RMweb Premium Colin Posted April 30, 2012 RMweb Premium Share Posted April 30, 2012 I have several examples of Hornby's rebuilt Bulleid light pacifics in my fleet - 3 have now failed with the same problem - very rough/jerky performance caused by an apparent tight spot. ("Classic" symptoms, the loco almost stops each revolution of the driving wheels, when the rods are positioned in one particular place) Of the 3 locos affected, one is now so bad that it has completely locked up and may well have damaged the motor, the other 2 still run but very poorly. I've carried out the usual checks - the pickups work OK, quartering appears satisfactory and detaching the motor in all 3 cases resulted in a very free running chassis. Inspection of the gear wheel on the driven axle revealed no evidence of damage or uneven wear. The motors all sit correctly as far as I can see - does anyone have experience of this problem, or do I just start checking out the price of replacement chassis (assuming they can be sourced)? Any advice greatly appreciated! 1 Link to post Share on other sites More sharing options...
steviesparx Posted April 30, 2012 Share Posted April 30, 2012 Not specifically with regard to BoB / WC locos, but I have bought a few Hornby 'Non Runners' over the last couple of years, sold cheap as returns... Various faults found, from 'dry' solder joints to 'jerkers' as you describe - I do wonder if they even get any track test before boxing and shipping... One Merchant Navy I bought ( same chassis as the BoB / WC I think ) had a quartering problem - looked OK, but found that by dropping off all the valve gear... Exhibiting similar problems was a Black 5, but even with gear removed still jammed - stripping it down found a crack in the gear wheel between motor and driven axle... Another 9F was completely seized, motor was OK but wheels didn't turn - corrosion in two of the axles... Sounds like you've already done some investigation, although the fact it's the same position it sticks in each time suggests gear or the quartering - doesn't explain the fact it runs OK with the motor removed - loose wheel perhaps, only a problem when being driven ?... I'd take off the valve gear both sides and see how it runs with just the motor, gear train and centre driven wheel, might help isolate the problem... 1 Link to post Share on other sites More sharing options...
RMweb Premium Colin Posted May 1, 2012 Author RMweb Premium Share Posted May 1, 2012 Thanks for that - hadn't thought to remove all the valve gear. If it still doesn't work I'll have to make up a train of Bulleids on their way to Woodhams! 1 Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted May 1, 2012 Share Posted May 1, 2012 Different model, I had the same fault description on the Q1. Free running chassis as a push along, no apparent quartering problem or gear train difficulties but a hesitation always at the same point in the wheelsets rotation when powered. So it had to be something on the drivers; similar to what Steviesparx experienced this turned out to be the axle gear having a crack in it. The crack only opened out under load, so it worked fine without the motor engaged as a push along chassis... 1 Link to post Share on other sites More sharing options...
RMweb Premium Colin Posted May 1, 2012 Author RMweb Premium Share Posted May 1, 2012 Thanks again - on this basis I've ordered some replacement wheel/axle sets. My modelling table will look like Eastleigh for a while after they arrive! 1 Link to post Share on other sites More sharing options...
RMweb Premium Colin Posted June 30, 2012 Author RMweb Premium Share Posted June 30, 2012 Just thought I'd add a postscript, albeit rather late - I finally got round to dismantling the "casualties", to find that all three suffered from exactly the same fault - the intermediate gear (a double gear wheel set up on a stub axle which sits between the worm and the driving axle) had cracked badly and was the cause of the problem. Spare gears were purchased from local Hornby agents John Dutfield (under £2 each from memory) and now all three locos run smoothly again - thankfully there wasn't any need to remove the wheels and/or valve gear! I can't help but wonder if there was a duff batch of gears - all the locos were among the earliest of the rebuilt light pacific releases; all my other locos are OK, but I'm thinking of getting a stock of gears in "just in case"! 1 Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted June 30, 2012 RMweb Gold Share Posted June 30, 2012 Interesting. So far none of mine have had the problem and they are fom the earliest batches onwards. However they don't tend to come out of the box very often do I might yet find one with a fault. I have had other King Authur with split gears that has been used even less than the rebuilds. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted July 1, 2012 Share Posted July 1, 2012 ...I can't help but wonder if there was a duff batch of gears - all the locos were among the earliest of the rebuilt light pacific releases; all my other locos are OK, but I'm thinking of getting a stock of gears in "just in case"! My own thoughts on this are that Hornby do appear to have occasional tolerance problems on turned parts. A plastic gear on a very slightly oversize shaft... Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted July 1, 2012 RMweb Gold Share Posted July 1, 2012 Interesting. So far none of mine have had the problem and they are fom the earliest batches onwards. However they don't tend to come out of the box very often do I might yet find one with a fault. I have had other King Authur with split gears that has been used even less than the rebuilds. I've got three but since only one of mine has a decoder in it, the other two are in their boxes. I ought to check them... Link to post Share on other sites More sharing options...
Il Grifone Posted July 1, 2012 Share Posted July 1, 2012 (edited) It's down to unsuitable materials. My (long) experience of plastic gears is that they tend to crack sooner or later.(It was a common problem with VCRs!) The shelf life of nylon appears to be about 10 years. Edited August 8, 2012 by Il Grifone Link to post Share on other sites More sharing options...
RMweb Premium Brit70053 Posted July 1, 2012 RMweb Premium Share Posted July 1, 2012 Its not a problem that's exclusive to any particular model, I've had split interim gears on a Britannia and a Stanier 2-6-4 Tank. It appears to be a case of the gear being force fitted onto the splined 'Gear axle' when the moulded hole in the gear is a little too small in diameter, resulting in a split over the radius of the gear. I carefully opened out the hole very slightly to create a less forced, but still secure, fitting over the splines when I replaced the damaged gears. Both locos now run superbly, but my fingers are tightly crossed that I won't come across this fault again. Regards, John 1 Link to post Share on other sites More sharing options...
RMweb Premium Colin Posted July 2, 2012 Author RMweb Premium Share Posted July 2, 2012 OK folks, one last question - does anyone know of an all-metal replacement as a more long-term solution to the problem - from one of our more enterprising small manufacturers perhaps? Link to post Share on other sites More sharing options...
roythebus Posted July 4, 2012 Share Posted July 4, 2012 I was just about to post the same problem...with mine, the problem isn't the gears, but the connecting rod getting bent on the leading axle crank pin. Have a close look and you may find yours is bent. There is insufficient clearance on these parts. The easy cure is to bend the coupling rod outwards. this jamming initially may cause the gears to crack under the strain. I haven't had a problem with my Q1 yet. The other thing I done with the Bullieds was to insert fibre washers behind the leading driving wheels to alleviate some of the side play. This is the other cause of the coupling rods jamming. No need to take the wheels out, get some Romford 1/8" fibre washers and cut a bit out, keyhole shape, and force them between the wheels and the chassis. this is more important for me because I use 14.8mm back to back for DOOGAF standards. Link to post Share on other sites More sharing options...
geoffers Posted July 4, 2012 Share Posted July 4, 2012 My 34003 "Plymouth" (the earliest release) showed the same problems of jeky movement etc. Rather thn mess around with it (no coupling rod jamming, no quartering issues...) I sent it back to Hornby. Turned out to be a spit axle gear. Hornby repaired it and sent it back within the week - FOC!!! So I only paid the original postage. I had expected a repair charge. So thanks Hornby. 34003 now runs sweet as a nut. Link to post Share on other sites More sharing options...
RMweb Premium Brit70053 Posted July 5, 2012 RMweb Premium Share Posted July 5, 2012 Hi roythebus, I tried to reply quoting the first line of your post #13 but its not registered, however just to caution against routine adjustment of parts which may appear to be incorrect at first sight :- There is a subtle curve designed into the Connecting Rod on Bulleid pacifics Chassis, to clear other parts of the motion, crankpins etc. This should not be straightened or otherwise adjusted unless running problems are being experienced. Regards, John Link to post Share on other sites More sharing options...
roythebus Posted July 5, 2012 Share Posted July 5, 2012 Thanks John, I did notice that, but on mine there was a lot of side slop on the leading axle which caused the problem. I've had the same problem on a BR standard class 5 (Bachy). Link to post Share on other sites More sharing options...
Tim Hale Posted July 9, 2012 Share Posted July 9, 2012 Has anyone mentioned the problem caused by an intermittent comnnection between the pick-ups and the contact to the motor? This can provide all the symptons of dirty wheels etc. but the real problem is hidden under the wheel keeper plate - the pickups are not directly soldered to the motor but transfer the circuit via a tenuous contact between a vertical conductor (it looks like the tip of ball-point) and the pickup etch. The connection is supposedly maintained by pressure applied by the keeper plate. Invert the loco in a servicing cradle, remove the keeper plate screws and carefully examine the contacts - if necessary clean with a light abrasive. I found cause and cure for this problem when changing the rear wheel set on my WC. Tim Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted July 9, 2012 RMweb Gold Share Posted July 9, 2012 (edited) Yes had this problem with earlier ones such as Wilion. Later ones have the pick up plate with slight bends innit to help maintain contact. They also tend to get oily. Also the actual contact wipers to the wheels collect dirt very easily. Ian Edited August 6, 2012 by roundhouse Link to post Share on other sites More sharing options...
RMweb Gold toboldlygo Posted August 6, 2012 RMweb Gold Share Posted August 6, 2012 Yes had this problem with earlier ones such as Wilton. Later ones have the pick up plate with slight bends innit to help maintain contact. They also tend to get oily. Also the actual contact wipers to the wheels collect dirt very easily. Ian If they've been sitting in the box for a while in warm environment (such as a loft) the factory lubrication does tend to seep all over the keep plate and on to the contacts. I've had enough of them apart over the years (over 100) to rectify most of the problems mentioned. Though I've been fortunate not to encounter the cracked drive gear on a Bullied, though I have on a couple of T9's. The early one's also have tendency to throw coupling rods if they've been miss-handled... Link to post Share on other sites More sharing options...
Tim Hale Posted August 8, 2012 Share Posted August 8, 2012 Wilton has developed a rather odd habit of the speedo cable fouling - the eccentric fouls the speedo cable and locks the drive. Is the best option to bend the eccentric* because the corresponding anchor point on the body does not respond well to bending. Tim *Are the bits on the crankpin in the following order: 1. Wheel 2. Spacer 3. Eccentric 4. Locking bolt Link to post Share on other sites More sharing options...
RMweb Premium Brit70053 Posted August 8, 2012 RMweb Premium Share Posted August 8, 2012 Wilton has developed a rather odd habit of the speedo cable fouling - the eccentric fouls the speedo cable and locks the drive. Is the best option to bend the eccentric* because the corresponding anchor point on the body does not respond well to bending. Tim *Are the bits on the crankpin in the following order: 1. Wheel 2. Spacer 3. Eccentric 4. Locking bolt Hi Tim, I've just checked my 'WILTON' and confirm you have the correct order for the speedo parts. I'd also agree it would be best to try to adjust the Eccentric to resolve your issue with the cable fouling. Fine nosed pliers would seem to be the best option for such a job. Good luck with it. Regards, John 1 Link to post Share on other sites More sharing options...
Tim Hale Posted August 8, 2012 Share Posted August 8, 2012 Hi Tim, I've just checked my 'WILTON' and confirm you have the correct order for the speedo parts. I'd also agree it would be best to try to adjust the Eccentric to resolve your issue with the cable fouling. Fine nosed pliers would seem to be the best option for such a job. Good luck with it. Regards, John Many thanks, Tim 1 Link to post Share on other sites More sharing options...
Tim Hale Posted August 9, 2012 Share Posted August 9, 2012 a. b. c. d. Not everything goes to plan. The speedo drive on Wilton just broke and this is the new speedo drive, unfortunately despite copying the original fixing, the eccentric crank fouls the speedo cable. This can be seen in Views a & b. but I just do not know what I did wrong. Tim 1 Link to post Share on other sites More sharing options...
RMweb Gold tarifa Posted August 9, 2012 RMweb Gold Share Posted August 9, 2012 Tim, Is the cramk the wrong way round?. I had a similar problem with the Scot. HTH Mike Link to post Share on other sites More sharing options...
Tim Hale Posted August 9, 2012 Share Posted August 9, 2012 Mike, It appears to be impossible to turn the eccentric over, the plastic pipe is too rigid. What concerns me is the extreme angle of offset in views b & c. Should the piece stuck to the loco body be angled so close to the wheel? Does anyone have a similar loco and can check this? Thanks Tim Link to post Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now