Author Topic: Stuart No 1  (Read 6158 times)

Online b.lindsey

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Re: Stuart No 1
« Reply #15 on: January 17, 2019, 01:51:37 PM »
Jo, I am assuming that that 1mm short length of the standard can be compensated for in the rest of the build correct? If not, could you just shim it up that 1mm and leave everything else the same?

Bill

Offline Jo

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Re: Stuart No 1
« Reply #16 on: January 17, 2019, 04:09:54 PM »
Yes Bill I am planning to leave an extra 1mm on the Soleplate under the bracket  ;)


The Sole plate is now dialled in on Tgs table. I now have some decisions to make: The bearing slots are over width but the lower bearings are also over width and the same width as the caps (outside width is correct). Looking further at both caps and lower bearings both are offset and would mount flush with the outside.

So I could throw away the caps and the lower bearings and machine the soleplate thinner to match the drawings or work with what I have got and accept that the inner showing face on the caps is going to be about 1mm short  :thinking:

Jo
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Offline bent

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Re: Stuart No 1
« Reply #17 on: January 17, 2019, 06:38:33 PM »
So, mechanically a 1mm thinner cap is no big deal, and it's just the aesthetics...but the caps are mostly hidden behind the flywheel and valve bearings, so, no biggy?

Offline bouch

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Re: Stuart No 1
« Reply #18 on: January 17, 2019, 07:50:21 PM »
Hi Jo,

I've built a #1, saving it from someone who "started it but couldn't finish it".  Mine was quite the disaster, but with a lot of perseverance, it runs quite nicely.  I needed to build a new crank, do some serious rebuilding of the crank bearings, and fix a LOT of issues.  I think the only parts I didn't need to re-work were the top cylinder head and the steam chest cover.  But, its a wonderful engine, and an absolute classic design.

When I got the castings, I was talking to a man well known in New England, Dan Fay, about the reversing gear.  (Dan's nickname was "grandfather steam"!)  He asked if I had gotten the reversing gear, and I said, "No, but I'm going to buy the casting set".  He immediately made it very well known to everyone within shouting range that that engine was NOT to be made with the reversing gear, for exactly the reason you have in your OP.   It is meant to run only one direction, so the forces are always pushing the crosshead against the upright.  Running in reverse, there's not a sufficient bearing surface, and it'll wear out quickly.

Dan also asked if I had the book on building it.  I said yes.  He said, "throw it out!  they build it backwards!"  He then explained that the book says to build it from the base casting, and work your way up.  He said that what you should do is build it from the cylinder down.  As you know, the most important part is to have the piston and crosshead guide perfectly square.  So, that's the point he said you should start from.  If there's any "out of square", then scrape the top of the crosshead guide as needed until the crosshead/piston will just slide with no binding whatsoever.  Once that's accomplished, then you can worry about the relationship between the base/crankshaft and the piston rod.  A few thou out there wouldn't be that big of a deal.  So, that's how I built mine.  I don't have piston rings in, and if I rotate the engine to "top dead center", then gravity invariably causes the crank to spin and the piston rests at bottom dead center.

Here's a short video from a few years ago of mine running on air at a model engineering show in Vermont.


I'll enjoy watching your build.

Offline Jo

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Re: Stuart No 1
« Reply #19 on: January 17, 2019, 08:15:19 PM »
The first pics from Eric  :)

He has been machining his sole plate (Have you spotted those desirable table clamps :P ). His choice to do the 8 degree angle was to tilt the head on his mill.... I was planning on tilting the soleplate :noidea:

He drilled his soleplate for 1/4" mounts on to the box bed but decided to sleeve down so that he can use 2BA studs with 2BA or 3BA sized nuts. (You may be able to just make out some of the original features/holes in the soleplate that contributed to the exorbitant price he was forced to pay for this casting set  ::) ) Eric tells me that he chose to mill two flats under the top of the stand rather than counter boring under where it bolts on the cylinder  :thinking: .

At this point we have to play spot the No 1 castings in the background of the photo. Some are virgins, some are "used" but he hasn't taken a shot of all of them together (there could be features that he doesn't want anyone seeing until they are fixed :-X )

Just to be different he chose to bore his cylinder on his Beaver mill using an automatic boring and facing head.  I did enquire as to why he is doing this on the mill but got a reply along the lines of "I fancied doing it that way".

I wonder why the ends of the cylinder on the No 1 are not counter bored  :noidea:.
Jo
« Last Edit: January 18, 2019, 06:55:24 PM by Jo »
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Offline Jo

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Re: Stuart No 1
« Reply #20 on: January 17, 2019, 08:20:18 PM »
Hi Mike (Bouch),

You have done a nice job of that engine. It looks like it predates mine - you can tell by the shape of the "S" on the Valve chest cover  ;)

Jo
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Online steamer

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Re: Stuart No 1
« Reply #21 on: January 18, 2019, 12:26:24 AM »
Hey Jo,

I trust the cross head bearing faces on the columns were flat?

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Jo

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Re: Stuart No 1
« Reply #22 on: January 18, 2019, 06:14:26 AM »
 :ThumbsUp: That was the best machined surface on the castings.  :)

Jo
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Offline Stuart

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Re: Stuart No 1
« Reply #23 on: January 18, 2019, 08:45:22 AM »
Jo

Great pics from Eric
But by ekk holy 13 amp sockets bat man in pic one ,looks like a dado strip

Got any snow yet ,had a sprinkle here

Stuart
My aim is for a accurate part with a good finish

Offline Jo

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Re: Stuart No 1
« Reply #24 on: January 18, 2019, 03:36:48 PM »
 :facepalm: You spotted that. That is one of my old 'mains socket strips' out of the back of Test equipment. I had about half a dozen... the Eric made friends with one, then another one, then  :noidea:


No snow yet just another set of castings  :-X Talked to Andy at Stuart turner about their No 1 on the stand and Eric just happened to mention that it is not built to drawing  ::)

Jo
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Offline bouch

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Re: Stuart No 1
« Reply #25 on: January 18, 2019, 05:09:16 PM »
Hi Mike (Bouch),

You have done a nice job of that engine. It looks like it predates mine - you can tell by the shape of the "S" on the Valve chest cover  ;)

Jo

Thanks for the compliment.

As for the age of the castings, I finished it in 1995.  I acquired the castings probably 4-5 years prior to that, and they were 2nd hand.  My understanding at the time was they were at least 10 years old.  So, they're 1980's vintage at the latest.

Mike

Offline Jo

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Re: Stuart No 1
« Reply #26 on: January 19, 2019, 05:46:02 PM »
The tops of the bearing surface and the Stand mount were taken down to height. The biggest challenge was deciding on the positioning of the dummy studs. In the end I decided to space them at 28.6mm out rather than the 26 on the drawing which means it will be easier to get a spanner on them, I can fit either 2BA or the 1/4 BSF but as I do not have any nuts that size I opted to use the 2BA.

Having drill for the standard it was obvious that the inside of the casting needed milling away so that it was level with the standard. Doing this I found that one of the inner edges of the casting was a bit short so added a bit  :)

Jo
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Offline Jo

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Re: Stuart No 1
« Reply #27 on: January 21, 2019, 02:28:56 PM »
The standard has to be mounted so that the cross head guide is in the centre of the sole plate so that was used to mark off the holes. Having drilled holes in the standard it is time to think about boring for the crankshaft  :thinking: I decided on a jig.

The starting point is to drill the bearing caps to fit then make a jig so that I can bore the pairs for the crankshaft... after a cuppa.

Jo
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Online b.lindsey

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Re: Stuart No 1
« Reply #28 on: January 21, 2019, 02:49:12 PM »
You are coming along rapidly on this one Jo. Hope the boring goes well for you.

Bill

Offline Jo

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Re: Stuart No 1
« Reply #29 on: January 21, 2019, 04:30:19 PM »
Thanks Bill,

The boring went well. I used a piece of silver steel of the appropriate size to check the fit for the crankshaft. And it looks promising as both bearings even line up  :)

Jo
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