A JLTRT Western that can swap between 31.5mm and 33mm?

[Dog Star]

Yup, a question.

How can the bogies of a JLTRT Cl.52 be built so that the Back-to-Back of the wheelsets can be changed thereby enabling the model to run on more than just our S7 layout? Put another way, by waving a magic wand at the bogies the model can run on track of either 33mm gauge or 31.5mm gauge. I appreciate that maybe JLTRT might be persuaded to provide enough parts and I could then build a pair of "31.5mm" bogies and a pair of "33mm" bogies... so swapping bogies achieves the objective - although the price, including two ABC diesel gearboxes, is likely to be rather steep! For example, two of ABC best etc. is more than £200, six Slater's wheelsets is more than £80 and then there is the JLTRT bill... a number approaching 400 could be in sight.

I am thinking that using gauge-specific axles with S7-profile wheels is a possible part of the solution; further, that the brake blocks / hangers are positioned for wheels at S7. Swapping axles means that the wheels need to be removable and hence the brake gear needs to be removable so as to not trap the wheels. Finally, the central side spring W/M casting needs to be removable from the bogie "footstep" W/M castings, again so as to avoid trapping the central wheels.

So far so good... except that sorting the fixing of the brake block hangers is not ameanable to the "normal" kettle building dodge of 12BA screws from the ouside of the top pivot because, without external bogie frames, the brake block hangers are highly visible. This is where my current thought process runs into a GWR Buffer Stop (which another WT-topic suggests was left behind at the STEAM exhibition last weekend).

For those who have built this kit... how would you approach the design problem?

thanks, Graham

 

[Dan Randall]

Yup, a question.

How can the bogies of a JLTRT Cl.52 be built so that the Back-to-Back of the wheelsets can be changed between 31.5mm and 33mm thereby enabling the model to run on more than just our 33mm (S7) layout? I appreciate that maybe JLTRT might be persuaded to provide enough parts and I could then build a pair of "31.5mm" bogies and a pair of "33mm" bogies... so swapping bogies achieves the objective - although the price, including two ABC diesel gearboxes, is rather steep!

I am thinking that using gauge-specific axles with S7-profile wheels is a necessary part of the solution; further, that the brake blocks / hangers are positioned for wheels at 33mm B2B. Swapping axles means that the wheels need to be removable and hence the brake gear needs to be removable so as to not trap the wheels. Finally, the central side spring W/M casting needs to be removable from the bogie "footstep" W/M castings, again so as to avoid trapping the central wheels.

So far so good... except that sorting the fixing of the brake block hangers is not ameanable to the "normal" kettle building dodge of 12BA screws for the top pivot because, without outside bogie frames, the brake block hangers are higly visible. This is where my current thought process runs into a GWR Buffer Stop (left behind at the STEAM exhibition last weekend).

For those who have built this kit... how would you approach the design problem?

thanks, Graham

Graham

I had thoughts about doing something similar with "Rifleman", but the only option I seriously considered, was a whole new set of bogie parts, motors, brake gear etc from JLTRT*. You also have to factor in the cost of another set of wheels, so it could get a little expensive and even if I had the cash available to do some narrow gauge bogies, I'd sooner spend it on something totally different like a coach kit or some wagons!

However, I'd still be interested to know:
a) If JLTRT would supply all the necessary parts for such a project.
b) How much they would charge.

If you find out, do tell please!


Regards

Dan

* As I haven't actually finished "Rifleman" in it's S7 guise yet, building another set of bogies is way down on my "to do" list....!

 

[lancer1027]

Yeah Dan you haven't finished Rifleman yet..........running for cover as i haven't finished Buccaneer either

Rob

 

[Scale7JB]

I would probably go down the route of wheels turned from solid so that there is a large collar on the back of the wheel in to which a grub screw could be used to adjust the b2b on each wheel, and then ignore the distance from the brake blocks (at S7 clearance width) to the wheel rim..

Just my tuppence worth...

JB.

 

[Overseer]

I can see how Scale7JB's suggestion could work. However, I think there could be a problem using the same wheels for both gauges due to the different standards. Wasn't the idea of the peculiar 31.5mm gauge that flange ways could be narrowed through crossing Vs to make the track look a bit better and avoid the excessive slop in the finescale O standards while still using standard finescale wheels? So if you use Scale7 wheels for the narrower gauge you reintroduce the mismatch in standards and the potential for poor running. Two sets of wheels and axles would avoid the problem, as would two sets of bogies or two locos.

 

[Dikitriki]

Hi Graham

Interesting conundrum.

I don't think you mean 31.5mm gauge. You mean normal 32mm gauge wheels - it is only the track that is narrowed to 31.5mm gauge.

I'm assuming you are using Slaters wheels. I think you can get round it by having just 2 sets of wheels, but use only the one set of axles - the normal 32mm axles. To get S7 spacing, solder a washer to the back of the S7 wheels. OK, I know you will have to file the hole square, and face it in a lathe to get truly accurate BTBs. Set the whole thing up for S7, then just change the wheels over and forget any discrepancy in brake placement. You will only need to make the centre casting removable, change the wheels and off you go.

By using 32mm axles and split axle pick up, there is nothing to adjust mechanically.

.......probably

Richard

 

[Scale7JB]

Thinking about it now, Slaters do sell square holed S7 spacer washers purely for this reason...

Part No. '7804S7'. Might be worth a try..

JB.

 

[Dog Star]

So if you use Scale7 wheels for the narrower gauge you reintroduce the mismatch in standards and the potential for poor running.

Probably so. If running with S7 wheels on 31.5mm track causes problems then FS wheels might need to be considered.

Two sets of wheels and axles would avoid the problem, as would two sets of bogies or two locos.

Yes, maybe two sets of wheels / axles may need to be considered - at least that price is circa £80 rather than at least £300 for wheels and motors. Two locos? Yup there are two Wizzos here.... the question just got stereo-ed .

regards, Graham

 

[Dog Star]

I don't think you mean 31.5mm gauge. You mean normal 32mm gauge wheels - it is only the track that is narrowed to 31.5mm gauge.

Yes, Richard, a rather loose bit of writing and since amended.

I'm assuming you are using Slaters wheels. I think you can get round it by having just 2 sets of wheels, but use only the one set of axles - the normal 32mm axles. To get S7 spacing, solder a washer to the back of the S7 wheels. ... Set the whole thing up for S7, then just change the wheels over and forget any discrepancy in brake placement.

A good suggestion - Slater's supplies packs of etched spacing washers, for use with the standard FS axle, to move wheels out to the S7 B2B. Still leaves the concern about getting the wheels past the brake blocks... unless the blocks are set from the outside diameter of the flange rather than from the tread.

By using 32mm axles and split axle pick up, there is nothing to adjust mechanically.

.......probably

Richard

The idea of split axles for this engine, to avoid potential problems with plunger / back-scratcher pick-ups, had come to the fore and ought to be part of the recipe. Not sure that I could make some, using 2mm GRP rod, to run true.

regards, Graham

 

[JimG]

Probably so. If running with S7 wheels on 31.5mm track causes problems then FS wheels might need to be considered.

Graham,

I wonder if it is worth investigating pushing S7 wheels in on the axle until the check gauge is such that wheels will not hit the crossing nose. It would mean that the S7 wheels would be a bit under gauge with a fair bit of slop in running (bit like 7mm FS on 32mm gauge ) and there might be more drop in at crossing noses, but might be worth a try to see if it works in practice.

Jim.

 

[adrian]

The idea of split axles for this engine, to avoid potential problems with plunger / back-scratcher pick-ups, had come to the fore and ought to be part of the recipe. Not sure that I could make some, using 2mm GRP rod, to run true.
regards, Graham

Another alternative is mounting them on a telescopic axle, like Alan Harris used to do with his wheels. Then have two sets of holes for the taper pin. Then you could take the pin out and slide the wheels in or out as required. That way you don't need to remove the wheels to change gauge. The only drawback I can think of is that when you're running S7 then there will be quite a bit of side play on the axles.

 

[demu1037]

Hi Graham,

As Adrian says, telesopic axles are possible, i have experimented with a Peckett 0-4-0 & it does work. The chassis is assembled as per kit but has S7 wheels that can be set to a norrower BTB - it will run on Peco points at least as well as it would with normal wheels. I'm not sure about 'the other gauge'. I'ved used removable spacers behind the plungers for S7 mode & rely on the plungers to limit the sideplay because the wheels dont come out easily - washers would probally be better!



Clearance in S7 is not quite sorted - note the con rod

Regards

Andy

 

[Dog Star]

This question continues to engage the thought processes... I am keen to try the "GRP rod" approach to split axles on the basis that the JLTRT resin bogie frame is crying out for split axle collection (and the consequent absence of plunger / back-scratcher pick-ups). Making such axles with two B-2-B settings, maintained by alternative holes for taper pins, seems to be a step too far at this time so the initial task is to make S7 split axles and then FS-versions if the S7-examples are successful.

... The only drawback I can think of is that when you're running S7 then there will be quite a bit of side play on the axles.

I am working on the principle that the "wheels with S7 axles" are going to need more thrust washers than the "wheels with FS axles" - I can see no alternative to that approach on the basis that the resin bogie frame is "not modified" when changing between S7 and FS operation.

If the brake gear is made removable, by dropping the brake hangers and pull rods down, then the outer pull rods shall need to be set to clear the front face of S7 wheels whilst the inner pull rods shall need to be set to clear the rear face of FS wheels.

Maybe there is some mileage in Dan's suggestion... provided that the cost-benefit looks acceptable.

regards, Graham

 

[Dikitriki]

I am working on the principle that the "wheels with S7 axles" are going to need more thrust washers than the "wheels with FS axles" - I can see no alternative to that approach on the basis that the resin bogie frame is "not modified" when changing between S7 and FS operation.

I got round that by suggesting the washer soldered to the back of the S7 wheel, and only using 32mm axles. The same number of thrust washers are required. I haven't checked, but isn't the distance over the outside faces of the wheels pretty much the same between 32mm and S7. If you set the brakes close to the outside face, you might be able to wiggle the Slater's wheels past the brakes without having to make them removable.

Richard

 

[Dog Star]

I got round that by suggesting the washer soldered to the back of the S7 wheel, and only using 32mm axles.

Thank you, Richard, for repeating that snippet - somehow I had missed the significance when the comment was posted the first time. S7 wheels with the central boss extended inwards is worth investigating as that approach means one axle length works for both wheel B-2-B dimensions (although such an approach does require a second set of Slater's finest).

 

[Dikitriki]

(although such an approach does require a second set of Slater's finest).

I can't see any way you can avoid the second set of wheels, given the differences in flange/tread profiles.

However, it would be a pretty neat trick if all the switch involved was a change of wheels and removing the centre casting. I'm just thinking of my warships now - they should be even easier. What is the distance between the outside faces of the wheels (tyres) in S7?

Richard

 

[Heather Kay]

Can I just remind Graham that Slater's FS wheels run quite happily on S7 permanent way, provided they're set to the correct B2B. Much of our early S7 stock ran with FS wheels, and most of our locos still do.

If you can live with the flange when in "S7 mode", then one set of wheels and a set of Slater's washers would seem to do the trick.

 

[Dog Star]

However, it would be a pretty neat trick if all the switch involved was a change of wheels and removing the centre casting. I'm just thinking of my warships now - they should be even easier. What is the distance between the outside faces of the wheels (tyres) in S7?

Richard, I shall measure a set of re-profiled Slater's wheels later today. As for your Warship(s), there is the S7 test track from the S7 South West Group which would provide an appropriate venue for your first foray into the world of wider gauge.

regards, Graham

 

[Dog Star]

What is the distance between the outside faces of the wheels (tyres) in S7?

Peter has a set of Slater's 3' 7" diesel wheels which have been turned to S7 profile. Measurements are as:-

Over front face of boss (without screw) - 40.3mm
Over front face of tyre - 38.6mm
Back to back of tyre - 31.6mm
Flange thickness at root - 0.76mm.

Anything else needed?

 

[Eastsidepilot]

Graham,
If you do go down the telescopic axle route the S7 stores sell both insulated and plain telescopic types, personaly this is the way I'd do it, one problem I see is the axle with drive gears on it. Not having seen the model in question how are the gearsets mounted on the axle?
I can make custom one off axles.

Col.