Author Topic: Stevens Model Dockyard Engine  (Read 3359 times)

Offline Michael S.

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Re: Stevens Model Dockyard Engine
« Reply #15 on: July 30, 2022, 08:12:05 PM »
Then it's an easy fix.
I'm always amazed at what a small amount of play in the bearing causes a knock.

Michael

Offline crueby

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Re: Stevens Model Dockyard Engine
« Reply #16 on: July 30, 2022, 09:54:57 PM »
Great detective work, and not stopping at the first thing found is good, there are often several things stacked up!

Offline Chipmaster

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Re: Stevens Model Dockyard Engine
« Reply #17 on: October 07, 2022, 09:56:55 PM »
New bronze sleeve 5/16 od x 1/4" id fitted to the crosshead.

IMG_5111 by Andy, on Flickr

IMG_5112 by Andy, on Flickr

Followed by a new stainless steel piston rod 5/16 diameter with 1/4" BSF thread at each end.

IMG_5099 by Andy, on Flickr

IMG_5100 (2) by Andy, on Flickr

IMG_5120 by Andy, on Flickr

A new pin was fitted to the cross head and the engine turns over very smoothly at this stage

Flickr video
IMG_5113 by Andy, on Flickr

The excess thread might permit fitting a slim locknut if there's sufficient clearance under the cylinder cover.

 IMG_5125 by Andy, on Flickr

Next step will be replacement of the rusty valve rod.

IMG_5121 by Andy, on Flickr

Andy

Offline Chipmaster

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Re: Stevens Model Dockyard Engine
« Reply #18 on: November 02, 2022, 08:19:15 PM »
At each end of the cylinder there was evidence of a plugged hole, ex cylinder drain cocks I presume but it looks like the thickness of flange at the end of the cylinder has been reduced, what happened to this bitza - weird.

 IMG_5177 by Andy, on Flickr
IMG_5180 by Andy, on Flickr

Buffed up.

IMG_5185 by Andy, on Flickr

The gland for the valve rod had an M10 x 1 pitch, I reckon the 1/4" bore male end union from the hydraulic brakes of a car had been used and the female part had been soldered onto the valve chest.

IMG_5211 by Andy, on Flickr

As it was very worn I bought an M10 x 1 male brake blanking plug then drilled and reamed it to 1/4".
IMG_5227 by Andy, on Flickr


IMG_5228 by Andy, on Flickr

Here it is on a new stainless valve rod complete with a new half of the pivot.

IMG_5229 by Andy, on Flickr

Reassembled with brass dome nuts and given a whiff of compressed air.

VNkfJWM_gGo
Buffed up it's looking better but there are still several issues to be corrected. The bent crankshaft is pretty bad and may have to be replaced if careful hammer blows don't straighten it. A new valve chest will be required because bodged/oversized holes around some of the studs have left almost no surfaces for the cover's gasket to seal against so it's leaking air at quite a rate.
It would be a bad idea to steam it with such a leak.

Andy


 

Offline Michael S.

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Re: Stevens Model Dockyard Engine
« Reply #19 on: November 03, 2022, 04:44:12 AM »
Hello Andy,
very nice old steam engine.
Maybe you can straighten your crankshaft on the lathe. I bend the end of the crankshaft in the right direction with my hand and check with the dial indicator. I wouldn't use the hammer.

Michael

Offline Jasonb

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Re: Stevens Model Dockyard Engine
« Reply #20 on: November 03, 2022, 01:19:16 PM »
It's certainly looking and running better than it wa sin your first post.

As to the crank, you know the saying " if in doubt, get the Stilsons out:ThumbsUp: