Halling Motor Problem

[berryr99]

Good evening,

I have a curious problem with 2 Halling Motor chassis. I am testing without the loco bodies on but the problem does not go away if bodies are mounted or weight is added to the chassis.

Basically they run really well in the fiddle yard or rolling road but hopelessly on the layout. My only thought is that is has to do with ballasting (the fiddle yards are not ballasted) and that the wheel flanges are somehow being lifted by the ballast. However I have other locos with wheels the same size as the Halling's and they run well on the layout.

I doubt if there is a layout problem as such as all my other 20 locos run well on it.

The chassis is a 09mm Gauge  23-30mm wheelbase 9.5mm Disc (MB0909D)  from Motorbogies .com and is fully run in. The other one (exactly the same) has never run on this layout before. I've also tried adjusting the wheelbase but still the same problem.

Another puzzling aspect is that I have another Halling chassis which runs in a railcar with no problems at all. The only difference is that this chassis has spoked wheels (the others are solid wheels)

I was wondering if anyone had any ideas about how to further diagose or fix the problem.

I'm afraid that unballasting the layout is not an option !

Thanks

Robert Berry

[rod335]

First thought is to check the back-to-back on the offending chassis. Is it the same (on both axles) as the one that runs alright? Difficult to think of anything else without seeing it.

Rod

[rod335]

Should also make it clear that you should check the back-to-back round the entire circumference of both wheel sets.

Rod

[B.Meldon]

I agree with Rod this sounds like a back to back problem.

There are some back to back gauges available, but you will find you have a wide variety of flange thicknesses in use so you can only use these as a guide and you may find you have to change the back to back measurements slightly depending on the flange design to get good running in whatever points you use.

You will also need to make sure you have no ballast above the top of the rail chairs. I have a modified small screwdriver with a slot cut in set at a fraction above the height of the chairs. (Made by the late jack Carter.) I can just run this along the rail and it will soon find any bits of ballast that are too high.

Brian Meldon

[berryr99]

Rod/Brian,

The back to back on the faulty chassis is slightly wider than the working one.

However I still don't understand why the fiddle yard lines give excellent running and the layout ones don't. The layout lines have no real curves on them and I know the track is well laid.

I ran a wheelset along the layout but can't see that any ballast is standing proud of the sleepers.

Correcting the back to backs is well outside my skill set so please can someone give me a hint about how to fix it - I'd say to push the wheels in on the axle but not sure how to do this

Thanks

Robert

[tedp]

judging from the number it is an inside frame chassis with solid wheels.



If you have a back to back gauge of 7.4mm, put each wheelset (or possibly both together) in a vice and slightly nip it in till the BTB gauge lightly touches each wheel back. That should move the insulated wheel a fraction along the axle. Don't overdo it as the way back is less simple.

[berryr99]

Thanks - I have a back to back gauge on order and will give this a try

Robert

[B.Meldon]

Rod/Brian,

The back to back on the faulty chassis is slightly wider than the working one.

However I still don't understand why the fiddle yard lines give excellent running and the layout ones don't. The layout lines have no real curves on them and I know the track is well laid.

I ran a wheelset along the layout but can't see that any ballast is standing proud of the sleepers.

Correcting the back to backs is well outside my skill set so please can someone give me a hint about how to fix it - I'd say to push the wheels in on the axle but not sure how to do this

Thanks

Robert

This is indeed a bit of a mystery Robert.

Back to back will make a big diference, but if the track is identical on the layout and in your fiddle yard then there must be another reason for your problem.

Is the track on the layout the same make and type as used in your fiddle yard? The reason I ask is that you will find that the actual rail gauge is different with some makes and models of track. (For those that do not believe me just try a 9mm gauge roller gauge on various proprietary sections of track you will find it will fit some but not others.)

Did you use an adhesive other than PVA for the ballast or for securing the track on the layout?

When you get the back to back gauge only change the items that are causing problems. If they are working fine than leave them alone. As I mentioned in the previous post the design of the wheels and the thickness of the flanges vary considerably and this has a direct effect on the ideal back to back measurements. So what works well for one chassis may not be correct for another.

Brian Meldon

[berryr99]

Brian,

Thanks for your thoughts.

The track used in the fiddle yards is Peco mainline 009 - just like the layout.

All track is secured with PVA and I was very careful in laying it

I have tested a little more on the layout and there's definitley some areas where it will run  and some where it won't. At the moment I can't see why this should be as all track is laid to the same standard and actually some of the curves are fine and some of the straights are fine as well.. I have tried weighting the chassis but there is no improvement

What is very odd is that my other Halling chassis with spoked wheels runs fine - and its the same diameter wheels as on the bad chassis. I'm thinking of getting hold of some spoked wheelsets and swapping for the solid ones if I can find a spares stockist.

Robert

[rod335]

Try swapping wheels, if possible, between the two chassis, this should show whether it is the wheels (most likely) or the chassis at fault. It may be that the ballasted track is more rigid being held in place by set PVA which is very hard and solid.

Rod

[berryr99]

Thanks Rod. I should have done that first

Will check and report back

Robert