Converting a Bachmann 7f to the Large Boilered Variety, now with various other S&D bits

[neilkirby]

Following my conversion of a Bachmann 7f to the earlier 1914 series (see http://www.rmweb.co.uk/community/index.php?/topic/108502-converting-Bachmann-7f-to-1914-build/page-2) I was left with the loco body of a GBL compound. so while thinking to myself 'What can I do with this?' I hit upon idea of using it for this project as a risk free way of attempting a conversion to the 1925 series, using it with plasticard wrappings to bulk it up to Robert Stevenson's beefier looking version. This is something I had previously considered using the Bachmann boiler, but bottled out at the thought of ruining a perfectly good 7f! If this goes horribly wrong I can re-attach the Bachmann small boiler with no harm done.

 

First I will show those unfamiliar with the GBL compound what I have to start with:

This I stripped of all the detail and fittings to get to this:

I then cut some plasticard to size and formed it to shape by wrapping it around some 22mm copper pipe and dipping it in hot water from the kettle. below is a later picture of a layer for the smokebox :

I then built up the lower part of the firebox which was missing due to the wheels and splashers on the compound. I also saw from the drawing that the firebox is tapered both to the top and sides, being wider and taller at the front edge compared to the back. so I also built up the front edge  of the firebox with the idea of forming a separate wrapper for this:

the second layer was carried forward to start filling out the smokebox as well:

After adding another layer on the smokebox I stood the boiler back onto the Bachmann body to get an idea of the fit:

This will need some material removed from the bottom of the front end to fit where the real one dipped into the gap between the frames. At the other end I needed to use as thin a layer as possible for the firebox wrapper as the back end looks to be about the same size as the small boilered variant where it meets the front edge of the cab, I chose not to use hot water to form this part, but use clamps while gluing instead. This is where things started to go a bit wrong! Once done, the sides didn't look too bad, with just some slight depressions where the clamps were, which I thought i could successfully fill with white stuff putty:

But what was more worrying was the top of the firebox wrapper has taken on a 'whaleback' appearance. After thinking about this for a while I thought that if I were to clamp it flat with a small piece of metal and dip it in the hot water again it would take up the flattened shape. This was the result!:

These sad remains have now been removed, and I am likely to try and build up the firebox from solid plasticard, filed to profile, and a final 0.010 layer over the top to give a nice finish (I might even try some brass shim for this). But currently this area is on hold for a while in case I can think of a better method.

I then turned my attention to the front end and produced a final layer for the smokebox using a suitably cut to size piece of plasticard, detailed using a rivet press:

I have previously forgot to mention that I have bought some parts from Alan Gibson for this project, namely a vacuum ejector, some Ross pop safety valves, a dome, a chimney for an Austin 7 (which was suggested by Colin at Gibsons as a suitable match and looks good to me)  But unfortunately no one makes a suitable smokebox door. I looked around for something suitable and on the 2nd attempt found this on Ebay which looks like it should be usable:

This was described as being for a Gresley A1/A3 .A little bit of work with trimming and filling, add some plasticard, handrail knobs and wire. and we get this:

and this is as far as I have currently got as I have had to take a break for the moment as my modelling stuff has been packed up due to having builders in, and moving the house around for Christmas. All comments and suggestions welcome. I hope to get back on this when the builders have left in a week or so.

 

Edit: just looking at that last pic again I am not happy with either the hinges, or the lamp bracket, and will have another go at both.

 

Neil

[neilkirby]

Ok after a break over Christmas, and we also had work done on the house. I have picked up the large boilered 7f conversion again. Not that I did nothing over the holiday, So a brief sojourn into that. First of all I re-motored a Hornby pug which was supposed to be a temporary straight out of the box, albeit renumbered and weathered as the Radstock 'Jocker' until I get my High Level kits version built. This basically  involved taking out the motor and mount, and fitting a Mashima 1015 fitted onto a piece of brass plate

About 6 months ago  I tried fitting the 1015 to the original, but cut-down motor mount, this ran nicely but somewhat noisy going forward, I assumed this was down to the plastic mount flexing and affecting the gear meshing. However it's still a bit noisier than I would like going forward, but purrs along almost silently in reverse. If anyone else tempted to have a go, it's a easy job with the original worm gear fitting straight onto the Mashima shaft.

 

The second little job I did was  to nick the steps off the remains of the GBL compound, which had previously be cannibalised for both my 1914 7f project,  and the large boilered 7f of the subject title

These steps I fitted to my damaged old mainline 2p

You can see the Pug with the cab back in place in the background, still to be weathered though. The finish on 40700 is a mixture of weathering and 25 years of dust from being in the loft! I have also recently purchased a replacement Hornby loco drive chassis to fit under this.

 

Back to the main event. After the failure of my previous idea to bulk out the firebox I decided to try a solid laminate instead. The new idea was to build up layers of 0.010" plasticard, one layer thick at the back and working up to 3 layers at the front, This was then to filed and sanded smooth and a final layer of either more plasticard, or some brass shim to be added as the outside surface, I haven't decided which yet, like this:

I have got part of the way with this still got the some sanding and the final layer to go, but in the meantime I thought I would put the parts together to see what it looks like:

The smokebox door and other fittings are only bluetacked on for the photos. Any comments or suggestions welcome.

Neil

[neilkirby]

Just a small update on my latest progress. First of all I have completed the firebox of the 7F, I used plasticard in the end, My decision was swayed by the fact that the toolmaker I was going to 'borrow' the brass shim off wasn't in at work yesterday. I am fairly happy with it but there is a slight blemish low down on the other side of the firebox, I will see what it looks like when it has some paint on it.

Also the boiler bands are attached and handrail positions marked. What I am really lacking is a suitable dome. I was thinking of one from the Austin 7, same as the chimney. But if anyone knows of something closer please tell me.  The eagle eyed may have noticed another part-built boiler in the background of the last photo, after finishing the previous 1914 conversion I thought I may just do another one at some point so I picked up a 2nd GBL compound, I then thought that while I am measuring and cutting plasticard I may as well do the other spare boiler, although I have no fittings bought for this one. (I might try the brass shim on the firebox)

 

Secondly, I have weathered and crewed the Pug, or more correctly known as the 'Jocker' on the S&D. With the second photo I placed something white behind the engine to show how much daylight is visible through the cab after re-motoring, I did  knock up a rough facsimile of a firebox & backhead to fit over the motor but I thought it looked too big and just drew more attention to itself.

Not really visible in these shots, but I was just checking my references on how much to overspray the LMS lettering when I noticed that 51202 had no whistle on the front of the cab, so I whipped this off and filled the hole just before spraying commenced

 

That's all for now.

 

Neil

[neilkirby]

Another Small update. Handrails & vacuum ejector done. The smokebox saddle is nearly complete. 

 

The ejector is a Gibson one, which appears to be for a right hand drive loco, I have done a bit of filing and bending to make it fit, a left hand one would have been better, but I think this will look okay when painted.

Just the sandbox fillers and reversing rod to do. and of course the dome that I don't have yet. Will probably end up with the Gibson Austin 7 version, although I may try and modify something I already have, but cannot see that going well!

 

Neil

 

PS Sorry about the poor quality of the photos, I took them this morning in the half light before going to work, but they are good enough to show the recent work.

[phil_sutters]

Will probably end up with the Gibson Austin 7 version, although I may try and modify something I already have, but cannot see that going well!

 

Good to see developments here. Although it is nearly half a century, since I fitted chimneys and domes on my S&D locos. I know that modifying existing shapes can be very tricky. I haven't looked hard, as I haven't needed to for my current project, but I don't see the line drawings that you got in the old Hamblings and W&H catalogues, in the current online listings. Those gave you a fair indication of the shapes and made it easier to select, even if it meant borrowing a chimney or dome from a different railway company.

 

 

I look forward to seeing how the big 7F turns out.

 

 

[neilkirby]

Another small update of progress over Easter,  Sandbox fillers fitted, the front ones are those cut off from my previous conversion to the 1914 build (not one for throwing anything away !) The rear ones and the reversing rod are made from Evergreen strip and I have also fitted the dome, this is the Gibson one for the small boilered type, with about 1.5mm taken of the top then a radius added with files, not 100% happy with it but it will do for now. Here she is standing face to face with her older, skinnier sister.

Next the paint shops!

 

EDIT After posting this I realised the angle of the reversing rod is all wrong, that will be adjusted before painting

 

Neil

[neilkirby]

I had to have the day off today, as I had a man from the council round to sign off our building work. but on the plus side while waiting I managed to paint and weather this project:

Pretty much complete now, except for a whistle, and a new number on the front. This was caused by a late change to 53808, as I wanted to do the one which had 'British Railways' on the tender until re-boilered. One other omission is that she has no front lamp bracket, I have some DCC Concepts working ones and I will attach that straight to the smokebox door.

 

Another thing I have not previously mentioned is that I had trouble with was the GBL compound firebox sides bowing inwards, these ended up being braced with .100" Evegreen square section. I am now wondering that when & if I ever get around to building the second one, whether to abandon the spare GBL boiler that I have already sleeved and just work on the now leftover Bachmann boiler from this one instead.

 

Neil