Dikitriki's 7mm Workbench: Scratchbuilt Wagon

[dikitriki]

Hi

Over the next 20 months or so, I have to complete a good few locomotives to provide the motive power for my Heyside layout. They will all be ex-LMS or BR standard locomotives, mostly steam, with just a couple of diesels thrown in. Some will be locos I have had at a nearly complete stage for some time, some will be from new kits, some will be reworks of either second hand or RTR items.

What is on the workbench will vary from month to month. I normally have lots on the go at any one time, but they all have their moment on the bench and progress as I find extra information or that elusive detailing part to move them on.

Currently on the bench is a Hughes Crab. I can move this on as the RCTS has just published an excellent book on the Hughes and Stanier 2-6-0s, and my copy arrived yesterday. The model is a loco I bought finished - painted and lined. A critical examination revealed that both the loco and tender bodies had been well-built, the tender chassis was OK but lacked detail, but the loco chassis was a strip and start again job. That's fine by me as I have a thing for chasssis detail, and few kits provide me with what I want. I didn't even test the loco before getting out the microflame and setting to work. Two evenings later and a bath in cellulose thinners (the chassis parts, not me), I had the makings of a kit. I confirmed that the original kit was a Chowbent Castings kit, which I have always liked the look of, and which is currently under the JLTRT label, but unavailable. I don't think it had had any running since being built, and the wheels (Slater's) were all rusty, but salvageable.

So, for the first instalment, the wheels, and more particularly, the balance weights. The rust was sanded off and the wheels blackened before anything further was done to see whether they were useable. The etched balance weights were prised off, filed to the correct outline (!) and duplicates made of thin black plastic card.



The etched one was attached to the front of the wheel, the plastic card one to the back, and the void filled with Milliput fine (white). This is a horribly tedious, time-consuming, messy and boring task, but adds to the character of the wheel.



The wheel is then cleaned up, and this is the easiest part of the operation fortunately, whereupon it is ready to be fitted back to the loco. I've still got a couple to finish off, so chassis pictures will appear over the weekend.



Richard

[alcazar]

Nice to see you back on here Richard, I have followed one or two of your threads with interest, and hope to do so again.

 

Was the milliput easy to get off the spokes?

[Western Star]

Good day Richard and a pleasure to see some more of your work. However, I am rather concerned about the up and coming product of Horwich... the photographs which you sent to me this day, entitled "Crab Wheels", presented very nice details of a Gresley tender. So how close is Heyside to The Plant? And what will your neighbours think of a Horwich Crab in lined Apple Green?

 

best wishes, Graham

[Ressaldar]

Hi Richard,

 

happy New Year to you.

 

Nice start to the Crab re-working, looking forward to the rest of the reports on progress.

 

regards

 

Mike

[Christian]

Hello Richard

 

Your latest post is well timed for me as I have to do the same for the wheels of my Finney A3.

The process certainly does improve the appearance of the wheels.

[dikitriki]

Nice to see you back on here Richard, I have followed one or two of your threads with interest, and hope to do so again.

 

Was the milliput easy to get off the spokes?

 

 

Pretty easy. Sometimes you can flick the excess off with a craft knife, sometimes it requires filing. It does leave a fine dust, and the wheels will need painting, but then they do anyway

 

 

Good day Richard and a pleasure to see some more of your work. However, I am rather concerned about the up and coming product of Horwich... the photographs which you sent to me this day, entitled "Crab Wheels", presented very nice details of a Gresley tender. So how close is Heyside to The Plant? And what will your neighbours think of a Horwich Crab in lined Apple Green?

 

best wishes, Graham

 

 

Ha! I thought you'd spot that. All the pictures were taken this morning, and I was too lazy to open separate files. Since your photos were transient, they were the ones with the misleading name. You must have wondered what I was sending you!

 

 

Hi Richard,

 

happy New Year to you.

 

Nice start to the Crab re-working, looking forward to the rest of the reports on progress.

 

regards

 

Mike

 

 

Hi Mike - and a happy and productive New Year to you too. I shall try to keep you entertained, but my speed will never match yours - roll on retirement!

 

 

Hello Richard

 

Your latest post is well timed for me as I have to do the same for the wheels of my Finney A3.

The process certainly does improve the appearance of the wheels.

 

 

I thought you might do the same. Keep up the good work on the A3. I don't remember steam either, and I can't work out why I like steam locos so much - all that lovely motion I think.

 

Richard

[dikitriki]

Hi

 

I've finished the wheels off and attached them to the chassis, and completed the brake gear. So some photos before I move on to the cylinders and brackets, and thence to the valve gear.

 

Additional components are the driving wheel springs (Hobbyhorse Developments, for the Jubilee, same centres), brake hangers and shoes and brake spreaders (Laurie Griffin), and the adjusters are built from brass tube and nuts. The brake gear is interesting as there are two brake cylinders - the front brakes are different from the other two pairs and have their own cylinder, a hangover from the days when pony truck brakes were fitted. The ash pan has been moved inwards (prototypically) to clear the cast springs. The original kit had etched springs as part of the chassis mainframes - a pet hate - and the ash pan/lower firebox was a continuous piece.

 

 

 

 

 

 

 

 

 

Richard

[Scale7JB]

Looking good...

 

I still gotta build that 9f eh ?!

 

JB.

[dikitriki]

Hi

 

I've found a little time to progress the crab, though I think it's going to come to a grinding halt shortly as I await various bits from JLTRT, Laurie Griffin and Sanspareil.

 

Current state of play is shown in the first two photos, and with the cylinders in place, it starts to take on the massive and distinctive proportions of a crab.

 

 

 

Though not intended in the kit, my cylinder unit will be screwed in separately. It still has to have the valve guide and motion support brackets added, as well as the front 4 sand boxes.

 

 

One problem on a lot of ex LMS engines is the lack of clearance on the front crankpin, whereby the usual fittings would not clear the back of the crosshead.I devised (though do not claim originality for the idea) a totally flush front crankpin mounting. I use a 10BA bolt as the pin, tap the top hat bearing 10BA, reverse it, and drill 2 holes in the flange. A home made peg spanner drives the tapped bearing home, but the clever bit comes in relieving the outer coupling rod laminate to clear the flange. The following pictures illustrate the problem and solution.

 

 

 

 

You can see, even now, how close it is. There is almost no sideplay on the first axle and only minimal clearance. It is, however, a very secure, and totally flush fixing.

 

Richard

[Horsetan]

I like watching these 7mm builds. They contain lots of useful lessons for 4mm

[alcazar]

Looking at the top, (clearances), pic, you can see that at least SOME of the problem is the cast crosshead just isn't a good fit on the slidebars.

[Scale7JB]

Looking great, those cylinder end castings are very nice.

 

Whose kit is this again ?

 

JB.

[dikitriki]

Looking at the top, (clearances), pic, you can see that at least SOME of the problem is the cast crosshead just isn't a good fit on the slidebars.

 

Indeed, but remember the picture is 4x full size. In practice, there is little more than working clearance, and even if everything was parallel, the fraction of a mm gained would not significantly ameliorate the problem. To correct the slidebars would mean not only shimming the slide, but bushing and reboring the stuffing gland. As it is, everything is free moving and there is sufficient clearance, so I am happy to leave well alone.

 

 

Looking great, those cylinder end castings are very nice.

 

Whose kit is this again ?

 

JB.

 

Thank you. It is a Chowbent Castings kit. Now with JLTRT and withdrawn, so your guess is as good as mine as to when it will reappear. Since I need at least one crab for Heyside, I bought this built, to refurbish. It's unheard of for me to buy a loco built by someone else, but this was built very competently for the most part. In theory, it's a quick way to get a finished crab, and I think it probably will be. Apart from the cab, the engine needs little work, and the tender needs attention to the chassis only. We shall see! I also have a Laurie Griffin Crab to build, but I think the Fairburn may be next under pressure from Dibateg.

 

Richard

[TheSnapper]

Awesome workmanship Richard!

 

Tim

[Horsetan]

I think I recognise the etchings. They appear to be the work of Ian Tattersall - his name also appears on the 4mm versions which were in the LMS series of kits by Alan Gibson.

[dikitriki]

Hi

 

More work on the crab chassis. I shall mostly let the pictures speak for themselves...

 

The first picture is a general shot of where I'm up to.

 

 

and a close up of the left hand side gear, minus the reversing links.

 

 

The next two show a close up of the valve gear, and I have married the Griffin cast valve gear to the Chowbent Castings castings. Not always straightforward, but it shows the advantage of the cast valve gear with the proper forks and sheer bulk of it.

 

 

 

The last two show the cylinder unit off the chassis. A bit of a headache here as the sand boxes have to be attached to this unit to lift off, yet the pipes have to be attached to the chassis. The solution was 'flying' sandboxes, or what is affectionately know here as the 'cocktail stick' approach to modelling.

 

 

 

The next side should be quicker as I have worked out the procedure on the first side, and then I will fit pick ups and have a play.

 

Richard

[Scale7JB]

Spectacular! Those LG rods really are very very nice eh !!

 

JB.

[Ressaldar]

Hi Richard,

 

great work as usual - it will be a shame to weather it at the end of the day.

 

regards

 

Mike

[Christian]

Very nice work Richard.

 

Are all of the valve componants supplied by Laurie?, they certainly look good especially the fork joints, much better than the etched offerings.

 

And what about that return crank? that looks very good indeed.

 

 

[alcazar]

I was about to mention that too. Is anything available from LG for the LNER pacifics? Or from Andy Beaton? I saw that he does A1/3/4 cast n/s slidebars etc? He also seems to do some Britannia stuff which might make the DJH Brit better?

[dikitriki]

Hi

 

Thanks for the comments. Since the LG components have generated some interest, I thought I would expand a bit.

 

The first pic shows what you get if you buy the full LG valve gear kit, including the coupling and connecting rods.

 

 

I used the Chowbent etched coupling and connecting rods, and acquired only LG's valve gear (the 4 nickel-silver sprues).

 

The next pic shows the right hand side set out.

 

 

I have heavily adapted the expansion link to fit the Chowbent valve gear support bracket. The valve spindle is not part of LG's valve gear, I'm using the Chowbent one, and the associated guides.

 

This pic shows the reversing parts yet to be attached to the left hand side - lovely castings.

 

 

The components yet to fit. This shows the forking and bulk that it is very difficult to capture in etches.

 

 

They have had the casting sprues cleaned off and a first 'rough' file. Probably 1/2 hour per piece now to finish and polish.

 

As an aside, I have a Griffin crab kit to do. I was going to do it at the same time, but I haven't started it as yet. In addition to all the rods etc. shown in the first picture of this post, you get all these castings - and this is for the engine only.

 

 

Ignore the fact that the etchings are the old Jidenco ones, and that they will therefore need a bit more work than modern etches, you get a stonking kit for your money.

 

Richard

[Christian]

Richard

 

Thank you for sharing details of the LG castings, I shall certainly bear them in mind for future builds.

 

I am most interested in the return crank, in particular how it fits to the wheel.

 

As you know I have a simular issue with my A3 and I need to find a better solution to fixing this crank to the wheel.

 

Your thoughts would be apprieciated.

 

 

[dikitriki]

Hi

 

The right hand side valve gear has been filed, sanded, checked for clearance against the next part, and polished. Now for the easy bit in assembling it.

 

 

 

Christian, you asked about the return crank.

 

I normally use Slater's 12 BA crankpins, as I have here and on the A3. If the return crank is a casting, ie there is enough meat in it to take a decent thread, I will simply tap it 12 BA and wind it on to the crankpin until it is tight. The chances are it will not be in the correct position, so I either thin the back of it, or more likely, thin a bearing a little until it tightens in the correct relationship to the wheel centre. It's a matter of trial and error, and only taking a little off, until it is correct. When it is correct, I remove the excess crank pin, file flush, and sand/polish smooth For the final assembly, I will use some thread lock adhesive to stop it working loose.

 

Where the return crank is a laminate (or where the casting is relieved on the back, as is the case with the crab) I solder a small top hat bearing in from the back. This gives a greater depth for the tapping, therefore a more secure fit, and provides in the flange of the bearing, a little distance between the rod and crank to minimise the risk of one catching the other. This avoids having to crank the crank unnecessarily. Again, tap 12 BA and the procedure is the same as above.

 

Yes, you can see, if you look very closely, the end of the crankpin, but by the time everything has been blackened and weathered, it will be all but invisible.

 

This pic shows the normal Slater's bearing (left) against the smaller top hat bearing I use, which is exactly the right size for 12 BA tapping without any further work.

 

 

Richard

[alcazar]

So whose top-hat bearings are the ones you use?

[smudgeloco]

Sheer enjoyment. Thanks for posting.