Casting Gloat

[Charles Lamont]

Arrived yesterday, a remarkably reasonable Ebay impulse buy, this venerable Stuart No 8 set probably should not be shown to that grumpy little elephant.
It is probably pre-WW2, with a pre-trunk-guide slipper crosshead.
There is also an external valve rod guide, which is going to be a bugger to do.
It is complete, in very good condition, and mercifully untouched, apart from the flywheel being faced undersize and rough drilled.
Even the treasured blue steel lagging sheet shows no rust.
The fasteners (86, of 20 different patterns) are mostly lightly rusted and are 1/8" and 3/32" Whitworth, rather than the BA threads of more modern sets.
The drawing is a real blueprint on which the dimensions are expressed with economy. 
I expect it will be some time before it comes out of the box again.

[cnr6400]

I see a custom two way lathe faceplate / mill & drill fixture in your future for machining that external valve rod guide.........(just polished the crystal ball this morning)     

[Jo]

Nice set of castings 

Arrived yesterday, a remarkably reasonable Ebay impulse buy, this venerable Stuart No 8 set probably should not be shown to that grumpy little elephant.

You are safe he is still polishing his latest Coles horizontal engine castings

Jo

P.S. He doesn't do Grumpy but he does know how to get his revenge   

[Jasonb]

I've found using other bits of the engine saves on having to make special fixtures. Mill the mounting face flat and drill the holes. Then mount your valve chest in the mill vice and clock in the valve rod hole, zero DRO or dials. Now screw the guide to the valve chest and drill and ream the hole without moving the table. Or if you drill and tap the holes before doing the 4-jaw work on the valve rod hole and gland you can leave it in the 4 jaw and just screw the guide into place and drill & ream which should keep it all concentric.



Looks like they did not have a guide when first introduced and it was added some time later but before the trunk guide ones came out.

http://stuartturnersteam.com/Horizon/No.8/No.8.html

[tangler]

Aahh, those lovely smooth shell castings.

Enjoy,
Rod

[ettingtonliam]

If its got the slipper crosshead rather than the trunk guide, its pre 1937/8  as my catalogue for those years comments that it has been redesigned with the trunk guide. The 1930 catalogue shows it with the slipper crosshead. Oddly, the illustrations for both types don't show a valve rod guide. Is it on the drawing?
As far as I know, the change to BA fasteners rather than BSW came after WW2, by the early 1950s.

Sorry, they won't be those smooth shell castings, that process didn't come in until post war, either.

[Charles Lamont]

Well, the valve rod guide is on the drawing, and the castings are definitely shell moulded.

[ettingtonliam]

Curious. what date is on the drawing?

I've just re-examined the catalogues. The guide is shown in the illustrations in 1921 and 1931, but not in 1930, even though its in the component list. They appear to have done away with it altogether when they changed to the trunk guide arrangement.

In a 1975 catalogue when talking about the shell moulding process (they were very proud of it) they say that they first used it 1955, so your castings can't be shell moulded, as they seem to date from the early 1930s or late 1920s.

[Charles Lamont]

The drawing is not dated.

[john mills]

I have a catalog for a local model engineering supplier with refers to jobs they did in 1935 no date for catalog
but it has the picture of that engine with the valve rod guide it can just be noticed.
It would be good to see it machined it has aged in a box for a long time already.
The quality of the castings shows the skill of the foundry trades men of that time when lots of castings were used
to make things .
John

[Chipswitheverything]

Interested to see Jason's photo of the set up for the guide.  Though it was so long ago ( no photos! ) I think this was essentially how I set up for the valve rod guide on the Stuart No 1 engine, certainly I used the engine as it's own jig without the need for other elaboration . The seperate guide adds interest and supports the rod better than just using the gland.  Dave

[Charles Lamont]

Yes, boring the guide in situ on the valve chest seems to be the way to go. With the right sequence, it can be done at the same set-up as boring the valve chest, reaming both in one swell foop.

Another mildly interesting thing about the kit; the piston rod and valve stem material is too yellow to be stainless steel. I think it could be nickel silver.

[ettingtonliam]

A 1921 catalogue says German Silver for the piston and valve rods. Is this the same as nickel silver?

[Charles Lamont]

Yes

[steam guy willy]

German silver = nickel silver ..quite Redly available ,  I often buy it  and it can look like steel but won't rust  of course   it is actually Nickel and Copper  I believe

Willy