Upgrading the old Hornby chassis and XO4 setup

[relaxinghobby]

Pre Ramble

 

When is a quick project not a quick project? When it goes wrong or at least because it does not go to plan. Or is it that we start a project full of hope, blissfully ignorant of the problems and pit fulls that lay ahead. Hopefully we start and with persistence and hope we can sort out the problems as they crop up and achieve a good model as a result.

 

 

 

 

My problem is adapting an old Hornby chassis with more recent wheels and motor which are not necessary, as it turns out, 100% compatible.

 

 

 

 

The first part went well, I managed to load Hornby 9F wheels into an old chassis block using top hat bearings, it will whiz up and down the track easily under finger power.

 

 

 

 

Then to motorise it, the 9F axles are nominally 1/8 inch but actually 4 thou smaller, not a lot it seems but this is a rattling sloppy fit to put it technically. There is now too much slop in the gear mesh. The pinion wheel can be centralised about its axle with a collar made of a suitably thickness of shim material forced between the axle and gearwheel.

 

 

 

 

The motor is a later XO4 replacement D13 type ? I am only guessing can any one recognise it? The motor fixing is only so-so, a home made cradle of brass strip and scrap rail soldered together. This has turned out to be only just strong enough and does not really enable much fine adjustment.

 

 

 

 

It runs , but there is gruonching and grinding from the gears in one direction, which I understand is not good. I think the problem is there is too much movement vertically between the pinion and worm because the axle has too much slop or vertical play in it's bearing.

 

 

 

I think the answer is to fit new top hat bearings with s smaller inside diameter hole that would hold the axle concentrically and keep the worm and pinion gear at their correct distance apart. So far I can not find any make of top hat bearing with a smaller size hole.

 

 

View of motor and it's cradle.

 

 

I have tried ones from Comet, MJT and Romford.?

 

 

 

 

Does any one have an answer to this problem?

 

Diagram to show the axel and bearing cross section.

 

A selection of shims, thin brass sheet about 0.006", beer can metal about 0.004" and motor car tappet adjustment shim steel in a range from 0.001" to 0.005", wrapped around a screw driver bladed and cut with scissors to make a collar.

[artisan100]

Sticking my neck out a bit here, but if the 'slop' is only 4 thou then I'm not sure it's enough to cause the trouble.

 

If you think the driven axle is undersize, try buying a new one and substituting that.

 

Or is it possible that the axles are correct at 1/8th of an inch but the chassis is designed for metric axles?

 

1/8th of inch is 3.18mm, and rtr manufacturers do tend to use metric more than imperial.

 

Just a few thoughts which may, or may not, help.

 

Anybody else got any ideas?

 

Geoff

[bertiedog]

The current axles will be metric at 3mm, (check though with micrometer or calipers), the old Tri-ang used larger than 1/8th axles so needed top hat bearings to reduce to 1/8th, (3.175mm) these were, and are still made by Markit (Romfords). From memory I think the outer diameter of Tri-ang was 5/32 inch (156.2 thou)

 

So to take a 3mm axle, the current type, it has to reduce from the 5/32 down to 3mm. These could be lathe turned, but an easy substitute would be to use 3mm brass tubing cut into short lengths for new bearings.

 

If the outer diameter does not actually match the old Tri-ang diameter use a wrap of shim or cigarette paper to increase it and aradite the bearings into the old chassis, whilst a dummy 3mm shaft is run through them as the glue sets to ensure complete accuracy.

 

The result is now a chassis that will take the modern 3mm shaft axles, with nice fit brass bearings.

 

But, and it's a big but, do not assume that the gear is soundly on and accurate, have a hard and critical look, spin it in the bearings, there must be no wobble in any direction at all, nothing. The method with the paper for the bearings may not be accurate enough, rope in a friend with a lathe if needed.

 

Also check each new Hornby wheel the same, they must run true, no wobble, or run out.

 

Now I am not getting at the quality of the Chinese wheels, they are good, but are castings, not turned, just accurate die cast plated wheels, and as such may run slightly out, more than say Gibson or Markit wheels.

 

So don't assume they are right, but check, spin and run a small indelible pen against the tyre, and see if it touches all round, the results may please or frighten you!! A very small amount out can be tolerated, but nothing easily visible.

 

The gear is far more difficult to test, but visually it should run true.

 

Now the final part is the motor, check the worm is true as well, they are rarely wrong, but what makes problems is the end play of the armature.

 

It can be taken up to near zero with washers between the worm and the motor bearing, but will need the worm slipped off, washers added and the worm pressed on till all end play has gone bar about a thou.

 

At this point, oiled, and with grease on the gear it should all run perfectly, quiet and powerful. But don't assume the motor is 100%..... again test the bearings are not shot, ( replaceable), and the armature is not bent, (very unlikely).

 

After all this you can rate yourself as an expert at Tri-ang chassis!

 

Stephen.

[relaxinghobby]

Thanks for the helping hints so far. I'm still in trouble, and I've tried to measure my way out of it.

The axle holes in the old Hornby chassis block are for 5/32" hole for there old 5/32 " axles and all the replacement top hat bearing have an out side diameter of 5/32" to fit into them.

 

These bearing have an inside diameter to suit Romford axles which are 3.1 mm in diameter and my cheap alternative wheels from the current Hornby 9F have axles of 2.9 mm diameter.

This means they are 0.2 mm smaller, this does not sound much but it means in practice these thinner axles can move backwards and forwards in the axle holes, If you look down on the chassis from the top you can see the pinion gear wheel

wiggling against the motor worm gear.

 

So to keep the wheels and axles steady I need new top hat bearings with smaller holes in them, to suit the new skinnier 2.9 mm axles of the 9F wheels.

 

I've got no lathe so I've tried to adapt the commercial ones and make them with a smaller hole. I've cut a slot in one side with a jewellers saw and then forced them to curl round into a smaller bearing using the chassis hole with some thin shim around the outside of the bearing to squeeze them down to size as they are pushed in.

 

This sort of works, it gives a smaller holed bearing but I can not control the process and keep ending up with a bearing hole that is now too small.

 

Does any one make a top hat bearing for a nominally 3 mm axle?

[bertiedog]

Thanks for the helping hints so far. I'm still in trouble, and I've tried to measure my way out of it.

The axle holes in the old Hornby chassis block are for 5/32" hole for there old 5/32 " axles and all the replacement top hat bearing have an out side diameter of 5/32" to fit into them.

 

These bearing have an inside diameter to suit Romford axles which are 3.1 mm in diameter and my cheap alternative wheels from the current Hornby 9F have axles of 2.9 mm diameter.

This means they are 0.2 mm smaller, this does not sound much but it means in practice these thinner axles can move backwards and forwards in the axle holes, If you look down on the chassis from the top you can see the pinion gear wheel

wiggling against the motor worm gear.

 

So to keep the wheels and axles steady I need new top hat bearings with smaller holes in them, to suit the new skinnier 2.9 mm axles of the 9F wheels.

 

I've got no lathe so I've tried to adapt the commercial ones and make them with a smaller hole. I've cut a slot in one side with a jewellers saw and then forced them to curl round into a smaller bearing using the chassis hole with some thin shim around the outside of the bearing to squeeze them down to size as they are pushed in.

 

This sort of works, it gives a smaller holed bearing but I can not control the process and keep ending up with a bearing hole that is now too small.

 

Does any one make a top hat bearing for a nominally 3 mm axle?

 

In case the top hat bearings are not done commercially, I had already mentioned 3mm brass tube, which is made, and widely available, but I will check on the actual bearings.(Eileen's Emporium can do the 3mm brass tube, you may be lucky and the outer diameter be near 5/32).(There are other suppliers and most model shops have the tube if they have metal centre stand).

 

Dependant on the supplier the 3mm,(internal), brass tube should be near the required Tri-ang size of 5/32, very unlikely to be over 5/32 outside diameter, under a bit does not matter, wrap it with paper smeared with epoxy glue, to enlarge the outer to the required 5/32.

 

You can also use aluminium foil.

 

After the glue sets fit the new bearings on to a brass or steel 3mm rod,(or spare axle),and using this as a guide to epoxy each bearing into place in the tri-ang block, leaving the rod in place till set hard.

 

Remove the guide rod, and the bearings can be filled flush with the chassis, you will need washers on the axle for spacing.

 

If the gear has a 5/52 hole the same method can be used with care, but make sure it does not wobble. It may be best to buy a 3mm fit new gear set for accuracy, Ultrascale and others do them.

 

Stephen.

[bertiedog]

You need a tube with outside diameter of 4mm approx, (3.968 exact), and 3mm is in Eileens listing in two types 2mm x3mm and 2.5mm x3mm, and I assume the outside would be the total, therefore both would be too thick, but call Eileens and get them to check the O/D, they may have other tube or suitable bearings from stock.

If these prove impossible, I could make a set for you, please PM

 

Stephen.

[hayfield]

I do not know if this picture will help, it shows various options to either improve or replace the Triang/Hornby chassis.

 

 

The chassis came with a loco I brought off Ebay, It has brass bushes so that standard 1/8" Romford axles could be used, The chassis can be further improved with a set of Mainly Trains etched coupling rods (forgot to put them into the photo).

 

Bottom right are the Romford 9/64ths axles, plain and knarled for the Hornby gear wheel. Romford also do 3mm axles to fit the more modern chassis, mine were 75p each so is it worth all the hassle of bearings?

 

Wills did 3 etched chassis FC100 to fit the Triang/Hornby 0-6-0T locos (Photo on box), FC101 to fit the Hornby Dublo (center) 0-6-0T chassis (see the rear tail fixings) and the FC102 to fit the Triang/Hornby 0-6-0 tender locos (bottom etch)

 

Southeastern Finecast have updated these to FC200, FC201 and FC202, I believe these have brake gear and I guess still have the same rear fixings, can someone confirm please.

[bertiedog]

Just for reference for all readers...

 

The need is not to fit 1/8th which is widely catered for, but the bigger jump from Tri-ang direct to the modern Hornby which is 3mm on the Chinese items.

 

The wheels here are a set of 3mm axle Hornby, and can't easily have the axle changed to 1/8th without attention in the lathe.

 

You could make in the lathe 5/32 axle to fit the 3mm Hornby, but this limits what gears fit, basically Tri-ang's original or Ultrascale's replacement type.

 

By jumping to a bearing that fits the new wheels it solves the chassis problem, but leaves the gear to do, it has to fit the 3mm axle, and the Tri-ang one would with a bush, but a 1/8th one would not.(too much play)

 

There are 3mm gears though, Gibson and Ultrascale do them, and any 2mm fit could be bored out in a lathe.

 

If anybody wants Tri-ang to 3mm(3/32 to 3mm axle) give me a PM, I can do a custom batch if there is a demand.

[hayfield]

I have just found a parts lost for a Southeastern Finecase loco and it has a photo of the chassis fret, I can confirm that the updated chassis FC200 has the Triang Hornby rear fixing mount, break gear and spring details. The fret also includes ashpans for the GWR 94xx and SR E2 and also different guard irons for both locos.

[bertiedog]

A question....memory fails me...is the old Tri-ang axle 5/32 or 9/64?, before setting up to make the bushes I need a definitive answer, and I have no Tri-ang to hand to check with a micrometer......any body know for sure???

Stephen.

[relaxinghobby]

Newer, better motor fixing

 

 

 

 

Here are a series of photos to show what I've done to make a more secure fixing for the motor and allow for some adjustment at the worm and pinion wheel meeting.

 

 

 

 

The old motor mount was too flimsy and allowed the motor to wiggle around and the worm to get out of mesh. It was made of 10 thou brass, much too thin, so the new one, the Mark II if you will is made out of 30 thou brass and holds the motor much more firmly.

 

 

 

 

I don't know what make the motor is, I got it second hand with the Romford gear set. It has five poles and starts at a much lower setting on the controllers knob, so it must be better?

 

 

 

 

It is smaller than the Hornby/Tri-ang original that it replaces. It's both shorter and narrower and lacks the fixing ears that slot into the chassis block and the rear hole for the fixing screw. I have cut out the mounting bracket to ape these features. A cardboard one was made first and when it was cut down to fit well I could use it as a pattern to cut out the more difficult to make metal one.

 

 

 

 

93 Motor in place.

 

 

 

94 Different angled view of the motor and it's mounting bracket.

 

 

 

95 Motor sitting on it's mounting bracket.

 

 

 

96 Disassembled.

 

 

 

 

 

 

 

 

 

 

1. Bracket with fixing ears to fit in slots 1. on chassis block.
2. Packing cardboard to go under hole 4 where screw 4 screws through to fix it all to the chassis.
3. Hole where screw 3 screws up into motor.

4. No four.

5. Hole to allow clearance for bolt 5 that holds the magnet into the motor.

 

[*]Motor has bearing that fits into slot at the front of the bracket.[*]Screw to fix motor to bracket.[*] Packing pieces of cardboard.[*] Bracket to chassis fixing screw.[*]Slot in chassis for fixing ear on bracket or Hornby X04 type motor.

[Simon G]

Hi,

I have done something similar in wanting to improve and upgrade old Triang/Hornby chassis. My solution with the motor has been rather simpler than yours as described earlier. I have purchased some 5 pole direct replacement X04 motors off ebay (Airfix did a pretty good one called the MRRC 1001 or something similar. These will slot straight into the chassis without the need for additional housing/fixing. Occasionally they need a little adjustment with fine washers under the fixing screw or filing a sliver off the chassis where the fixing screw goes.

 

To improve the performance further, I replaced the original magnets with new Rare Earth (Neo) magnets. If you are not familiar with these, the magnet strength is far superior to the AlNiCo one originally used by Triang/Hornby, and results in much better slow speed control for shunting etc, lower current drawn (and thus the motor runs cooler). The performance is then not far short of new Hornby locos in terms of slow running and controllability.

 

Like 'relaxinghobby', I am also trying to rewheel an old 0-6-0 jinty chassis. In my spares kit, I found some suitable wheels (not sure where they came from, but they are the right size!) which are better on modern track than the old Triang ones. So far the running is a bit 'stiff', so I am working on that. The other improvement I intend to try is to add pickups to the centre wheels. The current arrangement only picks up on the front & rear ones and is prone to stalling on points etc, as did all old Triang jintys when run slowly. I have bought some spring pickup wire and now need to get round to fixing it onto the current pickup system. If anyone has done this previously and has any advice, it would be most welcome!

 

Simon

[bigherb]

A question....memory fails me...is the old Tri-ang axle 5/32 or 9/64?, before setting up to make the bushes I need a definitive answer, and I have no Tri-ang to hand to check with a micrometer......any body know for sure???

Stephen.

Just found some old tri-ang axles which are 3.58mm which if my maths is right 9/64"

[Sheffield]

While I am quite ready to be corrected, I think the original Hornby 9F driving wheel axles are one eighth diameter, being rather unusual. Before I found this forum and learnt better I rewheeled a Triang 0-6-0 chassis block using eighth bushes I happened to have, driving wheels from the Hornby tender drive 9F and a five pole version of the X04 motor. I used a bush in the original gear wheel as well, and it all runs fine, as part of a 7mm narrow gauge loco. Indeed it is better than the modern Bachmann chassised locos which seem to develop a waddle after a while.

[MarkC]

9/64" is correct for the old Triang axles - Dave at Mainly Trains still does the Romford axles to suit

[relaxinghobby]

This project is grinding to a halt, I'm waiting to find some brass tube of the correct dimensions to arrive so I can make new and better bearings with it.

 

Although the loco does run, if not very smoothly, I've now found that the gear wheel is spinning on it's axle so that has to be fixed somehow? I had filed of the boss where the grub screw was so I can't use that, I had thought that I had the gear wheel securely jammed on, but it isn't.

 

I am beginning to think it is time to give up on this project, just paint it rust colour and park it in the scrap siding at the back of the layout.

 

 

 

 

Thanks Sheffield for the tip about the old Hornby tender drive 9F, I found a chassis for one at toy fair but the wheels looked like the older course flanges, I had hopped the newer wheels with there finer profile would work as I am using code 75 track with it's finer clearances.

 

 

[Scrapman]

Spining gear wheeels are not that uncommon. Usually cause is the hole is oversize. Mike Sharman (he of Flexichas fame) suggests a few fixes. Only ones that spring to mind are either to solder the gear to the axle, bush the gear or raise burrs on the axle using a centre punch. You could also try using a Loctite type retainer, the number 601 springs to mind but have never tried it so have no idea. Most of these dont work with Triang/Hornby plasic gears. Ultrascale do some Triang compatible gears but dont know if they do one to fit the China wheel/axle assemblies.

Trust this helps a bit.

This project is grinding to a halt, I'm waiting to find some brass tube of the correct dimensions to arrive so I can make new and better bearings with it.

 

Although the loco does run, if not very smoothly, I've now found that the gear wheel is spinning on it's axle so that has to be fixed somehow? I had filed of the boss where the grub screw was so I can't use that, I had thought that I had the gear wheel securely jammed on, but it isn't.

 

I am beginning to think it is time to give up on this project, just paint it rust colour and park it in the scrap siding at the back of the layout.

 

 

 

 

Thanks Sheffield for the tip about the old Hornby tender drive 9F, I found a chassis for one at toy fair but the wheels looked like the older course flanges, I had hopped the newer wheels with there finer profile would work as I am using code 75 track with it's finer clearances.

[hollywoodfoundry]

A god way to roughen up the surface of an axle to make it grip the gear better, is to place the axle on a hard surface and roll a small diameter round file back and forth over it, allowing the axle to roll with the file. Safer than using a centre punch as it is unlikely to bend the axle.

[Scrapman]

Mike Sharmans thinking on using a centre punch was not to rough up the axle but to give the gear wheel something to hold on to. The suggested method, as I remember it, was to put a centre punch mark on the top of the axle and another one underneath where the gear wheel was to fit. You just need to raise the metal so as to lock the gear in place. No siesmic swipes required and little danger of bending the axle.

A god way to roughen up the surface of an axle to make it grip the gear better, is to place the axle on a hard surface and roll a small diameter round file back and forth over it, allowing the axle to roll with the file. Safer than using a centre punch as it is unlikely to bend the axle.

[relaxinghobby]

So much for a quick project, it's beginning to drag a bit.

I've been waiting for some brass tube to arrive from Eileen's Emporium.

It is 3.0mm inside diameter, 3.5mm outside brass tube to make 3mm bearings. I've cut it into appropriate lengths using an X-acto saw with a fine blade .

Roughened them a bit by rolling them along a coarse file and then gluing them in with Araldite.

 

 

A tighter fit than the 1/8 th inch bearings, less axle wobble with than before, they will have to do. I'm stuck with them

because I glued them in.

 

 

She runs! from power applied with leads touching the wheel scrappers but not on the track. The pick ups did not seem to make proper contact with the wheels

although they were touching. Modern Hornby scrapers seem to have a dimple where they press onto the wheels.

So I dimplelised each one by pressing a pointer into each one against an anvil of cardboard on the bench.

They now pick up and the loco will run reasonably smoothly.

 

The pointer shows a tiny dimple just catching the light.

[relaxinghobby]

I've glued the worm wheel and it's shim collar solidly onto the axle with Locktite 'Stud n' Bearing fit', the stuff they sell for gluing car

engines together so bits don't drop off on the motorway.

So this chassis will never be dismantled again.

[relaxinghobby]

 

Not running at all well, there is a binding tight spot once every turn of the wheels and the motor gets very hot, so it's come back for a re-do. I can fit another chassis, the latest Rail Road one from the Hornby Jinty seen here can be got for under £24 and now the centre wheels are all metal, no rubber tire which is better for scale modellers with flattish layouts and no mountains.

 

This is a very nice chassis and should be fine for many conversions, it would have to be slightly shortened for this application.

 

I fancy trying an alternative approach, keeping the current chassis and making a two stage gear box using cheap plastic cogs form Maplin and dismantled toys I think. You can see one that has been drilled out to 3mm and is a good force fit on the Hornby 3mm axle. So no wobbly problems or out of mesh stuff and those great big coarse teeth are much more

forgiving of my engineering and manufacturing inaccuracies.

 

 

 

[hollywoodfoundry]

Unfortunately there is a lot more friction in a worm/worm gear drive system, so you may find those 'great big coarse teeth' become little ground away teeth in a very short time. Particluarly if they came out of a toy of some sort, as the plastic could be very ordinary. You really need plastic gears to be made from Acetal or Delrin to get away with using them as worm gears.

[relaxinghobby]

Thanks HollyWoodFoundry about the warning of the plastic worm and gears but I have a cunning plan.

 

I am trying to brew up some sort of two stage gear box using the Romford worm and gears, a motor mount bracket, and those plastic gears are the second stage gearing only.

 

See pictures below;

 

 

PLAN

 

AND SIDE ELEVATION

 

 

I don't know what the odds are that it will work?

[relaxinghobby]

I've recycled that bracket and using it with an etched 'worm to pinion gear wheel' fold up gearbox I'm trying to build a two stage gear box.

 

Slow progress as it's all trial and error, no real planning as I don't really know what I'm doing.

 

It's a pity there is no commercially available gearbox available for improving and re-motoring this old style of solid chassis.