Author Topic: Corliss Valve Duplex Triple Expansion Mill Engine  (Read 2256 times)

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #15 on: June 25, 2018, 08:48:04 AM »
Thanks for the comments on my roundhouse of locos (which is actually rectangular!), the others (4) are in our lounge with the stationary engines, all with acrylic covers, thank goodness, saving them from dust. ;D
There were six others that I've built...all have gone over the years to fund other projects, cars etc..
The 'Model Engineer' mags I still have all from 1954 when I started subscription, and collected back issues  to '38 and many before...at least they keep the loft warm and are a terrific resource for any club member building anything.  I've got to clear them out someday soon...tempus fugit!
My local club in Nantwich (S.Cheshire ME) 15 miles away has a 3 1/2" & 5" track a sixth of a mile long...many happy hours steaming there.
Anyway, I'll post some details and pics. of the Corliss Duplex soon.  Leave with a non-domesticated model engineer...attached
Stuart alias 'Jackdaw'

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #16 on: June 26, 2018, 04:05:38 PM »
Anyway, so much for the preface...the Corliss engine awaits.
I acquired a set of castings at a club sale about 10 years ago.  They had been donated by a dear friend who'd given up active live steam loco building due to failing sight. The ice cream box they came in weighed a ton !
The original design with its many variations, was the brainchild of Arnold Throp of Sheffield who I had the pleasure befriending at Northern Association of ME meetings.
He had written up a description of the engine in 'Model Engineer', I think in '78. ('Yes' 1978!).  He had made up wooden patterns for the necessary castings. The indomitable Peter Southworth rescued the patterns and started producing casting sets.  Upon his passing Bob Potter has picked up the baton still trading as 'Southworth Engines'.
The castings were to build a duplex (pair of engines with common crankshaft) with high pressure one side and low pressure 'tother with a condenser/'air pump' in tandem with the HP side (common through piston rods).
I planned to build the pair of engines with a HP/condenser one side and intermediate/low pressure the other side.   For this arrangement I needed a common bedplate for the IP/LP side.
The castiron bedplates were milled on the bottom and end surfaces. 
The centreline of each bedplate was carefully marked on all relevant surfaces and a set of jig-drilled  holes for fitted bolts completed. With temporary bolts fitted the whole of each side's bedplates could be set up on the miller and the the crankshaft bearing seats, cylinder bolting pads etc could be accurately machined. 
The keen-eyed will see that the combined IP & LP bed is made of aluminium it wasn't in the castings I obtained. :shrug:
That's the most tedious bit done now....if there is interest expressed in my continuation of the build I will try to do justice to the task. :atcomputer:
Cheers
Stuart alias 'Jackdaw'

Offline Ramon

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #17 on: June 26, 2018, 04:16:42 PM »
Hi 'Jack'

Re your preface - I think you need to check the fuel tank inside - sometimes the vent hole gets blocked and causes a vacuum  ;D Bugger to start once that happens,

Looking forwards to your comments on this engine as time progresses which will compliment my own.  Are you aware Arnold only made the patterns for a single (the one in ME) If you take a look at my thread post 1 and 21 it's mentioned there as I was the culprit who convinced Peter to do me some castings.

I mention Terry Fleet whom Arnold did the original design for - he's still about and I see him from time to time - all being well he'll have his duplex version at 'LowMex' this year

Reegards - Tug

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline vcutajar

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #18 on: June 26, 2018, 08:27:06 PM »
Hi Stuart

I would love to see a continuation of the Corliss build log.

Vince

Offline kvom

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #19 on: June 26, 2018, 09:24:04 PM »
When you say common crankshaft, does that mean a single piece or just connected with a coupler?

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #20 on: June 27, 2018, 08:38:06 AM »
The crankshaft is a single shaft with flywheel, gear eccentrics etc. keyed onto it.
Some Corliss engines had tandem cylinders in a single engine arrangement with a outrigger bearing fixed to the enginehouse floor.
I've attached a pic. of my build as-is part completed/assembled, started November 2017.  Build on hold at present for running locos on club track/grass-cutting/gardening/holidays etc....... :atcomputer:
Stuart alias 'Jackdaw'

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #21 on: June 27, 2018, 12:23:23 PM »
Hi All,
I next chose to do the flywheel.  Much as I would have liked the double width wheel, I used the one to hand.
I fastened the wheel to an angle plate that was set true to the X axis and milled the joint face carefully to cut where the barring teeth were so that the assembled teeth lined up.
My dear wife bought me digital readout for the lathe about 15 years ago for Christmas, and a 3-axis one for the miller the year after.  Such a boon ! One of the best pressies I've ever had....well next the the best she says !!
Using the d.readout I set-out the fastening pin holes in the hub and outer flange.
I could have made up a jig plate to do the job as an alternative.
Fitted bolts were made and the wheel assembled.   
It was then fastened to the miller table on packings and centred with a dti. and the hub faced off.
The cored hole in the hub was then opened out to reaming size (-.010") with a boring head and finished with a Brown & Sharp floating reamer. Hole size was checked with a plug gauge made up to crankshaft diameter.
My lathe, (a 5"DST 'Viceroy') was not quite big enough to machine the outside diameter and so I called upon pal Pete to use his Colchester Student.  Mounted on a true-running nutted mandrel, the outside diameter was turned and the rope grooves put in with a vee tool mounted in what was a boring tool.
Cheers  Stuart
Stuart alias 'Jackdaw'

Offline kvom

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #22 on: June 27, 2018, 12:33:52 PM »
What is the diameter of the flywheel (to get an idea of the overall size).  Interesting that the casting is in two halves; other than pins, how are they joined?

Offline jeff l

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #23 on: June 27, 2018, 03:12:14 PM »
Thanks for showing your setups great job on the flywheel.

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #24 on: June 27, 2018, 04:22:59 PM »
Hi,
The overall diameter of the flywheel is 10".
As with full-size flywheels the sections are bolted together with fitted bolts, an interference fit in the holes.
Many wheels weighing 30 tonnes or more were built with two, four, six sectors...sometimes more dependant on the number & positioning of the spokes.
The outer barring teeth, used to turn the engine off dead-centres, were'barred' 'round with a lever and fulcrum block to the side of the wheel.   Some other larger power configurations had a 'barring engine', a small auxiliary steam engine with a pinion on the driven shaft that was pushed into engagement with the wheel teeth and withdrawn when the main engine came on power.
Cheers,  Stuart
Stuart alias 'Jackdaw'

Offline ChuckKey

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Re: Mad Dogs, Englishmen and Model trains ?????
« Reply #25 on: June 27, 2018, 10:27:39 PM »
I don't do trains but thought this might interesting to those of you who do.

That's KN Harris (Steam Author) riding behind as passenger in the duluxe fashion plate suit.


And Bill Carter driving his renowned atlantic.

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #26 on: July 21, 2018, 05:11:38 PM »
Hi All,
When building a project like the Duplex Corliss there are often different courses  towards the (hopeful) final result.................. :naughty:
Having got the baseplates all temporarily assembled and the crankshaft bearing seatings machined I decided to work on the crankshaft components so that I had somewhere to hang the flywheel made in the last instalment.
The caps for the pedestal bearings were machined up from the gunmetal casting inherited with the casting set previously mentioned. 
The split 'brasses' were made up from blocks of machined-up phosphor bronze and soft soldered together so that the bore and the chamber for the oiling ring could be machined.  A pic of the 'internal' chamber tool attached.The solder is then melted and the parting faces lightly clean-up on fine emeryboard.
In the parts pile I hadn't shown this ring, which just a plain thin washer made of PB, it runs over the crankshaft and it 'drips' into the oils sump seen in the pedestal bearing base.
I've shown a pic of the crankshaft/big end of 'Elsie' a 180hp tandem compound engine held at the Northern Mill Engine Museum.  She was built by McNaughts in 1902 to power a cotton mill.  (HP and LP cylinders sharing a common piston rod.)
Stuart alias 'Jackdaw'

Online Ye-Ole Steam Dude

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #27 on: July 21, 2018, 06:05:56 PM »
Hello Stuart,

Beautiful machining and a great looking project, I will follow along.

Have a great day,
Thomas

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #28 on: July 23, 2018, 03:48:23 PM »
Hi All,
Thanks Thomas for the compliment....I try...well my mother found me trying!!
I had a few problems putting the pics up last session, so I'll try again.  'Elsie' is the Corliss tamdem at the Norther Mill Engine Museum.
I've put up a couple of pics of machining the eccentric rods.  They are rather slender items  5.5" (145mm) long; large diameter 3/16" (5mm) small end 0.140 (3.5mm)
The top slide travel is some 2.5"; so I opted for the set-over centre method  using a No.2 MT  boring head
with a ball-bearing centre up the spout. I try to avoid setting over the tailstock and disturbing the accurate alignment.
 This enabled me to use the power feed to the saddle making the job less onerous and giving a better finish.  Having five rods to make...two for each Corliss cylinder (HP & IP) and one for the low pressure slide valve cylinder.
Cheers,
Stuart
Stuart alias 'Jackdaw'

Offline Jakdaw43

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Re: Corliss Valve Duplex Triple Expansion Mill Engine
« Reply #29 on: July 23, 2018, 04:00:57 PM »
More pics.
Taper turning the connecting rods from heavier section black (hot rolled) steel to avoid distortion after machining....also cheaper  !
The 'brasses' made up from phosphor bronze with adjusting wedge.  Small end is fitted with lubricator, the bigend is lubricated by a rotating banjo fitting as seen in the pic. of 'Elsie'
Stuart
Stuart alias 'Jackdaw'