Genghis's 7mm Workbench

G

Genghis

Western Thunderer
Well the Taiwanese authorities let me back into the country before they announced the requirement to self-quarantine for 2 weeks, so I have had to go into the office........Have found time to get back to the workbench though.

The arrangement of pull rods is much simpler than on the MOK Arthur (see Oldravendale's excellent build) consisting mostly of 0.9mm wire. I was concerned to find a method where it would be possible to release the wheels which otherwise would be trapped by the rods. The answer was to fit some small bore tubing in two of the crossbeams allowing the rod to be unclipped from the other crossbeam and slid along. I hope it becomes clearer in the following pictures.

In place (look what happens when you leave a wheelset on the bench for a week)

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You can spot the tubes here:

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So the pull rod can slide to allow the wheels (the carriers for which are held by 10BA screws) to be removed.

And here are the bits prior to painting.
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I think the pull rods will be secure enough with a drop of paint: we'll see.

Just the tanks to clean up now. These will be fitted finally after painting.
 
G

Genghis

Western Thunderer
So here we are with the tender. The tanks at the rear are not yet secure and need strapping added: a job for the painter! Actually I think I need to find a replacement for these. They took some cleaning up. Resin castings would be nice, but expensive. Brass tube and etched inserts may be a solution.

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Meanwhile I have started on the loco chassis. First job, as always, assemble the coupling rods!
 
G

Genghis

Western Thunderer
The chassis build has moved along nicely.

First job as always is to sweat together the coupling rods and other motion parts. I then added the lower firebox parts and one of the frame spacers.

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It's going to be a rigid chassis build, but with the centre axle floating. the etches make provision for this so I elongated the middle axle bearing holes accordingly.

Using some 3/16" rods and a marked table the frames were tack soldered together.
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Then the outer bearings were fixed using the coupling rods to check for spacing.

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Then a check that the wheels touch the ground at the same time and the frame spacer soldering completed.

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The middle axle is sprung with some piano wire.

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Now we have a 6 wheel version!

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I have since added one more frame spacer at the front. Next I'll fit the crankpins and check that the chassis rolls freely with the rods on. Then I am going to move onto the body as I want to check on the motor gearbox fitting. I am using an ABC/Maxon combination.
 
G

Genghis

Western Thunderer
Well the nice man came around today with my mandatory stay-at-home form: £5000 fine for being caught outside home. Good job I have a supply of red wine and loco kits to hand..............

It's always nice when you put the rods on and a chassis rolls freely first time. Happy to report that I experienced that pleasure this morning.

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Work continues on the footplate, as per instructions, adding details.

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It's important to get the bend in the weighshaft right otherwise it will distort the running plate. There is a useful template in the instructions, but as the copy I have isn't printed full size it wasn't much help!

I have started on the cab and hoped to finish the main structure of it today. The sides and roof are one piece and have to be formed to fit the spectacle plate. I found that I had soldered the spectacle place almost in the right place so the sides didn't quite finish where they should. I probably could have gotten away with it, but I fired up the gas torch and disassembled it. I found it useful to use the rollers to preform the roof. I had annealed where the sharp bend will be formed but didn't want to make the roof too soft as it might bend in the wrong places! anyway I think that it will be possible now to start from the bottom of the spectacle plate and work up and round and down, but that is a job for tomorrow. A spicy lamb curry is on the stove and a bottle of red is crying out to be opened........
 
G

Genghis

Western Thunderer
The curry was good, as was the bottle of Spanish Grenache that went with it. One of the drawbacks of living here is the price of wine and beer which are taxed at the same rate as spirits. I can get a nice bottle of Macallan for £20, but a bottle of drinkable red is much the same.

So here are the disassembled cab bits.

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I had one more go at starting from the top middle and working down, gave up and started from the bottom. By the time I got round to the other side that also lined up, so I'll call that a result. Another time I would add the beading after forming to shape as it will mean making the bend at teh top of the cab sides easier.

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The internal bracing strip and external rain strips were added.

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A test fit to the footplate showed minimal filing required.

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The cab was then secured and internal details adding. The backhead and fall plate will come later.

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The running plate bracing was cut away.

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Now is head scratching time. The instructions and cd show a witness on the spectacle plate to form the lower part of the firebox but this is not present in this version. The rear section of the boiler/firebox is a complete tube, so some butchery will be required to open it up for the motor and to gain access to solder washouts etc. It is entirely possible that the lower sides of the firebox will be hidden by the whitemetal castings that are fitted in this area, in which case forming a firebox shape is not really necessary. I'll sleep on it before deciding what to do.
 
G

Genghis

Western Thunderer
An exchange of emails with Adrian Rowland (Northstar) confirmed that I am working with the production etches and that the witness mark on the spectacle plate present on the test build and featured on the CD that comes with the kit is missing in the production version. Also confirmed that some work is necessary in the firebox area to open it out for the motor.
I marked up the inside of the rear boiler/firebox section to locate the top. I then cut number 1 boiler spacer (fitted adjacent to the spectacle plate) so that it was no longer circular but had a 28mm flat on the bottom (the distance between the running plates). TDC also marked.

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This was then test fitted to the spectacle plate and the castings that site either side of the firebox placed to see how it will fit together.
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The modified spacer was then located inside the boiler firebox etch to mark where the firebox bend will be.

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A line was drawn between the marks on both sides and then another line, perpendicular to the edge of the etch and 50mm from the cab end to show where a cut is required.

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Three sets of piercing saw blades later, the cuts had been made and the firebox shape formed,

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Big mistake: it would have been much easier to solder the boiler formers in place first and form the shape later.

The rest of the boiler and smokebox was formed as per instructions, joined together and tested for fit.

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The sections should be held together by 6BA screws and nuts but unfortunately the nut in the former at the front of the taper section came partially unsoldered while I was soldering the former in place. So this joint is held by a peg and the soldering at the outer side. There is still the smokebox wrapper and boiler bands to follow so I think it will be robust. I now need to cut back the lower firebox sides, add the smokebox wrapper and then the smokebox front. After that I'll return to the chassis.

I discovered that I was in error in thinking that it is a £5000 fine for breaking quarantine: it's actually form £2500 to £25000. Some stupid foreigners have been rounded up for going to the pub. When you have been warned that your mobile phone location is being monitored, you have to be stupid to go out with your phone. I've got 4 kits to build after this so I am in no hurry to go out!

Keep safe everyone.

Dave
 
G

Genghis

Western Thunderer
Only one photo to show following several hours at the bench, and it doesn't look much different to the last one!
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Basically I have just done the jobs listed at the end of the last post, plus adding the washouts. I took my time to make sure it is right. I'll fix the boiler parts to the rest tomorrow and then decide whether to carry on with the original plan and revert to the chassis or carry on with the body.

Last day of isolation today so will put in an appearance in the office tomorrow, but many people here are now working from home and I'll probably join them to save the commute. Gives me more time at the bench! :)
 
G

Genghis

Western Thunderer
My thoughts that I would quickly fix the boiler were changed when I realised it would be better to mark up and drill holes for the handrail knobs and clacks. The masking tape is easier to mark up and stops the drill slipping, but then you knew that already........

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So some time today spent getting the cylinder furniture ready. I dislike drilling nickel silver castings. I have spoken with the caster about using plugs to get holes but that has fallen on deaf ears. A change of caster may well be forthcoming. Anyway, tomorrow promises to be fun putting this lot together.

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(Plus the valve spindles, which I forgot to add to the collection).

Another interesting point about building one of your 'own' kits is that you understand the packing instructions better. So when they say 'X' 10BA screws, it actually means 2 1/8" countersunk, 7 1/8" cheesehead, 4 1/4" cheesehead etc. A useful learning curve.

Keep safe. David.
 
G

Genghis

Western Thunderer
Not too much to report: cylinders and motion bracket constructed. I know that the crossheads slide, so the next job will be to see if any material needs to be cut from the slidebars to clear the connecting rods.

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Hmm... looks like a tweak to the cylinder wrapper is in order...............

Boiler not yet fixed so the gaps under the smokebox wrapper will disappear.
 
G

Genghis

Western Thunderer
Work has gotten in the way a bit so progress limited but I am now about to start a 4 day weekend so am expecting to have time for the good things in life.

Here is the cylinder/motion bracket assembly. There ought to be some oil pots on the slidebars. I don't think I have any suitable castings so it is something to consider for the future.

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I did get time to add the steps to the body.

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And realised that fitting the clack valve flanges would be easier at this time.

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Have also made a start on the bogie.
 
G

Genghis

Western Thunderer
Day 1 of the 4 day weekend saw progress. The bogie is complete:
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After that I spent time working on the motion. To my surprise nothing needed to be taken out of the slidebars: the con rod gets close but not that close. Union link has been fitted to check that the chassis rolls freely with rods on: it does, except when the excess crankpin length hits the con rod, but clearly that isn't going to be an issue when the pins are trimmed back. I decided that fitting the union link to the drop link before the drop link was fixed would be better.

So here it is to date with chimney and dome just out of the packet: body and bogie just placed for effect: not necessarily in the right place!

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Not that many bits left in the box now.
 
G

Genghis

Western Thunderer
Today my mojo put on its face mask and wandered out of the door..........so not as much progress as hoped.

The motion is pre-assembled.

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All pretty much as per the instructions except that the return cranks have been tapped 10BA to help with securing them. I also added a thin 12BA washer between the eccentric rod and the overlay for the return crank so that it clears the raised square on the overlay. The overlay is free to move and will be secured to the crank when all is fitted and proven to be well.

I have yet to decide how to secure the radius rod in the expansion link: probably a steel rivet.

One good point about today: I found my jar of solder paint. It made soldering the pinned joints less stressful.

Tomorrow is a day trainspotting. I'm off to the Taiwan Railways depot at Changhua. This hosts TRA's growing collection of working steam locos.
 
G

Genghis

Western Thunderer
I uploaded these from my phone and haven't been able to edit the text properly. The place is Changhua near Taichung in the middle of Taiwan. It is home to TRA's collection of three or four working steam locos. I had hoped to see the Pacific and the Mikado but they were away somewhere on display or working. It's a holiday weekend here (Tomb Sweeping) so possibly working.

Apologies for the orientation of the shots.

Very much a typical railway depot, except that TRA has constructed a viewing platform on top of an outbuilding so visitors can get a better view.

Quite a selection of locos most of which are now quite old. Also some ancient coaching stock. The hydraulic diesel DHL110 is newre but these are not well liked compared to the ancient GM locos.

You can see the standard collection of new brake blocks and R71 has the words 'Christmas Tree' painted on in invisible ink.

CK124 has a makeshift tender to give it extra range.

The GE (US) electrics were the source of some dispute between GEC (UK) and TRA. TRA issued a tender for locos with 4 driving wheels per bogie so GEC produced the now withdrawn E100 series Bo-Bos. GE produced the heavier and more powerful A1A-A1A electrics which still survive today in three series (E200, E300 and E400). These still work the passenger Chu-Kuang limited express trains but an order for more intercity EMU's is likely to see the work for these gone.

When you have finished rebuilding your diesel and have bits left over, what do you do? Build a statue of course.

A grand day out!

Now back to the S15!
 
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