7mm Mickoo's Commercial Workbench

mickoo

Western Thunderer
Wow, amazing work on the valve gear. I take it the brass tube in the above photo is used to thread on the balance weights and gubbins, and then just push the axle through the tube ?

Stephensons Link Valve Gear is very commonly used, any chance you could print some of them ? I have recently fitted some inside valve gear to one of my locos, and although there is a great sense of achievement to see it all wiggling around, the wiggling is hardly noticeable :rolleyes:… I for one would benefit greatly, as my next two loco both have Stephensons valve gear, and life’s too short..

Cheers, Martyn.
The problem here (as explained several times elsewhere....social media.... in the last few hours) is that it's all bespoke to this model, which makes it sort of commercially unviable, unless you start to add in grey areas to compensate.

However, it is viable if you expend some energy in communicating accurate measurements for a specific given model and there are decent drawings to work from.

There's a lot of compensation on this 4F due to the narrower frames for OF, narrower than they actually need to be in all honesty....well unless you wish to run it around your Xmas tree curves that is. That applies to the cylinder block, motion bracket and thickness of cranks and motion etc, I also had to hack the top off my leading axle horn guides or cut through the slide bar. There's also some simplification of parts, whilst you can draw it in CAD and then ramp up the resolution in the print there does become a point where the energy expended is not worth the final result buried deep in an engine.

The brass tube slides through the main cranks and eccentrics and then over the axle, just gives a better running surface when that end sits on top of the axle. The other bits and pieces are just metal pins to fix it all together. Because I had already fixed the cylinder block in I had to make the slide bar assemblies separate, otherwise they could be part of the motion bracket.

The connecting rod little ends are not pinned but a snug fit in the crosshead, a dab of Loctite will secure them pretty well, same for the expansion links into the rocking levers and weight shaft drop links.

I get where you're coming from with life's too short to make it all working and I'd love to streamline these modules for others, which engines were you considering?
 

3 LINK

Western Thunderer
I have two locos planned for the winter months, a Churchward/Collett 2884 class 2-8-0, and a Churchward mogul 2-6-0 which will be either a 63xx or a 73xx.

I can understand some of the complexities of designing something like this in 3D, and from what you have explained to me, it is a far from simple task. Plug in and play would be great :rolleyes:.

All the best, Martyn.
 

mickoo

Western Thunderer
I have two locos planned for the winter months, a Churchward/Collett 2884 class 2-8-0, and a Churchward mogul 2-6-0 which will be either a 63xx or a 73xx.

I can understand some of the complexities of designing something like this in 3D, and from what you have explained to me, it is a far from simple task. Plug in and play would be great :rolleyes:.

All the best, Martyn.
Who's kits?

GWR is pretty standard with set rod lengths depending on wheel diameter basically, plus there's no inside cylinder block to contend with or motion bracket, therefore the only critical dimension is the centre of the eccentrics to the centre of the rocking arms.

All in all, very simple to do and certainly cost effective, it's when you start adding slidebars and crossheads and cranks and lifting links it all gets messy.
 

3 LINK

Western Thunderer
The 2884 is from the Scorpio range and the mogul from Warren Shephard. Regarding the distance between the eccentrics and the rocking arms, I will have to ask Jeff Ennis as I know he has all the dimensions from when he did the research on the 2884.

Martyn.
 

mickoo

Western Thunderer
I've got a MOK 75000 build to start next week and the client wants a Mk2 tender with smaller windows, the kit does parts for a Mk2 but the rear spectacle plates are the larger type. Not sure as yet as to why or where the bigger windows were fitted as both Mk2 and 2A can have smaller windows.

I need to work up new etch sheets for the tender front and rear with the smaller windows, there will probably be a couple of spare sets (to fill the minimum etch sheet size order) so if anyone want's some to share the costs, just shout out :thumbs:

The artwork will go in Monday so as to avoid delays in the build.

Image2.jpg
 
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mickoo

Western Thunderer
The 2884 is from the Scorpio range and the mogul from Warren Shephard. Regarding the distance between the eccentrics and the rocking arms, I will have to ask Jeff Ennis as I know he has all the dimensions from when he did the research on the 2884.

Martyn.
Okay, no problems, I'll see if I can find some works drawings as well, you'll need the weight shaft and that'll have a metal pin right across so you'll need to drill the frames in the right place to support that and possibly make up a little stub at the front where the rocking arm attaches to.

There's also a big casting on the side where the expansion link swing links attach to, you're going to need to drill that and solder a bit of wire in to support that as well.
 

3 LINK

Western Thunderer
That would be a great help and most appreciated, I still have a load of castings left over from various kits, mainly JLTRT. And I think I have the rocking arm covers, so every little helps.

Are you going to the Guildford trade show next month ?
 

mickoo

Western Thunderer
Hope they’ve got the heating on this year…


Regards

Dan
So do I, I popped into the Skating rink next door and it was warmer in there :eek:

I'm taking full thermals, working on the theory it's easier to take them off than to put them on if you don't have them.

If it's cold again this year then I suspect many will never go again and I'll hang it out until I've seen all my clients and then leave, perhaps empty tables will be the prod they need to sort it out......doubt it though.
 

SimonT

Western Thunderer
The reach rods are different. The 2884 are 5'0" and some 64ths, the 43 family are 4'2" and some more unreadable 64ths. In addition, the expansion link hangers are different lengths.
 
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