Vintage Steam Engine.

For technical tips, questions etc. on all subjects except Engines and Boilers.
Mike Rometer
Full Steam Ahead
Full Steam Ahead
Posts: 829
Joined: Sat Aug 13, 2011 6:41 pm
Boat Name: B.N.Y.S.
Location: Middle Earth

Vintage Steam Engine.

Post by Mike Rometer » Tue Jul 21, 2020 6:57 pm

Mostly for general interest, here are some pictures of an engine I was privileged to work on today.
The attachment President (1).JPG is no longer available
A Sissons of about 1954 vintage. That was about the time that I first started messing with things mechanical! :)
Attachments
President (1).JPG
President (1).JPG (147.31 KiB) Viewed 1002 times
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
Mike Rometer
Full Steam Ahead
Full Steam Ahead
Posts: 829
Joined: Sat Aug 13, 2011 6:41 pm
Boat Name: B.N.Y.S.
Location: Middle Earth

Re: Vintage Steam Engine.

Post by Mike Rometer » Tue Jul 21, 2020 6:59 pm

Unfortunately is has a heavy clonk, seeming to come from the bottom end. (I personally haven't heard it, but am guided by someone who has)
President (4).JPG
I've measured the crank pin at 2.994" all over, and though it has a couple of 'marks' on that I will erase with some fine emery and oil, looks good. They really are not serious.
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
Mike Rometer
Full Steam Ahead
Full Steam Ahead
Posts: 829
Joined: Sat Aug 13, 2011 6:41 pm
Boat Name: B.N.Y.S.
Location: Middle Earth

Re: Vintage Steam Engine.

Post by Mike Rometer » Tue Jul 21, 2020 7:00 pm

President (6).JPG
I reassembled the bearing, off the shaft, and the measurements are nowhere near as good, 3.004" - 3.006", but there are no signs of serious wear. In fact not a lot more than normal bedding in. 0.010" seems rather a lot, I would have expected something less than 0.001" per inch dia. It's an easy fix as there are slippers either side than can be reduced to close the excess. My thoughts are perhaps to remove a touch too much and set back up with shims, which could be removed/adjusted at a later date when things start to rattle again. Thoughts? :?:


Whoops! Stuck this in the wrong section. Dohhh!
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
Steam Captain
Full Steam Ahead
Full Steam Ahead
Posts: 111
Joined: Mon Oct 26, 2015 2:32 pm
Boat Name: No Boat Yet

Re: Vintage Steam Engine.

Post by Steam Captain » Wed Jul 22, 2020 6:33 pm

Ah, good old technic. I like engines with a one-sided slide and a rod stay opposite the slide.
User avatar
RNoe
Full Steam Ahead
Full Steam Ahead
Posts: 117
Joined: Sun May 26, 2019 5:29 pm
Boat Name: Cluaran
Location: Northern Oregon

Re: Vintage Steam Engine.

Post by RNoe » Wed Jul 22, 2020 11:13 pm

Yes: A good idea to mill down the slippers and install shim packs for easier future adjustments.

I have heard that there exist companies that will make shim packs to your specifications, and trimmed to the profiles required.
I'm in the market for exactly that. Several of us are preparing to pour 2 new 3" Babbitt bearings in a 10-ton Aultman Taylor steam traction engine.
We want shim packs installed for future adjustments and maintenance.

If anyone reading this knows of specific companies that will provide shim packs, please share that info.
I will also share as I learn more.
RussN
User avatar
marinesteam
Full Steam Ahead
Full Steam Ahead
Posts: 283
Joined: Thu Nov 19, 2009 2:51 am
Boat Name: TBD
Location: Colorado USA

Re: Vintage Steam Engine.

Post by marinesteam » Thu Jul 23, 2020 1:31 am

Make your own shim packs. I sandwich the shim material between 1/8 aluminum plates then drill holes and mill as needed. The shims for the lower conrod bearing were drilled then put into the assembly and filed to the profile.

https://www.mcmaster.com/laminated-shim-stock

Cheers
Mike Rometer
Full Steam Ahead
Full Steam Ahead
Posts: 829
Joined: Sat Aug 13, 2011 6:41 pm
Boat Name: B.N.Y.S.
Location: Middle Earth

Re: Vintage Steam Engine.

Post by Mike Rometer » Thu Jul 23, 2020 9:11 am

This one means two sets of shims as the slippers are handed, though the difference seems to only be the guide spigot holes, I suppose it might be possible to make a common set if the spigots allow.

(wanders off back to the workshop to check.)
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
User avatar
barts
Full Steam Ahead
Full Steam Ahead
Posts: 898
Joined: Wed Nov 18, 2009 6:08 am
Boat Name: Otter, Rainbow
Location: Menlo Park, CA
Contact:

Re: Vintage Steam Engine.

Post by barts » Sat Jul 25, 2020 4:07 am

With 0.010" clearance on a 3" crankpin you'll definitely get a healthy 'clonk'. From http://edge.rit.edu/edge/P14453/public/ ... arings.pdf:
The basic guideline universally used for diametral journal bearing clearance is 1.5mils-per-inch of journal diameter. That is, a 4 inch diameter shaft would need about 6 mils of diametral clearance. Always check if the specifications you see are for diametral clearance. Some manufacturers specify radial clearance- which is really difficult to measure! If the application has atypical loads and/or speeds, then this clearance rule may need to be adjusted.The bearing should be held in the housing with a zero to 1 mil interference fit. A loose bearing will have vibration problems and too much housing interference can reduce the clearance in the bearing. The issue of tolerances should also be considered. Clearance values are usually given as a range. The limits suggested here for minimum allowable clearance is 1.0mil-per-inch shaft diameter plus one mil. The maximum allowable is 2.0 mils-per-inch. Remember tolerance costs money.
- Bart
-------
Bart Smaalders http://smaalders.net/barts Menlo Park, CA
Mike Rometer
Full Steam Ahead
Full Steam Ahead
Posts: 829
Joined: Sat Aug 13, 2011 6:41 pm
Boat Name: B.N.Y.S.
Location: Middle Earth

Re: Vintage Steam Engine.

Post by Mike Rometer » Sat Jul 25, 2020 8:59 am

Bart, my problem with this one is that it appears it may have come from the manufacturer that way! :shock: There is very little ovality in the bearing, maybe 0.0005" indicating that is near enough the size it was machined to.

The consensus now is to remove around 0.012" from the slippers and insert a 0.004" shim, with some other thickness's on stand by, re-assemble on the pin with a touch of 'blue' and check for high spots. I have advised that the oil be changed from the current SAE 140 to something a bit thinner, at least at the start.

This thing is turning a BIG wheel, 36" X 48"!
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
User avatar
barts
Full Steam Ahead
Full Steam Ahead
Posts: 898
Joined: Wed Nov 18, 2009 6:08 am
Boat Name: Otter, Rainbow
Location: Menlo Park, CA
Contact:

Re: Vintage Steam Engine.

Post by barts » Sat Jul 25, 2020 4:08 pm

Bart, my problem with this one is that it appears it may have come from the manufacturer that way! :shock: There is very little ovality in the bearing, maybe 0.0005" indicating that is near enough the size it was machined to.
Wow... that's alarming. I'd make sure the engine is otherwise true and orthogonal - a bent crankpin could cause this, but it would be out a lot, and running a dial indicator along the length of the crankpin with the crank suspended by the bearings should show that. If it is too tight on reassembly w/ reasonable clearance, look for this.

Hmm, on second thought that would make the bearing wear barrel shaped, which I assume is not the case. A puzzle.

Best of luck -
- Bart
-------
Bart Smaalders http://smaalders.net/barts Menlo Park, CA
Post Reply