Converting RTR locos

[David Thorpe]

I think we're all impressed by the quality of modern RTR locos, but it pains me to buy one and then have to throw away the chassis and mechanism in order to convert it to P4 with not only wheels but also a new compensated/sprung chassis and a gearbox and motor (particularly troublesome in my case as it is quite likely that the new "upgraded" chassis may not run as well as the original had done ). I was therefore wondering if anyone has had any experience of using the original RTR chassis with nothing more than new wheelsets? Gibson, for example, offer replacement P4 conversion wheelsets with 3mm axles for a variety of steam locos including some big ones, so presumably contemplate that such conversions will/do take place using the original RTR chassis.

DT

[grovenor-2685]

Personally I have four locos converted with the said Alan Gibson wheels, a Jinty, a J94, a WD 2-8-0 and a Black 5 4-6-0. The first 3 run just fine but are. of course slow speed freight locos.
The latter i am less happy with and it needs more work. Its a bit hesitant and for that I think I need to rethink the pick ups. Also at passenger speeds roadholding drops off and this is where I think springing is needed.
Regards
Keith

[Philip Hall]

I think this is now an established way of getting a new P4 engine without having to build a chassis. Some of them are easy, some less so, but all the ones I've done, for myself and customers, have worked well and I think I'm quite fussy. My experience has been with Bachmann (SR N Class, GW 45XX, BR 76xxx, BR 82XXX, LNWR G2A, ROD 2-8-0), Hornby (SR T9 & M7, Stanier 2-6-4T, SR King Arthur, GW Grange, GW 28XX) and one Heljan diesel, which was very easy. There's been a lot written on here about conversions by many folk including yours truly and there have been a number of articles in MRJ as well which have covered quite a bit of the subject (Grange, M7, T9 etc.) Pete Hill has converted just about everything there is to convert, and he's had no insurmountable problems, although admittedly he's doing it in EM. P4 might sometimes require more care with clearances, but then it always does.

I think Keith may have a point about high speed road holding, but all I can say here is that we have had a Hornby M7 literally hurtling through the fiddle yard on the Epsom Club's 'Wadhurst' (which has some very complicated pointwork on curves) with no problems at all, steady as a rock. Ditto a Hornby T9, not quite hurtling, but still a decent 60 -70 mph or so. Both these were fitted with Ultrascale wheels. I've done most of my conversions with Gibson wheels and these are very nice as well.

I have no experience of the new Brassmasters 'Easi-chas', with overlays and springs, but I'd like to try one one day.

Have a go is the best policy, see how you get on, and the Forum and all that has been written elsewhere is here to help you.

Philip

[David Thorpe]

Thanks Keith and Philip for these replies. I was rather surprised (gratifyingly so!) as I'd sort of started believing that if you wanted a steam loco in P4 you had to have a compensated or sprung chassis, and that meant building one. I'm going to give it a go on a Hornby Black 5 (although somewhat apprehensively in view of Keith's experience). Just a couple of points - when you do such conversions, do you add cosmetic sideframes in order to pad the chassis out, or do you just add washers to the axles? And do you use the existing valve gear?

DT

[martin goodall]

My experience has been confined to converting certain GWR types, using Ultrascale wheels (I prefer these to the Gibson product - Ultrascales are well worth the price, and the wait).

The two main problems likely to be encountered with such conversions are :

(1) chassis block out of true, so that the crank pins won't match the coupling rods. The only practical answer is to adjust the rods.

(2) the motor may not be all that good. I have bought a couple of Mashima 1420 motors to replace the motors in my two Bachmann panniers (as previously described in this forum by Tim Venton).

The motors in my 45XX and Collett Goods seem OK, so won't be replaced.

I began converting a Hornby 14XX (48XX) but then decided that a High Level etched frame would be a better bet, but like Davey Tee I am not happy about going this far to 'convert' an RTR model.

[grovenor-2685]

Cosmetic side frames are optional but do improve the looks. I have a non-level layout and need to get in as much weight as possible so I use lead sheet for the cosmetic side frames which helps considerably.
Regards
Keith

PS I don't agree with MArtin wrt Ultrascale wheels, I have one set which show no advantage whatsoever over the ones I have from AG.

[John Fitton]

I am in a dilemma on this subject too. I have quite a lot of successful diesel and electric conversions with the ultrascale sets, and except for some of the newer six axle locos these have very good roadholding. I have a lot of steam locos waiting for conversion. I have the brassmaster easichas for the A1, but I havent plucked up the courage to have a go yet!! Partially on-topic I plan to have tender drives for some of the locos to add tractive effort to the loco drive. I think I will convert some of them first, as they resemble diesel locos mechanically. Perhaps the sight of steam loco tenders whizzing around loco-less will get me motivated!!

John

[Philip Hall]

I often (but not always) pad out the frames, but I prefer Plastikard for that. I don't do it if you can't easily see the difference; on a Hornby M7 I widen the frames over the bogie and at the front end but not between the drivers, as the pickups are made in such a way as to make it awkward and the steps conceal this anyway. The opposite of this is a 28XX or a ROD 2-8-0 where there is acres of empty space everywhere and it looks awful if you don't do it.

Rods and valve gear are often fine enough these days although I will invariably reduce the size of the coupling rod bosses once they're bushed, apart from the ROD 2-8-0 where they're OK. I don't thicken up coupling rods as I take the view that they're not as obvious as (say) the big end on a connecting rod, which I do usually solder another layer to. You'll have to do this with a Hornby conn rod anyway because they tend to fix their conn rods behind the crosshead, so I often have to take off the crosshead, drill for a new pin and fettle the end of the widened rod so it is more in line with the crosshead. Try it first before you take it apart, you might not need to bother and there's no point in making work. I doubt you'll have to recentre a Hornby coupling rod, but you may well have to for a Bachmann engine as Martin says. Generally I check Bachmann but don't bother with Hornby. The Class 5, as I recall, has a sprung rear axle (or the one I saw reviewed had) which will help with roadholding. Gibson wheels are just fine, usually concentric and nicely moulded, but if you do get an 'off' one Colin Seymour will always exchange. See the advice on wheel fitting on here in many places. Ultrascale are just that bit better, being more rigid with tyres moulded on rather than pressed. Either is fine.

I wouldn't bother with a Hornby 14XX, this definitely needs a new chassis. It dates from Airfix days and although the motor and gears are now improved a bit, it's still not good and a pig to balance. I have an early one with Ultrascale wheels and a big can motor instead of the awful Airfix effort but despite this it won't pull more than five wagons and makes a noise like a concrete mixer full of cast iron lumps.

There was an article in MRJ a while back on the Hornby Black 5 by Gerry Beale, and he outlined the small improvements he made, like a new buffer beam.

Philip

[grovenor-2685]

I have dug out a few pics, somewhere I have more but they will take a while to find.
This is the WD 2-8-0

90566-LHS-1.JPG

and tender

90566-tender-1.JPG

The underside of the loco shows the extra side frames.

90566-underside1.JPG

and in more detail the pick ups, the extra pick up on the veroboard is the synch cam for the sound chip.

90566-underside2.JPG

under the tender a comet tender chassis was modified into two parts, each with springy equalising beams and using branchlines wheelsets one end picks up from the left rail and the other from the right rail pick up is from 8 wheels on the loco and 4 (2 each side) on the tender.

90566-tender-2.JPG

Regards
Keith

[grovenor-2685]

Here are the frames for the Jinty showing the lead cosmetic additions more clearly.

chassis-1.jpg

chassis-2.jpg

chassis-3.jpg

And the keeper plate with modified pick ups so they reach the wheels, later I replaced the plastic brake rods with brass as they did not look presentable.

keeper-1a.JPG

and the AG wheelsets assembled ready to install.

wheels-2a.jpg

Regards
Keith

[grovenor-2685]

Lastly a couple of pics of the J94

J94-underside-2.JPG

The brakes were cut from each side of the keeper plate and refitted to the required spacing using the white plasticard spacers.
Here is one of the brake shoe sets as removed, ready to be re-assembled.

J94-brakes-2.JPG

Regards
Keith

[HowardGWR]

I've brought over my subject from the chassis suspension thread as this post is better here, being specific to RTR conversion. I put this query to RMWeb but no joy so far.

I am thinking of attempting this project (Hornby Star RTR to P4). There is a very useful pdf produced by AG (Colin Seymour) which you can download from the catalogue here

http://www.alangibsonworkshop.com/Hornb ... ersion.pdf

On the sixth page there is a photo of the frame and mechanism and the cover one has to remove clearly must block any daylight under the boiler. I don't suppose this matters too much, as there is not much of that to be seen anyway behind the splashers. I have one question to those of you who may already possess one. What is that 'thing' that sticks up above the frame just behind the leading driver? Has it to do with DCC (about which I am totally ignorant)?

[Philip Hall]

I haven't had one of these to take apart yet (although I might have in a month or so) but would think that this is just part of the weight at the front end of the chassis.

These notes are by Pete Hill, who knows his stuff in these matters, so if you follow his advice you'll not go far wrong. As you're doing it in P4 ather than EM, you'll need to do a little more with the front crankpins to make them as flush as possible. I use a modified Ultrascale flush crankpin here as it's much easier than trying to thin down the Gibson ones.

Philip

[steamraiser]

I have only skim read this thread as I have used drop in wheel sets to convert rtr steam locos to P4.
The one point I make is to thoroughly test run the loco in its OO form to ensure that you are satisfied with its performance.
Changing the wheels to P4 will not improve a poor performer.
I also have subsituted a Mashima motor in a Bachman pannier.
The other area that needs checking is the clearance, in the main between the inside faces of the splashers.
I place a pair of wheels (Not assembled on the axle) either side of a my back to back gauge, then measure with a vernier calipre across the outer tyre faces.
IIRC I look for a clearance of 22.5mm inside the splasher faces.
Dont to forget to allow for some sideplay in the wheels.

Gordon A
Bristol.
Still waiting for his Sentinel to arrive.

[HowardGWR]

Peter and Gordon (hmm that rings a bell somewhere) thanks very much. I assume Pete Hill did not meet the 'rear of splasher' width problem, of which Gordon warns, otherwise he would have mentioned it in his article. The AG conversion kit includes spacers for taking up slack. It looks an interesting project so I'll try and take photos as I go along. Don't hold breath though, this is an armchair modeller you are reading here! If you get there first Philip, I will look forward to hearing how you got on.

On the RMWeb post, I just moaned (slightly) that the train set version is not apparently to be released separately, as that is the version many would wish to model (albeit with substitution of 'logos'). 1930s condition with original cylinders, but perhaps with a 'Hall' boiler (patch on side of smokebox). There is also of course the type with 'Castle' steampipes (new 'steam pipe entry at top' cylinder casting i.e. Castle castings, and Hall boiler - Prince Henry was an example). Again, I suppose all these mods can be achieved, but it is supposed to be an RTR exercise!

It should be pointed out that it would not surprise me if Ultrascale do not bring out their own pack for this engine.

[grovenor-2685]

I have added a new page to my website with pics of the Jinty, some are repeats of those above but there are a few more.
http://www.norgrove.me.uk/Jinty.html
Incidentally with the lead sideframes and lead also packed in every available nook and cranny, eg side tanks, dome etc. the all up weight is now 308 grams which gives it good tractive effort.
Regards
Keith

[neilp4f1]

Does anyone have the details of anyone who will take on commissions of rtr conversions?
I would like to have some good reliable runners that help give me confidence in any of the track I build.
Many thanks
Neil

[grovenor-2685]

Does anyone have the details of anyone who will take on commissions of rtr conversions?
I would like to have some good reliable runners that help give me confidence in any of the track I build.
Many thanks
Neil

Philip Halldoes that, but I've no idea how long his waiting list is. However it really isn't hard to do a Bo-Bo diesel or an 0-6-0t like a pannier or Jinty yourself. There is lots of guidance on here.
Regards
Keith

[Highpeak]

One of the engines on my wishlist is the Stanier 2-6-4T. Right now there are a few examples listed at Hattons, the less expensive of which are noted as poor runners.

My question is how well does this convert to P4, in which case a good runner would be needed, or is a better approach to buy a poor runner and build a Comet chassis for it?

[Philip Hall]

I did a 2-6-4T a very long ago and it ran very well. The die block and slide bar brackets were a bit fragile but survived the conversion tussle.

Philip

[Highpeak]

Thanks for that reply, I'll get one of the runners and see how it goes.

I did a 3F Easichas which is now running smoothly, the lesson learned from it was that it would have been a good idea to run it in first before doing the conversion, some of what I thought were the results of poor workmanship on my part turned out to be just a bit of stiffness in the mechanism that went away in due course. I'll make sure this one runs well before the conversion.