NRM Deltic Conversion to P4

John Fitton

NRM Deltic Conversion to P4

Postby John Fitton » Thu Mar 17, 2016 9:53 am

Hello,

I am about to order the latest NRM Deltic model which I have found from the RM site has six-axle drive, unlike the production model which has awful 4-axle drive.

Has anyone converted the model with Ultrascale wheels, and how does it perform? I couldn't locate a conversion set readily on the U/S site.

John Fitton

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grovenor-2685
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Re: NRM Deltic Conversion to P4

Postby grovenor-2685 » Thu Mar 17, 2016 10:41 am

Branchlines may have a suitable set, they do stub axles suitable for LMS 10000 as well as ordinary 2mm axles. You need to know the bogie design.
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Keith
Grovenor Sidings

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Re: NRM Deltic Conversion to P4

Postby ianpenberth » Thu Mar 17, 2016 4:05 pm

For the record, more recent Bachmann production Deltics have had a six-wheel drive unit, similar to the Class 47 and the NRM Prototype Deltic.

Assuming that these models have not been 'updated' to use half-axles with plastic gear muffs, the Branchlines wheels with solid axles are a suitable choice.

The Prototype Deltic has a similar wheelbase to the Class 47 and suffers from similar problems when converted. You might - ahem - consider a sprung chassis?
Ian
PenBits Model Railways - Diesel bogie springing and detailing

John Fitton

Re: NRM Deltic Conversion to P4

Postby John Fitton » Thu Mar 17, 2016 10:57 pm

ianpenberth wrote:For the record, more recent Bachmann production Deltics have had a six-wheel drive unit, similar to the Class 47 and the NRM Prototype Deltic.

Assuming that these models have not been 'updated' to use half-axles with plastic gear muffs, the Branchlines wheels with solid axles are a suitable choice.

The Prototype Deltic has a similar wheelbase to the Class 47 and suffers from similar problems when converted. You might - ahem - consider a sprung chassis?

Actually this is what I was wondering. I will consider for sure!

John Fitton.

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Re: NRM Deltic Conversion to P4

Postby Horsetan » Fri Mar 18, 2016 9:26 am

You won't regret it! :thumb
That would be an ecumenical matter.

John Fitton

Re: NRM Deltic Conversion to P4

Postby John Fitton » Fri Mar 18, 2016 11:03 am

Horsetan wrote:You won't regret it! :thumb


Hi,

Could you share some experiences or details?

John

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John Donnelly
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Re: NRM Deltic Conversion to P4

Postby John Donnelly » Fri Mar 18, 2016 1:51 pm

John Fitton wrote:
Could you share some experiences or details?



I can :D

Having never even soldered before, I'm in the process of building one of Ian's sprung chassis here: viewtopic.php?f=122&t=4720 (OK it's for a BoBo rather than a CoCo but it's just fewer bearings to deal with)

I cannot sing it's praises highly enough in terms of ease of build and the instructions that allow even a ham fisted beginner like me to put it all together and for it to work.

As Ian mentioned, Bachmann's CoCo chassis have a tendency to have a centre axle that is ever so slightly lower than the outer axles which, with just a wheel swap, is enough to make them fall off even straight track.

I'll admit to being a little sceptical about the whole springing thing prior to starting on the 24 but now I'm a convert and intend to, ultimately, convert all my locos using Ian's kits.

Other than asking numerous questions over the last 3 S4Ns I have other connection to Ian other than being a very satisfied customer.

John

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Re: NRM Deltic Conversion to P4

Postby Terry Bendall » Fri Mar 18, 2016 2:18 pm

John Donnelly wrote:As Ian mentioned, Bachmann's CoCo chassis have a tendency to have a centre axle that is ever so slightly lower than the outer axles which, with just a wheel swap, is enough to make them fall off even straight track.


Yes they do sometimes. Two good tips which I picked up from Phil Eames of Calcutta Sidings fame ...

Before you removed the OO wheels check with a steel rule to see if the centre axles is lower than the other two. Doing that enables it to be corrected and you know it was not the conversion that caused the problem. I usually pare out a sliver or two of plastic from the bottom of the slot with a scalpel. The other tip is to use Gibson wheels for the centre axle and Branchlines for the outer ones. The Gibson ones are apparently slightly smaller in diameter.

Terry Bendall

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Re: NRM Deltic Conversion to P4

Postby dal-t » Fri Mar 18, 2016 2:40 pm

Terry Bendall wrote: I usually pare out a sliver or two of plastic from the bottom of the slot with a scalpel.


This is probably one of those idiot questions (well, it's certainly an idiot asking it!) but if the axle is too low, don't you have to create some leeway at the top of the slot to correct it?
David L-T

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Re: NRM Deltic Conversion to P4

Postby ianpenberth » Fri Mar 18, 2016 3:08 pm

Also be aware that the wheels that Bachmann fit to the Deltic Prototype are significantly under scale diameter.

Ultrascale tend to stick to the (model) manufacturers' original diameter with their 'drop in' conversions, to 'preserve the original ride height' IIRC is the reason.
Ian
PenBits Model Railways - Diesel bogie springing and detailing

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Re: NRM Deltic Conversion to P4

Postby grovenor-2685 » Fri Mar 18, 2016 4:37 pm

This is probably one of those idiot questions (well, it's certainly an idiot asking it!) but if the axle is too low, don't you have to create some leeway at the top of the slot to correct it?

Yes but Terry was holding it upside down when doing that!
Mind you in some cases the amount that you would need to remove is impractical.
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Keith
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Re: NRM Deltic Conversion to P4

Postby Terry Bendall » Sat Mar 19, 2016 12:44 pm

grovenor-2685 wrote:Yes but Terry was holding it upside down when doing that!


Apologies for not making my comment clearer and thanks to Keith for explaining things.

I have converted a lot of Bachmann class 37s and a few 47s and have rarely had much of a problem with the centre wheels being lower that the others. Luck or what?

ianpenberth wrote:Ultrascale tend to stick to the (model) manufacturers' original diameter with their 'drop in' conversions


This is a problem that some may not appreciate. The Ultrascale wheels are a direct replacement for the OO ones and if there are mistakes in the dimensions of the OO wheels they will almost certainly be replicated with the P4 ones. My preferred choice for conversion of diesel models is the well know solution of using Black Beetle coach wheels as sold by Branchlines in conjunction with the original drive gears. Much cheaper, normally no supply problems and not very much more difficult to do.

Terry Bendall


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