Converting the Dapol Mogul

[Brendan LlewellinParticipant]

Has anyone converted a Dapol Mogul, or had any thoughts on the subject?

[Bill EatonParticipant]

There is a lengthy thread on RMWeb headed “OO Gauge GWR Mogul and Prairie” which includes a number of posts by Frank Davies, who has built a new chassis for the Mogul which begs the question whether a conversion is even possible. This link might take you there:

https://www.rmweb.co.uk/community/index.php?/topic/129125-oo-gauge-gwr-mogul-and-prairie/

 

[Dai DaviesParticipant]

But for us mere mortals – Frank is an engineer/modeller par excellence- I would check whether the wheels could be pulled out, whether you need to scrape out wheel arches, etc. I believe the manufacturers are missing a trick by not being as friendly about such conversions: they provide more and more detail but don’t help modellers who probably best appreciate the detail. Hey ho, rant over.

[Bill EatonParticipant]

As a fellow mere mortal I agree entirely Dai. The idea of buying a RTR model and then effectively discarding the entire chassis and mechanism and replacing with a kit or scratchbuilt chassis and new motor/gearbox has little or no appeal for me. What I wish to do is exactly as you describe. I do not mind having to buy new wheels if that is necessary. So, any info I can find on the feasability of relatively straight forward conversions is always welcome.

[Dai DaviesParticipant]

Hello Bill, I don’t know the vagaries of the Dapol Mogul drive train, but generally the conversion is a lot easier when there is a single driving axle.  I have done a few Bachmann and Hornby locos by wheel-pulling, and some with Alan Gibson replacements. As it happens, I don’t need any more Moguls, so won’t be able to contribute much more. Over to you!😉

[Bill EatonParticipant]

Hello Dai. I have never tried wheel pulling, maybe I should give it a go. I have always thought that, with the great majority of locos having inside frames and with the ends of the axles being flush with the outer edge of the wheel boss, pulling the wheels outwards would lead to the wheels not being sufficiently secure on the axles. Therefore, I have assumed that keeping the existing RTR wheels would involve replacing the OO gauge axles with longer ones to suit EM gauge. Am I missing something here?

[Dai DaviesParticipant]

It is a suck it and see situation. Sometimes there is still sufficient grab, sometimes not. I know of some locos on exhibition layouts that were still chugging  away with the wheels pulled out, and with no apparent detriment to behaviour. On the other hand, my Bachmann 64xx needed axles and wheels replaced.

[Graham HudsonParticipant]

Hi Brendan,

I have done a Dapol GWR mogul for a customer. I used Gibson standard wheels on 2mm axles made by turning the pin points off standard wagon axles. The driving wheels were bushed with Branchlines 1/8″ to 2mm reducing bushes fixed with Loctite. You do need to add Loctite when pressing them on to the new axles and must use a suitable press such as GW models as you will only get one chance at this. This is because th Loctite will grab the axle so well that trying to use a wheel puller will wreck the wheels. The tender had gibson wheels fitted onto the original Dapol axles. Note that Gibson also makes similar bushes but I have found them eccentric! The loco was able to negotiate an A5 turnout and curves below 36″ radius even though there is not much side play possible.

[Brendan LlewellinParticipant]

Thank you Graham

That is just the sort of info I was looking for. Any comments on pickups or crankpins?  I have not yet had one of these locos to disect but would like to add one to my fleet.

[Graham HudsonParticipant]

Hello Brendan,

I can help with crankpins and pick ups on the Dapol mogul but details would take up a lot of space here. If you would like to hear more I can be emailed at g.hudson722@btinternet.com . A photo of the underside of the tender might help as my own notes are not detaile enough.

[Harry RylandParticipant]

I have also done one of these conversions.  As others have done, I used the existing tender axles but with Alan Gibson wheels.  I used a new 2mm axle for the pony wheels but kept the Dapol spacer and put it on the new axle.  I also used the available bushes for 1/8″ to 2mm on the driving axles.  I used the Alan Gibson ones and they were fine.  I found that 1.5mm of spacing washers either side were necessary on the front and rear drivers while 1mm was enough on the centre axle.  You need them on the rear axle otherwise the crank pin nuts can hit the fairing under the front of the cab.  The Dapol crankpins are 1.5 mm so Alan Gibson crankpins fit the existing coupling rods and connecting rod, though I left out the very thick washer that Dapol put between them.  The existing pickups worked fine with just a bit of a tweak.  You just need to be careful that the two wires to the Dapol pickup strip pass either side of the square block below the leading end of the keeper plate.  Otherwise they get caught between and cause trouble.

[Andrew AvisParticipant]

I have not had much success with pulling wheels out and tend towards fitting Gibson’s.

The lack of meat left on the axle is one problem that has been identified above. This seems to be less of a problem with non-steam outline models.

The other is the wheel profile. First the OO wheels tend to be a lot thicker thus reducing the amount of space you have inside the splashers/body/frame. The second problem is that the flanges are deeper and tend to run over the chairs of the track. and the third is that the thicker flanges can give you problems with crossing flange clearances on turnouts.

[Bill EatonParticipant]

I hope someone can help with a quick query – in order to use Alan Gibson wheels, which require a 1/8th” axle, on a Dapol mogul or large prairie which has 2mm axles, can I use the EMGS axle described as “EM Shoulder axle 1/8″ -2mm” which has product reference SKU: 5901?

[Trade OfficerKeymaster]

Hi Bill

It’s the other way round I’m afraid

The axles in question are to for a wheel requiring a 2mm axle into a chassis needing a 1/8″ axle. 

 

John

[Bill EatonParticipant]

Thanks for the clarification John. I am glad I asked the question! It seems that the 1/8th to 2mm bushes will be the solution.

[Brendan LlewellinParticipant]

Harry, thanks for that info. Very useful. What about the brakegear, is there enough clearance or does it need to be modified?

[Harry RylandParticipant]

The brakegear didn’t present any problems.  As I remember, I may have done the odd tweak with the pliers and a few passes with a suitable file but nothing major.  That’s probably why I forgot to mention it!

[Graham PriceParticipant]

Presumably the forthcoming Dapol Manor will have essentially the same chassis and the same issues. It will be interesting to compare the competing Accurascale Manor, since when Accurascale first appeared they were  anxious to ensure their products were conversion-friendly.

As a side point, 2mm bore/1/8″ OD bushes used to be available from EMGS stores and I  have used them successfully to convert the traditional Triang/Hornby chassis using the 9/64″/2mm axles also from the stores. They don’t appear in the current list – perhaps they were  the Gibson ones. They were a running rather than an interference fit on the conversion axles but loctite fixed them.

[Patrick HuntParticipant]

Hi,

1/8 to 2mm reducing sleeves are listed in the Alan Gibson catalogue. Packs of 30.

Hope this helps.

Patrick

[Brendan LlewellinParticipant]

Thanks for all the info, folks, the bits are ordered. I’ll let you know how the job goes.

[Harry RylandParticipant]

I hope it goes well.  I have written a more detailed description of what I did and  I understand that it will appear as a manual sheet with the next newsletter (number 232) which should appear in early April.

[Author]

Posts