Hornby dublo

[NCB]

Well,here`s Fighter Pilot in Golden Arrow livery.3railed,Dublo coupling fitted,ready to haul a Pullman train.

 

 

 

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                         Ray.

Nice! With flanged centre wheels, how does it do on curves?

 

Nigel

[sagaguy]

Nice! With flanged centre wheels, how does it do on curves?

 

Nigel

No problem at all.

 

                   

 

                 Ray.

[Golden Fleece 30]

Nice! With flanged centre wheels, how does it do on curves?

 

Nigel

You will find there is a bit of lateral play on the centre wheels and the coupling rods are in two pieces, both held by the centre crank pin, which also gives more play. The centre wheels are also lightly sprung. This design was Wrenns which was completly different to a Dublo chassis, they used the same one in the Royal Scot too.

 

Garry

[Wolseley]

Just an idle thought while reading of all this activity with Wrenn "Spam Cans" - could a Tri-ang "Winston Churchill" body (and, yes, I do realise that they are not the same class) be adapted to fit a Dublo West Country chassis?

[sagaguy]

The Royal Scot is a doddle to convert,you can use a normal Dublo p/up unit on it.

 

                     Ray.

[sagaguy]

Just an idle thought while reading of all this activity with Wrenn "Spam Cans" - could a Tri-ang "Winston Churchill" body (and, yes, I do realise that they are not the same class) be adapted to fit a Dublo West Country chassis?

The problem is that the Dublo chassis would still have the wrong valve gear.Possibly,a Hornby spamcan with B-B set to 14.5mm + a tad may be a better bet.I did contemplate one but the Wrenn locos came up for sale.

 

                  Ray.

[Golden Fleece 30]

Just an idle thought while reading of all this activity with Wrenn "Spam Cans" - could a Tri-ang "Winston Churchill" body (and, yes, I do realise that they are not the same class) be adapted to fit a Dublo West Country chassis?

I don't see why not, I fitted one to a Tri-ang Britannia body after swapping its wheels for the Spam Can build I did with an A4 chassis.  Valve gear is not an issue as the parts not needed can be removed.  I also ended up at one time having Wrenn Spam Can valve gear etched to use for this purpose.

 

Garry 

[Golden Fleece 30]

The Royal Scot is a doddle to convert,you can use a normal Dublo p/up unit on it.

 

                     Ray.

Is this a different chassis block to the Spam Cans? I was led to believe they were the same with just the wheels and valve gear differences.  Mine are all put away so no chance of looking at both.

 

Garry

[Wolseley]

I don't see why not, I fitted one to a Tri-ang Britannia body after swapping its wheels for the Spam Can build I did with an A4 chassis.  Valve gear is not an issue as the parts not needed can be removed.  I also ended up at one time having Wrenn Spam Can valve gear etched to use for this purpose.

 

Garry 

 

 

I might give it a go sometime then.  Nice as your Britannia conversion is though, I won't be doing one as I already have a Trix Britannia.

Edited November 28, 2018 by Wolseley

[Golden Fleece 30]

I might give it a go sometime then.  Nice as your Britannia conversion is though, I won't be doing one as I already have a Trix Britannia.

I have a Trix one too but at the time I was seeing what bodies I could fit Dublo chassis's to.  I had a couple of Trix Scotsmans but fitted Dublo/Wrenn chassis's to these as well.  If you do a Tri-ang Spam Can body you will obviously need to remove the backhead and cab floor though.

 

Garry

[sagaguy]

Is this a different chassis block to the Spam Cans? I was led to believe they were the same with just the wheels and valve gear differences.  Mine are all put away so no chance of looking at both.

 

Garry

Hi Garry,it`s similar but not quite the same.The armature worm is still foraward of the worm wheel but it has the convenient hole to take the retaining screw for the P/Up assy.

 

                        Ray.

 

                 

[sagaguy]

Looking at my pic again,i wonder if the co-bo/emu collector might be a better bet as it`s a bit shorter.

 

                              Ray.

[Golden Fleece 30]

Looking at my pic again,i wonder if the co-bo/emu collector might be a better bet as it`s a bit shorter.

 

                              Ray.

Possibly Ray as the rear shoe is close to the chassis.  On one or two locos I ended up grinding a recess for the shoe, definitely on an 0-6-2 where I had moved the collector back a few mm's.

 

Garry

[sagaguy]

The standard collector assy.works fine,you do have a slight adjustment fore & aft but if i were to do this again,i would order a shorter assy.

 

                      Ray.

[Wolseley]

Just an idle thought while reading of all this activity with Wrenn "Spam Cans" - could a Tri-ang "Winston Churchill" body (and, yes, I do realise that they are not the same class) be adapted to fit a Dublo West Country chassis?

 

Well, it looks like it's more than an idle thought now - I put in a bid at the starting price for a Dublo West Country chassis on eBay and just found out that the item had ended and no-one else had bid on it.  I will have to convert it to three rail, the valve gear will obviously have to be modified and I will have to find a way of safely removing the backhead and whatever else from the Tr-ang/Hornby (I can't bring myself to call it Hornby) body I just purchased (it was a "Buy it Now" item, as was the tender I just bought), but here goes - all I have to do now is wait for it to arrive....

[Golden Fleece 30]

Well, it looks like it's more than an idle thought now - I put in a bid at the starting price for a Dublo West Country chassis on eBay and just found out that the item had ended and no-one else had bid on it.  I will have to convert it to three rail, the valve gear will obviously have to be modified and I will have to find a way of safely removing the backhead and whatever else from the Tr-ang/Hornby (I can't bring myself to call it Hornby) body I just purchased (it was a "Buy it Now" item, as was the tender I just bought), but here goes - all I have to do now is wait for it to arrive....

3-railing the West Country chassis is easy as a standard Dublo assembly fits. There are different ways to short the wheels and in the past I have drilled a hole in the insulating bush between the wheel and axle and forced a brass pin in to short it out, it is permanent though. Electrical conductivity paint between the axle end and wheel boss, I don't like but can be easily removed, or drill and tap a hole in the chassis block side to hold a tag with a wiper on the wheels.

 

Cutting the backheads out is easy as I use a Dremel with a cutting tool (like a milling cutter end mill or slot drill).

 

Garry

ps, its all still Tri-ang to me even the China made ones as that was their heritage.

Edited November 29, 2018 by Golden Fleece 30

[Wolseley]

3-railing the West Country chassis is easy as a standard Dublo assembly fits. There are different ways to short the wheels and in the past I have drilled a hole in the insulating bush between the wheel and axle and forced a brass pin in to short it out, it is permanent though. Electrical conductivity paint between the axle end and wheel boss, I don't like but can be easily removed, or drill and tap a hole in the chassis block side to hold a tag with a wiper on the wheels.

 

I already have a couple of spare Dublo pick-up assemblies, one of which I will be using on this chassis.  As for shorting the wheels, I was going to drill the bush and force a brass pin in (something I still have to do to a couple of Cities I three railed a while ago).  I hadn't thought of electrical conductivity paint, but I don't see it as my preferred option - although I was thinking of getting hold of some and trying it to repair a break in the element of the rear window demister in my car (one of those after-market stick on ones from the 1960s), but I digress.....

 

Cutting the backheads out is easy as I use a Dremel with a cutting tool (like a milling cutter end mill or slot drill).

 

I don't have a Dremel at the moment, but it's something that has been on my want list for a while now.  I now have a reason for getting one.

 

Edited November 29, 2018 by Wolseley

[Golden Fleece 30]

 

As for shorting the wheels, I was going to drill the bush and force a brass pin in (something I still have to do to a couple of Cities I three railed a while ago).  I hadn't thought of electrical conductivity paint, but I don't see it as my preferred option - although I was thinking of getting hold of some and trying it to repair a break in the element of the rear window demister in my car (one of those after-market stick on ones from the 1960s), but I digress.....

 

 

 

 

 

The brass pin method was my preferred option too.

 

I well remember those silver lined stick on demisters :-), :-), :-)

 

Garry

[Il Grifone]

omis

 

Garry

ps, its all still Tri-ang to me even the China made ones as that was their heritage.

 

For me too!  To qualify as 'Hornby' etc. it has to be made in a 'Meccano' factory, preferably 'Binns Road'.

 

I always short out the insulation with a piece of phosphor- bronze strip bearing on the back of a wheel and secured under a convenient screw (usually the top of the pickup assembly. Only one is sufficient I find.

 

I doubt that conductive paint would support the current  in a window demister. It is possible, as there was a product on sale years ago. I'd try fixing a bit of wire or better braid from coaxial cable across the gap and holding it in place with sticky tape. A bodge, but cheap.

 

I have the remains of a Tri-ang WC/BoB* body in a box somewhere. The taper in the sides is incorrect IIRC. I got it from a 'cheap' bin at a fair for the etched plates, but they had been bug messed up. There's the pair my Dublo WC came with somewhere too, but they had suffered the same fate. A pity as they were from one that didn't have the town 'coat of arms' ('Brentor' IIRC, named after a large rock).

 

* The only difference between the two classes is in the name seies AFAIK. There were differences between individual locomotives and especially the tenders. The Dublo/Wrenn version is part of a small series (4 IIRC).

[sagaguy]

This is my way of doing it,doesn`t wreck the wheels,could be returned to 2 rail in half an hour if i ever wanted.Just reuse the original p/up wire,solder to a piece of brass,the wheels are then grounded to the chaasis through the countersunk screw.The only mod to the chassis is countersinking the hole to allow the screw to hold the brass plate tightly.The 3 rail collector assembly is fitted on top in the normal way.

 

 

                    

 

 

               Ray.

Edited November 30, 2018 by sagaguy

[MikeCW]

I've been off air for a week or so as our 8 year old lap top computer gave up working and it was cheaper to buy a new one and transfer the solid state hard drive from the old to the new machine, rather than repair it. That seemed symbolic of the comments passed on this thread about the mechanical fragility (or built-in obsolescence) of the current range of Chinese-built model locomotives versus the old-school engineering of 60 year old Hornby Dublo products. Anyway,I've caught up and read with interest the discussion on Spamcans, Wrenn chassis, de-insulating wheels etc.

 

While this is old hat to the regulars on this thread, I thought some of the casual "browsers" might appreciate a report on my three-railing a two rail Bo Bo. As is well known, the 2 rail version of the Dublo Bo Bo was the failure of the Binns Road locomotive range.  The combination of traction tyres and the fore and aft rocking motion of the motorised bogie under load resulted in unreliable electrical pick-up under "normal" operating conditions i.e. rarely cleaned track, minimal locomotive servicing, and carpet fluff and other contaminants on the layout.  As a result, there are plenty of second-hand two rail Bo Bos around at reasonable prices.

 

My starting point was a sad looking Bo Bo picked up on the local internet auction site.

 

And yes, I  get satisfaction out of using old, well cared for tools.  The screwdriver with the darker handle was my late grandfather's, a Gallipoli veteran of the Great War.

 

In brief the three-railing exercise involves three steps: removing the insulating bushes from the insulated wheels on one side of the locomotive and replacing with metal bushes (or otherwise bridging the electrical gap; removing the two-rail pick-up and fitting a three-rail alternative; and making the minimal, consequential wiring changes to the motor brushes.

 

I was originally going to turn up some bushes to replace the insulated ones but decided that the precision required to get a press fit would mean several failures, and so, to save time and blood pressure, I opted for a set of four from the Dublo Surgeon (Dennis Williams).  The three rail pick-up skate in the above photo is Marklin Part No. 7164.  This is a short pick up which, end to end, is practically the same length as the rubbing points on the shoes on the standard Dublo pick-up. (Longer Marklin skates can cause shorts if you are using the standard Dublo turnouts.) I bought mine from Gaugemaster for 3-4 pounds.

 

 http://www.gaugemaster.com/item_details.asp?code=MN07164

 

 

 

After removing the body I unsoldered the wire that connects the two rail pick up to the motor brush. I then unscrewed the whole unpowered bogie from the plated steel spine.  Note that this bogie is insulated from the spine, which itself is "live" to the powered bogie.  Power from the uninsulated wheels on this unpowered bogie flows up the centre post to the tag, which is clamped to the top of the post, but insulated from the spine by the shouldered screw and fibre washer in the top right hand corner of the photo.This is an unusual electrical pick-up arrangement, where one bogie is live to one rail, the other bogie and spine is live to the other rail.  (When we are done, everything will be live to the two outside rails except the centre-rail pick-up and the motor brush to which it connects.) Finally, not shown in this photo, I unscrewed the two rail pick-up itself - the black plastic block shown still in situ between the wheels of the bogie.

 

 

 

 

Before removing the insulated wheels, I checked the gauge of each wheelset to ensure that, when I pressed them back on, they would be in the same position.  Keeping the axle ends flush with the wheel boss should ensure this, but I wanted to check progress when I came to pressing them back on.  Wow! the wheels were spot on to the NMRA standard which I use on my "scale" model railway, and which is pretty much the RP25 standard used by Bachmann et al today. Hornby Dublo standards were certainly "fine" for the 1940s and 50s.

 

 

 

 

Next I pulled off the insulated wheels. Where possible I used a wheel puller - a gift from the family of an old chap, a former engineering officer in the merchant marine, whom I knew in his retirement until he died a few years ago.  The family kindly gave me his taps, dies and a selection of small modelling tools, knowing I would both use and care for them. It's not possible to get the legs of the puller behind the wheels in all cases as the gap between bogie chassis and wheel back is too tight. So even leverage pressure using two small screw drivers will ease them out a millimeter or two.  It doesn't really matter if you don't use a puller and just lever them off, trying to keep them as square and straight as you can.  The bushes may distort but they will be binned anyway.

 

 

 

The wheels came off with the plastic insulating bushes in place. To drive these out I found a 2.8mm diameter nail, cut and smoothed off, to make a punch of the right size.  Resting the wheel on top of the slightly open jaws of the vise, I tapped them through and ensured that the wheel bores were clear for Dennis Williams' bushes.

 

 

 

 

 

Pressing in the metal bushes was straightforward. Start them by thumb pressure, or a very light tap with a small hammer, then press them home in the vise.

The next step, which I didn't photograph, was pressing them back on to the axles,  I did this the same way, putting the bogie, with axle and undisturbed wheel in place, and the wheel with the new bush  at the other end, all very carefully lined up in the vise to ensure all was square, and pressing them nearly home.  A check with the standards gauge, and a final squeeze to seat them back in place.  The one difference was that this time I remembered to put the soft jaws (aluminium angle) in the vise.  The sharp eyed engineers among you will be about to tell me off for the small scars on the wheel bosses caused by the serrated jaws of the vise when I pressed in the bushes.  Mercifully these are hidden by the bogie side frames.

 

Next: Installing the three-rail pick-up.

 

Mike 

Edited November 30, 2018 by MikeCW

[Golden Fleece 30]

You will find that the trailing bogie was modified sometime to take two lightly sprung plungers pushing down on the axles to help current collection.

 

Having both bogies live resulted in the couplings being mounted on very thin bakelite spacers to prevent shorting out in certain positions, as happened with early 2-rail City locos which had the tender pin mounting changed from metal to fibre board.  These Bo-Bo spacers can crack and allow the couplings to droop but replacements are available although I milled some from brass for myself, 3-rail does not have the shorting issue.

 

I have used Dennis Williams de-insulating bushes, and made my own from brass and aluminium but it was easier to pin the wheel to axle rather than replacing the bush on steam locos.

 

Garry

[sagaguy]

Very good Mike,the only thing i don`t understand is the need to remove wheels.I just use the original 2 rail p/up & short it out to the chassis or where that isn`t possible(very rarely)i make a nickle silver wire bearing on the top or the backs of the wheels as in my R1 conversion & 2 rail emu conversions.

 

 

                   

 

                   

 

 

       I also use Marklin 7164 skates,to mount them,i use where it`s neccessary,2mm copperclad PCB sheet but that`s because i was given a large sheet from my work place when i retired 14 years ago & i still have enough left over for another 50 or locos.I find it drills & taps wonderfully,i have to be careful theat the very short 8ba csk screw i use to attach the skate doesn`t short out on the existing 2 rail p/ups but a couple of layers of black pvc insulating tape cures that.I`ve just received some M2 nylon csk screws & taps so in certain instances,these will be a better bet.

 

                                 Ray.

[Il Grifone]

I don't have a 2 rail Bo-Bo (my D8017 has a 3 rail chassis - I had converted it to 2 rail EM using Nucro/Jackson wheels, but it has been converted back). However the problem is obviously that the traction tyres are both on the same axle (it's not 100% in 3 rail) and i would have thought would be use the solution every one else uses. One wheel/axle in the power bogie picks up current and the insulated one has the traction tyre. The other bogie then picks up from the other rail.

 

A better solution IMHO might be to eliminate the traction tyres altogether and add a large weight in the space between the bogies.

 

Somewhere on You-tube there is a demonstration of a rewound Bo-Bo hauling long trains.

 

Dublo wheels should have a back to back of 14.2mm which makes them a bit tight for scale track (BRMSB/NMRA*).though they have the correct BRMSB check gauge of 15mm. easing them out to the NMRA minimum of 14.4 will ease the situation and still be within the NMRA check gauge (15.2mm IIRC) The NMRA flange is a fraction thicker than the BRMSB one.

 

* I don't like to continually refer to the obsolete BRMSB standards, but they have never been replaced and vintage wheels (and modern Hornby) are to this standard.

 

Almost everyone seems to use Peco Streamline which is not really to any standard but their own. (Fine scale expects excluded here of course.)

[Il Grifone]

omis

 

       I also use Marklin 7164 skates,to mount them,i use where it`s neccessary,2mm copperclad PCB sheet but that`s because i was given a large sheet from my work place when i retired 14 years ago & i still have enough left over for another 50 or locos.I find it drills & taps wonderfully,i have to be careful theat the very short 8ba csk screw i use to attach the skate doesn`t short out on the existing 2 rail p/ups but a couple of layers of black pvc insulating tape cures that.I`ve just received some M2 nylon csk screws & taps so in certain instances,these will be a better bet.

 

                                 Ray.

 

2mm PCB is unusuai. it's usually 1.6mm-1/16" (1.5mm fibreglas/paxolin + 0.1mm copper). it works just as well of couse. My supply came from when I was made redundant on closure of my workplace* nearly thirty years ago. I still have a lot and some brass sheet etc.

 

* The result of political interference by the Italian government and subsidies to Southern Italy (Illegal under EU rules - we had a list of these at work at the time. I noted that they had all been translated into Italian, except for the one referring to this which had been left in French.

Britain never seems to have grasped the function of the EU - everyone agrees and then carries on as before....

 

Surely using metric threads on Hornby Dublo is heresy - only B.A. and 5/32" Whitworth allowed. 

Edited November 30, 2018 by Il Grifone