Hornby Ruston 48DS to P4

decauville1126
Posts: 47
Joined: Tue Mar 12, 2013 8:50 am

Hornby Ruston 48DS to P4

Postby decauville1126 » Sat Sep 24, 2022 6:56 pm

I realise that this may have been looked at before, but I wanted to see just how easy - or not! - it could be economically done.

So the donor is one of the liveries I wouldn't have bought but it came at an excellent price from a classified ad on RMWeb. First job was to check it ran, which it did beautifully. Looked absolutely unused - wrong! First job was to separate the body from the chassis. Out with the four corner screws but no way was it coming out. Had to lever it out and then it became apparent why - the motor had been wrapped in some black tape that took an awful lot of IPA to shift, plus scraping. Off with the keeper plate, unsolder the wires to the pickups and remove the wheelsets.

I'd thought about possible options:

Reprofile the Hornby wheels using a P4 form tool I bought a while back from the society. Longer axles needed.
Fit 2mm society rims (they're almost P4) onto machined-down Hornby wheels. Longer axles needed.
Use Gibson 10.5mm disc wheels and think about current collection later.

Decided to go for the latter option as I had plenty to hand. The original wheelsets are on 2mm axles with knurled portions for the plastic wheel bushes and gear wheel and are easy to strip with pullers. Just the flanged brass axle bushes and gear wheel are retained.

P1050247.JPG


22.6mm was determined as a good axle length between the axlebox inside faces, so the Gibson axles were filed back and the new wheelsets built up. The gear wheel seems a reasonable push fit.

P1050253.JPG


So that's about it so far. Severe grinding will be required to the inside of the frame to clear the wheels (but it seems thick enough), and the keeper/pickup plate will need thought as the stalks for the brake shoes are only 0.7mm thick, so my usual way of drilling 0.5mm and mounting on wire won't do. But I tend to do things in achievable phases. Possibly make a brass understrap to mount the brake shoes, and just solder wire extensions to the pickups.

I'd like to separate the body from the chassis but despite removing the two tiny screws underneath nothing seems to want to budge. Am I missing a trick here? Also probably the lifting eyes - which are plastic - will get trashed but I can live with that. Please don't expect fast progress but I was pleasantly surprised how quick I got this far.
You do not have the required permissions to view the files attached to this post.

decauville1126
Posts: 47
Joined: Tue Mar 12, 2013 8:50 am

Re: Hornby Ruston 48DS to P4

Postby decauville1126 » Sun Sep 25, 2022 6:34 pm

A bit of free time today saw a tad more progress. I found an internet site describing fitting a sound card and dcc decoder which explained how to get the cab and bonnet off. It mentioned glue seep causing reluctance to part and so it proved. A scalpel along the base of the cab from the front, await the cracking sounds, and away it comes! Seems as if there was also some glue in other places too. The cab roof also came away with teasing - again it had been glued on.

First job was a holding jig made from a piece of skirting board with spacers and clamp from coffee stirrers and lollipop sticks to hold the frame. This gave a hand hold and helped protect the lifting eyes. Grinding out with a minidrill was surprisingly easy as the mazak seems quite soft. A few times the drill slipped and nicked the outside face but the loco will be repainted anyway, possibly retaining the wasp stripes.

P1050260.JPG


Once all were ground out the chassis and wheelsets were dropped in and metered for short circuits - thankfully none at this stage.

P1050262.JPG


P1050263.JPG


A quick check of ride height was 14mm, so spot on give a tad. A quick test with butanone on the keeper plate shows it's not solvent weldable so it'll probably be a buckle for the brake shoes, and the current collectors will be extended with wire. I think the original Hornby wheels gave a good appearance in terms of size due to their larger flanges, and that 10mm would probably be a wee bit more preferable, but I can live with the 10.5mm Gibson's. Easy enough to later pop in a couple of extra holes per face. Yes it's tight inside the frame but there's plenty of meat to grind into.
You do not have the required permissions to view the files attached to this post.
Last edited by decauville1126 on Sat Oct 01, 2022 8:58 pm, edited 1 time in total.

User avatar
Noel
Posts: 1972
Joined: Wed Jun 23, 2010 1:04 pm

Re: Hornby Ruston 48DS to P4

Postby Noel » Sun Sep 25, 2022 7:25 pm

It looks as though both wheels on one axle are in need of some adjustment...
Regards
Noel

Porcy Mane
Posts: 129
Joined: Wed Apr 11, 2012 4:55 pm

Re: Hornby Ruston 48DS to P4

Postby Porcy Mane » Sun Sep 25, 2022 9:14 pm

Hello,
Since their introduction I've converted a few of the 48Ds to both EM and P4 using a variety of different methods. I had written the different methods up on RMweb but all of the pics have disappeared since the site crash earlier in the year. Hope you find the following pics of some use.

First up to separate the cab/bonnet from the cast running plate; the metal cab is retained by two countersunk screws accessed from the bottom of the running plate. Ringed below. The plastic bonnet itself is retained in position by the cab casting. Both release from the running plate with the two cab screws removed.

48DS-Hornby-008-EditSm.jpg


48DS-Hornby-045-EditSm.jpg


Initially I was going to try to use Gibson lowmac wheels but milling some clearance would be needed so I decided to try black beetle wheels (Branchlines) and strangely these slipped between the running plate casting with no machining being necessary. I still milled some clearance for one P4 conversion as I had to do it for EM. For the EM conversions the machining was necessary along with deepening (heightening it in reality) the clearance as the extra height of the larger EM flanges was causing occasional shorting.

48DS-Hornby-011~013-EditSm.jpg


48DS-Hornby-063-EditSmDIME.jpg


I also have used the original wheels by thinning the width down to 2mm by turning material from the front face. I re-profiled the flange to something what looked like a P4 profile (this was in the days way before the society wheel profile tool became available) and the loco with these wheels ran fine but I wasn't happy with the wheels fidelity with prototype.

48DS-Hornby-066-EditSm.jpg


48DS-Hornby-067-EditSm.jpg


PO-WR-617-Darlo-030-EditSm.jpg


Finally and what was always my original intention, was to use 2mm society 10mm tyres grafted onto the original wheelsets. At only 1.3mm wide I thought the tyre a little thin and risked dropping into crossing flangeways. The photograph should show how I machined the original wheel to accept the 2mm society tyre whilst retaining an overall tyre width of 1.8mm. I also thought the 2mm soc. flange a little deep so reduced it a small amount using a file.
To improve electrical pick up I added a little compensation by extending the area in which the bearings sit upwards, by about 0.25mm and using a piece of 2mm ½ round brass sitting in a 2mm slot to make a central pivot point. Sometimes I use a bit of 10BA threaded brass to make a height adjustable pivot as seen in the Peckett chassis below the 48DS

48DS-Hornby-087-editSm.jpg


I use a back to back measurement of 17.76mm but have always re-used the original Hornby axles. Beware the pick ups as I found them very brittle and not very tolerant to much bending.

Just seen that you've found out how to release the cab while I've bee typing but I'll leave my bit in should any one else feed the need to strip a Ruston.

Hth

P

P.s. Forgot to say when I originally posted this: Big thanks to Mick Simpson of the 2mm Society for sorting out the supply of the tyres. Even though I've managed to loose two.
You do not have the required permissions to view the files attached to this post.

David Knight
Posts: 810
Joined: Sun Jul 20, 2008 6:02 pm

Re: Hornby Ruston 48DS to P4

Postby David Knight » Mon Sep 26, 2022 1:50 pm

Interesting thread! While I have no intention of converting a Hornby Ruston in the immediate future the tip on compensation for both the Ruston and especially the Peckett is really useful. I have a Barclay in the “to do”queue that that should benefit from the idea. Thank you :thumb :thumb :thumb
Cheers,

David

User avatar
Triode
Posts: 149
Joined: Thu May 16, 2019 10:20 am

Re: Hornby Ruston 48DS to P4

Postby Triode » Thu Sep 29, 2022 2:10 pm

Interesting to read the various ways people have approached this - along with the recent article in Scalefour News about building a chassis for a leftover Hornby body.

Here is my effort (which has since been painted). I used Branchlines/Black Beetle 10.5mm wheels and drilled the missing holes using a milling machine as a drill press for accurate spacing.

Speaking of milling machines, I also used it to open out the chassis for the new wheelsets. Unfortunately I didn't secure it well enough and the loco suffered some damage. I managed to patch this up mostly; the cab steps are a bit battered on one side, but this seems to have happened to the real thing too!

I replaced the pickups with phosphor bronze strip soldered to PCB and glued in place. Similar to their 08, I can't seem to get on with Hornby's pickups for P4 conversions.


DSC_1100.JPG


DSC_1098.JPG


Cheers,

Liam
You do not have the required permissions to view the files attached to this post.

decauville1126
Posts: 47
Joined: Tue Mar 12, 2013 8:50 am

Re: Hornby Ruston 48DS to P4

Postby decauville1126 » Fri Sep 30, 2022 12:00 pm

Thanks to those adding ideas and examples - we all seem to have got there in various ways. I would normally have whacked the footplate casting on the milling machine too but wanted to do a real basic no-frills job.

Anyways, have got there in the end. Extended pickups from 0.3mm brass wire and the backs of the brake shoes sanded thinner so they only slightly rub on the wheel treads and flanges rather than removal and fitting to a strap. The axle length takes out side slop when assembled rather than using washers. I also junked the dcc socket and wiring, ground a nice large slot up the front of the chassis block, then reconnected the keeper plate pickups to the motor with a JST1.25 micro connecter. This allows individual removal of components and also swapping in a Deltang Rx65 micro receiver with a small lipo, or gang thereof, battery and step-up board, although this will fill up the cab space a lot.

P1050267.JPG


Cost? Just a pair of Gibson Lowmac 10.5mm wheelsets from stock to hand, say £3.00 and I reckon about 3 hours if done in one hit. Now had Hornby been design-clever (!) they could have easily designed-in the required space and Ultrascale could have done drop in replacement wheelsets. But what we have is an attractive small loco that lends itself to adaptation. But I do feel that for a well-worn time-ravaged and battered project then Mike Edge's brass kit is a better starting point.

P1050271.JPG
You do not have the required permissions to view the files attached to this post.


Return to “Diesel and Electric Locomotives”

Who is online

Users browsing this forum: ClaudeBot, magpie-crawler and 0 guests