presumed that as the Hornby loco/tender connection has two contacts insulated from each other, it picked up power from both running rails. I'll have to find the multimeter and see what the actual feed is, otherwise (me being thick here) I can't see an advantage in rewiring. If the loco only picks up from one rail then I'll have a bash with your suggestion. Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted July 6, 2011 RMweb Gold Share Posted July 6, 2011 Did you fashion the pickups yourself or did you use a Hornby set ? Made my own ones; I'll take a pic later. Link to post Share on other sites More sharing options...
amdaley Posted July 6, 2011 Share Posted July 6, 2011 Made my own ones; I'll take a pic later. Cheers. Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted July 7, 2011 RMweb Gold Share Posted July 7, 2011 As promised: Two strips of copper-clad (C+L sleeper material) glued to the base of the chassis with superglue, and then pickups made from 0.45mm nickle silver wire obtained from Mainly Trains. These can be easily adjusted to bear onto the wheel rims without imparting too much drag on a free-rolling chassis. The loco-tender connection is a two-pin plug supplied by Comet. Also visible is a square of black plastikard glued to the tender base to force the cogged wheel to keep in mesh. This is necessary because as supplied the original back-to-back of the tender drive was a little tight, but if you open up the back to back the gears are prone to slipping out of mesh. Ultra low-tech but it works! Link to post Share on other sites More sharing options...
amdaley Posted July 7, 2011 Share Posted July 7, 2011 That's excellent.Thank you Barry. Link to post Share on other sites More sharing options...
Sam Moss Posted July 7, 2011 Share Posted July 7, 2011 The benefit from rewiring is that the side of the current you need for the drive to operate (The side that the traction tyres are on the tender) will be passing through the more reliable bottom contact pin rather than te flimsy finger contacts. (The other one would just be Hornby loco's with this method work alot better. The finger contacts will then just be used as extra pick ups to pick power from the rail that the tender is already live to. If you get my drift? Link to post Share on other sites More sharing options...
dave flint Posted July 8, 2011 Author Share Posted July 8, 2011 I do indeed. I will have a go at rewiring the things, but I'm not happy with the arrangement at all. On taking the locos (James and Edward) apart, there is a lot of room in the barrel of the boiler, particularly so with Edward. I also have an order for some of the stay alive loco decoders from DCC concepts. I'm tempted to ditch the Hornby power arrangement through the coupler. I wonder if anyone can recommend a micro connector that I could reliably use for three wires.....one track feed and two motor feeds to/from the tender. I can then house the decoder in the loco itself. Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.