7mm Martin Finney 7mm Duchess

Ian@StEnochs

Western Thunderer
Richard,

A tip I got from the late Colin Binnie many years ago for making hex fittings was to use a pin vice with a hexagonal body to hold the material when shaping when the hex body gives you an easy indicator of the hex sides. If your pin chuck has a round body, find a nut that will slip over the round body and glue it behind the chuck end.

Jim.



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This is mine. A standard Eclipse pin chuck with an M6 nut forced onto the body. In use the set up rests on one flat and the knurled body with the stock protruding. A couple of strokes with a file held horizontally and then roll onto the next flat. Repeat until a perfect hex is produced. My chuck holds up to 1/16" rod or tube. If you need bigger hex than that hex brass rod is available.

Ian.
 

Dikitriki

Flying Squad
Thanks Jim amd Ian. That makes perfect sense. I have made 3 more unions this evening which will be used on the Duchess - I wasn't happy with the one I made earlier which is now scrap. I shall try to get some better pics tomorrow when the light is better.

Richard
 

Silverystreaks

Western Thunderer
Richard

Re your scratch build unions, just wondering, would it be possible to make these available as lost wax castings not only for the kits but as listed detail parts

Regards
Bob
 

Dikitriki

Flying Squad
Richard

Re your scratch build unions, just wondering, would it be possible to make these available as lost wax castings not only for the kits but as listed detail parts

Regards
Bob

Hi Bob,

I'll have a chat with the guys. The problem I see is getting the 0.45mm hole through. Casting starter hole dimples would not be a problem - asking people to drill 0.45mm through the length of the casting might be too much.

Richard
 

adrian

Flying Squad
I'll have a chat with the guys. The problem I see is getting the 0.45mm hole through. Casting starter hole dimples would not be a problem - asking people to drill 0.45mm through the length of the casting might be too much.
and then it needs cutting off the sprue and cleaning up with a file, 1 in 5 will probably bounce off the floor and disappear into the ether. Now I know how it's done I think I'd prefer to make them myself, probably no more work than drilling and cleaning a cast item. (edit: forgot to add being a cheapskate probably cheaper too.)
 

mickoo

Western Thunderer
I'm with Adrian they're much easier to make than cutting off a sprue and trying to drill holes deep enough to get a good fixing on, though Simons idea of 3D printing is appealing.

For the pedantic those are actually couplings, a union has only one nut and joins two bespoke fittings together with machined faces. Visually a coupling may have three nuts, the smaller being the two fittings the larger the joining nut between the two. Some unions may have two nuts or just one depending on how the fittings are attached to the pipes, those fittings with a nut generally being screwed on. Unions nuts are grouped together virtually touching.

A coupling has two nuts and a body between them and pipes are usually held in place / sealed with an olive.

None the less all very neat work:thumbs:

MD
 

Steph Dale

Western Thunderer
It can be done. Whether it will be or not is slightly another matter!

I've got some ridiculously small HO scale unions in stock at the moment. The trick is to drill them through while still on the sprue, thread them on to the wire and solder in place, then cut the sprue off.

Simple really - no small parts whizzing around.

Steph
 

Silverystreaks

Western Thunderer
Hi Bob,

I'll have a chat with the guys. The problem I see is getting the 0.45mm hole through. Casting starter hole dimples would not be a problem - asking people to drill 0.45mm through the length of the casting might be too much.

Richard

That's a very good point you raise Richard. I can envisage an upturn in the sales of the appropriate sized drills. I break too many as it is
Regards
Bob
 

OzzyO

Western Thunderer
A small correction it is not a displacement lubricator. It is a syphon lubricator, that uses a "wool" trimming to regulate the amount of oil that will run down the pipe. Not a very nice job cleaning one of them out or cleaning the trimmings.
If you would like to see how to make one of the trimming please let me know and I'll post the diagram up for all to see.

OzzyO.
 

Peter Cross

Western Thunderer
The pipe work looks great. I always try to get it to look right. But have not so far paid as much attention to the finer detail that you have done. Keep it up it inspires us all I do believe.
 

Dikitriki

Flying Squad
Backhead stage 2

Attention is now transferred to the bottom left quadrant of the backhead - the combined steam and vacuum brake and steam sanding control and all the associated pipework. You do have to consider the best order to fit the fittings and pipework, bearing in mind the pipework weaves above and below adjacent pipework. In this case there are 2 small pipes from the steam sanding control that go under the rest of the pipes, so these have to be done first.

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I can see from the horrible close ups that I have been too mean with the solder where the pipes enter the fittings. I shall go round with just a dot of 100 degree solder to fill the gaps. I didn't notice this even with my loupe on, but the pictures say otherwise. Serves me right for playing with the camera macro focus:)

Richard
 

Giles

Western Thunderer
The workmanship in this gives more pleasure than a Faberge Egg...... I would love to see this in the flesh some day!
 

Dikitriki

Flying Squad
Thank you Giles, that's a very flattering comment. It will be on the Finney7 stand, unpainted initially, for the next few shows - Reading and Bristol are the next two.

Backhead Stage 3

Upper left quadrant now. the only tricky thing here is that a number of the pipes have to be exactly the right length. Still, the first attempt is a good pattern for the second I find.

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The hole in the middle of the backplate is for the sand gun. They were removed pretty early on and blanked over. There is a nice casting in the kit for the gun and handle, but no etch for the blanking plate, so the next task is to fabricate that from scrap etch. Not much left in this section.

Richard
 

Dikitriki

Flying Squad
Backhead Completion

I have added the sandgun blanking plate, regulator, firedoor operating mechanism (which needed a set adding to clear the tray) and tray and heat shield (attached to the backhead rather than the floor as the backhead is to be removable). So the backhead is now finished. Despite it being busy with a lot going on, with the quality of the castings and etchings and the different diameter pipework, there is a pleasing finesse to it. The drawing Martin provided is very good and the hardest part about the whole lot is drilling the holes in the castings for the pipes. My drill attrition rate is high!

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I shall be working my way round the cab next.

Richard
 

adrian

Flying Squad
Very nice! Although what are the plans for the painting? or is that someone else's problem? Will there be any copper showing and if so is it maskol first and remove or just paint it all and polish the pipework later?

the hardest part about the whole lot is drilling the holes in the castings for the pipes. My drill attrition rate is high!
It's not just me then! I have become particularly adept at dressing small drills with a mini diamond sharpening plate to prolong their life.
 
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