Model Railway Forum banner

What locomotive would you most like to see in OO scale?

18626 Views 115 Replies 32 Participants Last post by  kristopher1805
Just for fun I thought I'd ask this question since I've been thinking about this recently. What is the best locomotive that you can't find in OO scale?
1 - 5 of 116 Posts
Rather than new models being created, notwithstanding that some models may have actual dimensional/shape errors, I'd prefer that manufacturers fix the problems on their existing models. Manufacturers have been making model trains for long enough to know what works and what doesn't. Unfortunately, we seem to have had a few new 'kids on the block' who thought they knew better and this has resulted in mistakes which have long since been solved suddenly rearing their heads again almost like no-one ever learns!

Things I would like to see fixed:

1) The Hattons/Heljan class 14 is an absolute disaster: Heljan Class 14 Modifications - Model Railways On-Line Please fix it Hattons/Heljan before you start reproducing more of this tat!
2) The Kernow class 41 had a motor that was completely unfit for purpose. I believe that it had origins from a 'new kid on the block' who also created similar problems in another range of locos
3) Dapol need to get their class 22 gear ratios right. At the moment, it is too high such that the motor can't turn slow enough to make the loco creep along without jerking to the vibration of slow motor revolutions. Optimal gear ratios have been known for half a century. Why are we still getting this wrong ?
4) Hattons need to fix their P tank so that it actually accepts the decoder that they advertise for it! Or at least make the model so it will accept other decoders without requiring chassis grinding: Hattons SECR P Tank Review - Model Railways On-Line
5) Loco manufacturers to stop putting body attachment screws directly behind the centre of buffer beams. Believe it or not, some of us actually fit prototype couplings and are not wedded to the NEM socket fad, so we need the space behind the buffer beam! Put the screws on the corners, not the middle!
6) Manufacturers to design their locos in ways that make them straightforward to dismantle. Hornby have go this right. Bachmann have always been a bit behind with their steam locos. Heljan completely stuffed up their class 14
7) Dapol need to fix their quality control on their electronics: many of their locos seem to be delivered with defective motherboards in their first release. Upside down decoder sockets or incorrectly/oppositely wired wired sockets are not on!

I just want to see manufacturers stop making stupid mistakes with really basic stuff that were long since fixed in the hobby half a century ago!
See less See more
Dear Graham,
One of the problems with the Heljan/Hattons class 14 is that it is essentially an 0-8-0 chassis, length wise - it’s due to the jackshaft drive being within the main wheelbase.
If the prototype had the drive at the end like a class 03 for example, us modellers would have had less problems!
I had one of these when they were first released, I ran it in well on 00 track with analog control and all was well. Later I fitted my pre-ordered set of P4 wheels from Ultrascale, I had to wait some time for these.
Having read up numerous times how to go about it, I was very, very careful - one of the first things I did was to remove the cab steps for example! Yes, I had trouble fitting a decoder but I managed it okay. I spent time, money and effort finding something small enough that could actually power it but I did it because I wanted it to work! Not a problem now though, it’s easy to get such powerful but tiny decoders.
I actually wrote up how I did it all for my club magazine, the MMRS “Link”, no idea now what issue, sorry. My friend and colleague from that time, Craig Welsh, was going to etch a P4 chassis but I don’t know if he ever did.
All I’m saying is that I don’t think this model is quite as bad as you are indicating and believe me, if I get a chance to knock Heljan - I take it!
John E.
Thanks John.

I agree that the class 14 is essentially an 0-8-0, however, I'm not sure that makes any difference when compared with the 03 because that also has 4 axles and is essentially in an 0-8-0. The only thing that makes the two different is that the position of the jackshaft of the 14 causes the coupled wheelbase to be longer. Irrespective of that, the principals of how the coupling rods are aligned and the level of side-play apply equally to both types on all axles, jack or wheel.

I approached my class 14 with a completely open mind. I knew it had excessive axle side-play that was causing it to 'waddle'. I had an idea that some kind of washer or padding was going to be necessary. I also knew that it had jerky motion in one direction. It also seemed to 'lift' a bit on one corner. I figured that this may either be decoder related or mechanical and quickly realised it was more likely to be the latter as decoder issues usually occur in both directions.

I approached it methodically and carefully - I've hand built dozens of locos in my time (4mm and 7mm), so I'm probably a bit of a first time starter.

To be able to fix the side-play, I had to find a way to remove the wheels. I didn't want to remove wheels from their axles as I didn't want to mess up the quartering. This meant I was either into e clips or some kind of padding out of the chassis facia. I chose the latter and quickly found the chassis facia was made of an awful type of plastic that can't be glued and it is actually 'hot melted' to attach it to the metal inner chassis block. I persevered and 3D printed some extra 'horn guides'. These solved the side-play issue.
The jackshaft needed an 'e clip' type solution for which I made up plastic washers and this also worked fine. It was at that point that I found that the coupling rods are not all in line because the jackshaft is not the same length as the wheel axles. Problem #1 which I couldn't solve, but I could put up with it as it wasn't going to cause a physical problem no that I had the new horn guides in place.
I then started looking for the cause of the jerkiness. Initial thoughts were to change the decoder, but that didn't work because the model is extremely (and unnecessarily) tight on space, meaning that only certain decoders would fit. OK fair enough. The motor in this loco appears to be very good, so I decided to stay with it and the decoder. It was at this point that I discovered that the rotation of the wheels was binding at one point (when hand operated) and it wasn't because of my horn guides. So I started dismantling the model. And it was at this point that I really began to realise what a hell-hole this model is for dismantling. When you try to dismantle something and bits won't come off because they have been designed as a one way fit, one can no longer relate the problem to my ability are care in dismantling it. Things are inaccessible, footplates need bending to get them off over the motor because there are clips under it to stop it going the other way, wires which are too short to release things, non-use of plugs, so any wires that do break have to be long as they are accessible. Drive gears which can't be removed unless you bend the chassis facias (which can't be removed as they are hot-melt fitted). Wires running in channels which directly line up with the slot such that when you refit the cab, it damages the wires. Screws in the top of the hood against the cab - what about the other end ? Nothing to hold it down, so it doesn't sit straight above the buffers and can appear twisted.

I finally found the cause of the jerking - a malformed gear with uneven tooth spacing. I approached Ultrascale for a replacement, but at £50 startup costs and an 8 month delivery, I respectfully declined. But one thing Ultrascale did point out is that the gear in question is fixed to another gear which the motor worm drives, yet that gear is not properly manufactured with 'helical' teeth to match the motor worm thread.

I'm afraid I have to say that this model is as bad as I indicate. The more you work on it, the more you observe that it is riddled with cheap-skate short cuts, very poor design and some poor manufacture. In 40+ years of modelling, I've never seen a loco this bad although one or two lag some way behind.

Don't get me wrong, I actually like the loco. The body looks superb. It's a shame the mechanism doesn't match the appearance!

It should have a solid block chassis, same as Bach and Hornby do it, but it hasn't because it is using the chassis construction method used by Heljan on their Diesel bogies...and it doesn't work on this type of loco because all the weight ends up above the footplate (no gap between bogies to under-sling weight), contributing to a top heavy model and a 'waddle' and leaving no space for decoders or speakers.
See less See more
  • Like
Reactions: 2
I have a class 14 but have never got round to fitting a decoder. Perhaps I should just put on the shelf for display only.

This model appears to have a good motor so as long as a reasonable decoder is used, I don't think you'll have a problem with it.

It's more about finding a decoder which will physically fit and then going through the fight of taking this model apart, fitting the decoder and then getting it back together properly - that's the fun part!
  • Like
Reactions: 3
Not ever having seen this model apart, is there any prospect of positioning the decoder in the cab? I have the class 15 and 16 models from Heljan, and on both the treatment of the cab interior below the window line eats into available interior space, a thick moulding positioned well above the mechanism parts. On the class 16 this was visually intrusive, and I replaced it with a folded piece of black paper which concealed the mechanism and took up much less space and was thus 'invisible'. Had it been necessary to find space for a decoder on this model that would have made a suitable location.
Afraid not. The cab detail is moulded as part of the upper metal chassis block and also forms part of the motor housing as can be seen in the middle left of this picture: Gauge Articles/Locomotives/IMG_1326.jpg

The cab is an obvious place, but unfortunately, the poor design of this model didn't consider it.
  • Like
Reactions: 1
Just an update to my earlier comments on this thread about the Heljan class 14: Heljan Class 14 Modifications - Model Railways On-Line

I contacted Heljan for an update on getting replacement gears for the class 14. Their response:

"Replacement parts for the Class 14 will be produced at the same time as the new batch of locomotives and will be sent to our spares agent, Gaugemaster, as soon as possible after the arrival of the shipment. Unfortunately we don't have an ETA for them yet. The factory working on this project (and various other new models) closed permanently at the beginning of this year and we were forced to switch production to another supplier. This will cause a delay, the extent of which is not yet clear, but we still hope to see them this year."

This is seriously concerning - looking like a wait until later this year. The chickens of the 'globalisation fad' are finally coming home to roost!

A brass chassis is beginning to look like the only realistic proposition.
1 - 5 of 116 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.