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Discussion Starter · #1 ·
Hi,
I'm returning to Railway Modelling after a 30 year gap and this is my first post on here. Like many, I've been salting away stuff in my loft against "the day". I've decided to go DCC and I've been digging out locos to assess suitabilty (and rediscover what I've got!).
I've test run 2 43xx moguls, 2 "Manors" and 3 Standard 4MT 4-6-0's on a length of Peco track. All run OK except they waddle from side to side like a duck! These were all bought new and it's the first time they've been run.
The driving wheels look to be running true as far as I can tell and haven't come loose on the axles. The valve gear isn't sticking or catching and the quartering looks equal. There is a large amount of side play - presumably to get round "train set" curves.
If I run them in as recomended is this likely to improve?
I don't want to go to all the trouble of converting these chassis for DCC, if they have a permanent gait like a sailor with a wooden leg!
I've thought about widening the plastic keeper plate with plasticard strips to reduce the sideplay on perhaps 2 of the driving wheels, but then it might cause problems on curves and pointwork.
Anybody had this problem and solved it?
 

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You may have one or two slightly wobbly axles if they have been a long time in store, which won't help, but you can correct those once you have got your eye in. The main problem is just what you surmise, too much sideplay on the driven wheels in particular. You can take most of the sideplay out of the leading and trailing coupled axles ( the method you propose of sticking plasticard to the sides of the keeperplate is the one I have used) and they will still go round 2nd radius, but will be much more stable. A centering spring for the leading truck will not hurt either. Converting the split chassis types to DCC is a little extra work, as you have to drop the driven wheels out of the bottom of the chassis, in order to separate the halves enough to isolate the motor terminals, before a decoder can be installed. There are guides on line with illustrations. It's worth doing in my opinion, as the motor is a good one and they perform very welll; and once the knack of doing the job is acquired it doesn't take that long.

Welcome back to the madhouse! Have you seen all the new stuff that's come out while you were resting?
 

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Discussion Starter · #3 ·
Welcome back to the madhouse! Have you seen all the new stuff that's come out while you were resting?
[/quote]

Thanks for the reply 34C. As you've probably guessed, The Cambrian is my favourite theme, though "somewhere in the Shrewsbury area" is more likely so I can run a Castle,King,Grange, Hall, Black5 and 8F - in fact almost anything WR/LMR goes!

I'm pleased you think it's worthwhile persevering with the Bachmann chassis. I've already given up on an old Mainline "Manor". The expensive solution has been to put the body on a Hornby "Grange" chassis. It's been great for rediscovering "butchery"skills, and it's as smooth as a smooth thing. I used the GW "Llanfair Grange" version, so I got a 3500 gal. tender with pickups, and of course, it's DCC ready! It's an early candidate for the SWD sound decoder, detailing and painting BR lined green.

Yes, I've seen all the new stuff - it's all amazing isn't it? Makes me feel like chucking all my old Will's kit/Triang abortions away, but I'm just too sentimental(no, I'm not going to attempt DCC with them)!
 

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Hi - I have found that one of the worst causes of waddle in early Bachmann locos (the ex Mainline stuff) is the slightly flexible black plastic wheel spoke 'insert' most of them used. It seems to soften and expand slightly with age (a bit like me!). As the metal wheel rim does't allow it to expand its diameter, it bulges out unevenly on one side fouling the connecting rods and forcing the loco to jerk sideways. Turn the loco over and have a look, if you can see any plastic spoke detail, that is probably the problem. Best way of dealing with it is to remove the insert, shave round its circumference & replace. (or remove completely and paint the metal wheel spokes black/gunmetal). Worth a try?

Regards

David
 

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I also have many Bachmann Pannier and Prairie tank locomotives and found that each drive wheel has a plastic electrical insulator inserted into the center of wheel hub, the axle is then pressed into the drive wheel. If this is not done perfectly, the axle will be slightly off center causing the wobbling effect you have experienced with your locomotives. I have contacted Bachmann about this problem and they have sent me complete drive wheel replacement sets that have reduced the effects. Since your locomotives are older models I don't know if they still stock spare wheel sets for them.
 

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Discussion Starter · #6 ·
[quote name='Dinwiddy' date='7 Sep 2007, 21:55' post='35453']
Hi - I have found that one of the worst causes of waddle in early Bachmann locos (the ex Mainline stuff) is the slightly flexible black plastic wheel spoke 'insert' most of them used. It seems to soften and expand slightly with age (a bit like me!).

David,
Award yourself a gold star!
I've just had a look under a magnifying glass and this problem is present on 2 of the locos (although not the others).
You can see the insert flex inwards with slight pressure from a small screwdriver and it definitely fouls the crank pin.
I wonder if the extreme temperature changes in the loft have caused it?
Did you remove the con rods and take the insert out to reduce the circumference, or just pull it out of the wheel recess and rotate it on the crank pin? I'm not sure whether these crank pins are a screw fit or a push fit. I'm assuming a spot of cyano will help keep it flush.
Regards
Dave
 

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The crankpins are push fit on all the split chassis units I have had apart, including the Mainline and Replica models. However being an ER type I have no overlap with the models you own, so cannot speak specifically about these. The wheel insert deformation is interesting, read about it previously, but have never seen it. Something else to look out for is the remnant of the casting feed on the loco tyre: one V2 had a distinct 'kick' from this cause, quickly rectified with a few wipes of a flat fine cut swiss file.

Although greatly appreciating these models (for ER folk Bachmann were a life saver in offering RTR models of much needed types) I am hoping Bach make rapid progress in fulfilling their announced plan to replace all the split chassis mech models with 'current standard' versions.
 
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