Bachmann split chassis locos

[Lissadell]

I think the problems with this design of chassis are well known, but I wonder if there is any variation with time?

For example: some of the B1 locos go back to the late 1990s and seem to be regularly advertised with the expected problems - wobbly wheels, distorted spokes causing a knock or binding.

 

However, the last ones produced (31-713) - just before the introduction of the later style chassis - appeared in 2009/10.

 

Does anyone have examples of these last produced models ie Gazelle (but not the 2003 version of the same name) that is or indeed isn’t as yet displaying the usual problems.

 

Broadening the question across the range of Bachmann split chassis based models, are late produced models displaying the faults that can be present on older versions of the same model?

 

Would welcome hearing of colleagues experiences.

 

Thanks

[Bill Radford]

Both my B1s - Springbok & Gazelle - have retired to the spares box in the sky. Both early examples. Both bodies are running again with the new tin can chassis acquired cheeply.

 

The only other split chassis loco I have is an Ivatt 2-6-2T which despite making occassional grinding noises still runs well as the Tutbury Jinny.

[cypherman]

Hi all,

I did have a plan to repair my Bachmann std 4 engines. All 4 have the wobbly wheel syndrome. There is some one who says they can flatten the wheels so they run true again. They use a heated jig I believe. I think he goes by the name of 'The railway doctor'. My only worry is that they will warp again later. My next idea was to replace the wheels altogether by putting bearings into the slots and making my own power contacts.I was unable to find a suitable bearing that would allow them to be isolated from the frames. Any ideas on that would be gratefully received.

[34theletterbetweenB&D]

The split chassis mechanisms were made of the same materials from  start to finish, as far as one can easily tell. I would expect the two main life limiting problems to be unchanged: fracture of the plastics used for the axle muffs and gears, wear out of the very thin plating essential for good conduction in the conduction path.

 

 ...All 4 have the wobbly wheel syndrome. There is some one who says they can flatten the wheels so they run true again. They use a heated jig I believe...

 Simple enough to either remove the plastic insert entirely and paint wheel centre black, or remove insert, trim round edges and superglue into place flat.

 

My next idea was to replace the wheels altogether by putting bearings into the slots and making my own power contacts.I was unable to find a suitable bearing that would allow them to be isolated from the frames. Any ideas on that would be gratefully received.

 Don't bother would be my summary, based on experiments here and elsewhere that I have seen so far. This because it is elaborate construction work to add both securely and accurately located bearings fully isolated from the chassis halves (or to make split axles if the bearings are not isolated) and also to find and secure a suitable gear onto the driven axle. It is no more work to make a kit chassis to take the new wheels. If wished you can salvage and reuse any or all of: motor; side rods, gear and cylinders; carrying wheels and bogie/truck frames.

 

Then  again, you mght be the one who 'cracks it', against the odds which seem stacked against. Let us all know if you do,

[The Johnster]

I have to say that, in my experience, which has been with 57xx and 56xx mainline type chassis, upgrading to current spec is the best option; the modern chassis are bombproof reliable, very smooth and slow running, not to mention near silent.  Not what you want to hear, as this is the most expensive option.

 

My view has always been that the Mainline type split chassis was a very good idea; a chassis with no friction from wiper pickups and a coreless motor (the Chris Petherton concept) should in theory be a perfect runner so long as the wheels are true and square to the track and the back to backs are good.  But as executed by Mainline, the concept is fatally flawed, because of the use of a pancake motor that had to be geared down to develop any useable power (these mechs are known bad haulers) through a series of spur gears which induced friction and noise, more than negating the advantage gained by losing the wipers, and because of poor choices of material for stub axles.  Rough driving could throw the quartering out, and mine all eventually died from either this (rough handling at shows by club drivers, not by me) or the axle wearing through the chassis block to the top.  

 

Given the quality of materials available to RTR manufacturers who have to meet a competitive market price, we are probably better off with our conventional pickups and can motors with worm and cog drive; they run as well as it is reasonable to expect from a mass produced item.  But, back in the 70s when Mainline were one of the flag bearers of improved realism and quality of running in RTR, conventional chassis from Triang Hornby were pretty rough and crude, and those from LIma, more like Mainlines with the pancake and spur gears, were just plain 'orrible; the very improvement in standards which Mainline and Airfix originated has been their downfall in terms of chassis design (I thought the Airfix 14xx sprung plunder 'ball point' pickups were a brilliant idea when I first saw them, but keeping them clean proved their nemesis).  

 

Standards have improved steadily and relentlessly over the intervening 40 odd years, and even Hornby have, eventually, caught up.  The Mainline split chassis could have been the way things went, and seemed a very good idea at the time.  The motors were, in the event, too small and needed to run too fast to be conventionally geared while retaining clear cabs for detail, and the materials used were not up to the job; a near miss, but a miss for all that.

[Lissadell]

Both my B1s - Springbok & Gazelle - have retired to the spares box in the sky. Both early examples. Both bodies are running again with the new tin can chassis acquired cheeply.

 

The only other split chassis loco I have is an Ivatt 2-6-2T which despite making occassional grinding noises still runs well as the Tutbury Jinny.

Could you explain please, what do you mean by a “tin can” chassis which you say was cheap to acquire?

 

Thank you

[PM47079]

Yes indeed. I have a 43xx mogul with the expansion of the wheel centres. I would be interested in getting a new chassis if possible

[Butler Henderson]

Bachmann have (or at least did have) stocks of the axle centres for you to do diy repair. Alternatively Peters Spares sell them (I suspect for more that Bachmann given their spare parts pricing being normally ££ more than elsewhere)

[The Johnster]

For the 43xx, I'd say there is sadly very little chance of a replacement chassis unless you are prepared to kit build.  The only alternative that occurs is to use an Airfix large prairie chassis from an eBay donor loco; not sure if the motor can be kept out of the cab, though.

[DCB]

For the 43xx, I'd say there is sadly very little chance of a replacement chassis unless you are prepared to kit build.  The only alternative that occurs is to use an Airfix large prairie chassis from an eBay donor loco; not sure if the motor can be kept out of the cab, though.

The early Airfix/ Hornby 61XX chassis is pretty awful. I haven't seen anything post about 2012, but I have worked on both huge motor Airfix and tiny motor Hornby and out of about half a dozen one runs Ok and another runs. Both are Hornby neither has traction tyres, one came without and is totally feeble, the other had tyres but I swapped a wheelset.  That leaves at least 4 needing attention/defying all efforts to make them run acceptably/ or at all, As for use in a 43XX they have large cast inserts in the tanks and there cannot be much strength left of you cut them off.

I would actually like to put a Bachmann 43XX chassis under a Hornby 61XX. My solution was a Triang Hornby Hall chassis with Romford wheels. If I did another I would use the Bachmann 43XX rods and re drill the rear axle hole but mine has run for over 20 years with minimal attention and I don't like to fiddle with it. I also have two Trang Hornby Hall chassis under 61XX and 81XX with Hornby Dublo and Romford wheels which have been my bankers for 30 plus years.

We had a Cambrian Coast set with Bachmann Manor and 43XX new. I think it was about the last Bachmann split chassis version and the 43XX threw a driving wheel after 30 minutes.

[DCB]

I think the problems with this design of chassis are well known, but I wonder if there is any variation with time?

For example: some of the B1 locos go back to the late 1990s and seem to be regularly advertised with the expected problems - wobbly wheels, distorted spokes causing a knock or binding.

 

However, the last ones produced (31-713) - just before the introduction of the later style chassis - appeared in 2009/10.

 

Does anyone have examples of these last produced models ie Gazelle (but not the 2003 version of the same name) that is or indeed isn’t as yet displaying the usual problems.

 

Broadening the question across the range of Bachmann split chassis based models, are late produced models displaying the faults that can be present on older versions of the same model?

 

Would welcome hearing of colleagues experiences.

 

Thanks

The early B1 had rear axle drive with traction tyres and was worse than the later ones.   The wheel centres warp if you use the right oil, but the wheels don't stay on for that to be a problem.

I fitted pickups to a late B1 last week. The running was vastly improved but the wheels fall off.  Hoping Peters spares have an answer with new axles.  

[bike2steam]

Thank heavens for the Comet (now Wizard) chassis kits, all bar one of my old split chassis locos have been converted over the years. All those converted are tender locos which had tender pick-ups added before conversion, and found it had vastly improved the running. The one exception being an Ivatt 2-6-2T, sold to me as a non-runner, suffering the usual problem of muck on the driving wheel axle journals, now runs quiet and smooth - a rarity for a split chassis. 

[34theletterbetweenB&D]

Some of Bachmann's split chassis mechs were notably better than others. Of those I owned and ran to wear out the B1 and V1/V3 were joint best, the A4, then the J39, and then bringing up the rear the V2: which was a noisy dog from new but would keep going until the plating terminally wore through. There was some scope for improvement by attending to alignment of the two chassis halves, and this was very marked on the A4 mechanism which could be tinkered with until it was as quiet and smooth as the B1s and V1/V3 usually were 'as supplied'. The J39 and the V2 were not really open for improvement in my experience. Following adjustment they degraded back to graunching noises very quickly.

 

I'd got all mine worn out and scrapped by 2007, except one particularly sweet running B1 with tender pick ups on the axle ends made from salvaged A4 split axle tender wheelsets which lasted until Bachmann and Hornby jointly hit us with superior options. Lots of the parts live on though: the split axle carrying and tender wheels have been redeployed. How much I wish the RTR manufacturers would continue with this no incremental friction pick up technique generally on unpowered wheels...

[melmerby]

The early Airfix/ Hornby 61XX chassis is pretty awful. I haven't seen anything post about 2012, but I have worked on both huge motor Airfix and tiny motor Hornby and out of about half a dozen one runs Ok and another runs. Both are Hornby neither has traction tyres, one came without and is totally feeble, the other had tyres but I swapped a wheelset.

I have 2 of these.

The first Hornby release (bought S/H) and the the latest DCC ready variant (new).

Agreed, no chance of use under a Mogul but both of mine run well and I'm curious to know why you consider the motor "tiny"

 

Keith

[Bill Radford]

Could you explain please, what do you mean by a “tin can” chassis which you say was cheap to acquire?

 

Thank you

Sorry, 1960s ex-slot car lingo! The current/new chassis has a motor in a metal "can" as opposed to an open frame X04 motor (old Triang motor that was in Scalextrix as well as many trains). They were complete locos which were found at toy fairs at low prices.

[Lissadell]

Thank you to all those colleagues who shared their experiences and made suggestions in answer to my original question.

 

Much appreciated.

[NFWEM57]

Have just come across this thread.  I am about to convert a number of Mainline/Bachmann split chassis locomotives acquired for little cost by using Alan Gibson wheels sets mounted on 5mm or 6mm brass bushes and then using plunger type pickups.  The original motion gear is retained and new crank pins to match will be manufactured.   Plenty of almost mint condition locomotives out there being sold very cheaply with wobbly wheels and for the cost of a set of wheels and a few other parts, a solution.  I am converting to EM but it will work for OO as well.   I will publish the conversion in a thread if there is still any interest?

[cypherman]

Hi all,

Well since I last posted in this topic I have sorted out my 4 Bachmann 4mt's. I have put wheel pick ups on all the driving wheels and keep the original bearing/pick ups on the engine well lubricated. Had one chassis that hard worn the bearing areas oval and was useless. Removed all the black plastic wheel inners. Cut out the dummy wheel weights and glued them back in place. Then painted the wheels black. I used a piece of this steel with a slot for the axel to slide behind the wheels and with gentle pressure straightened them. The lip from the edge of the wheels where the plastic inner sat is only noticeable if you actually look for it.  They now run as good as new. So good that my one Mainline 4mt got a replacement Bachmann chassis and received the same treatment.

[The Johnster]

Oval worn bearing areas destroyed two of my ML pannier mechs, having worn through to the top of chassis blocks, and I have a 56xx mech which I keep as a spare with a vague idea of putting a Bachmann body on it one day but which is close to breaking through to the block tops, so these comments are of interest to me.  I also have an early Bachmann split chassis 43xx mech, can motor with worm and idler gear drive, which runs superbly, very much better and quieter than the old ML mechs.  These sometimes come up fairly cheaply on the 'Bay, and I would not hesitate to buy another.

[melmerby]

23 minutes ago, The Johnster said:

Oval worn bearing areas destroyed two of my ML pannier mechs

Would've been nice to actually use my Mainline Pannier, 43XX & Manor

Unfortunately in the years between purchase brand new in the 1970's and attempted use some decades later, the pannier chassis had suffered from the dreaded mazak rot and had cracked in several places and had lots of distortion.

The driving wheels were locked solid in the frame and when I tried to dismantle, it fell into several pieces and some crumbly bits.

The 43XX suffered the same fate.

However the Manor chassis had survived but the wheels/axles are U/S due to the plastic bit splitting whilst in storage, so after converting it to DCC it is now useless after very little running. (Roll on Accurascale !)

 

[The Johnster]

My original ML 43xx and Manor were put permanently out of quarter by rough driving from a club member at a show, who can still be seen operating layouts at shows but is a reformed character nowadays. 

[trevora]

37 minutes ago, melmerby said:

Manor chassis had survived but the wheels/axles are U/S due to the plastic bit splitting

shapeways do replacements

[DCB]

15 hours ago, NFWEM57 said:

Have just come across this thread.  I am about to convert a number of Mainline/Bachmann split chassis locomotives acquired for little cost by using Alan Gibson wheels sets mounted on 5mm or 6mm brass bushes and then using plunger type pickups.  The original motion gear is retained and new crank pins to match will be manufactured.   Plenty of almost mint condition locomotives out there being sold very cheaply with wobbly wheels and for the cost of a set of wheels and a few other parts, a solution.  I am converting to EM but it will work for OO as well.   I will publish the conversion in a thread if there is still any interest?

I will be very interested,   Are you using the existing chassis halves spaced apart or new side frames?  If existing make sure all the axle holes are at right angles to the direction of travel, plenty are not.   If new a brass chassis an EM chassis can have most common 00 motors down between the frames and most 00 ones cannot, with thinner frames and the extra 1.5mm gauge you can get an extra 2mm, so I would design a very different frame for EM with the motor between the frames to an 00one with the motor above.   What the old split chassis does well is get round sharp curves as there is a lot of side play, so much that with a 19" 3rd radius minimum radius  I shim the trailing wheels to stop the locos crabbing.   The plungers sound good, the Airfix 14XX were hopeless as their internal coil springs couldn't take a dead short for long but the concept is good especially in EM with extra space between the frames.

[sjp23480]

What is the considered opinion on the LMS 4-6-0 Bachmann split chassis.

 

I have several of the later ones (2005-) in my stash and a little concerned that they will need replacing! :-(

 

Steve 

[melmerby]

3 hours ago, DCB said:

the Airfix 14XX were hopeless as their internal coil springs couldn't take a dead short for long but the concept is good

I've used the Gibson plungers and they work well. I've used them on a Comet 43XX chassis (replacing the Mainline one mentioned above.)

The springs dont pass any current so no problems there. The only problem I find is that the thin end doesn't take a bend easily without breaking off.