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Dikitriki's 7mm Workbench: Scratchbuilt Wagon


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Hi Richard,

 

Glad to see you back on RMweb, I can understand the frustration of ill fitting parts as I have just had to part scratch build a boiler saddle and a pair of steam pipes. I will not name and shame as in their defence they have always been very good with replacements return of post and helpful advice, and being that the saddle and pipes were made of white metal I suspect that maybe the moulds have seen better days. On a different subject looking back at your Heyside topic and the track work part in particular, did you use Templot for the track plans or did you use some C&L templates ? Anyway soon be time for Telford to get my yearly fix,

 

All the best, Martyn. P.S. Congratulations on being picture of the week.

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Hi Martyn

 

I feel I know where I'm going with the Fairburn now, so it's all steam ahead. In fact the one side of the valve gear is now fully assembled and working, so I'm really happy with the way it's all worked out. But it has taken a huge investment of time and effort. I shall take a photo tomorrow.

 

'Tis a compliment to have pic of the week - there's some serious competition on this forum. For the record, the 8F is a San Cheng model and was detailed and weathered by Clive Neale, one of the Heyside regulars.

 

I'm really looking forward to Telford. If you (or anyone else) wants to say hi, I shall be at the test track L10 at 1.00 both days.

 

The pointwork for Heyside was all Templotted. I keep meaning to update the blog, but the sad fact is I'm much happier with threads than blogs, so I've let it go, but rest assured, work is progressing.....painstakingly slowly!

 

Regards

 

Richard

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Hi Richard,

 

The valve gear and those castings certainly look so much more prototypical and business like, and it must be rewarding for you to see it all in motion.

 

 

I thought it was Templot, I brought Templot about a month ago but what with work,kids,etc I have not had the time to get to grips with it, and from what I have found so far there's alot to take in.

 

And as for Telford I will pop round to the test track and say hello, and hopefully you can help me with a couple of questions that are better explained in person ( if you know what I mean ):huh:.

 

Regards, Martyn.

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Hi

 

And here is the completed valve gear, at least the one side. The other side should be much quicker now I've sussed the geometry.

 

post-3059-128194621662_thumb.jpg

 

Still stacks to do. You will note that the expansion link is above the topmost part of the slidebar support bracket. Since the bracket is flush with the underside of DJH's incorrectly located floor :angry: , I shall have to cut some slots in the footplate to clear the expansion link. Same for the reversing lever I think. Since I had the opportunity, the reversing mechanism works, and will be servo operated in due course.

 

I still have to fill in the frames above the weighshaft cut out, but I shall attach this to the removable cylinder unit. I was more concerned with getting the valve gear working at this stage.

 

Richard

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All looks very neat Richard, well done. How are you intending to drive the servo so that it works correctly in relation to the power/speed of the loco?

 

Hi Al

 

Is this possible?

 

To be honest, I had not thought beyond forward and reverse, and was quite pleased the valve gear was actually reversible in the first place. If someone knows how to do what you suggest, then please let me know. I obviously have quite a lot of room available in the tanks, but my knowledge of electronics is minimal at best.

 

Richard

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Hi Al

 

Is this possible?

 

Richard

 

Good day Richard,

 

I recollect that one of the West Mersea supporters has done this with a LNER engine... and that the result was put on the old RM Web. "Scale7JB" comes to mind.

 

regards, Graham

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  • 2 months later...

Hi

 

Well, I managed to find my workbench amongst the dusty archives. It's over a month since I last posted, and not much seems to have happened in the interim - very busy doing not much.

 

I did manage to get both sides of the Fairburn valve gear completed, and fitted the chassis to the body. That was a game as I had to file relieving slots in the footplate - which runs incorrectly along the bottom of the tanks - for the expansion links and reversing lever. Here is the current state of play.

 

post-3059-012546000 1287418155_thumb.jpg

 

I have attached the rear bogie temporarily, but I have problems with the rear loco frames.

* They are attached to the loco body and not the chassis. That makes it near impossible to attach the injectors and all the pipework and brackets. Oh, hang on, DJH didn't include those......

* They bear little more than a passing resemblance to the profile of the real thing.

 

So I am going to have to scratchbuild the rear frames after dismantling my work of a few years ago.

 

I am actually quite pleased with the way it's shaping up now, as I feel I have overcome the really difficult bits. Well, apart from one that I am still thinking about. I've mentioned that the floor runs incorrectly along the bottom of the tanks. It's a real problem at the back of the bunker where the error is obvious as the footplate lip above the buffer beam is visibly in the wrong position.

 

Anyway, the Fairburn is put to one side while I ponder, and I am returning to the Aspinall saddle tank. I put some information about this on a blog I started, but I prefer the workbench format, so, while I won't repeat everything, here are some views of the current position:

 

post-3059-017435300 1287419322_thumb.jpg

 

post-3059-000961400 1287419364_thumb.jpg

 

post-3059-014133200 1287419290_thumb.jpg

 

Work on this loco stalled while I considered whether I wanted to fit inside valve gear in. In the end, I felt that I would not be happy if I didn't, so I am. This time it's Stephenson's Link, and again from Sanspareil. Again, I have no instructions as these are a set of castings that he has not released on the unsuspecting public. I am tasked with taking loads of photos for the instructions, so I thought I would do it on my workbench. This is probably going to be more useful than the Joy's valve gear as it is much more common. Here are the components:

 

post-3059-046837400 1287418185_thumb.jpg

 

post-3059-009506900 1287418206_thumb.jpg

 

post-3059-033316300 1287418236_thumb.jpg

 

post-3059-034005800 1287418259_thumb.jpg

 

The concept here is different from Laurie Griffin's in that the cranks and eccentrics are cast as one. This should make the construction of the crank axle that much easier, nor do I have to attach the eccentric strapping before soldering the axle in as you do with Laurie's, so less risk of getting solder where you don't want to. The crank casting is not perfect - there are a couple of holes in the eccentrics, but I do not see this causing a problem, and they will, of course,be invisible on the finished valve gear. Lots of bits, some duplication, and a very nice hand lever.

 

Now off to have a pleasant browse through Barry Lane's L&YR loco book before getting stuck in.

 

Richard

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Richard

 

Glad to see you back at work again so to speak, you must be having the same problems with spare time as me. Not much is happening this end either but that is all about to change.

 

That Fairburn seams to be becoming a bit of a pig but I am sure you will win it over eventually.

 

Glad you are back on the Aspinall but how could you even think of not installing the inside valve gear, shame on you! I shall pull my chair up again on this one, inside valve gear has really peaked my interest, I have Finneys 1854/2721 to build with inside motion, can't wait but it will be a while before I start, Spearmint needs to be finished first and the MOK 4MT keeps looking at me!

 

Keep up the good work,

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Those castings for the Stephenson's gear look rather tasty... what do you get for the reversing shaft? and for the reach rod?

 

You seem to be able to obtain all sorts of interesting bits and pieces, so how does Joe Public get details of what castings are available from Ian?

 

regards, Graham

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Richard

 

Glad to see you back at work again so to speak, you must be having the same problems with spare time as me. Not much is happening this end either but that is all about to change.

 

That Fairburn seams to be becoming a bit of a pig but I am sure you will win it over eventually.

 

Glad you are back on the Aspinall but how could you even think of not installing the inside valve gear, shame on you! I shall pull my chair up again on this one, inside valve gear has really peaked my interest, I have Finneys 1854/2721 to build with inside motion, can't wait but it will be a while before I start, Spearmint needs to be finished first and the MOK 4MT keeps looking at me!

 

Keep up the good work,

 

 

Thanks Christian

 

Work is mad at the moment, and I find myself working most weekends, with little spare time. It's very frustrating.

 

You're right about the inside valve gear. Once you know you can do something, it's very difficult to go backwards and then not do it. I was never really happy with my decision to omit it, just being lazy I guess. I consider myself properly chastised.

 

 

 

Those castings for the Stephenson's gear look rather tasty... what do you get for the reversing shaft? and for the reach rod?

 

You seem to be able to obtain all sorts of interesting bits and pieces, so how does Joe Public get details of what castings are available from Ian?

 

regards, Graham

 

Hello Graham,

 

The reversing shaft and reach rod are assumed to be either in the kit, or fabricated by the builder. I don't see how any caster could provide the reach rod given the huge number of different shapes.

 

I haven't used any component that is not available to the general public. Iain Young of Sanspareil can be frustrating to deal with, and there are no organised lists like that from Laurie Griffin. However, he does have a huge range of castings that by and large complement Laurie's range. I have a good idea of his range having known him a very long time, but I just ring him at the workshop (repeatedly if necessary) and ask him what he does I might need! His workshop number is on the GOG website.

 

Richard

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Hi

 

I've managed to find time to do a little preliminary work on the crank axle. I filed off the casting pips and used broaches, reamers and files to make sure that a Slater's axle could pass through the whole ensemble. Not too freely, but not a force-fit either.

 

I then came up against a problem - the shape of the cranks is incorrect for the Aspinall tank. The ones provided are rounded, whereas the real ones are rather squarer. I decided that there was enough meat on the castings to reprofile them and set to work with a large file. I suspect the shape I ended up with is a little on the small side, but closer to the original. I did not quite capture the angular transition at the ends as I would have had to make the cranks too small to do so.

 

These photos show the difference - the axle is only placed in position.

 

post-3059-092513800 1287682065_thumb.jpg

 

post-3059-020155800 1287682053_thumb.jpg

 

post-3059-035364800 1287682077_thumb.jpg

 

And this is what the original looks like. A Barton-Wright 0-6-0 tender loco of the type rebuilt into the saddle tank. These pictures are reproduced by kind permission of Rail-Online.co.uk

 

post-3059-025281200 1287682110_thumb.jpg

 

post-3059-057567200 1287682149_thumb.jpg

 

You can see the more angular nature.

 

There is also another cracking photo here http://www.lyrtrust.org.uk/images/752/752_20.jpg this time of the saddle tank.

 

Richard

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Hi

 

I've managed to find time to do a little preliminary work on the crank axle. I filed off the casting pips and used broaches, reamers and files to make sure that a Slater's axle could pass through the whole ensemble. Not too freely, but not a force-fit either.

 

I then came up against a problem - the shape of the cranks is incorrect for the Aspinall tank. The ones provided are rounded, whereas the real ones are rather squarer. I decided that there was enough meat on the castings to reprofile them and set to work with a large file. I suspect the shape I ended up with is a little on the small side, but closer to the original. I did not quite capture the angular transition at the ends as I would have had to make the cranks too small to do so.

 

These photos show the difference - the axle is only placed in position.

 

post-3059-092513800 1287682065_thumb.jpg

 

post-3059-020155800 1287682053_thumb.jpg

 

post-3059-035364800 1287682077_thumb.jpg

 

And this is what the original looks like. A Barton-Wright 0-6-0 tender loco of the type rebuilt into the saddle tank. These pictures are reproduced by kind permission of Rail-Online.co.uk

 

post-3059-025281200 1287682110_thumb.jpg

 

post-3059-057567200 1287682149_thumb.jpg

 

You can see the more angular nature.

 

What a cracking series of photos! If only all-in-one assemblies like this were available for 4mm scale.

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Richard,

 

Great to see the thread up and running again, watching it has reignited my passion as my life has been sadly devoid of modelling since I came back from Telford. SWMBO and I had a chat ( one of those one way ones :blink: ) and agreed to finish off our extension before christmas so to that end i'm off to tile the kitchen floor and here's to modelling in the new year :D Look forward to seeing the valve gear finished,

 

Best regards Mick

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Richard,

 

Great to see the thread up and running again, watching it has reignited my passion as my life has been sadly devoid of modelling since I came back from Telford. SWMBO and I had a chat ( one of those one way ones :blink: ) and agreed to finish off our extension before christmas so to that end i'm off to tile the kitchen floor and here's to modelling in the new year :D Look forward to seeing the valve gear finished,

 

Best regards Mick

 

 

You'll need to take the modeling with you to work Mick... do it in your lunch hour..!! wink.gif

 

JB.

 

 

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Richard,

 

Great to see the thread up and running again, watching it has reignited my passion as my life has been sadly devoid of modelling since I came back from Telford. SWMBO and I had a chat ( one of those one way ones :blink: ) and agreed to finish off our extension before christmas so to that end i'm off to tile the kitchen floor and here's to modelling in the new year :D Look forward to seeing the valve gear finished,

 

Best regards Mick

 

Hi Mick

 

I'm glad I've helped with your modelling mojo. I know the sort of chats you mean. I always maintain my wife and I never argue, she just has blazing monologues. :lol: :rolleyes:

 

I've now got the crank axle firmly (I hope) attached to the axle. I drill through the cranks and axle so I can pin the joints. A bit belt and braces, but I want to do this only once. I use solder paste from C&L and brush flux around the joints as I am using the microflame to make sure I have a good flow of solder everywhere. I keep some very cheap kids brushes (you know, the 10 for £1 plastic ones) especially for the task, expecting to write them off. I'm not worried about excess solder here, probably the one time I will say that, and just rely on a good clean up later.

 

The following photos show one side immediately after the soldering, the second side after a basic clean up.

 

post-3059-030432100 1288003365_thumb.jpg

 

post-3059-005882200 1288003375_thumb.jpg

 

post-3059-070981600 1288003399_thumb.jpg

 

I also found time to start the preparation of the slidebars. The bars will need straightening, and the crosshead filing to make sure it drops smoothly all the way down under gravity.

 

post-3059-069012500 1288003352_thumb.jpg

 

Richard

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Hi

 

Well, I managed to find my workbench amongst the dusty archives. It's over a month since I last posted, and not much seems to have happened in the interim - very busy doing not much.

 

I did manage to get both sides of the Fairburn valve gear completed, and fitted the chassis to the body. That was a game as I had to file relieving slots in the footplate - which runs incorrectly along the bottom of the tanks - for the expansion links and reversing lever. Here is the current state of play.

 

post-3059-012546000 1287418155_thumb.jpg

 

I have attached the rear bogie temporarily, but I have problems with the rear loco frames.

* They are attached to the loco body and not the chassis. That makes it near impossible to attach the injectors and all the pipework and brackets. Oh, hang on, DJH didn't include those......

* They bear little more than a passing resemblance to the profile of the real thing.

 

So I am going to have to scratchbuild the rear frames after dismantling my work of a few years ago.

 

I am actually quite pleased with the way it's shaping up now, as I feel I have overcome the really difficult bits. Well, apart from one that I am still thinking about. I've mentioned that the floor runs incorrectly along the bottom of the tanks. It's a real problem at the back of the bunker where the error is obvious as the footplate lip above the buffer beam is visibly in the wrong position.

 

Richard

 

The Fairburn is looking great. More and more I'm thinking that I want to give mine the same treatment. I would rather spend the extra money and time to make something really nice and accurate than something just OK. Especially that rear bogie. The cast version looks SOOOO much better than the original.

 

I haven't looked too much at the instructions, but I can't beleive the rear loco fram is attached to the body and not to the rest of the chassis. tHat seems, um, odd at best. But it also seems that it wouldn't be too hard to use some scrap brass as straps across the inside of the frames to solder the two frames together, and then have the body simply rest on the frames...

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The Fairburn is looking great. More and more I'm thinking that I want to give mine the same treatment. I would rather spend the extra money and time to make something really nice and accurate than something just OK. Especially that rear bogie. The cast version looks SOOOO much better than the original.

 

I haven't looked too much at the instructions, but I can't beleive the rear loco fram is attached to the body and not to the rest of the chassis. tHat seems, um, odd at best. But it also seems that it wouldn't be too hard to use some scrap brass as straps across the inside of the frames to solder the two frames together, and then have the body simply rest on the frames...

 

Thanks Mike. It is difficult to build a model from the box when you know how wrong it is, especially if you have the ability to improve it.

 

You're right in your approach to the rear frames, except that those provided by DJH bear little resemblance to the actual shape of the real thing. It's fairly straightforward to scratchbuild two new sideframes, solder some spacers in and attach them to the rear of the chassis. I'm only temporarily moving on to something simple - like inside valve gear

 

Richard

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Hi

 

A bit more progress on the inside valve gear.

 

I have finished the crank axle, and checked the connecting rod big ends rotate easily (they do). I have not yet fettled the eccentrics or checked the fit of the eccentric strapping.

 

post-3059-064771800 1288468758_thumb.jpg

 

Since I have no space between the frames to fit hornguides and the crank axle, I am again forced to use the frames as hornguides, cutting them to fit the bearing directly.

 

post-3059-032184400 1288468793_thumb.jpg

 

Of course it would have been easier if I had decided to fit inside valve gear before completing the chassis.....And if the frames were further apart....

 

The last picture is of a cut down bearing with an original. I think it's cut down enough, but it's all very tight.

 

post-3059-048899100 1288468768_thumb.jpg

 

I shall have to attach some strips to the inside of the chassis to stop rotation, and make the springs screw-in to retain the bearings.

 

Richard

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Of course it would have been easier if I had decided to fit inside valve gear before completing the chassis.....And if the frames were further apart....

 

The last picture is of a cut down bearing with an original. I think it's cut down enough, but it's all very tight.

aaah - the joys of 29mm frame spacers with Scale7!

 

Anyway nice to see this progressing and it's looking good.

 

 

 

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  • 1 month later...

Hi

 

I've managed to get the crank axle revolving freely between the frames, but talk about fag paper clearances....I now need to work out some method of springing the axle.

 

post-3059-086075200 1291571920_thumb.jpg

 

From the side you can see how the outer cranks have to run inside a ground out arc on the inside of the springs. The springs retain the bearings which had to be cut into the frames rather than run in separate hornguides, and the springs are themselves retained by 2 countersunk screws. I've had to make good the pick up plunger holes, and I shall fill these later today before soldering in the slidebars.

The ash pan was not provided in my kit, so it was scratchbuilt from brass. They seemed to vary from loco to loco, so this is representative rather than very accurate!

 

post-3059-006889100 1291571974_thumb.jpg

 

I cleaned up the slidebars so that the crosshead and piston slid freely under gravity (they dropped out when I turned it upside down)and soldered it to the back of the cylinders.

 

post-3059-060166000 1291571939_thumb.jpg

 

post-3059-026814300 1291571957_thumb.jpg

 

I then realised that the front spacer would prohibit any movement of the pistons. Perhaps if I'd decided to put inside valve gear in from the first, instead of partway during the build, I would have created less difficulties for myself. My solution was to drill holes in the spacer to allow for the piston movement. I shall see later whether they are in the right place!

 

post-3059-072758100 1291571931_thumb.jpg

 

I'm hopeful it might get easier from here.

 

Richard

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Hi Ken

 

Thanks. That's the beauty of this forum - there is always something to inspire, to encourage one to push personal boundaries further. For my part, I often look to see what you are up to, and am always amazed at the speed and accuracy shown on your production line. I was admiring the Jinty on Geoff's stand at Reading.

 

Back to the valve gear. I spent last night working on the slidebar unit. Everything has to slide freely now, because once it's installed, you can't get at it - both the crossheads and the valve spindles were carefully checked and polished. The ends of the slidebars were trimmed back a little and squared up, and a modest taper filed on the ends. I attached the slidebar support/valve spindle support bracket, together with a representation of the angle to tie the top and bottom outside slidebars together. It's now ready to install, and the interesting work can commence :)

 

post-3059-045177000 1291810462_thumb.jpg

 

post-3059-020997700 1291810479_thumb.jpg

 

Richard

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The ash pan was not provided in my kit, so it was scratchbuilt from brass. They seemed to vary from loco to loco, so this is representative rather than very accurate!

 

post-3059-006889100 1291571974_thumb.jpg

 

Looking at this photo, It seems to me that the brake rigging will interfere with the main rods. Looks like at some point, the main rod will have to pass through the brake rigging to get between the "low midstroke" position and the "front dead center" position. Or is that just an optical illusion?

 

I'm thinking that the prototype would have solved that problem or the brake rigging would be in a different place, but I can't work out the geometry in my mind.

 

BTW - That crank axle looks great!

 

Mike

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