what motor for my 47xx

[rovex]

I recently bought a brass and whitemetal model of a 47xx of Ebay. Its been fairly well built and sits on a brass chassis. 

 

The chassis is brass, the two sets of inner wheels are flangeless and there is no motor or gears (or indeed any pickups).The wheels turn fairly freely, apart from one set but it probabyl only need some lubrication.

 

I'm puzzled as to the original builders intentions as the bottom of the firebox where presumably the motor would have sat has been filled in with plasticard and a representation of the bottom of the firebox made. This will need to come out.

 

The boiler, running plate and top of the firebox is brass, the sides of the firebox and the cab are whitemetal. As I say its been well built but some remedial work is going to be needed.

 

The tender is a mixture, the top looks to be from a Hornby King, the chassis is brass, again reasonably well built but would probably benefit from lubrication.

 

So my question is what would be the best motor to fit, and what gears do I need and from where?

 

Also I'm thinking of replacing the crank rods which are whitemetal and I've a feeling that brass would be preferable. Any thoughts.

 

Finally and just out of interest anyone got any ideas as to the manufacturer?

 

For what use there are I include some fuzzy photos (I really need another camera)

 

Thanks as usual for all assistance

 

[Austrag]

The camera is fine, your focus isn't.

 

If you don't get answer soon, then I will at my club tomorrow. They use lots of kit built loco's and will know. Regards David

[buffalo]

Go to the HighLevel site and download their gearbox planner. It shows the outlines of all their gearboxes and can be used to compare with the sapce available. Use the largest motor that will fit. With the popular Mashima range, the numbers are the dimensions in mm excluding the shaft, so you should be able to get a good idea as to what will fit in conjunction with the gearbox planner. Try to avoid the 12xx range as they are a bit less powerful than any of the others.

 

White metal rods? It must have been intended as a static model. Nickel silver is the usual material for rods in 4mm.

 

Nick

[34theletterbetweenB&D]

Fit it with the new set of rods including the slide bar assembly before going any further, and achieve a free rolling chassis ahead of any thoughts of powering it. Building a good 8 coupled chassis isn't the easiest thing, and you need this proven to be right to be worth going further.

 

There's a decision on which axle to drive, I'd go for axle 3 and shift the frame spacer as required. Layout of motor in the middle of the boiler above axles 2 and 3, gearbox down through firebox between axles 3 and 4 so fully concealed, then turns forward onto axle 3.

 

The restrictions on the motor width, a Mashima 1426 or 1430 would be my choice as the largest type you can definitely fit in easily - the '14' element is the width in millimetres. A '16' type might go, but probably needing a little cutting back of the aperture in the underside which might compromise appearance.

 

The gear ratio is a compromise between optimum smoothness at dead slow, and ability to achieve a scale maximum speed if that is required. I'd suggest 40:1 or thereabouts for DC operation to yield the normal full service speed range. Use a higher ratio if it is only ever going to move slowly. If it is going to have a DCC decoder, give it 30:1, the decoder will take care of the slow speed smoothness, and it will then also really gallop - if that is what is required.

Edited February 4, 2015 by 34theletterbetweenB&D

[rovex]

Thanks for all the helpful replies. Having dug the chassis out again last night. The motion probably is nickel silver, I think it was the fact that the crank rod from the piston to the wheels on one side has been bent to fit that made me think it wasn't.

 

Given the wheels a bit of an oiling and it now seems to run along smoothly. I shall try pushing it along the track at home and see how that goes.

 

Dean

 

PS, with regard to which axle to drive, the wheels on the second and third axles are flangeless and does this make a difference as to whether they should be driven?  I don't have overtight curves, the usual really peco medium points are probably the tightest curves.

 

My obvious concern is that if I drive a flangeless wheel then if this comes off the track on a curve the train will lose traction.

 

I could replace one or both sets of flangeless wheels but will need to check whether this impacts on the engines ability to get round the layout.

 

problems problems

Edited February 4, 2015 by rovex

[bigherb]

Thanks for all the helpful replies. Having dug the chassis out again last night. The motion probably is nickel silver, I think it was the fact that the crank rod from the piston to the wheels on one side has been bent to fit that made me think it wasn't.

 

Given the wheels a bit of an oiling and it now seems to run along smoothly. I shall try pushing it along the track at home and see how that goes.

 

Dean

 

PS, with regard to which axle to drive, the wheels on the second and third axles are flangeless and does this make a difference as to whether they should be driven?  I don't have overtight curves, the usual really peco medium points are probably the tightest curves.

 

My obvious concern is that if I drive a flangeless wheel then if this comes off the track on a curve the train will lose traction.

 

I could replace one or both sets of flangeless wheels but will need to check whether this impacts on the engines ability to get round the layout.

 

problems problems

It doesn't matter how many wheels are driven, it is the weight on the driven wheels that gives the traction. An 0-4-0 will have the same traction as an 0-8-0 of the same weight. The problem with the prototype railway was the maximum axle load, the heavier the loco the more axles needed to spread the load. We don't normally have that problem with models so a 0-8-0 running with only four wheels on the track would pull just as well.

[Horsetan]

I recently bought a brass and whitemetal model of a 47xx of Ebay. Its been fairly well built and sits on a brass chassis. 

 

The chassis is brass, the two sets of inner wheels are flangeless and there is no motor or gears (or indeed any pickups).The wheels turn fairly freely, apart from one set but it probabyl only need some lubrication.

 

I'm puzzled as to the original builders intentions as the bottom of the firebox where presumably the motor would have sat has been filled in with plasticard and a representation of the bottom of the firebox made. This will need to come out.

 

The boiler, running plate and top of the firebox is brass, the sides of the firebox and the cab are whitemetal. As I say its been well built but some remedial work is going to be needed.

 

The tender is a mixture, the top looks to be from a Hornby King, the chassis is brass, again reasonably well built but would probably benefit from lubrication.

 

What a fascinating hybrid!

 

The whitemetal bits look like they are derived from the old Cotswold / NuCast kit

 

The brass running plate and turnings might be Crownline in origin - the chassis almost certainly so; it may have started life in the old Hornby "King"-to-47xx conversion kit.

 

It might well be that the completed model was intended to be a static exhibit, or to have a powered tender - hence the firebox bottom and ashpan detail.

[34theletterbetweenB&D]

....I could replace one or both sets of flangeless wheels but will need to check whether this impacts on the engines ability to get round the layout....

 Oh it will. How much is the question. You need a width of 13mm at most over the widest point of the chassis where the wheel bosses bear, and the rods jointed, to have a hope of managing the nominal 36" average radius of your medium radius streamline points would be my educated guess. Then you have the trouble of whether any wheelset flange is going to contact the modelled brakes, because they look conductive to me.

[hayfield]

Lee

 

Looks a nice loco, trying to think of the maker. I have a feeling its something like A1 models or Proscale ?. Go for a free running chassis, don't push but just incline the track slightly and see if it rolls freely. High level/ Comet gearboxes are super, think 2 stage ones are better and if poss fit a nice big flywheel. Should get a nice big Mashima to fit inside the boiler

[Horsetan]

ProScale never produced a 47xx and neither for that matter did A1.

 

The only outfits to have done anything 47xx-related in the last 40 years are:

 

Cotswold / NuCast (full kit)

Kemilway (chassis only)

Crownline (conversion from Hornby "King")

PDK (full kit)

Martin Finney (full kit)

[DCB]

I would either drive the front or rear axles (Or both) or change to all flanged wheels.  I am sure powering a non flanged wheel will result in broken coupling rods, My K's 42XX snapped its coupling rods as did my K's Dean Goods chassis.  A friend has a white metal 00 gauge 47XX with all wheels flanged which copes with 19" radius curves and 2ft radius points.  However it is slow and lacks power and traction due to a Mw 005 5pole X04 clone motor with 40 :1 gears.

X04 s don't like metal bodies in my experience.   With their limited sphere of operation, fast freights and Saturday relief passengers a model 47XX does really need to be both fast and powerful  so being something of a phillistine and with a 47XX planned using a Hornby King I would look into a big tender mounted motor.driving one or more Loco axles through a driveshaft with a universal joint., or powering the loco and having a tender drive unit as well.

.  

It doesn't matter how many wheels are driven, it is the weight on the driven wheels that gives the traction. An 0-4-0 will have the same traction as an 0-8-0 of the same weight. The problem with the prototype railway was the maximum axle load, the heavier the loco the more axles needed to spread the load. We don't normally have that problem with models so a 0-8-0 running with only four wheels on the track would pull just as well.

bigherb, The idea that it is not the number of wheels but the weight on them that limits traction is not my experience.  More weight does give more traction but with diminishing returns and in my experience with a given weight increasing the number of wheels in contact with the track also increases traction. I have proved this with weighting various locos and noticed how a brass chassis under my 28XX pulled much better with 8 flanged romfords than with 4 fanged and 4 non flanged which did not actually touch the rails.  Even for a given weight a 4 wheel chassis pulls best with the weight evenly distributed.   Nose heavy 4-6-0 locos never pull as well as Pacifics with equal weight but more evenly distributed and a Wrenn 8F with a big Ringfield Motor in the cab pulls 32 wagons where my K's  ROD body on another Wrenn 8F chassis and of equal weight but nose heavy with a computer motor in place of the Ringfield can barely manage 18.

Edited February 6, 2015 by DavidCBroad

[russell price]

I have something similar in the tuit pile a Cotswold 4700 with a brass boiler! No footplate though! Maybe it was going to be exchanged for a brass footplate?? As for driving the non flanged wheels I can’t see any problems with that . As for broken coupling rods etc???? Triang drove the flange less wheels for millions of locos without issue!!