Author Topic: Greene Automatic Cutoff Steam Engine  (Read 1228 times)

Offline kvom

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Greene Automatic Cutoff Steam Engine
« on: April 16, 2019, 07:49:51 PM »
I will be picking up a set of castings at NAMES for this engine.  The origins are from Historic Models and Reproductions from whom I got the castings for the Joy engine.  The plans and castings are now owned by Downriver Tools.  From their website:

Quote
- Improved Green Automatic Cut-Off Engine

This horizontal steam engine castings and drawings kit is based on the original automatic steam cut-off engine design by Nobel Green in 1838. The model has a 1 1/2 inch bore, 3 inch stroke and the flywheel is 11 ½ inches diameter.

This engine, built by the Providence Steam Engine Company in Providence, Rhode Island, incorporated variable steam cut-off several years before George Corliss patented his famous variable cut-off Corliss valve gear.  Our model is based on a 150 HP, 17 inch bore and 36 inch stroke Improved Green Automatic cut-Off Engine that has been restored and preserved by the New England Wireless and Steam Museum in East Greenwhich, RI.

Green’s engine design used what has been known as a detachable valve-gear.  The detachable valve-gear varies the steam cut-off point by using the engine governor to raise or lower trip points that operate levers to open the steam inlet valves.  The higher the trip point, the longer the steam inlet valve stays open allowing more steam into the engine’s cylinder.   The detachable valve gear was designed by Frederick Sickels and patented in 1841.  Sickels was only interested in the marine applications of his valve gear and sold the rights to use his patent on land based engines to the Providence Steam Engine company.  Then, when George Corliss introduced his variable cut-off valve gear in the late 1840’s, the Providence Steam Engine Company sued Corliss for patent infringement.

The court battle between George Corliss and the Providence Steam Engine Company raged on for over 10 years and became a landmark court case over what can and cannot be patented.  In the course of the court battle, Corliss won an injunction preventing the Providence Steam Engine Company from building and selling the Green designed engine.  The court case was finally settled in Corliss’ favor and Corliss’ original patent was extended by the US patent office on the basis that the law suits had prevented Corliss from benefiting from his patent.

In 1869, the Corliss valve gear patents finally expired and the Providence Steam Engine Company began producing the Green engine again.  The Green Engine was given some minor upgrades and changes and then introduced as the “Improved” Green Automatic Cut-Off Engine even though it was basically the same engine Noble Green designed in 1838. 

Specifications:

Scale: 1 inch = 1 foot (1:12)
Cylinder: 1-1/2 inch bore x 3 inches stroke
Flywheel: 11-1/2 inches diameter
Overall size: 22-1/2 inches x 12 inches x 12 inches high

I suspect this will prove a good challenge.  The photo below is from their website and represents the only example I've seen running (twice at NAMES).  I don't know the builder's name, but he likes to surface grind as much of the parts as possible.  Mine will look a bit different color wise, and probably not as finely built.  I purchased the plans a year ago so I've had some time to get an idea where the problems will be.
« Last Edit: May 02, 2019, 04:36:31 PM by kvom »

Offline crueby

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Re: Green Automatic Cutoff Steam Engine
« Reply #1 on: April 16, 2019, 08:03:02 PM »
That should be a very interesting model.... Gotta go check the popcorn kernel supply...

Offline fumopuc

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Re: Green Automatic Cutoff Steam Engine
« Reply #2 on: April 28, 2019, 07:53:56 PM »

[/size]
Hi Kirk, here a model build from bar stock of one of our German forum member.

http://www.dampfundmehr.de/HP/green/im_bau/green_0.htm
Kind Regards
Achim

Offline crueby

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Re: Green Automatic Cutoff Steam Engine
« Reply #3 on: April 28, 2019, 09:12:33 PM »


Hi Kirk, here a model build from bar stock of one of our German forum member.

http://www.dampfundmehr.de/HP/green/im_bau/green_0.htm

That is a beautiful model! One bit I have never seen before is a part on the crankshaft next to the eccentric and the governor belt takeoff - looks to be hinged over to the base casting, and wobbles back and forth - some sort of oil pump? You can see it in one of the photos, and partway through the video at timestamp 1:15. Any idea what it is?

Offline Admiral_dk

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Re: Green Automatic Cutoff Steam Engine
« Reply #4 on: April 28, 2019, 09:19:01 PM »
I might be mistaken, but look later in the video where you see the bottom two valves controlled by an axel that only oscillates a few degrees back and forth ....  :old:

Offline crueby

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Re: Green Automatic Cutoff Steam Engine
« Reply #5 on: April 28, 2019, 09:24:54 PM »
I might be mistaken, but look later in the video where you see the bottom two valves controlled by an axel that only oscillates a few degrees back and forth ....  :old:


Aha! Thats it, that second eccentric drives  that axle in a small back and forth rotation. Clever!


Thanks!

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #6 on: May 02, 2019, 04:04:32 PM »
I picked up the castings at NAMES.  Here they are laid out on the shop floor with a 12" rule for comparison (penny might have not been indicative):



A test fit shows that the flywheel can be mounted on my 10EE lathe, but it's unlikely I can use it to turn the rim, given that the crossfeed is limited.  I plan on doing it with an endmill on the CNC mill.

Online Jasonb

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Re: Green Automatic Cutoff Steam Engine
« Reply #7 on: May 02, 2019, 04:18:06 PM »
Look a nice set of castings.

I would have thought you only need about 3/4" cross feed movement at the most to do the rim. Upside down boring bar mounted on the side of the toolpost facing you usually reaches out far enough to do face & side, run in reverse.

« Last Edit: May 02, 2019, 04:22:08 PM by Jasonb »

Offline kvom

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Re: Green Automatic Cutoff Steam Engine
« Reply #8 on: May 02, 2019, 04:34:55 PM »
With the Joy engine 10" flywheels I was at the utmost to turn, and these are 11".  I probably need to make a custom tool holder.

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #9 on: May 10, 2019, 02:02:41 AM »
I have been studying the Solidworks model I got from Dennis Howe.  These are more informative than looking at individual drawings.  I spent the day assigning contrasting colors to the parts in order to see how they fit together more easily.  A zillion parts in this one.  A majority of the nuts are 3-48.

The operation of the exhaust valve is interesting as noted in a previous post.  Driven by an eccentric, the strap is connected to a pivoting part whose motion rocks the long exhaust rod *(second pic).  At the other end an oscillating linkage drives the "grate" valve, shown in the third.  Both halves of the valve have matching through slots that when matched together open the cylinder to the exhaust,  The use of multiple slots allows evacuation of more exhaust for an engine that might run a high speed.

Offline crueby

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Re: Greene Automatic Cutoff Steam Engine
« Reply #10 on: May 10, 2019, 02:05:54 AM »
Now that is some clever engineering in that engine! I can see why the 3D model made it much clearer, the individual parts would be meaningless. The gimbals on the eccentric follower is pretty neat!
 :popcorn: :popcorn: :popcorn:

Offline jeff l

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Re: Greene Automatic Cutoff Steam Engine
« Reply #11 on: May 10, 2019, 03:38:06 AM »
Just to clarify Downriver tools does not own Historic Models and Reproductions , they merely have the engines on their website to help sales .

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #12 on: May 10, 2019, 01:22:11 PM »
Thanks for clarifying Jeff.

I have scheduled a 2 day trip June 4-5 via Boston  to visit the NE Wire and Steam museum where an original engine has been restored.  I have an expiring SW airlines credit that will pay for most of the airfare.  I haven't been back to Boston since I spent 6 months contracting there 20+ years ago.
« Last Edit: May 10, 2019, 01:47:38 PM by kvom »

Offline jeff l

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Re: Greene Automatic Cutoff Steam Engine
« Reply #13 on: May 10, 2019, 01:29:22 PM »
 Kirk ,The New England Wireless and Steam museum is on my must see list i hope to make the trip soon . I see from the photo of castings that you are missing the governor stand , castings arrived yesterday so I will get this casting out to you .Jeff

Offline RonGinger

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Re: Greene Automatic Cutoff Steam Engine
« Reply #14 on: May 10, 2019, 05:03:52 PM »
The New England Wireless and Steam Museum is well worth the visit. They have a couple big annual events, the SteamUp  is usually the first weekend in October. That day the big vertical boiler is fired up and several of the big steam engines are run.

Be sure to check ahead to see if they will be open when you want to visit- its a rather small place and not always open. The founder, who was almost always there, died a few months ago and I am not sure what the opening schedule will be.

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #15 on: May 10, 2019, 07:04:53 PM »
I just checked the website to see that they're not open every day.  Sent a message asking to visit the day I'm in MA.  If not I'll probably just head to Newport for the afternoon.  I have an airline credit that is use it or lose it, si I'll be doing the trip regardless. 

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #16 on: May 15, 2019, 12:10:41 AM »
June 6 is volunteer workday at the museum, so I extended my trip by one day to participate.

Yesterday I decided to start the build by attacking the flywheel casting.  It's a big bugger: almost 12" diameter and probably over 20 pounds.  There's no real way to mount it on my lathe to start, so I started by reducing the lump of iron on the wheel's axis.  (These were needed in the mold to keep the wheel portion from cooling too rapidly).  Here's the setup using 123 blocks to raise it enough to clear the other lump.  Removed enough so that the remainder is inside the rim.



Back at it today.

Turned it over to mill the other "lump".  Now the rim can rest on the table, and the clamping is somewhat more secure.



Next the inside of the rim is machined to remove the draft.  This surface will be used to secure the wheel on the lathe via the 4-jaw chuck.  I was nervous about clamping too hard on the spokes, so this operation was done with many passes of 5 thou stepover.



Final operation on the mill was to face the side of the rim.  This gives a straight edge needed to ensure that the wheel is straight when mounted on the lathe.



Now for mounting on the lathe using my large 8" 4-jaw chuck, with the jaws on the inner rim.  Turning the lathe on a low speed allow verification that the inside face of the rim is close as possible to running true.  Then I centered the wheel using the inner rim as a guide.  Note that all of the machining done on the chuck side will be modified later.  Once centered, I used my 1/2" boring bar to turn the inner rim, and then faced the side of the rim and the hub.  The length of the hub was faced to close to the final size.



Next I turned the hub using a cutoff tool, then drilled the center 1/2" and bored to 0.855".



Final op for the day was to ream the center hole with the .875" reamer, which I had as this was the size of the axles on the Kozo loco.


Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #17 on: May 15, 2019, 12:13:07 AM »
The face of the rim is now the reference surface for further ops, as is the center bore.

Offline crueby

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Re: Greene Automatic Cutoff Steam Engine
« Reply #18 on: May 15, 2019, 12:14:50 AM »
Off to a great start, thats quite a big wheel.


 :popcorn: :popcorn: :popcorn:

Offline jeff l

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Re: Greene Automatic Cutoff Steam Engine
« Reply #19 on: May 15, 2019, 03:58:28 AM »
Kirk , You didn't waste any time getting this project started , good job .

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #20 on: May 15, 2019, 10:54:24 PM »
Not as long in the shop today, but some progress.  I moved the wheel from the lathe and mounted on the CNC mill table with the reference rim face down.  Centered on the bore, and then milled half of the outer rim.  Second op was to face the side of the rim to make it parallel to the reference  face.



Next session I will carefully move the clamps one at a time so as not to disturb zero position, then then mill the hub.  Once that is done, flip and mill the other half of the outer rim.  Surface finish looks decent, but I'll try to polish it once back on the lathe.

Turning the rim on the lathe using an upside down boring bar would have been easier, but my lathe has always refused to run in reverse.


Offline crueby

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Re: Greene Automatic Cutoff Steam Engine
« Reply #21 on: May 15, 2019, 10:58:45 PM »
Very nice!

One suggestion I would make is before removing a clamp, add another one out on the rim on the same side as the one you are moving - I have had things shift slightly when moving them one at a time like you mention.

 :popcorn: :popcorn: :popcorn:

Offline b.lindsey

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Re: Greene Automatic Cutoff Steam Engine
« Reply #22 on: May 16, 2019, 06:57:30 PM »
Off to a great start Kirk. It's a big un but at least the other castings should be easier to hold.  Will be following along.

Bill

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #23 on: May 16, 2019, 07:06:37 PM »
Finished the milling.



Slight mismatch on the rim that should be fixable later on.  Once I can get a 7/8" axle secure in the hole I could use the mill as a lathe to true it up.

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #24 on: May 16, 2019, 11:05:28 PM »
Next up are the castings for the main journals.  As the bottom surface seems the most level, I sawed off the excess of the pour and face milled.



Then the top surface was milled to be parallel to the bottom.



Then  one face was milled to provide a flat for a parallel.



Then the entire side could be milled flat.



Then it was reversed to mill the opposite side.  Dodging hot chips is not fun.

Next time in the shop I'll do the other one the same way.  My intention is to eventually machine the holes for the bearings on both pieces together.  I'll see if that's possible in the end.

Offline Dave Otto

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Re: Greene Automatic Cutoff Steam Engine
« Reply #25 on: May 16, 2019, 11:24:18 PM »
It seems that the sides of the bearing castings would look better if they had been left as cast; Is there a reason that they need to be milled flat?

Dave

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #26 on: May 17, 2019, 12:18:11 AM »
I'm too dumb to do anything but follow the drawings and 3D model.  The other three builds of which I'm aware also made the sides flat and parallel.  There was a lot of extra metal in the casting vs. the drawings, with more to come off on all 4 machined surfaces.

Offline Dave Otto

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Re: Greene Automatic Cutoff Steam Engine
« Reply #27 on: May 17, 2019, 12:43:34 AM »
Makes since, I was just wondering.

Thanks,
Dave

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #28 on: May 18, 2019, 03:48:20 PM »
Machining the tops of the bosses for the mounting screws.  Took about .160" off using precision Mark I eyeball.



Piece measures 3.818" tall vs. 3.54" in model.  I will remove metal from the tops of both at the same time.

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #29 on: May 19, 2019, 03:26:08 AM »
After machining the 2nd journal to the same state as the first, I clamped them together to perform the next ops on each simultaneously.



These ops were as follows:

1) Machine top surface to bring part height to 3.55".

2) Machine the sides to give a strip .15" high.  This removes the case surface and provides references for determining the center line of the parts.

3) Mill the center slot .75" deep to widen it to 1.374".  The bearing cap will subsequently sit on the resulting ledges, which in turn will be on the horizontal centerline of the bearing.

For the next shop session I need to further machine the side strips so that the two top surfaces are .463" across.

Online sco

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Re: Greene Automatic Cutoff Steam Engine
« Reply #30 on: May 19, 2019, 11:51:42 AM »
Kirk,

The starting point with the flywheel a few posts back where you started to machine the flywheel on the mill before it went on the lathe - was that using a rotary table to turn the flywheel or CNC?

The Lane and Bodley has a very similar sized flywheel (might even be the same casting) which I have hanging over me - it's way to big to fit on my lathe so was wondering about at least rough machining the rim on the mill.

Simon.
Ars longa, vita brevis.

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #31 on: May 19, 2019, 02:34:07 PM »
CNC mill initially to machine the inner rim.  This allowed mounting with the 4-jaw.  A rotary table would work as well or better as long as there is a means to clamp it centered. 

Before any of that I manually milled off most of the outside area where the iron was poured so that it would clear the ways.

I am considering a fixture to mount the wheel on the mill spindle in order to get a good finish on the outer rim.  That will need to wait until the center keyway is broached.  The fixture will start with a 1" round rod turned to 7/8" leaving a collar on one end;  diameter reduced to .75" on the other.  Keyway milled on the 7/8 diameter portion.  Then the wheel is put on with keystock and resting on the collar, while the 3/4 portion is clamped into a R8 collet on the mill spindle.  Then with a lathe tool clamped in the mill vise, very fine cuts taken until the rim is smooth.  I doubt more than 10 thou needs to be removed.

Online Jasonb

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Re: Greene Automatic Cutoff Steam Engine
« Reply #32 on: May 19, 2019, 04:06:26 PM »
Do the drawings show such a thick rim? Seems this engine along with many similar US engines tended to have a much thinner section to the rim which would be nice to reproduce, you could even add dummy bolt flanges and a joint line to get the look of a two part flywheel.


Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #33 on: May 19, 2019, 10:26:56 PM »
The drawing shows a very thin rim, and the 3D model shows it as .16".  However, all three model builds I've seen pics for leave the cast rim quite thick.  While accuracy is nice, I suspect that having more weight on the rim helps in allowing the model to run slowly.  I don't intend to take off more than is needed for a good finish.

I'd guess that the original builders opted for thinner rims to make casting them easier (and probably less expensive).

Offline Art K

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Re: Greene Automatic Cutoff Steam Engine
« Reply #34 on: May 19, 2019, 10:32:05 PM »
Kirk,
I didn't even see that you got this casting at the show. I must have been to busy or... I did finally meet Jeff & his wife while I was packing up on Sunday. He gave me a few of his business cards & I will post them at shows. You are making good progress and coming up with good workarounds for machines to small for the job.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline jeff l

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Re: Greene Automatic Cutoff Steam Engine
« Reply #35 on: May 19, 2019, 10:46:58 PM »
The L&B and the Green automatic share the same flywheel ,and can be machined to a thin rime but I agree with Kirk I would leave it a little thicker .
I have in the works a pattern for a two piece flywheel for both of these engines , most people who bought or inquired about the castings asked why the flywheel wasn't a two piece one , trying to make every builder happy here .

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #36 on: Today at 12:53:07 AM »
Milled the outside edge to bring the top surface width to spec.  Then roughed the bearing cap castings to square the sides and bottom.  Also took a slight edge off the rounded ends in order to be able to obtain a center line with an edge finder.



Further machining of the caps will require accuracy as they fit closely to the journals as shown here:



Here the bottom of the cap is to meet the internal ledge while the slots in the cap meets the top of the journal.