Bachmann 93xx Pony Truck

[sjrixon]

Help.. I have a Bachmann 93xx and whatever I've tried it likes to derail the front pony truck. You can see from this picture I've tried adding a fairly significant amount of lead, but I still have issues..

 

 

Anyone found something that works better?

[brossard]

My first comment is to ensure the back to back of the wheels is correct.  I use 14.5mm in 00.

 

Secondly, on some models the frames are quite narrow leaving a lot of slop.  By adding washer(s) you can tighten things up.  I improved the running of my 45XX this way.

 

Thirdly, having the coupling on the pony truck is asking for trouble IMO, this is difficult to remedy I will concede.

 

Let us know what you find.

 

John

Edited October 3, 2016 by brossard

[petrox]

Help.. I have a Bachmann 93xx and whatever I've tried it likes to derail the front pony truck. You can see from this picture I've tried adding a fairly significant amount of lead, but I still have issues..

 

 

Anyone found something that works better?

I had the same issue with both of my 93xx/43xx models - as well as adding lead as you have, I have fitted a U-shaped length of wire from the pony mounting point to reduce the amount of sideways play of the pony truck - afraid I can't illustrate with a photo but if you experiment a bit I'm sure you will find a similar solution - anyway it works on my models, no derailing now.

Hope this helps.

[sjrixon]

I like that idea. I could wrap something around the screw to create a spring type thing. I'll have play! Thanks.

 

I've checked the back to back and it's fine. Which is good as the front wheel is a solid axle.

[DCB]

On two loco drive Hornby 28XX a friend tested on our layout (Peco code 100) we found the guard irons in front of the wheel treads were fouling the track and causing it to derail, trimming 1mm or so cured this. Your guard irons also look low.

 

Our Bachmann 93XX has a lot of weight on the pony truck and a H/D coupling and works fine. To reduce the side play with solid axles you will need U shaped spacers to fit over the axles which will be an almighty fiddle.   Our Mainline 43XX broke their pony truck axles and now have Wrenn leading wheels with huge flanges.  They also have Hornby County powered Tenders as the Mainline motors expired.

 

My own ancient Mainline 43XX has a Romford wheeled Triang Hornby Hall Chassis. The Pony Truck is a brass Tube with the axle through soldered to a brass strip.  The coupling pivots on the pony truck pivot but floats guided by pins so the coupling can rise without lifting the wheels. Plenty of play allows the wheels to twist to accommodate dips in the track and two vertical pins soldered to the axle tube stop the coupling moving sideways out of line with the pony truck. With little to do the wheels seem to stay on the track

 

I adopted this method to allow banking with H/D couplings but all my GW 2-6-0 and 2 cyl 4-6-0s have this system now. It works well with Tension Lock couplings though it really needs a metal coupling soldered in place as there is little room for screws.

[sjrixon]

This was the first prototype.

 

 

Failed I removed the brake fittings and added a small amount of copper clad and then a V-shaped section of 0.45mm brass wire. I think it's almost too good and on sharp curves into the layout fiddle yard it pushed off the front wheels. I'm thinking that if I make it two straight sections touching the wheels it should reduce the spring and allow a little more movement. It's a club layout I'm testing with so won't know until next week.

Edited October 5, 2016 by sjrixon

[Richard Mawer]

I have had major issues with the pony truck of two 43xx's. They are Mainline bodies (not that this makes any difference) on Bachmann split chassis. I replaced the chassis because of axle failure on the Mainline's.

 

The pony trucks have always had a mind of their own. However, having tried a number of things, mainly being added weight, I think I have sorted it. I have reduced the side- play on the driving axles. Please see entry #275 of my layout thread :- http://www.rmweb.co.uk/community/index.php?/topic/102581-buckingham-west/

 

Cheers

 

Rich

[sjrixon]

Thanks Rich.. I thought i'd fixed mine, but last week it started playing up.. So this gives me something else to try!

[sjrixon]

With no sign of anyone ever releasing a new Mogul I need to crack this one.. I want to move on to some detailing and generally tidying this loco up.. 

 

This was my next attempt to fix the running, I cut the bar I'd placed under the front wheels.

 

 

It was better.. But still not perfect. I guess some of the track I'm running on isn't ideal, some baseboard joins are wider then you would like. But that's an old club layout for you!

 

So the next try is to remove some slop from the wheels. With this in mind, I've just slid some plasticard behind the wheels on both sides. More testing here we come!!

 

[Richard Mawer]

Hi Scott. That's exactly how I did mine.

 

 

They have both been running been running for many laps (perhaps 30+ now) round my continuous run where they used to derail every 2nd or 3rd lap, and I haven't had a single derailment - fingers crossed.

 

I have had to file the plastic strips a little thinner around the middle to give a little more play to the central axle. It was just binding a little on the sharper curves. I suppose that depends on the thickness of the shim in the first place. It still stops the twisting movement which was due to too much play in the front and rear axles and seems to keep the pony pointing forwards. I still have a good amount of lead on the pony. Just in case.

 

I hope yours works ok. I look forward to reading an update.

 

Rich

[Richard Mawer]

Scot,

 

Whilst the shims have cured the waggle of both my 43xx's and hence stopped the pony trucks derailing, I am finding the locos very underpowered and unable to haul enough up my incline. They pull even les now because of the resistance from the shims. I can't add any more lead to them either. There just isn't room. On top of that, one of them popped a wheel centre. I have read elsewhere of them doing this. Its something to do with the type of plastic I think. So all in all I am mightily unhappy.

 

I costed up getting Comet chassis built, and whilst they would be brilliant and solve all the issues, I cannot justify the cost when I have so much more to do on the layout. So I have gone low-fi retro. I have bought a couple of Hornby motorised tenders (from a 28xx and a County) and will de-motorise the 43xx's but use their pick ups and have the tenders push the loco bodies around. I just can't see an alternative for mine.

 

I'm pleased (but jealous) that yours seem to be working fine.

 

Cheers

 

Rich

[sjrixon]

Could the 43 be a slightly older chassis? Certainly not having any issues with the wheels rubbing.

[DCB]

Scot,

 

Whilst the shims have cured the waggle of both my 43xx's and hence stopped the pony trucks derailing, I am finding the locos very underpowered and unable to haul enough up my incline. They pull even les now because of the resistance from the shims. I can't add any more lead to them either. There just isn't room. On top of that, one of them popped a wheel centre. I have read elsewhere of them doing this. Its something to do with the type of plastic I think. So all in all I am mightily unhappy.

 

I costed up getting Comet chassis built, and whilst they would be brilliant and solve all the issues, I cannot justify the cost when I have so much more to do on the layout. So I have gone low-fi retro. I have bought a couple of Hornby motorised tenders (from a 28xx and a County) and will de-motorise the 43xx's but use their pick ups and have the tenders push the loco bodies around. I just can't see an alternative for mine.

 

I'm pleased (but jealous) that yours seem to be working fine.

 

Cheers

 

Rich

 A friend has 2 Mainline 63XX with Hornby 28XX type powered tenders, The pick up is tender wheels one side and loco wheels the other but securing the drawbar is a bit difficult without shorting the two sides of the split chassis but the pulling power is more than twice that of the Mainline 63XX.  

Edited February 7, 2017 by DavidCBroad

[Il Grifone]

I think that the problem could be the pony pivot is too far forward, which would cause the pony wheels to adopt too sharp an angle to the rail on curves. Of course, too much slop in the driving axles and in sufficient weight on the pony truck don't help.

 

There is a formula for the correct position of the pivot so that the wheels are radial (someone will probably work out that it's right after all!).

 

https://www.scalefour.org/resources/baldry.html

[sjrixon]

I totally agree it's in the wrong place.. But that's something that's slightly more difficult to fix!

[Richard Mawer]

I think that the problem could be the pony pivot is too far forward, which would cause the pony wheels to adopt too sharp an angle to the rail on curves. Of course, too much slop in the driving axles and in sufficient weight on the pony truck don't help.

 

There is a formula for the correct position of the pivot so that the wheels are radial (someone will probably work out that it's right after all!).

 

https://www.scalefour.org/resources/baldry.html

 Hi,

 

I agree with you and Scott, that it is wrong, but as Scott says, trying to change it is quite a large task. They are what they are.

 

Scott and I both identified the key issue with the chassis - too much play in the driver axles allowing the bodies to waggle and change the angle of the truck when approaching points. We also both came up with shims between the axles and chassis block to reduce this. Scott has had better results than me in as much as his are now useful engines. Mine were struggling with haulage capacity even before the shims were added. I have added as much weight as I could fit, but they still hated the combination of more than 3 coaches and the incline. Everything else romps up - well except the Dukedog, but I am going to add weight to that if I can. Even the City 4-4-0 pulls 5 coaches up the incline. Now the 43's don't even like 3 coaches.

 

So motorised tenders are my next attempt.

[Silver Sidelines]

Might the motorised tender from a Mainline/Replica/Hornby Dean Goods be of use?

 

Ray

[Il Grifone]

Might the motorised tender from a Mainline/Replica/Hornby Dean Goods be of use?

 

Ray

 

Unfortunately it's not the correct tender, but the drive unit might be persuaded to fit under the Bachmann tender body*. I think the nearest R-T-R tender is the one fitted to the GWR 4-4-0 County. Many years ago (long before the advent of the Mainline model), I used a K's tender drive unit under a Tri-ang Dean single tender (again not correct) to power my Kitmaster 43xx ('City of Truro' boiler on prairie chassis). They do turn up from time to time on eBay.

 

* A white metal body would provide weight, but the detail is inferior to the Bachmann one.

 

I did the calculation and my result is almost exactly an inch, but this assumes no 'slop' and, while I don't have a Bachmann 93xx, I would assume that it's much the same as a  Mainline 53xx and there is no shortage of this item. Even ignoring the play in the axles, there's plenty between wheel and rail in 00. Now if I can find where I put mine....

 

EDIT Possibly unclear - by 'item' I meant 'slop' not 53xx.

Edited February 9, 2017 by Il Grifone

[81C]

The pivot screw on the pony truck appears to be wrong the correct one will reduce the movement at that point. 

[DCB]

Might the motorised tender from a Mainline/Replica/Hornby Dean Goods be of use?

 

Ray

The Airfix/ Hornby Tender drive unit is pretty bad, six traction tyres make it pull reasonably but the 5 ton heap of coal on the tender it needs to hide it looks bad and the way mine hopped around led to a new loco drive chassis and a Dapol City of Truro Tender for my Dean Goods.   The Airfix Castle tender drive was pretty bad too, I replaced one with a Hornby County Tender Chassis with the Airfix 4000 gallon top. I know the frames are wrong but the wheelbase is right unlike the Hornby GW 4000 gall powered tender.

.

Edited February 9, 2017 by DavidCBroad

[Silver Sidelines]

Good Morning David

..The Airfix Castle tender drive was pretty bad too, .

A rather sweeping statement.  I found the Airfix Castle Tender Drive very good and still have one fitted in an old Dapol County.

 

http://youtu.be/v2eIreMpfmk 

 

I only parted with my Airfix tender drive Castles when the latest Hornby incarnation appeared.  The Tender drive unit was far superior in haulage capacity to the first Dapol / Hornby engine driven versions.

 

Ray

Edited February 9, 2017 by Silver Sidelines

[DCB]

Good Morning David

A rather sweeping statement.  I found the Airfix Castle Tender Drive very good and still have one fitted in an old Dapol County.

 

I only parted with my Airfix tender drive Castles when the latest Hornby incarnation appeared.  The Tender drive unit was far superior in haulage capacity to the first Dapol / Hornby engine driven versions.

 

Ray

Hi Ray.

Your County runs much better than my Castle ever did.

I had an Airfix Castle when they first came out and modified the tender body to flush sided County type with a Royal Scot tender underframe and 5013 style front frames etc.  This meant the Tender was then an 8'6" wide County  7 ton type not a Castle 8' wide 6 ton.  Back in those days a Hawkesworth tender was quite something and I also converted some Hornby Tinplate Duchess of Montrose tenders to Hawkesworth type (ish)

The Airfix plastic tender chassis and non see through wheels let it down as did the driving wheels tendency to skid along the track rather than revolving.  The chassis was borrowed for a friend's white metal (Bristol models?) Star but after more issues with skidding and brush gear problems with the brush inserts coming loose in the motor frame I discarded the loco pick ups, shorted the driving wheel tyres to the axles, fitted romford top hat axle bearings and wired one side of the loco to the tender drawbar and fitted a Hornby 4-4-0  County Tender with a 4000 gallon tender top which may well be Airfix.  It has since run many miles with no problems, not as powerful as in Airfix power days.  Now little used as we find traction tyres make the track dirty.

Edited February 9, 2017 by DavidCBroad

[Silver Sidelines]

I cannot see the underside to see how it is attached!

https://flic.kr/p/QHo9ck

Ray

[Il Grifone]

This might help, but the General Arrangement drawing is really needed. The small dome on the front running plate covers the top end of a spring*. The pivot can be seen to be behind the leading driving wheels, but, since the play is relatively greater in the model, the pivot needs to be farther back to compensate.

 

https://www.accucraft.uk.com/content/uploads/43XX.jpg

 

* I don't think I have any further details of this, but it's not really relevant.

Edited February 10, 2017 by Il Grifone

[Silver Sidelines]

I wonder if you got sorted.  Whilst searching on eBay for an unrelated item I spotted this listing for a 43xx pony truck.  It might be of interest to someone reading this thread?

 

Ray