Author Topic: Chris's Mann Wagon Build  (Read 54156 times)

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1260 on: January 11, 2021, 10:01:35 PM »
Started in on the crossheads, beginning with the HP cylinder one. Turned a length of bronze bar to size and drilled the hole for the piston rod on the lathe, and then held it in a 5C collet block for shaping the rest of the way. Milled the opening in the end for the connecting rod first

then milled away the flat on the side. Took it back far enough for both crossheads, since I can leave the rod in the collet from here on.


Turned the collet block 90 degrees to drill the hole for the wrist pin

Then sawed off the piece to length, and cleaned up the cut face on the lathe. Here it is on the engine...

The forward end of the block is threaded, and there is a lock nut on the piston rod end to hold it in place. So, on to the second crosshead, for the LP side. Another verse, same as the first!

Offline gary.a.ayres

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Re: Chris's Mann Wagon Build
« Reply #1261 on: January 11, 2021, 10:48:06 PM »
I look on in awe.

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1262 on: January 11, 2021, 11:27:24 PM »
I look on in awe.


Practice makes prefect. Perfict. Pherphect. ... or not...    :cheers:

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1263 on: January 12, 2021, 11:21:57 PM »
Today made up the shoulder bolt pivots for the crosshead/con-rod connection - had to go thin on the heads to get them to fit in the guides.

And then spent a while getting the crosshead guides and lower end caps all bolted up with the gaskets. The LP studs were easy to tighten up, but there is very little  room on the HP side so had to go one flat at a time, lots and lots of turns!

Then loctited the valve rod support arms into position on the guides, using a section of the valve rod stock to align them. Will let that set up overnight, next up will be the valve sliders/rods/nuts/clevises.

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1264 on: January 13, 2021, 02:36:37 AM »
Just went into the shop, and did a quick test, wanted to see the pistons moving with the crank. So, ran in the pivot bolts and a couple bolts on the motor mount, turned the flywheel halfway round, and...


 :facepalm:




The con rods hit the ends of the guides as they came over the top/bottom of the crank. Hmm... All works in the CAD version, so checked some dimensions. Turns out I left the con rods too tall in the center so they interfere with the ends of the guides.




So, next time the conrods come out and take a trip back to the mill for some dieting! Easy fix, just need to pay closer attention to the dimensions.

Offline MJM460

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Re: Chris's Mann Wagon Build
« Reply #1265 on: January 13, 2021, 04:05:40 AM »
Hi Chris, very important test that.  You did it deliberately didnít you?  Yes?  Just to check those dimensions?

And you know what they say, much easier to machine it off than to machine it back on again!

On the other hand, these days with additive machining....

Great progress even allowing for minor setbacks.

MJM460

The more I learn, the more I find that I still have to learn!

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1266 on: January 13, 2021, 02:20:54 PM »
Hi Chris, very important test that.  You did it deliberately didnít you?  Yes?  Just to check those dimensions?

And you know what they say, much easier to machine it off than to machine it back on again!

On the other hand, these days with additive machining....

Great progress even allowing for minor setbacks.

MJM460
Oh, um, yeah, deliberate test, yeah thats it!   :embarassed:     :Lol:


Fortunately its an easy fix, its not hitting by much and at the design dimensions should clear fine.


 :cheers:

Offline cnr6400

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Re: Chris's Mann Wagon Build
« Reply #1267 on: January 13, 2021, 03:34:30 PM »
The key phrase when this sort of little hoo ha occurs is "tolerance stackup test - all part of the development."     :Lol:   :cheers:

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1268 on: January 13, 2021, 06:49:45 PM »
The key phrase when this sort of little hoo ha occurs is "tolerance stackup test - all part of the development."     :Lol:   :cheers:
This particular one was a stack-up (to use a polite phrase! ) of one part - the con rods were made .100 wider than the design, so they hit the ends of the guides at the highest angles in the crank travel. I got one trimmed down this morning to proper size, looks to be what it needed. One more later and another reassembly test.

Offline ddmckee54

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Re: Chris's Mann Wagon Build
« Reply #1269 on: January 13, 2021, 08:38:37 PM »
Better hurry up on that reassembly test Chris, I would imagine that there is more than one elf starting to turn blue holding his breath and wondering 1) Will it fit? and more importantly 2) Will it still look pretty?

Don

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1270 on: January 13, 2021, 09:36:41 PM »
Better hurry up on that reassembly test Chris, I would imagine that there is more than one elf starting to turn blue holding his breath and wondering 1) Will it fit? and more importantly 2) Will it still look pretty?

Don
And 3) Can we take it out for a beer run tonight!  :Lol:

Just finished up in the shop, got both con rods taken down to the designed thickness, and they clear just fine now!   :DrinkPint:
The shop elves will have to take my car out as usual for beer though, still need to make the valve sliders/rods/nuts/clevises, and some piping.  And make the pipe flange gaskets. And bolt the engine onto the boiler. And get the burner fit. And time the valves. And touch up the paint. And get the cargo bed bolted back on. Oh yeah, and drill the stack for the exhaust pipe to go in. And all the other little details I am not thinking of!
Wow, those elves are gonna be THIRSTY!   :lolb:

Offline cnr6400

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Re: Chris's Mann Wagon Build
« Reply #1271 on: January 13, 2021, 10:11:59 PM »
You say that as if their being thirsty was a new thing....... :Lol:

 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1272 on: January 13, 2021, 10:39:04 PM »
You say that as if their being thirsty was a new thing....... :Lol:

 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
True. So, thirsty and angry about it!?

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1273 on: January 15, 2021, 11:16:20 PM »
Couple days out of the shop, mainly taking care of my mother (priority! ), back at it again this afternoon. Got the holes drilled/tapped for the drain cocks that will be in the bottom of the steam chests (no room for ones on the cylinders), and also got a start on the HP slide valve. Started with a length of bronze bar held in the 5C collet block, and shaped the end to size (those square blocks are great for this, very repeatable clamping in the vise).

Then milled in the opening in the underside. Actually did these first two steps twice, since the first time I made the opening in the bottom too deep, and it would have connected with the valve rod.   :wallbang:

Turned it over, and milled in the slots for the valve rod and adjusting nut using a small end mill

Here is the part so far, cut off from the main bar. Still need to trim it to final length, take some material off the top, and lap the bottom smooth for a good seal. You can see the drain cock in the steam chest in the background.






Offline Flyboy Jim

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Re: Chris's Mann Wagon Build
« Reply #1274 on: January 16, 2021, 02:43:06 AM »
Looking good Chris.  :ThumbsUp: Like you I love my 5c collet blocks.  :)

Jim
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".