Curing Bachmann split chassis pick up woes

[DCB]

I have long believed the problem with Mainline and Bachmann split chassis locos is the lack of wiper pickups.   20 years ago I fitted a mainline 03 204hp diesel chassis to a Bachmann 03 which had motor failure and fitted wiper pickups to the trailing wheels. This still works and probably has never received any attention since.

We have a few Bachmann split chassis locos which worked for a bit and then started running like arthritic three legged crabs.

The impending release of the Hornby Lord Nelson prompted me to drag the Bachmann version out of the dead engine shelf. It jerked and jumped as expected.

We serviced it, lubed it with Peco Electrolube which we thought was conductive but does not seem to be which made it worse .

I decided to fit pickups to the side of the chassis and drilled holes between centre and rear driving wheels above the centre line of the axles. I snapped two 10 BA taps, that Mazak really is complete rubbish. Couldn't get the broken taps out so I drilled and tapped 6Ba between the wheels, fitted brass strip pickups and the wheels fouled the screw heads, I filed them away and it ran really smoothly, about 20 scale MPH flat out.  I ran it for ages and it speeded up to about a scale 60 and now runs quite well forwards but is still medium evil backwards.

Not to be defeated I looked at the B1.  Moulded detail on the Chassis prevented a repeat of the LN set up and the motion bracket was in the way for the front and centre pick up solution.  However lateral thinking suggested if the pickup was pushed over the motion bracket spigot and rested on the axles then no fixing would be needed. I pried off the cylinders and the glued on motion bracket.  I made the pickups, they were too short, they should have reached the leading edge of the front driving wheel tyres and rear of the centre driving wheel tyre but I assembled it, scraping the black off the chassis behind the brass pick up and spraying the pickup with rattle can matt black and glued the motion bracket back in place.

I reassembled it and tried it.  It went great straight away, forwards and backwards, starts stops  runs slowly pulls 8 coach trains, its actually usable again.

I think the LN problem is too much drag on the back axle and not enough weight at the back so it will be coming apart again for a B1 style conversion.

If anyone is interested see my photo.

[34theletterbetweenB&D]

Even with wiper pick ups added, once you wear through the tyre plating, the model is 'all used up'. I operate pretty intensively, and on the heavier locos thought I was doing well if I got six years working life out of them. The pattern of motor in your picture appears to be 'unburstable', never had one fail, and it is a good unit in my experience of it. I have redeployed a couple into old kit chassis, and will hopefully do more in time. The worms are on TIGHT!, and I broke my ancient worm puller the first one I tackled.

[Guest Mancunian]

I have long believed the problem with Mainline and Bachmann split chassis locos is the lack of wiper pickups.   20 years ago I fitted a mainline 03 204hp diesel chassis to a Bachmann 03 which had motor failure and fitted wiper pickups to the trailing wheels. This still works and probably has never received any attention since.

We have a few Bachmann split chassis locos which worked for a bit and then started running like arthritic three legged crabs.

The impending release of the Hornby Lord Nelson prompted me to drag the Bachmann version out of the dead engine shelf. It jerked and jumped as expected.

We serviced it, lubed it with Peco Electrolube which we thought was conductive but does not seem to be which made it worse .

I decided to fit pickups to the side of the chassis and drilled holes between centre and rear driving wheels above the centre line of the axles. I snapped two 10 BA taps, that Mazak really is complete rubbish. Couldn't get the broken taps out so I drilled and tapped 6Ba between the wheels, fitted brass strip pickups and the wheels fouled the screw heads, I filed them away and it ran really smoothly, about 20 scale MPH flat out.  I ran it for ages and it speeded up to about a scale 60 and now runs quite well forwards but is still medium evil backwards.

Not to be defeated I looked at the B1.  Moulded detail on the Chassis prevented a repeat of the LN set up and the motion bracket was in the way for the front and centre pick up solution.  However lateral thinking suggested if the pickup was pushed over the motion bracket spigot and rested on the axles then no fixing would be needed. I pried off the cylinders and the glued on motion bracket.  I made the pickups, they were too short, they should have reached the leading edge of the front driving wheel tyres and rear of the centre driving wheel tyre but I assembled it, scraping the black off the chassis behind the brass pick up and spraying the pickup with rattle can matt black and glued the motion bracket back in place.

I reassembled it and tried it.  It went great straight away, forwards and backwards, starts stops  runs slowly pulls 8 coach trains, its actually usable again.

I think the LN problem is too much drag on the back axle and not enough weight at the back so it will be coming apart again for a B1 style conversion.

If anyone is interested see my photo.

 

Interestingly I recently had a split-chassis B1 which had a wire connection to each half but it also had each half centre drive-wheel arches drilled to accommodate suitable springs so that the metal cap/bearing of the back of the wheel and the spring were constantly in contact.    If this was done to each chassis wheel-arch then, to me this would be easier than fitting extra pick-ups to the wheels.    Personally I would solder the spring to a small flat washer/metal piece for the wheels to be in contact with. The springs would only need to protrude slightly to give contact and continuity.    This would also give a full and independent wheel-springing.

 

The models that I had previously converted had each half wired to the pick-ups and the wheels were fitted with DCC Concepts pick-ups but, whilst they're easy to fit to the tender with a drop of superglue, they are difficult to fit to the loco' wheels as they must be kept away from the lowest point of the wheel-flange otherwise they will cause the loco' to stick when crossing points and also affect the B 2 B setting, obviously!    Four thin wires (2 x Motor and 2 x Pick-up) are then joined to an insulated 8-pin circuit-board within the tender.    Bachmann can supply (NEW) the same style/size of motor and large flywheel as fitted to the split-chassis models...all you will need to do is send Bachmann an original motor with its worm-gear fitted.    I only have one model with a weak motor.    In total I have 16 x B1's to date with the older bodies running on the new-type chassis.

 

All that said, I have only three original Bachmann B1 loco's which now need to receive the later style chassis (31-714/31-716/716A) chassis.    Certain Hornby draw-bars can be made to fit, albeit, possibly, with some slight modification.

[DCB]

The B1 derailed and lost a driving wheel so I had to push it back on but it happily chuntered smoothly round for an hour while I worked on the Lord Nelson.  

The Neson had my pickups which I screwed to the chassis side so the pressed against the backs of rear and centre driving wheels.  It was smooth but very slow and didn't like reversing.  So following the B1 I moved the pickups to centre and front. However there is no room for a screw head so I drilled and tapped the chassis 6BA and just hung them on a bolt and cut the head off. Its almost invisible up against the running plate. The springy copper strip just gently bears against chassis and wheels. That is it bears vertically on the driving wheel journals as well as laterally against the tyres.  It was lapping the layout at a good lick hauling 13 bogies after attention, that is a lot more than before I did it. and it runs smoothly. These are locos which were far too rough to use and the total expense was a bit of scrap springy copper coloured metal out of a dead computer.. 

I am going to experiment with sprung pickups vertically inside the chassis halves next, as suggested in a topic about Bachmann B1s posted yesterday.

[Il Grifone]

I have long believed the problem with Mainline and Bachmann split chassis locos is the lack of wiper pickups.   20 years ago I fitted a mainline 03 204hp diesel chassis to a Bachmann 03 which had motor failure and fitted wiper pickups to the trailing wheels. This still works and probably has never received any attention since.

We have a few Bachmann split chassis locos which worked for a bit and then started running like arthritic three legged crabs.

The impending release of the Hornby Lord Nelson prompted me to drag the Bachmann version out of the dead engine shelf. It jerked and jumped as expected.

We serviced it, lubed it with Peco Electrolube which we thought was conductive but does not seem to be which made it worse .

I decided to fit pickups to the side of the chassis and drilled holes between centre and rear driving wheels above the centre line of the axles. I snapped two 10 BA taps, that Mazak really is complete rubbish. Couldn't get the broken taps out so I drilled and tapped 6Ba between the wheels, fitted brass strip pickups and the wheels fouled the screw heads, I filed them away and it ran really smoothly, about 20 scale MPH flat out.  I ran it for ages and it speeded up to about a scale 60 and now runs quite well forwards but is still medium evil backwards.

Not to be defeated I looked at the B1.  Moulded detail on the Chassis prevented a repeat of the LN set up and the motion bracket was in the way for the front and centre pick up solution.  However lateral thinking suggested if the pickup was pushed over the motion bracket spigot and rested on the axles then no fixing would be needed. I pried off the cylinders and the glued on motion bracket.  I made the pickups, they were too short, they should have reached the leading edge of the front driving wheel tyres and rear of the centre driving wheel tyre but I assembled it, scraping the black off the chassis behind the brass pick up and spraying the pickup with rattle can matt black and glued the motion bracket back in place.

I reassembled it and tried it.  It went great straight away, forwards and backwards, starts stops  runs slowly pulls 8 coach trains, its actually usable again.

I think the LN problem is too much drag on the back axle and not enough weight at the back so it will be coming apart again for a B1 style conversion.

If anyone is interested see my photo.

 

The fracture of the taps shows the alloy is anything but "rubbish". It is very hard and needs careful cutting. Unfortunately that is the trouble. While the ideal solution for bearing surfaces is materials of different hardness, it's better that the axle is hard and the bearing soft as the latter is easier to replace. Once the bearing surface is worn, electrical contact is lost and new wiper contacts are the only solution, seeing that replacement wheelsets are almost certainly unobtainable.. Pickups on the tender (where possible) are another solution to consider, as sooner or later the wheel treads will wear too.

 

The earlier Mainline chassis using the same split axle system are prone to the dreaded zinc pest. Now that is rubbish alloy for which there is no excuse. The problem was recognised before WWII and solved during the war

Edited January 14, 2019 by Il Grifone

[SweenyTod1]

I found a solution to an old J72 tank with poor running issues. Once stripped down with the wheels out, I found that the axle surface faces had a wax type of residue on them and can only assume that it was applied a preservative, but not being conductive, far from helpful! I cleaned it off abrasively and sqirted switch cleaner on the contact surfaces. Magic! It runs as it should, a bit noisy from the motor, but acceptable. If you have an old split chassis loco that doesn't run well, its worth a look at the axle recesses and the stub axles.

Hope that is helpful.

 

Tod

[kevinlms]

14 hours ago, SweenyTod1 said:

I found a solution to an old J72 tank with poor running issues. Once stripped down with the wheels out, I found that the axle surface faces had a wax type of residue on them and can only assume that it was applied a preservative, but not being conductive, far from helpful! I cleaned it off abrasively and sqirted switch cleaner on the contact surfaces. Magic! It runs as it should, a bit noisy from the motor, but acceptable. If you have an old split chassis loco that doesn't run well, its worth a look at the axle recesses and the stub axles.

Hope that is helpful.

 

Tod

I think the residue you found was the original lubricant that has died over the years. Not surprising as it must be nearly 40 years old!

[34theletterbetweenB&D]

20 hours ago, SweenyTod1 said:

... squirted switch cleaner on the contact surfaces...

Short term gain, potentially will cause failure in the medium term. The nylon used to make the plastic insulating muffs and gears, (and also whatever compound is used for the cosmetic wheelface inserts on many of the breed) has proven very apt to degrade from contact with lubricants and solvents. Hopefully you will get away with it.

 

The manufacturer's recommendation - last time I looked! - was Propan-2-ol (Isopropanol, Isopropyl alcohol, IPA) for cleaning, and then very light application of Woodland scenics white grease. You clean out when the running degrades, the once white grease will clearly indicate the why, as it will be near black from the insulating oxidised fines worn off the conductive platings on the  bearing surfaces.

[SweenyTod1]

I used Servisol Super 10 switch cleaning lubricant, "containing greater than 30% Aliphatic hydrocarbons" (what ever they are?) and have had no issues so far. I did this umpteen years ago and its used as a shunter, so it doesn't rack up a high mileage. I bought the loco second hand back in the 70s, so it owes me nothing, but continues to serve. Long may it continue and very likely to outlive me!

 

Tod

 

 

PS Bachmann still can supply new axle bearings/gear. Having recently needed to renew them on another loco,they appear to be a different material.

Edited April 1, 2019 by SweenyTod1
missed a bit by pressing the return button.

[RobjUK]

17 hours ago, 34theletterbetweenB&D said:

The nylon used to make the plastic insulating muffs and gears, (and also whatever compound is used for the cosmetic wheelface inserts on many of the breed) has proven very apt to degrade from contact with lubricants and solvents.

 

That is a myth.

Nylon and all normal engineering plastics are _not_ damaged by conventional mineral oils or silicone type lubricants.

 

The commonest cause of failure of nylon gears is dehydration. 

Nylon 6 contains about 2.5 - 3.5% water under ideal conditions. If it dries out over time due a hot and low humidity environment, it both becomes brittle and shrinks, which can cause cracking.

 

Lubricant compatibility info; see page 5 for the table:

https://www.ecllube.com/resources-for-engineers/tutorials/ECL_Tips on Lubricating Plastics.pdf

 

A couple of examples relating brittleness to moisture content:

http://www.atlanticfasteners.com/simple-remedy-for-dry-brittle-nylon-parts/

https://onlinelibrary.wiley.com/doi/abs/10.1002/adv.1989.060090206

 

[34theletterbetweenB&D]

57 minutes ago, RobjUK said:

 

That is a myth.

Nylon and all normal engineering plastics are _not_ damaged by conventional mineral oils or silicone type lubricants.

 

The commonest cause of failure of nylon gears is dehydration. 

Nylon 6 contains about 2.5 - 3.5% water under ideal conditions. If it dries out over time due a hot and low humidity environment, it both becomes brittle and shrinks, which can cause cracking...

 

What is not a myth is that these parts regularly become brittle and fail. We don't know for sure what the polymer compound used is, nor do we know for sure all the contents of lubricating and cleaning products, many of which are not encompassed within 'mineral oils and silicones'.

 

I imagine that Bachmann's recommendations of Propan-2-ol for cleaning and a proprietary grease which has some emulsified water content is germane to prevention of dehydration.

 

 

[JST]

Interesting! I converted my old (about 25 years +) Bachmann Lord Nelson to DCC and it runs really well. I did notice that the front bogie picks up power which I guess did not happen on the even older examples. It will run over electrofrog points with no problem when the frog is not powered.

[RonnieS]

On 11/01/2019 at 03:09, DavidCBroad said:

I have long believed the problem with Mainline and Bachmann split chassis locos is the lack of wiper pickups.   

 

I decided to fit pickups to the side of the chassis and drilled holes between centre and rear driving wheels above the centre line of the axles. I snapped two 10 BA taps,

On my 2 surviving split chassis locos I think the tender pick up addition might be worthwile. However to add the wiring to the loco. I need to drill and tap the loco chassis (or self tappers?) Any ideas  or tips on drilling and tapping mazac anyone?

[34theletterbetweenB&D]

Don't bother? The plastic inserts or plugs that hold the chassis halves together make ideal mounting points to attach wiring tags for this purpose, if the loco doesn't already have dedicated screws provided to attach wiring from carrying wheels. (Of those I have seen, many of the locos with carrying wheels have such connections provided, sometimes not even used! Also, on some of the LMS 4-6-0s, there's provision for a smoke unit, and the smoke unit's plastic pot was arranged to clamp wires into the recess between the chassis halves, make a substitute plug and you can do the same.

 

One thing to take care over, cut an access channel for the wire/tag into the location holes to clear the plastic inserts completely so that there is no constriction from one side as the plugs go into the holes, as that leads to the plugs slowly splitting.

[RonnieS]

Thanks. You have helped again*****

[TerryD1471]

I have a number of these chassis, mostly Jubilee/Scot ones, some of which still run sweetly, but others of which were terrible. The first bad 'un I decided to drill and tap two holes (one each side!) at the back of the chassis and insert a short length of threaded brass rod. Wires were soldered to these and run through to tender wiper pickups. This has turned it into a sweet runner.

 

Capitalising on this, I took another couple of bad 'uns and cut away the middle section of the rear end of the plastic chassis keeper plate (to gain access to the two halves of the mazak chassis) and drill, tap and insert threaded rod similarly. Two pieces of copper clad were superglued to the underside of the keeper plate and wiper pickups soldered on and connected to the threaded rod. These too now run very well.

 

Summing up, it doesn't seem to matter whether you use tender or loco pickups, as each work equally well. I will endeavour to attach photos at some point.

[RonnieS]

Cheers TD. My experiment will be the 43xxs (I have 3 plus a spare chassis) I am either going to drill and tap or try self tappers. I have still (3 years on) not got around to building that Comet chassis!

Edited April 26, 2019 by RonnieS
bad english

[DCB]

My Split Chassis Bachmann Manor decided to play up this evening.  One of the wheels on the trailing axle which has washers to reduce the side play but no pickups decided to fall off.  Well became first wide to gauge and then disengaged the square peg on the stub axle from the plastic axle centre or Muff  and lost the quartering.

I decided to superglue the wheels back on but quickly realised pushing one wheel and stub axle into the axle muff was pushing the other wheel out, Hydraulic ing.  So I drilled a tiny hole into the middle of  the plastic axle muff and squeezed both wheels inward, Superglue emerged from the hole.  Ten minutes later the glue had set and I carved off the surplus and it looks like a proper job.  Time will tell but its looking very positive with the whole axle now full of superglue, all the surplus oozing out of the hole in the middle and no surplus oozing out onto the stub axles ...

 

Edited November 13, 2022 by DCB

[NFWEM57]

I have selection of split chassis locomotives I am about to start converting to EM gauge, including several 4MTs, a 43xx,  several 69xx and several A4s.  All will be getting Alan Gibson wheels with either spring pickups or 0.25mm Beryllium Copper wiper pickups.  I will be uploading under Modifying & Detailing RTR stock.

 

On Mazak, have milled, drilled and tapped with no issues.  For tapping use a spiral point tap for through holes or a spiral flute tap for blind holes.  However, such taps are not cheap.  I use a spring loaded tap follower when I need to tap a hole and mount the tap and tap follower in a pillar drill or lathe tail stock.

 

Patrick

[Free At Last]

6 hours ago, NFWEM57 said:

 I use a spring loaded tap follower when I need to tap a hole and mount the tap and tap follower in a pillar drill or lathe tail stock.

Well, I never knew about that. Just searched it on YouTube. I've learnt something this morning.

Edited April 14, 2023 by Free At Last

[NFWEM57]

Glad it was useful information.  And the beauty is you don't have to keep reversing the tap, straight cut and the tap follower keeps a constant pressure on the tap and keeps it in line.   Image is of a M1.4 tap being made in a set of new crank pins I made for a Bachmann MT5 so I could use the original motion gear with Alan Gibson wheels.  I used an M1.2 tap drill, not an M1.1 as recommended.  Tap handles too big so use a piece of chocolate block to rotate the tap.

 

Edited April 14, 2023 by NFWEM57
typos

[drgj]

Talking of soft and hard bearings wearing.  What happens is the harder surface wears more than the softer one funnily enough. This is because particles embed in the soft one and these then wear the hard surface. This happens in engines, anyway.

 

Dave

[rogerzilla]

On 24/04/2023 at 08:38, drgj said:

Talking of soft and hard bearings wearing.  What happens is the harder surface wears more than the softer one funnily enough. This is because particles embed in the soft one and these then wear the hard surface. This happens in engines, anyway.

 

Dave

Also happens on bicycles, where rubber brake pads embed grit and chew up the aluminium alloy rims.  Alloy chips from the rim also get embedded in the pads, so the problem accelerates.  Hard pads wear the rims less because they don't embed grit.

 

In a cleaner environment like a car engine, it is the soft bearing shells that wear first, since the main cause is metal-on-metal contact at startup.

 

A steam loco is somewhere between the two cases!