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OO gauge GWR Mogul and Prairie


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13 hours ago, Chuffer Davies said:

Hi Izzy,

I’ve not heard of the Whitbourne models chassis...  There are so many small businesses, it’s hard to keep track of them all.  
 

I’ve only  designed a replacement chassis for one outside cylinder loco before and not Great Western, but for that I just scaled down the prototype’s dimensions over the cylinders and slide bars.  As you indicated this then required the leading crank pin to be recessed to avoid the cross head interfering with the crank pin in EM but as yet I’ve no dimensions for the distance over leading crank pin faces in S4.  If you can provide them I can ensure that the slide bars are set far enough apart for S4 even if this means off setting them slightly in the cylinders.

 

The Dapol wheels do look rather good but commercial wheels tend to be too wide causing problems with clearances and so I’ll have to wait and see if they are suitable.  I have a set of Ultrascale wheels in stock so these are what I’m expecting to use. 
 

Regards,

 

Frank
 

 

 

 

 

Hi Frank,

 

As Miss P says, long gone, a product from the 1980's when I built most of them for others. Very good even for today, with adjustments for current tastes, hornblocks, csb's etc. You will understand I have no interest in GWR myself. But in recent times I 'found' a new/boxed Mainline 43xx in the loft along with all the conversion bits so made it up as a change from the norm. It is this recent experience which reminded me of the aspects to watch out for.

 

As to P4 standards I can do no better than direct you here; 

https://www.scalefour.org/p4-standards/

 

But basically you need 22mm minimum inside splashers for clearance. I have used Gibson wheels and they are just under this figure over tyre width, about 21.7mm nominal, and 22.7mm over the centres. Obviously this latter measurement varies according to the wheel centre design/profile. Most P4 wheel tyres are 2mm width, again nominally.

 

Here is an upended shot of the loco showing the clearance behind the slidebars. Enough.....just.

1332967201_RMweb09.jpg.d3520953833797a1bb93bc60ac3b5097.jpg

 

And the right way up.

 

949877763_RMweb10.jpg.f53c0bd348e9bd7e1a06580e5b6077d7.jpg

 

Sorry it's a poorish shot, not quite sharp.

 

I think this is better

 

915596274_RMweb08.jpg.fe082a4528fcb31923ed8ed8ce0f4bef.jpg

 

It's uses a Mitsumi motor & HL 60-1 box plus a Zimo MX600 decoder.  I haven't bothered with sound as per my other 4mm locos since I don't really need/want it being an exGE modeller.

 

Anyway I hope this info helps, and I'm sorry for intruding on this Dapol thread.

 

Izzy

 

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Here are a few photos of my sound installation:

 

MogulCoalGrille1.jpg.fc46af44cc3bc74605d824080af3a949.jpg

 

I removed the plastic coal load and to improve the sound, I cut a hole in the tank, covered with insect mesh, then glued chunky loco coal in using Copydex. The gluing takes a few iterations to ensure that the mesh is hidden and to build the shape you want.

 

The result is that sound will now come directly from the speaker, through the grille, and between the coal lumps, instead of being bounced around in the plastic tender body and coming out underneath.

 

I used a Zimo 40*20*9 speaker because I thought it gave the best sound of the speakers I tried without requiring any grinding of the tender weight block. The corners of the 3D printed speaker had to be rounded off to allow it to sit down in the cast metal speaker well and thus allow the body to fit down properly.

 

Back together:

MogulCoalGrille2.jpg.5421c06fad3f7f4c8c6b1a3ad6025342.jpg

 

The running plates line up, there was no feeling of the body flexing when the screws were tightened so it's just about a perfect fit and it sounds great (within the limitations of the sound project.)

 

IMG_20201122_092015r.jpg.f579eca29fc7cb1aff9cef34c3f23ba6.jpg

I have used this technique before but this is the first time I've been able to show the tender with a partial load instead of brimming with coal and that made me realise that it would be better to (a.) weather the coal space before fitting the coal and (b.) have some finer grade bits around while being careful they don't block the grille. The advantage of using Copydex is that I can easily remove the load and do that one day.

 

So, room to improve but I think the basic technique is sound (ha ha!).

 

P.S. If you're fitting your own sugar cube speaker in the smokebox it's very important that it is sealed to the clip-on enclosure otherwise you might get buzzing on sounds like the whistles. I used Copydex for that too.

 

Edited by Harlequin
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3 hours ago, Izzy said:

 

 

Hi Frank,

 

As Miss P says, long gone, a product from the 1980's when I built most of them for others. Very good even for today, with adjustments for current tastes, hornblocks, csb's etc. You will understand I have no interest in GWR myself. But in recent times I 'found' a new/boxed Mainline 43xx in the loft along with all the conversion bits so made it up as a change from the norm. It is this recent experience which reminded me of the aspects to watch out for.

 

As to P4 standards I can do no better than direct you here; 

https://www.scalefour.org/p4-standards/

 

But basically you need 22mm minimum inside splashers for clearance. I have used Gibson wheels and they are just under this figure over tyre width, about 21.7mm nominal, and 22.7mm over the centres. Obviously this latter measurement varies according to the wheel centre design/profile. Most P4 wheel tyres are 2mm width, again nominally.

 

Here is an upended shot of the loco showing the clearance behind the slidebars. Enough.....just.

1332967201_RMweb09.jpg.d3520953833797a1bb93bc60ac3b5097.jpg

 

And the right way up.

 

949877763_RMweb10.jpg.f53c0bd348e9bd7e1a06580e5b6077d7.jpg

 

Sorry it's a poorish shot, not quite sharp.

 

I think this is better

 

915596274_RMweb08.jpg.fe082a4528fcb31923ed8ed8ce0f4bef.jpg

 

It's uses a Mitsumi motor & HL 60-1 box plus a Zimo MX600 decoder.  I haven't bothered with sound as per my other 4mm locos since I don't really need/want it being an exGE modeller.

 

Anyway I hope this info helps, and I'm sorry for intruding on this Dapol thread.

 

Izzy

 

Hi Izzy,

Thanks for the pictures.  I have to admit the P4 wheels do look superb.   Your pictures allow us to compare the new Dapol offering to the old Mainline body.  I have to admit that there's not a lot in it, both capture the look of the prototype convincingly.  So the Whitbourne chassis was a product of the 80's, I might well have been a customer had I known of them at the time.  I certainly built a number of Perseverance chassis around that period.    

 

I've looked at the S4 Society data sheets before but the critical measurements for spacing the slidebars are not provided and can not be reliably determined.  Your post triggered a distant memory and I remembered that I have a set of P4 mogul wheels (Ultrascale)  that were included in a kit I purchased years ago, so I'm going to gauge up a pair with the appropriate crank pins so that I can measure the distance across the faces of the lead crank pins.  I'll then add 0.4mm to allow for clearances and this will give me the dimension required between the backs of the cross heads.

 

Thanks,

 

Frank

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12 minutes ago, Chuffer Davies said:

I've looked at the S4 Society data sheets before but the critical measurements for spacing the slidebars are not provided and can not be reliably determined.

 

GWR outside 2-cylinder sets had 6'10" piston centres. Slidebars are typically 5.5" wide, and 2.5" high (at their thickest point). The c 2000 redesign of the Comet cylinder set put the piston centres on 28mm, the previous 27.7 being a bit uncomfortable.

 

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19 minutes ago, Miss Prism said:

 

GWR outside 2-cylinder sets had 6'10" piston centres. Slidebars are typically 5.5" wide, and 2.5" high (at their thickest point). The c 2000 redesign of the Comet cylinder set put the piston centres on 28mm, the previous 27.7 being a bit uncomfortable.

 

Considering how little clearance there is in 00, I'm surprised you can get them to work in P4

I've used Markits wheels in 00 with Comet 43XX frames and motion and the clearance is minimal.

 

 

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I spent a couple of hours tarting 'down' mine a bit. Paint finish has been given a matt all over. I have added real coal, lamp, crew. weather sheet, painted the tyre rims black and rods oily steel, removed front coupling socket added microstrip to cross heads to give an impression of a tree dimensional casting. I also changed the number. 6336 was a Welsh engine in the 1930's so not much chance it would be on a local Bristol- Salisbury train. 6348 was an Oxley engine but did make it to Westbury on freights from Bordersley. Westbury has 'borrowed' it on local duties, before she returns back to the midlands on the north bound working.

 

As point, be careful if you touch the pony wheels. Mine was running fine then derailed all over the place. I had managed to push in the split axles and altered the gauge. My bad but sorted now. A touch of superglue and the gauge is now maintained. On trial it hauled seven heavy kit built coaches on the up and down incline circuit with no issues. The first rtr steam that has done that on my line.

 

Mike Wiltshire1945349702_Mogul(1).JPG.fd64633165aa4ece05bbb87b2fed5479.JPG1572401508_mogul(3).JPG.49b67ebe3c87de95ccdb8bc5f2928227.JPG1602891203_Mogul(4).JPG.0a62dd64211c5889252377b47d652387.JPG948987721_mogul(2).JPG.59556979f19743e1b8b2ab59f7f63050.JPG

 

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3 minutes ago, Coach bogie said:

I spent a couple of hours tarting 'down' mine a bit. Paint finish has been given a matt all over....

 

Mike Wiltshire

 

 

Looks excellent. What did you make the weather sheet out of? 

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3 minutes ago, Pteremy said:

 

Looks excellent. What did you make the weather sheet out of? 

Black tissue paper from one of my wife's shoe boxes - she won't notice. Got away with that one when I detailed up an open cab Pannier. retaining wire is a single strand of wire from bell bale.

 

Mike Wiltshire

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1 hour ago, Chuffer Davies said:

...Your pictures allow us to compare the new Dapol offering to the old Mainline body.  I have to admit that there's not a lot in it, both capture the look of the prototype convincingly. 

Perhaps. But if you place them side by side the Bachmann version shows its age in terms of the thickness and size/presence of moulding detail.

 

But on a positive note whereas Dapol has accurately modelled late moguls - so approx 63xx numbers - the Bachmann version has the characteristics of earlier batches in the series - thinner motion bracket, the earlier side splashers, and a tall safety valve cover. So it still has value if you are after the earlier versions.

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Has anyone had issues with the loco seizing up?

 

Although the instructions say running-in is not needed, thats what I am now doing. It seems to be running better, (on DC), but is still not perfect.

 

There doesn't seem to be any rhyme or reason to where / how its seizing and/or sticking when going round at slow speed on the rolling road.

 

I will preserve and see how I get on tomorrow.

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7 hours ago, Neal Ball said:

Has anyone had issues with the loco seizing up?

 

Although the instructions say running-in is not needed, thats what I am now doing. It seems to be running better, (on DC), but is still not perfect.

 

There doesn't seem to be any rhyme or reason to where / how its seizing and/or sticking when going round at slow speed on the rolling road.

 

I will preserve and see how I get on tomorrow.

 

Can you try it on track? Personally I'm not a fan of using rolling roads to run locomotives in; the dynamics are different. If you're not happy with track performance, I'd suggest looking closely to see if it needs a drop or two of oil. I know it's not supposed to be needed, but you never know.

 

Nigel

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4 hours ago, NCB said:

 

Can you try it on track? Personally I'm not a fan of using rolling roads to run locomotives in; the dynamics are different. If you're not happy with track performance, I'd suggest looking closely to see if it needs a drop or two of oil. I know it's not supposed to be needed, but you never know.

 

Nigel


Strangely I also thought of that. I have a circle of track that I was going to put together.

 

Clearly I’m hoping it frees up, as it was getting better yesterday. Failing that I will be laying out some track somewhere.

 

Thanks for the suggestion.

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5 hours ago, Neal Ball said:


Strangely I also thought of that. I have a circle of track that I was going to put together.

 

Clearly I’m hoping it frees up, as it was getting better yesterday. Failing that I will be laying out some track somewhere.

 

Thanks for the suggestion.

 

I think you want some straight lengths in your test track, so you can see how the loco behaves on the transition from straights to curves.

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1 minute ago, Budgie said:

 

I think you want some straight lengths in your test track, so you can see how the loco behaves on the transition from straights to curves.

A figure of eight would be good to see how it goes round curves of opposite hand too.

 

And some points...

 

Oops, we've got a trainset!

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10 hours ago, NCB said:

 

Can you try it on track? Personally I'm not a fan of using rolling roads to run locomotives in; the dynamics are different. If you're not happy with track performance, I'd suggest looking closely to see if it needs a drop or two of oil. I know it's not supposed to be needed, but you never know.

 

Nigel

I had a similar problem with my Terriers. Cleaning the wheels and oiling helped a lot. From the reports on here, it seems that some Moguls run well but others are problematical. 

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1 hour ago, Budgie said:

 

I think you want some straight lengths in your test track, so you can see how the loco behaves on the transition from straights to curves.

 

1 hour ago, St Enodoc said:

A figure of eight would be good to see how it goes round curves of opposite hand too.

 

And some points...

 

Oops, we've got a trainset!

 

55 minutes ago, No Decorum said:

I had a similar problem with my Terriers. Cleaning the wheels and oiling helped a lot. From the reports on here, it seems that some Moguls run well but others are problematical. 


Thanks very much for the comments. 
 

Today as they say is a different day..... I started with the loco going backwards,  which it happily did for 1/2 hour.... as soon as I set it to go forward, it stopped straight away. I was in the middle of soldering, so gave carried on and left the loco for the time being.

 

to be continued....

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This is part 2 of my explanation into how I intend to go about converting a Dapol mogul to EM gauge:

 

I took delivery of my 63xx on Monday and as I have no facilities for OO models I immediately set to and invalidated any warranty by significantly dismantling the loco and tender. 

 

The tender frames sit in a rebate around the inside of the valance.  There are four small screws, one in each corner, that attach the frames to the body and then two further screws that allow the speaker housing to be removed from the top of the frames.  Detail is excellent and whilst there are a couple of things to put right on the whole I'm delighted with the tender.

 

In the following picture I have already removed the brass shim pickups from the top of the frames because they were preventing me from taking some of the measurements I needed.

1560872427_TenderDismantled.jpg.5dd53b7728595e2d9b834ab42a01319d.jpg 

The locomotive splits down into three main parts: the chassis, the footplate and the cab, boiler, smokebox assembly.

 

The chassis is retained with three screws, two small ones under the cab and one between the front of the cylinders.  It is necessary to remove the circuit board for the DCC chip through the smokebox door opening before the chassis will drop away from the superstructure.  As you would expect the bottom of the boiler barrel comes away with, and is part of the chassis's casting.

 

The superstructure comprises a cast metal (Mazak?) footplate and a plastic moulded cab, boiler, smokebox assembly.  Once the chassis has been removed this reveals a single screw under the centre of the cab floor to release the back of the plastic assembly from the footplate.  There are four small clips that also hold this assembly to the footplate, these release very easily once the screw under the cab has been removed.

 

765004142_63xxDismantled.jpg.3e66270af7e7ff49ba1829ed346135e8.jpg

  

I still need to study the model in more detail but I do foresee some immediate challenges for my conversion. 

 

As far as the tender is concerned I think I may end up retaining the brake hangers because removing plastic from behind the frames to make space for etched hangers will be difficult without damaging the external detail.  Fortunately the brakes are not aligned with, and are significantly outboard of, the OO wheels so should line up reasonably well with EM wheel sets.  The good news is that there is clearance (just) for a motor inside the tender albeit approximately 0.2mm.  

 

The loco is going to be more challenging because the metal footplate curves down to follow the bottom of the cab sheets.  This means that the metal of the footplate's rear will occupy the space I need for the universal joint in the drive train.  I'll need to think seriously about how to mitigate this but its not going to be insurmountable I'm sure.  

 

The next stage is to finalise the components for the tender before taking on the challenge of designing how to install the drive train under the cab of the locomotive.  

 

Watch this space.....

 

Frank

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I've just been catching up on the slidebar discussion but haven't noticed any comment on how far the slidebars are apart. The prototype drawing shows they should be 1' 4"  (5.33 mm) apart. My model measures only 4.6 mm, so here's another reason that the ends of the slidebars are turned up.

 

David

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1 hour ago, David Burton said:

I've just been catching up on the slidebar discussion but haven't noticed any comment on how far the slidebars are apart. The prototype drawing shows they should be 1' 4"  (5.33 mm) apart. My model measures only 4.6 mm, so here's another reason that the ends of the slidebars are turned up.

 

David

The Hornby 61XX are about 5.2mm apart.

 

What are the measurements for the slide bars & connecting rods on the drawing?

Hornby have 20mm (5'0") long slide bars and 28mm long (7' 0") connecting rods.

Cylinder centres are about 27.5mm or 6' 9"

 

(As my 63XX hasn't arrived yet I can't check that)

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10 minutes ago, melmerby said:

The Hornby 61XX are about 5.2mm apart.

 

What are the measurements for the slide bars & connecting rods on the drawing?

Hornby have 20mm (5'0") long slide bars and 28mm long (7' 0") connecting rods.

Cylinder centres are about 27.5mm or 6' 9"

 

(As my 63XX hasn't arrived yet I can't check that)

I don’t have a GA drawing for the mogul but do have a drawing for the County 4-4-0.  According to that drawing the distance between the inside faces of GW slide bars is 1’4” (5.33mm).  I would agree that the Dapol slide bars appear to be too close together which explains the need for the excessive tapers at the ends of their slide bars.  It’s still a very good model but it does seem an unnecessary compromise on the part of Dapol. 
 

Frank

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9 hours ago, Neal Ball said:

 

 


Thanks very much for the comments. 
 

Today as they say is a different day..... I started with the loco going backwards,  which it happily did for 1/2 hour.... as soon as I set it to go forward, it stopped straight away. I was in the middle of soldering, so gave carried on and left the loco for the time being.

 

to be continued....


All fixed now, no thanks to Dapol who I phoned thus afternoon and were not helpful at all.

 

See the comments and photos on my Henley page if Your loco will not run correctly / seizes up. Hopefully there is no lasting damage.

 

Note: If you are going to remove the body, the Next18 socket is too big for the bottom of the boiler. You need to jiggle around with it to get it out.

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7 hours ago, Chuffer Davies said:

This is part 2 of my explanation into how I intend to go about converting a Dapol mogul to EM gauge:

 

I took delivery of my 63xx on Monday and as I have no facilities for OO models I immediately set to and invalidated any warranty by significantly dismantling the loco and tender. 

 

The tender frames sit in a rebate around the inside of the valance.  There are four small screws, one in each corner, that attach the frames to the body and then two further screws that allow the speaker housing to be removed from the top of the frames.  Detail is excellent and whilst there are a couple of things to put right on the whole I'm delighted with the tender.

 

In the following picture I have already removed the brass shim pickups from the top of the frames because they were preventing me from taking some of the measurements I needed.

1560872427_TenderDismantled.jpg.5dd53b7728595e2d9b834ab42a01319d.jpg 

The locomotive splits down into three main parts: the chassis, the footplate and the cab, boiler, smokebox assembly.

 

The chassis is retained with three screws, two small ones under the cab and one between the front of the cylinders.  It is necessary to remove the circuit board for the DCC chip through the smokebox door opening before the chassis will drop away from the superstructure.  As you would expect the bottom of the boiler barrel comes away with, and is part of the chassis's casting.

 

The superstructure comprises a cast metal (Mazak?) footplate and a plastic moulded cab, boiler, smokebox assembly.  Once the chassis has been removed this reveals a single screw under the centre of the cab floor to release the back of the plastic assembly from the footplate.  There are four small clips that also hold this assembly to the footplate, these release very easily once the screw under the cab has been removed.

 

765004142_63xxDismantled.jpg.3e66270af7e7ff49ba1829ed346135e8.jpg

  

I still need to study the model in more detail but I do foresee some immediate challenges for my conversion. 

 

As far as the tender is concerned I think I may end up retaining the brake hangers because removing plastic from behind the frames to make space for etched hangers will be difficult without damaging the external detail.  Fortunately the brakes are not aligned with, and are significantly outboard of, the OO wheels so should line up reasonably well with EM wheel sets.  The good news is that there is clearance (just) for a motor inside the tender albeit approximately 0.2mm.  

 

The loco is going to be more challenging because the metal footplate curves down to follow the bottom of the cab sheets.  This means that the metal of the footplate's rear will occupy the space I need for the universal joint in the drive train.  I'll need to think seriously about how to mitigate this but its not going to be insurmountable I'm sure.  

 

The next stage is to finalise the components for the tender before taking on the challenge of designing how to install the drive train under the cab of the locomotive.  

 

Watch this space.....

 

Frank

 

Thank you for posting this. Is there any room for adding extra weight to the loco?

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10 minutes ago, Budgie said:

 

Thank you for posting this. Is there any room for adding extra weight to the loco?

That would depend on whether you are happy to change the wiring regime?  The smoke box is currently used to house the DCC cicuitry.  If you did away with the printed circuit board then the there is probably 25+mm depth inside the smoke box where ballast could be added.  If you still want DCC you could then put the chip in the tender by re-jigging the draw bar's 4 way wiring to carry the track feed from the wheels to a chip in the tender and then the connections from the chip to the motor.

 

It all depends how brave (or foolish?) you are. 

 

Frank  

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