Scalefour Workbench - a demo becomes reality (P4 Hornby 08)

[John McAleely]

At the recent workbench Mike Ainsworth demoed the procedure he wrote up recently in Scalefour News - using Ultrascale wheels to 'P4' a Bachmann Jinty.

This was great to watch (it took only a few minutes), and I asked lots of questions to help me complete the project I've half started - P4ing a Bachmann Class 20.

However, I've discovered various parts of that are rather well stored at the moment, but I did have to hand the second set of wheels I bought, and a suitable donor loco - a Hornby 08:

P4-Hornby-08-01.jpg

You can see I've already patched the number, and changed the couplers.

I found this document from Hornby very useful:

http://static.hornby.com/files/ss-278e- ... ve-462.pdf

It makes it clear which screws hold each part together, and also which parts the chassis breaks down into.

First step was to take off the body. As with the Jinty, this proved unecessary, but I felt more comfortable with it off as I mucked around with the chassis:

P4-Hornby-08-07.jpg

(You can see I've been here before - the Digitrax DCC decoder is not Hornby-standard )

There's a wire to watch for that is part of the marker lights, and it straddles the body and chassis. Watch for it as you take them apart:

P4-Hornby-08-06.jpg

[John McAleely]

Next step was to remove the coupling rods. This was easy - they are held in place by small bolts that simply unscrew:

P4-Hornby-08-09.jpg

then it was time to remove the keeper plate (easy, three screws), and then remove the lower brake and axlebox mouldings.

This was more of a challenge - they seemed to be glued in on my model (at one end), so one side came out, but broke cleanly at one end (the break is not visible on the re-assembled model), and the other I never entirely removed:

P4-Hornby-08-10.jpg

P4-Hornby-08-13.jpg

You can see I'd removed the wheels by the second shot, and also moved the pickups enough to get the centre wheel out. This stage took me quite a while, and much scratching, pulling and consultation of the service sheet. It will be much easier next time!

All of this detail plastic is very flexible and forgiving - something I repeatedly thanked the designers for as I bodged around with my assorted tools.

[John McAleely]

Early on, I applied the 'Birchwood Casey Super Blue' to the ultrascale wheels, per the instructions on the bottle. Dead easy, and hugely improves the look. Here's one done:

P4-Hornby-08-03.jpg

And here they all are in place:

P4-Hornby-08-15.jpg

[John McAleely]

OK, so the last big step was to re-assemble these bits:

P4-Hornby-08-16.jpg

On to the model:

P4-Hornby-08-21.jpg

Looks easy, but it was very fiddly. The second pic shows how I used a piece of paper to minimise the risk of the nut & washer disappearing into the mechanism.

Lets just say that there was a reason for that, and that complete disassembly of the 08 chassis is pretty straightforward too

I also initially put the coupling rod on 'backwards', so that the knuckle near the middle fouled as the wheel rotated. Easy to spot when I looked after a brief interruption from a friend curious about what I was doing. Not so easy to spot in the five minutes or so before the interruption!

The coupling rods are also handed - one for the left of the loco, and one for the right.

[John McAleely]

Right. Time for a trial run. Cue brief interlude while I find my DCC controller has critical bits stored elsewhere, so I quickly whipped out the DCC chip, and restored the blanking plate so that I could rig up a DC controller. I did wonder if the blanking plate would be worth keeping...

My main mistake here was to try running with only one coupling rod on, and no keeper plate in place. Then the chassis basically 'unwound' itself and the coupling rod would bend at its joint. It took me a couple of goes to realise that fitting both *and* the keeper plate would probably solve the problem.

Sure enough it did. Initially hesitant, the chassis was soon making its 4 inch journey with aplomb:

P4-Hornby-08-23.jpg

I put the body back on, and posed it in my new P4 'train', and I now am the proud owner of a P4 loco. I wouldn't claim it is more than the RTR loco from Hornby, but they have made a nice model, I think:

P4-Hornby-08-30.jpg

[John McAleely]

Finally - unlike the Bachamann Jinty chassis (and their 08), there appears to be no springing in the Hornby chassis.

The two unmotored axles do have a bit of slop in the mountings for the bearings, so I guess I will learn how this performs 'for real' when I have access to a P4 layout to try it out on. Anyone else got any experience with the Hornby 08?

[Hardwicke]

As I have mentioned elsewhere before I wrote an article on the Hornby 08 in Scalefour News. I found that the semi functional metal axleboxes in the chassis were a bit tight but after a quick and careful filing of them they would move up and down. This improved the running and I'm sure you could add a small amount of springing to this.
Both my Bachmann and Hornby ones need some attention to moved cranks now as per the real thing. They have had at least 70 hours of exhibition running between them plus home running.

[John McAleely]

I wrote an article on the Hornby 08 in Scalefour News.

Do you recall which issue this is? And do you know if its online?

[rule55]

I wrote an article on the Hornby 08 in Scalefour News.

Do you recall which issue this is? And do you know if its online?

I was just re-reading the article the other day. It's a two-parter, issues 154 and 155, and both are online.

[John Bateson]

The article in 154/155 was from Dave Booth - I think the article noted earlier in this thread was from 'Hardwick'?
EditorJohn

[rule55]

Oops, my apologies, more than one Hornby 08 article! Try issue 145, also available online.

[John McAleely]

Two useful articles, over three copies of the magazine:

• 145: A similar conversion to the one I did, which reports reliable running (phew). I would certainly have benefitted from reading this first. I didn't know the 08 was known as a DEJ/4, so it took a couple of scans to locate the article.
• 154: A more advanced conversion which adds a sprung middle axle. Something for a future version of me.
• 155: Fitting Hornby's notoriously poor early 'DCC' decoder. Mostly of historical interest, now that Hornby no longer sell that decoder.

The links will presumably only work for members.

[Philip Hall]

Looking at your picture of the Ultrascale wheelsets, it seems you have round brass bearings to fit in the chassis. I think that the conversions which have been written about (I'm sure this applies to Dave Booth's) refer to chassis which have square bearings. Certainly the conversion I did to EM a few years ago did, so maybe Hornby have changed things. I think that was how Dave B came to spring his.

Philip

[John McAleely]

This thread resulted in a kind offer from Mark to allow me to try out my first P4 conversion on his Portchullin layout at the recent Epsom show.

Here it is, trundling over pointwork, on public display:

08Portchullin.jpg

However, all was not plain sailing. Lessons learned:

- The metal blacking does affect the ability of the loco to pick up from the track, so it all needed cleaning off (with fibreglass brush) from the tread and back of the wheels (where the pickups contact) before the loco ran smoothly.

- I hadn't trimmed the bolts holding the coupling rods on, which I think was the cause of a spectacular jam against the platform edge, due to being out of gauge. They are now trimmed

- There is a spot on Portchullin where the trackwork is a bit bumpy. The lack of suspension on the 08 combined with this to mean it came off here two times of three. I think a future project will be to make this chassis suspended somehow.

Thanks to Mark for letting me try this out in full public display, for troubleshooting the loco's initial falterings, and for the chance to help operate his layout for a while.

[John Maclean]

Well, after reading this thread I was able to convert my own Hornby 08 with a set of Ultrascales and very little fuss.

I now have two P4 locos, a Hymek being my first conversion. Both trundle over my small test plank quite happily. A small step, but as a P4 newcomer I found it very satisfying.

This was my first adventure with crankpins, and once I'd managed to source a suitable nut spinner on this side of the pond all was good.

I am left with one question re the crank pins though. How does one trim them to length?

Thanks,

John.

[grovenor-2685]

How does one trim them to length?

Xuron track cutter or similar good wire cutter, then smooth off the ends with a flat needle file. Do it in situ with the nuts in place and everything working.
Keith

[John McAleely]

Well, after reading this thread I was able to convert my own Hornby 08 with a set of Ultrascales and very little fuss.

Thank you. Mine still sees occasional service - I'm still working on a layout to run it on!

Xuron track cutter or similar good wire cutter, then smooth off the ends with a flat needle file. Do it in situ with the nuts in place and everything working.

For the record, that's what I did with mine. Of course, doing it in situ means that if you ever do disassemble things, the action of unscrewing the nuts will clear out any distortion of the thread caused by the cutting & filing.

[jim s-w]

Good stuff

I found that with the ultrascales (for the Bachmann 08) the quartering would go after a while. In the end I drilled and pinned the drive axle

HTH

Jim

[Trevor Grout]

Good stuff

I found that with the ultrascales (for the Bachmann 08) the quartering would go after a while. In the end I drilled and pinned the drive axle

HTH

Jim

Jim, that's exactly that happened to mine, Although still requiring time in works to fix, Thanks to that nice Mr Rogers sending me a full set of replacement cranks with crank pins FOC a few weeks ago.

Although it will have to wait as I am still fiddling with the green Hornby 08 trying to find the best position for the sound decoder to live, I only need 0.5mm more space at the top.... Grrrrrrr
as it runs so well and sounds good, next job will be to conversion to P4, the wheels are siting on the bench in the pending box with many others..

Regards

[Colin Parks]

Forgive me for re-kindling this topic John, but I have only just seen it.

There seems to be a lot of talk about quartering of the Ultrascale wheels shifting and also the same with the cranks. I have Hornby 08 to convert and my wheels have just arrived from U/scale. I wonder has anyone tried Loctite 435 for holding the wheels/cranks in position? The idea of having to pin wheels to axles doesn't appeal to me.

All the best,

Colin

[grovenor-2685]

With the 08 its only the cranks you are worried about not the wheels. As they come ready assembled taking them apart to add loctite puts the onus of quartering them back onto you. I would just use them as they come, then if you do get a problem later add the loctite when doing the fix.
I did my 08 with a very early set of the Ultrascales and I did get one crank slip after a few months. I just twisted the crank back into line and its been OK for years since, and it does get into wheelspin situations occasionally which must put the maximum stress on. Maybe I have just been lucky! I did make a mental note at the time to use loctite if the problem recurred but so far so good.
Keith

[Colin Parks]

Well, thanks for the reassuring advice re. the 08 cranks grovenor.

I suppose unless there is some slippage, there wouldn't be enough of a gap for the Loctite to penetrate where needed anyway. It has to be said that the Hornby 08 wheels as supplied on my older 00 model can be turned on their axles by firm finger pressure ( do not ask me how I know this!) though they have not given any trouble with the loco in service at numerous exhibitions.

The pictures that John has posted of the conversion process are most useful. It does look a tad more fiddly than the Ultrascale download would suggest. The most interesting photo to see is the one that shows there are two pick ups contacting each wheels rim. I suspect my 08's pick ups have never been working correctly from the start and once assembled the loco's pickups cannot be adjusted.

The 08 to be converted to P4 is a later version with sound (since removed) and does have the round bearings which move to a limited degree up and down in their machined slots in the cast chassis block. This has allowed a primitive form of springing to be installed on the rear axle. The older 08 dates from 2006 and has square hornblock type brearings which are tight in the chassis block.

By the way, what on earth are you doing to your poor 08 to get 'wheelspin situations'?!

All the best,

Colin

[John Donnelly]

My Hornby 08 has turned out to be a terrible runner even with extra picks and now one of the crankpins is loose despite the fact that it has problably run no more than about 20 metres since it was converted. When I get a chance, I'm going to go for a complete strip down as, on the odd occasion that it did run correctly it was very slow and controllable.

John

[grovenor-2685]

By the way, what on earth are you doing to your poor 08 to get 'wheelspin situations'?!

Trying to push to big a train up hill
Regards
Keith

[Will L]

By the way, what on earth are you doing to your poor 08 to get 'wheelspin situations'?!

You should always ensure that your loco can spin their wheels when faced with an immovable object, as you're likely to roast the motor if it can't. Even a heavily weighted loco should be quite capable of doing this and if it can't it usually manes you need to free up the mechanism. Not having a continuous run of my own, my loco's are often "run in" leaning against a buffer stop of some sort.