Jump to content
 

Hornby R751 engine rebuild


andyman7
 Share

Recommended Posts

Back on the wider shores of RM web the Triang (later Hornby) Class 37 is an obsolete relic, but for those of us with the collecting bug (or a bit of OCD) it is a model with a fascinating history, made from 1966 to around 2007 across numerous variations starting life in Margate and ending up as a China-made model until the acquisition of Lima gave Hornby the tooling for a much more up to date and accurate model.

 

Now this is one model I have avoided trying to get all the versions of but key variants that 'tell the story' are a different matter. The most recent of these was to try and get a 1977 transition version that featured the revised TOPS number but was still mounted on the old worm-drive chassis and X337 power bogie. The Class 37 and Hymek were the only two models to survive the transition to Ringfield motors - everything else from the Triang era being deleted and replaced by new models. The Hymek did better out of this by gaining bogies with the correct wheelbase; the Class 37 lost its incorrect A1A bogies for a set of also incorrect Class 47 bogies (although the class 47 sideframe design did bear a slight resemblance to the correct pattern).

 

The chassis change required the footsteps below the doors to be opened up to accept chassis clips, and the deletion of the screw boss inside the bodyshell. Aroud this time, the self coloured blue plastic began to be matt lacquered and the number tool was updated from D6830 to 37 130 (actually the same TOPS number that the real D6830 acquired, showing a distinct lack of imagination in the era before muitiple renumbered versions of a model became common). Pat Hammond's book doesn't include the variant with the later number but earlier chassis in his hsitory of Triang and Hornby volume 3 but I knew they existed and looked to track one down. What I ended up with was a virtually mint chassis and body with all fittings but missing the motor bogie. Having picked up many spares over the years I realised that I had pretty much all the bits plus the knowledge to construct an absolutely accurate late production X337 that would match the model, and realising how tremendously exciting this is (!) I decided to document the process. First the parts for the motor bogie:

 

IMG_20200802_134833.jpg

Edited by andyman7
  • Like 4
Link to post
Share on other sites

The armature is a brand new old stock one I had, bought in the 1980s from Blackwells of Hawkwell when they had huge stocks of the obsolete Hornby parts from the old mechanisms. The bogie keeper plate is another new old stock item, correct later design with flush screw holes. The brass pickups have the later pattern capacitor fitted. The one new part is a Peter's Spares remanufactured 'top hat' to hold the assembly together. This (like the keeper plate) is moulded in Polystyrene which really doesn't like the mineral oils that these mechanisms spent most of their life lubricated with. Over time they degrade and eventually become brittle and this has in turn exhausted new old stock spares. This was my first chance to use a remanufactured one and it is superb, everything fitted together perfectly.

 

IMG_20200802_134836.jpg

  • Like 3
Link to post
Share on other sites

The X337 motor bogie was initially a self powered standalone unit, but after 1973 production was modified to allow for a pair of additional trailing bogie pickups, which my late chassis has. So the first job before any assembly was to solder the green and black wires to the brass pickups. This is much better done before assembling the motor bogie as the plastic top hat housing doesn't really like the proximity to a hot soldering iron. The top motor assembly is then put together. For the lower part, it's a bit fiddly to get the armature in with the pole pieces around it and the magnet in the right way round (it can go in either way but if it's the wrong way the loco will go in the opposite direction to everything else). All the time, the magnet needs to either be in place with the pole pieces and armature, or held on a suitable metal 'keeper' to prevent loss of magnetism. 

 

IMG_20200802_135642.jpg

IMG_20200802_135940.jpg

IMG_20200802_140757.jpg

Edited by andyman7
  • Like 5
Link to post
Share on other sites

Once assembled, the task of getting the motor to turn over began. These motors pull a fair bit more current than modern motors, and we are talking about a brand new assembly of old parts with oxidisation on conductive areas etc. I used an old school controller and with a bit of prodding got it to begin to turn. I then lubricated it with a modern synthetic oil that will not eat the polystyrene parts, made some adjustments to brush tensions etc, and bench ran it to lets the parts bed in. In no way is it fully run in, but it is functioning. Finally a correct pattern MkIIIc metal X171 coupling was fitted using the correct post-1975 metric crosshead screw (there, I said I knew my stuff...).

 

These last photos show the body and chassis - you can see that the body retains the filled in cab footsteps so although this is a 1977 body, it can only be fitted to the old pre-Ringfield chassis. Also, underneath the body, the Triang name has been deleted - this was a very late change as most ex Triang locos retained the moulded Triang name for quite a few years after loss of the trademark in 1972.

 

So there you have it - this may be unusual but it is not in any sense valuable and the whole exercise is one for my entertainment (and hopefully yours...well, up to a point....)

 

 

IMG_20200804_204747 (2).jpg

IMG_20200804_204906.jpg

IMG_20200804_205022.jpg

Edited by andyman7
  • Like 8
Link to post
Share on other sites

The supply of original parts is not quite exhausted...

 

We have inherited a large amount of spares for Tri-ang and Hornby Dublo models from the stock of a service dealer, including a box of the top hat mouldings and spider pick ups.

 

We are still sorting out the spares...

 

It may be worth saying that these parts were used on the Hymek and TC Series Budd Railcar short wheelbase bogies, as well as the EM2, and Class 31/ Class 37 bogies.

  • Informative/Useful 1
Link to post
Share on other sites

They are useful spares The top hat mouldings or prone to fracture (or even melting!) and the spiders wear out.

 

A small piece of phosphor bronze soldered to one of the spiders (to make contact with the brush which hinges on the plastic) increases reliability as the complex earthing arrangement on the pivot can be eliminated.

 

A project (on hold as always!) is to do one as 'Andromeda' in Europhoenix livery.

Edited by Il Grifone
  • Like 1
Link to post
Share on other sites

11 hours ago, Sarahagain said:

The supply of original parts is not quite exhausted...

 

We have inherited a large amount of spares for Tri-ang and Hornby Dublo models from the stock of a service dealer, including a box of the top hat mouldings and spider pick ups.

 

We are still sorting out the spares...

 

It may be worth saying that these parts were used on the Hymek and TC Series Budd Railcar short wheelbase bogies, as well as the EM2, and Class 31/ Class 37 bogies.

35 years of collecting means I have a pool of the spares common and less comon but there are always gaps. Useful to hear about the 'top hats'. Now if you happen to have any X117 wheel/gear/axle assemblies with the smooth treads as used in 1970s production R157 DMUs I'd love to know because they are rare as hen's teeth because the available spares were used to replace the godawful ridged wheels on earlier versions as well as on Blue Pullmans!

Link to post
Share on other sites

Interesting topic - I have just two of them No 37 073 and 37 130. Apart from not having run since being bought new in tiddly umpty - last century, anyway - they're still good to go. They were originally bought with the intention of running a full length MGR train - the train was only completed a couple of years ago - but I think they might have been seriously underpowered for the job!

 

Here's a picture of them with their Bachmann replacements:

 

DSCF0031.JPG.8475bb8b0034aeb0a1171d0fed407a6c.JPG

 

Cheers,

 

Philip

  • Like 3
Link to post
Share on other sites

There's plenty of power from the motor and space for a second power bogie and weight. It just requires a hefty power supply to supply the current.

 

I reamed out HD wheels to fit the plastic axles for my Tri-ang DMU to get rid of the knurled horrors. They do have an awful profile, but were to run on HD track.

 

I have four of them (2 green,1 blue and a Railfreight). There are enough bits to build a chassis (I think) and I need a body for 'Andromeda' *. The question is: hand paint the complex livery or 25 quids worth of decals?  Some sort of constant lighting is also needed for the headlights. I was thinking along the lines of a 3v disc battery and white LEDs controlled by the polarity and presence or lack of, traction voltage. My Danish and American locomotives will all need the same circuit, so it's development will not be wasted. (Another project - I bought the batteries about a year ago (Poundland - usual disclaimer). They are good until 2028 so no immediate hurry.)

She will also need something to pull. I have a few air-braked vehicles, but Rule 1 will have to be called into play....

 

* Other names are possible https://europhoenix.co.uk/fleet.php

I gather this is out of date as there are also 'Cephus' and 'Cassiopeia'.

 

Edited by Il Grifone
  • Like 2
Link to post
Share on other sites

I did something similar last year, having "inherited" a "spares or repair" 37 as part of a lot on ebay, I was after the SR EMUs which were also part of the lot. The body had seen better days, and the motor bogie was missing many parts, many of which I had to hand, including a new motor magnet, whilst the rest came from Ebay. I rebuilt the motor bogie, fixed many of the chips on the body, repainted the roof, gave it full height yellow ends and renumbered it. I'm very pleased with the result, a new loco for nothing.

 

As Sarah says, the bogie design was first used on the EM2, then the Class 31. 

  • Like 1
Link to post
Share on other sites

13 minutes ago, GoingUnderground said:

As Sarah says, the bogie design was first used on the EM2, then the Class 31. 

As far as I know the bogie design was first used on the TT A1A and then copied on the 00 models. TT were also the first models with the tension lock coupling that became the norm for many years after. 

 

Garry  

Edited by Silverfox17
  • Agree 3
Link to post
Share on other sites

On 05/08/2020 at 19:40, andyman7 said:

35 years of collecting means I have a pool of the spares common and less comon but there are always gaps. Useful to hear about the 'top hats'. Now if you happen to have any X117 wheel/gear/axle assemblies with the smooth treads as used in 1970s production R157 DMUs I'd love to know because they are rare as hen's teeth because the available spares were used to replace the godawful ridged wheels on earlier versions as well as on Blue Pullmans!

What is the diameter over the tread of the X117 wheels?  I have quite a few small smooth Triang wheels I bought from Cheltenham Model Centre years ago at about 50p for 4 which I mistakenly thought I could use.. No gears/ axles just wheels.  They are smaller than Dock Shunter,  I no longer have any AIA/37/Hymek worm drive chassis for comparison.  

My Triang 37 grew a Lima Power bogie, and the Hymek will one day arise with cast bogies both ends spoked wheels and the chassis milled out for daylight round the equalising beams

Edited by DavidCBroad
  • Like 1
Link to post
Share on other sites

I haven't either to hand, but IIRC* the Class 31 etc. bogies have smaller wheels than the Dock Shunter/pseudo F7 etc. bogies. Fitting the smaller wheels would help with the excess height of the latter.

 

*As in 90% sure.

  • Agree 1
Link to post
Share on other sites

25 minutes ago, Il Grifone said:

I haven't either to hand, but IIRC* the Class 31 etc. bogies have smaller wheels than the Dock Shunter/pseudo F7 etc. bogies. Fitting the smaller wheels would help with the excess height of the latter.

 

*As in 90% sure.

They are smaller diameter. 

 

Also off topic, the brass cog wheel is the same as used in the TT Jinty, Castle, Britannia etc but not the A1A and DMU.  The only difference is the 00 ones need a Romford bush as the axles are slightly different 9/64" as opposed to TT at 1/8".

 

Garry 

  • Like 1
Link to post
Share on other sites

Is that the 'Scotsman' concerned in the video? A blue version is again very rare. They cost around £10 in the fifties which was around a weeks wages and would have bought a complete Hornby Dublo train set. Dublo never made anything in BR blue (Korean war shortages I suspect) and only got around to BR livery in 1953. The 'Scotsman' chassis is marked 'Foreign' on the centre rail collector. One couldn't mention 'Germany' back then! So much so that we refused to join the European Common Market when it started. We soon realised our error, but have forgotten since.... (Sorry politics!).

  • Like 1
Link to post
Share on other sites

5 hours ago, DavidCBroad said:

What is the diameter over the tread of the X117 wheels?  I have quite a few small smooth Triang wheels I bought from Cheltenham Model Centre years ago at about 50p for 4 which I mistakenly thought I could use.. No gears/ axles just wheels.  They are smaller than Dock Shunter,  I no longer have any AIA/37/Hymek worm drive chassis for comparison.  

My Triang 37 grew a Lima Power bogie, and the Hymek will one day arise with cast bogies both ends spoked wheels and the chassis milled out for daylight round the equalising beams

They are smaller than the dock shunter ones - the X117 has a metal axle so one of the wheels is fitted with an insulated bush whereas for the A1A/EM2/Hymek, a plastic axle is used so both wheels are all metal force fit. It's the ones that come in a bushed/unbushed pair that are the ones needed for X117.

Edited by andyman7
  • Agree 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...