OO gauge GWR Mogul and Prairie

[1466]

16 hours ago, Chuffer Davies said:

I’d be very grateful if someone who has received there model could measure the distance between the inside of the splashers and the inside of the tender frames.  To convert to EM without radically re-profiling the splashers the clearance needs to be at leat 22.5mm.  Having come to grief on the Heljan 47xx where both the splashers and the tender needed significant modifications to fit EM wheel sets I’m nervous to order a Mogul without knowing what I’m up against.

Thanks,

Frank

Dear Frank

i haven’t run my Mogul yet and don’t want to take it apart so take what follows with a faint scepticism . The only place I could get the vernier alongside the splashers was at the very end of the rear splasher where I could ,by eye , lay it alongside and estimate rather than close the vernier .

The distance there is 22.8 to 23.00 mm I estimate.

B to B is around 14.2 mm .Across the drivers flange to front 2.8 mm . 

I can’t get at the driver’s axle diameter yet but they run in brass bearings.

I estimate there is 0.8 mm clearance between front connecting rod nut and cross head .There is , I think, potential here to thin the nut and tweak the cross head out .  Gibson’s and/or Ultrascales may be thinner .My cross heads appear to be knock kneed and aren’t parallel to the footplate ... maybe an illusion 

 The tender across the frame is 21.8 mm . The diameter of the axles is 2.75 (!) and flange to front  is 2.8 mm.

From what I have estimated I think a conversion to EM is a possibility. The footplate/valance is I guess metal and the body is plastic .My concern right now is the diameter of the driving wheel axles .

I would welcome somebody checking my estimated dimensions ( Mogul ) .

Hope this helps .

Ken 

PS I’ll try to post photos later .!

 

[melmerby]

Novel current collection using the flanges.

 

 

[1466]

31 minutes ago, Harlequin said:

I have opened up the tender to investigate what sort of speaker can be fitted:

 

The chassis is plastic, most of the weight comes from the casting. The casting includes the speaker well and two fixing screws - looks designed for a very particular speaker.

 

As you can see the weight can be removed but then the close-coupling mount (the spring and Y shaped part) for the rear coupling is uncovered. So if you wanted to remove or replace the weight to fit a different speaker you'd have to arrange something to keep the coupling in place.

 

Pickup wipers bearing on the wheel flanges.

 

Harlequin , that is very helpful . Would be  you be able  please to measure the “slot” in which the wheels run to confirm my estimate of the dimensions?

Im interested to see if EM wheels would fit .

Thanks

Ken 

Edited November 14, 2020 by 1466
Typo and politeness

[gwrrob]

Is the coal load removeable on the tender chaps.

[1466]

27 minutes ago, Harlequin said:

I have opened up the tender to investigate what sort of speaker can be fitted:

 

The chassis is plastic, most of the weight comes from the casting. The casting includes the speaker well and two fixing screws - looks designed for a very particular speaker.

 

As you can see the weight can be removed but then the close-coupling mount (the spring and Y shaped part) for the rear coupling is uncovered. So if you wanted to remove or replace the weight to fit a different speaker you'd have to arrange something to keep the coupling in place.

 

Pickup wipers bearing on the wheel flanges.

 

Thanks again, Harlequin.

You promoted me to take out a set of tender wheels ( the rearmost). I was hoping to substitute Alan Gibson’s but ... the  axle length is non standard at 25 mm and they are not pinpoints but “blunt” although radiused at their ends.

It adds another issue to converting to EM gauge .

Ken 

 

[1466]

5 minutes ago, gwrrob said:

Is the coal load removeable on the tender chaps.

Yes the coal load is easily removed and the coal space looks good .

Edited November 14, 2020 by 1466
Typo

[Harlequin]

4 minutes ago, gwrrob said:

Is the coal load removeable on the tender chaps.

Yes. In fact it almost drops out when you turn it upside down.

 

[Chuffer Davies]

33 minutes ago, 1466 said:

Dear Frank

i haven’t run my Mogul yet and don’t want to take it apart so take what follows with a faint scepticism . The only place I could get the vernier alongside the splashers was at the very end of the rear splasher where I could ,by eye , lay it alongside and estimate rather than close the vernier .

The distance there is 22.8 to 23.00 mm I estimate.

B to B is around 14.2 mm .Across the drivers flange to front 2.8 mm . 

I can’t get at the driver’s axle diameter yet but they run in brass bearings.

I estimate there is 0.8 mm clearance between front connecting rod nut and cross head .There is , I think, potential here to thin the nut and tweak the cross head out .  Gibson’s and/or Ultrascales may be thinner .My cross heads appear to be knock kneed and aren’t parallel to the footplate ... maybe an illusion 

 The tender across the frame is 21.8 mm . The diameter of the axles is 2.75 (!) and flange to front  is 2.8 mm.

From what I have estimated I think a conversion to EM is a possibility. The footplate/valance is I guess metal and the body is plastic .My concern right now is the diameter of the driving wheel axles .

I would welcome somebody checking my estimated dimensions ( Mogul ) .

Hope this helps .

Ken 

PS I’ll try to post photos later .!

 

Hi Ken,

many thanks for the information, all very encouraging so far.  
Given you have reported the width across the inside of the tender frames is 21.8 mm the next question is what is the thickness across the outside of the frames?  This is because I need to know if there is sufficient material to remove 0.4 mm from the inside of each frame.  Also what material are the tender frames made from? I assume plastic but would be good to know for sure.

Thanks,

Frank

[Butler Henderson]

51 minutes ago, melmerby said:

Novel current collection using the flanges.

Wonder what the long term wear is like.

[atom3624]

Nice to see a properly designed casting / weight in a tender.

 

Tenders often appear overlooked - people forgetting they weighed over half the weight when full, of a 100-ton Pacific!

 

This is obviously smaller, but the ratio between tender and locomotive fully laden I would bet is higher again.

 

Wiki states loco 'full' was 63t, tender 41t (normal tons).

 

Al.

Edited November 14, 2020 by atom3624

[1466]

43 minutes ago, Chuffer Davies said:

Hi Ken,

many thanks for the information, all very encouraging so far.  
Given you have reported the width across the inside of the tender frames is 21.8 mm the next question is what is the thickness across the outside of the frames?  This is because I need to know if there is sufficient material to remove 0.4 mm from the inside of each frame.  Also what material are the tender frames made from? I assume plastic but would be good to know for sure.

Thanks,

Frank

Hi Frank

I have just measured across the insides of the W irons  on the tender ... 22 mm . I have tapped the frame with a screwdriver and it sounds like plastic . 
The tender wheels are very difficult to remove and almost impossible to replace  . At the moment, I think the critical issue is going to be the tender axles  diameter ; it’s non  standard  length  and the axle ends are plain not pinpoint . If the electrical circuit must be completed with the tender coupled I.e. it won’t run without, retaining  or replacing the original tender wheels might be key .
Have you seen Harlequin ‘s helpful post of the tender ?

Ken 

 

[1466]

I hope this view of the tender underside shows clearances 

Ken 

[1466]

Loco Chassis 

Ken 

[melmerby]

13 minutes ago, 1466 said:

Hi Frank

I have just measured across the insides of the W irons  on the tender ... 22 mm . I have tapped the frame with a screwdriver and it sounds like plastic . 
The tender wheels are very difficult to remove and almost impossible to replace  . At the moment, I think the critical issue is going to be the tender axles  diameter ; it’s non  standard  length  and the axle ends are plain not pinpoint . If the electrical circuit must be completed with the tender coupled I.e. it won’t run without, retaining  or replacing the original tender wheels might be key .
Have you seen Harlequin ‘s helpful post of the tender ?

Ken 

 

Tender wheels don't seem to conform to any standard. most are not pin point (are any?)

Check out Bachmann's tender wheels, the ones I have seem similar to those shown in the pictures above.

Some are split axle which is better to arrange current collection.

[SteamingWales]

Mine has arrived and looks like I got a Friday afternoon model

 

One buffer rolling round the packaging and the other one basically hanging off. Doesn't look like they have been glued!!!

 

 

The smokebox dart is also missing. First looked as though it had broken off but there is no stub within the door and you can fit a 0.7mm drill bit in. Whilst looking at the tender it spat out the whole dart

 

 

Not a good start to my Dapol loco experience 

 

Hopefully it run, then I'll give it some TLC it deserves as apart from the bits falling off this looks to be a great model and echoing what others have said it's up there with Bachmann

 

[adb968008]

5 minutes ago, SteamingWales said:

Mine has arrived and looks like I got a Friday afternoon model

 

One buffer rolling round the packaging and the other one basically hanging off. Doesn't look like they have been glued!!!

 

 

The smokebox dart is also missing. First looked as though it had broken off but there is no stub within the door and you can fit a 0.7mm drill bit in. Whilst looking at the tender it spat out the whole dart

 

 

Not a good start to my Dapol loco experience 

 

Hopefully it run, then I'll give it some TLC it deserves as apart from the bits falling off this looks to be a great model and echoing what others have said it's up there with Bachmann

 

It begins...

[Butler Henderson]

Indeed, lack of adequate glue inflicts the products of most manufacturers at some point; I have just spent 2 hours hunting for the fuel filler cap that fell off my Harry Patch HST power car. Found thankfully. Back on topic from 1466s photo what exactly have they done to ensure adequate pony truck swing on 438mm curves, there must be something tweaked re the pony truck or the cylinders.

Edited November 14, 2020 by Butler Henderson

[WisTramwayMan]

1 hour ago, adb968008 said:

It begins...

If you look at the Rails website at least 2 of the locos used for the photos have one of the front buffers pointing noticeably inwards and not flush with the front buffer-beam.

 

I received mine (7310) this morning and, sure enough, one of the front buffers was rattling about in the packaging. Upon inspection, it did not appear to have been glued at all, but was easy enough to push back into its correct position. I didn't use any glue, as having trial positioned it it was a pretty firm, snug fit so left it as it was - if it comes lose again I'll put a tiny dab of glue 'n' glaze on it.

 

Other than that, the loco appears totally A1, for which I am grateful after the (first batch) Terrier experiences.

 

Competitively priced as well.

[MikeParkin65]

3 hours ago, Butler Henderson said:

Wonder what the long term wear is like.

Also how quickly they will become dirty picking up track dirt as well as the normal build up of 'black stuff' that build up on wheel backs, treads and pick ups.

[tomparryharry]

1 minute ago, MikeParkin65 said:

Also how quickly they will become dirty picking up track dirt as well as the normal build up of 'black stuff' that build up on wheel backs, treads and pick ups.

 

I 'think' the idea was to arrange the tender, such that the pickups bear upon the flanges, leaving the  wheel treads and wheel back relatively clear of 'black stuff'.  In this instance, they would have a narrow point of contact, far narrower than before, but keeping a decent electrical connectivity.  

[The Johnster]

I had buffers and couplings fall off my Hornby 4287, so it seems unfair to criticise Dapol in particular for this when they are not alone in culpability.  Quality control will never be 100% for anyone, as even quality controllers have Friday afternoons...  so long as the missing bits are in the box somewhere, it is easy enough to glue them back on.  But it doesn't create confidence in QC or build standard in general.

 

My 42xx, renumbered to long term Tondu resident 4218, is a satisfactory model and a very good performer (it 'plods' just like a real 42xx) but has suffered issues with crankpins coming loose and allowing enough play on the centre driver to allow the piston rod to come out of the rear of the cylinder.   I now check over all loco acquistions for loose bits, screws, cankpins, as well as removing the coloured lube grease and using my own lube.   A once over of wiring and soldered joints is done as well.

[SteamingWales]

Having put 7310 back together and run in I'm very happy with my model 

 

Just a shame about the QC but everything was there are easily rectified.

 

Time for her to join the rest of the fleet at Cambrian Shed-



 

[The Johnster]

Re flange pickup, there are pros and cons I think.  Pros; less surface contact means less rolling friction (which will improve slow running and smooth starting and stopping), at the same time allowing a greater pressure of the pickups on the flange than would be possible with tyre rear pickup, and being easier to conceal and less visually obtrusive.  Are the loco wheel pickups on the flange as well?  Another advantage should be less need for adjustment as the flange will slide across the surface of the pickup as opposed to being pushed out of shape when the loco traverses curvature, and the pickups and flange edge should be easier to keep clean, being in a less awkward location.

 

Cons; the flange doesn't pick up current from the railhead, the tyre does, so the tyre needs to be kept clean anyway, though you no longer have to worry about the back of it.  You have to remove the tender (and possibly loco) body to get at the pickups and some users will not be comfortable with this, which will lead to dirt building up and resultant loss of performance.  My view is that for pickup from undriven wheels, split chassis collection is best, but brings it's own set of problems.

 

I doubt that wear will be much of a problem though it may be after a period on locos with very high mileage that are used at consistently high speeds. 

[tomparryharry]

If it does work satisfactorily, then the tender pickups will likely appear on the SE&CR D class.  

[melmerby]

IMHO the best tender pickups are those that press on the axle on a split axle set up.

You can put quite a bit of pressure on them and still have less drag than other means.

Bachmann do this on some of their tenders and I have done the same with a recent 2251 fitted with a suitable, but not originally wired, tender