Hornby Adams Radial Problems.

[waz]

Hi Chaps.
I've had a Hornby Adams Radial for some time but is very seldom used due to the fact that it rairly makes it's way all around the track without slipping to a stop. I realise that they are a peculiar model and some people have the same prob with both Hornby and Oxford Rail models. Is there some kind of hack to resolve the problem so I can enjoy this wonderful model?
My Best Regards
BILL.

[Bufferstop]

There are two problems which plague models of this prototype, one is the length of its wheelbase the other is weight distribution. I'm not familiar with either model, but would expect them to need the bogie pivot to move from side to side. If the driving wheels keep the body in line with the track centre line , then the bogie centre pin needs to be able to move sideways to accommodate the curvature of the track. Possibly the pin moving in a slot across the bogie. Check whatever mechanism there is allows this to move freely. Which brings us to weight distribution. There needs to be enough to keep the bogie on the track and no more, all the rest of the weight needs to be on the drivers. At the time these models were announced there was a collective intake of breath from older modellers who knew of the design's problems in model sizes

[waz]

Hi Bufferstop !
Thanks for going to the trouble of your lengthy explanation. The rear bogie does indeed swivel on a pin in a slot at the rear and moves freely. It's okay on straights but not on some bends. Not all the bends are tight. The drive wheels just skid as they have no traction. It dose seem like the weight is firmly on the driving wheels so I don't know the answer. Many thanks for your evaluation I'll keep trying and see if I can come up with something.

My Best Regards
BILL.

[Dad-1]

Hi WAZ,

Is that slipping to a stand without a couple of coaches ?
I'd be looking to see if there was any space for additional ballast in the smoke box.
Anything added must be forward of the 2nd drivers axle.

Geoff T.

[Chops]

One imagines that adding any weight to this will be very troublesome. What comes to mind is a pellet of depleted uranium, that would be
small enough. Just kidding, of course. Does it allow for traction tyres?

[waz]

Hi All.
Thanks for that Dad-1. No coaches on it. Perhaps a qube yard of readymix might do the job? Thanks for the tip. @Chops. No there is no provision for traction tyres unfortunately. But thanks for the question.
My Best Regards
BILL.

[Mike Parkes]

Check the pick up contact strips are bearing on the back of the wheels at all times as the axles slide from side to side. If not use a small screwdriver to hold the contact strip on the back of the wheel and another to cretae a slight bend in it which has enough force to hold the strip on the back of the wheel.

[Chops]

A most interesting and attractive model, such a rotten shame it is dying on the vine. Out of curiosity I looked up Sam's Trains Reviews regarding this particular item, and it received an unusually high ranking, 5/5, for both mechanism and performance. I trust Sam, many have a differing opinion, because if something is poor he will call it poor. This is something I'd have dropped some coin upon, so I am most interested to hear what becomes of this. I hope that you find a solution.

I am grasping at straws here, but from seeing Sam's Radial with the gear box cover off, is there any possibility that there is a maladjustment of the bearings causing an uneven displacement of the drivers? Sam did mention that the Hornby version was well weighted. I've had at least one Hornby product flail helplessly because the center drivers of the 0-6-0 (NOT the Terrier, but some lower end tank engine) barely grazed the rail heads and were thus worthless for tractive effort. Very annoying. I eventually binned the ruddy thing.

https://www.youtube.com/watch?v=6XY93gbu48E

[waz]

Hi Chops !
Thanks for your interest. Yes, Sams Trains do a good evaluation on it.I like Sams Trains, thats the reason I got the Hornby version as against the Oxford Rail one. The Oxford Rail version had the same problen as this one. It's to do with the configuration of the wheels and the rear bogie. It's got a good weight so should'nt skid like it does. I don't get it out often so I will take it out of its box this afternoon and take another look at it. Having said all that, whilst I have a great deal of track, it was laid with too much haste and could put some of it down to that. That said, my other 22 locos have no problems. If I eventualy have any sucsess I will endevour to let you know. My many thanks.
@Mike Parks.
The problem is not the elctrical contact. When it stalls on the track the wheels continue to turn and skid so the contacts are good no problem there. Many thanks for you sugestion and interest and your post. Please excuse my poor smelling.
My Best Regards to you both,
BILL.

[Mike Parkes]

Sounds like the bogie and/or pony truck have too much downwards pressure and are lifting the driving wheels off the track.

[Chops]

That would explain a lot! If that would fix it, I might be in the market for one.

[Bigmet]

Sounds like the bogie and/or pony truck have too much downwards pressure and are lifting the driving wheels off the track.

The model designer is between a rock and a hard place on this type of wheel arrangement, with carrying wheels both sides of a short driven wheelbase. The drivers need to be stable on the rail for good traction and pick up, and with as much weight as can be got with a small body, and the carrying wheels must neither take too much weight as Mike Parkes mentions, nor must they rise so much that the flanges start contacting the underside of the bodywork, because then 'the brakes are on'. (Take a look at the clearances on the model underside from top of flange to underside structure.)

I have had both the Hornby and Oxford versions to look at, and they suffer the same problems and are pretty much equivalent in mechanical quality and potential performance. (I slightly favour the Oxford mechanism for its 50:1 reduction ratio, good choice for slow speed control and appropriate for the speed range of the protoype.)

Now it's brutal reality time:

...whilst I have a great deal of track, it was laid with too much haste and could put some of it down to that. That said, my other 22 locos have no problems...

This loco will do best on dead level track. Mark the locations where it slips , then sight along the rail tops to see if there are humps and/or dips; both are equally problematic, and need to be corrected. This is worthwhile for more than just this loco, everything will run better, and of course if you buy locos with other 'awkward' wheel arrangements such as 0-4-4T, 4-4-0, 4-4-2, singles; they'll thank you for it...

[Chops]

I've been drooling over the Oxford Radial for a time now, and have greatly enjoyed their Dean Goods. That 50:1 gear ratio is a strong selling point. I like things on the slow side; not blasting around like slot cars. Purchasing anything out of the UK is always a throw of the dice, as if it is a dud, returning it by international mail is frightfully expensive. But your Oxford, Bigmet, works pretty good for you?

[SRman]

If it is of any help, I am also happy with my Oxford Radial.

There were minor criticisms of it in the motor block showing where there should be daylight, but with mine being a BR black example, this isn't really obvious unless one is looking for it.

Mine being one of the very first releases needed a slight modification to the front coupling pocket to increase the clearance over the top of it (something Oxford fixed on all subsequent releases).

It runs smoothly and is powerful enough to manage four coaches or three plus a 4-wheel luggage van - more than the real ones were asked to haul on their own on the sharply curved and hilly Lyme Regis branch they worked.

[Bigmet]

...But your Oxford, Bigmet, works pretty good for you?

Full disclosure. I got to work on a friend's purchase to 'disappear' the motor (easily done, delete the flywheel from the drive train, move motor) made various small adjustments such as SRman mentions to give it the best chance of pulling well, and thought it pretty good. So I then bought a cheap one as a mechanism for a project, and that runs well too, under its new outer shell, mechanism unmodified except for removal of the outside cylinders and connecting rods.

Just two tests of the Oxford in my hands, and one of the Hornby more recently, so hardly exhaustive.

And the simple fact is that 'everything' in current design RTR OO locos runs well for me, so my opinion cannot be relied on!

This is because I have built many small mechanisms and know what to look for in the way of troubles and how to adjust. The truth is that a RTR loco is an assembled kit, and the more awkward the challenges a protoype's design presents, the more critical both the model design and assembly become. A compact 4-4-2T is about two thirds of the way up the awkwardness scale for a RTR OO steam model. I built a couple from brass kits in the long ago, that's how I know...