Author Topic: Chris's Build of Battleship Ohio Engine  (Read 117351 times)

Offline tghs

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Re: Chris's Build of Battleship Ohio Engine
« Reply #15 on: August 02, 2022, 04:44:05 PM »
looks like they just enlarged things
what the @#&% over

Offline steamer

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Re: Chris's Build of Battleship Ohio Engine
« Reply #16 on: August 02, 2022, 11:49:26 PM »
Conical cast pistons are much stronger
"Mister M'Andrew, don't you think steam spoils romance at sea?"
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Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #17 on: August 03, 2022, 12:05:21 AM »
Conical cast pistons are much stronger
Ah!   Strength would be a big factor on these, given the high steam pressure used. I guess that if the cone adds strength, they could minimize the thickness and the weight too, weight being important on a ship, and moving weight important at high speeds for vibration. On the Holly pumping engine, which was slow speed and lower pressure, the piston heads were flat but a lot thicker.  Lots of engineering!

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Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #18 on: August 03, 2022, 01:21:13 AM »
This evening saw the first of a long series of sessions making a CAD version of the Ohio engine plans in Fusion. Starting at the bottom with the engine bed, here is the first sketch for the top view, which will be used to start extruding out the top/bottom plates. There are all sorts of ribs and flanges between the plates, those will be another set of sketches. Interesting that the bulk of the measurements are all millimeters - it was a German designed engine after all - but a few places, like bolt holes, are in inches. The text is all in both German and English. These plans must be the version that the engine builder, in the US, used.  Going to be a long project to convert them to the 3D CAD model, lots of the shapes are pretty complex, and I will be working on this sporadically between other projects.
Here is a screen grab of the engine bed top view. The three sets of vertical lines are where the joints are between the castings. The row of circles along the bottom are the mounting pads for the posts along the front that hold up the cylinder blocks, the narrow rectangles in a row along the back are the mount pads for the larger rear support columns - this engine has the main supports at the back (with crosshead guides) and posts at the front just like the Sabino engine (just a whole LOT bigger! )



Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #19 on: August 04, 2022, 06:57:41 PM »
Lots more CAD sketches on the engine bed pieces, and started extruding shapes from them. So far most of the frame pieces are shaped, main things left to draw up are the bearing blocks. Note that the height of the top plates is higher at the back than the front - the bearing blocks will span this height change.  There are also more brackets/tubes for supporting the vertical and angled cylinder supports along the front edges.



These parts are going to be interesting to make - probably will piece them up from thin bar stock. Or combination of that and milling from thicker chunks. Or any of the other 87 ways they could be made! Long time till I need to decide that.

Offline cnr6400

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Re: Chris's Build of Battleship Ohio Engine
« Reply #20 on: August 04, 2022, 08:04:29 PM »
The bedplate designer must have been from Gusset City, Massachusetts!  :Lol:  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #21 on: August 04, 2022, 08:23:59 PM »
The bedplate designer must have been from Gusset City, Massachusetts!  :Lol: :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
Looks a lot like a modern one designed by a welding machine manufacturer. The whole thing is 1.25" and 1.5" thick plate steel.

Offline derekwarner

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Re: Chris's Build of Battleship Ohio Engine
« Reply #22 on: August 05, 2022, 12:31:01 AM »
So Chris....is the height difference/relationship mirror reversed on the opposite engine? 

[both lowers inboard facing each other :headscratch:] ...

I imaging they would have been cast steel ?

Derek
« Last Edit: August 05, 2022, 12:39:03 AM by derekwarner »
Derek L Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia
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Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #23 on: August 05, 2022, 01:36:00 AM »
So Chris....is the height difference/relationship mirror reversed on the opposite engine? 

[both lowers inboard facing each other :headscratch: ] ...

I imaging they would have been cast steel ?

Derek
Yes, the two engines would be mirror images of each other in all respects.


There are only a few places on the plans, like cylinder liners and valves, where the call out the metal used, so I don't know for sure what the beds were made of. Not sure yet what I will use, depends on which method I pick to fabricate them.


Chris

Offline derekwarner

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Re: Chris's Build of Battleship Ohio Engine
« Reply #24 on: August 05, 2022, 04:18:23 AM »
With the enormous repetitious construction  :facepalm: of all of those webs & gussets in the engine base beds  .......not be a great contender for 3D printing?

Do you use one of those metal dust or brass-filled polymer printing wires?

Derek
Derek L Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia
www.ils.org.au

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #25 on: August 05, 2022, 04:37:09 AM »
With the enormous repetitious construction  :facepalm: of all of those webs & gussets in the engine base beds  .......not be a great contender for 3D printing?

Do you use one of those metal dust or brass-filled polymer printing wires?

Derek
So far I've never tried any of the filiments like that, just the PLA, so I'm not sure what the properties of the prints are from them. I do know that they require special nozzles and can be hard on the feed mechanism in the print head. The engine bed on this engine needs to be quite rigid and strong, it will be supporting a lot of weight and holding the uprights to the cylinders against all the force on the crankshaft, and the plates making the bed will only be about 1/16" thick, depending on the scale I wind up picking. Besides, I enjoy making the parts in metal wherever possible rather than watching the printer go for days on end.
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Offline Mcgyver

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Re: Chris's Build of Battleship Ohio Engine
« Reply #26 on: August 05, 2022, 02:57:36 PM »
Wow, what a great project and major undertaking!

On the base plates, what are the dimensions of each section?  If not too large, I'd be thinking lost resin casting in AL, but as that is what is currently on the brain....well its the current hammer so everything looks like a nail.  Amazing stuff though, resin printing is so much finer resolution than filament. 




Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #27 on: August 05, 2022, 03:17:44 PM »
Wow, what a great project and major undertaking!

On the base plates, what are the dimensions of each section?  If not too large, I'd be thinking lost resin casting in AL, but as that is what is currently on the brain....well its the current hammer so everything looks like a nail.  Amazing stuff though, resin printing is so much finer resolution than filament.
I don't know what scale it will be till the CAD work is done, but in general the engine will be something in the 2 to 2.5 feet long, around 10 inches deep, so the bed plates will be big, though the plates will be something around 1/16" thick.


It will be metal, not plastic, and I have no ability in casting. So, they will be pieced up in somme form, but all those decisions are months away.

Offline ddmckee54

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Re: Chris's Build of Battleship Ohio Engine
« Reply #28 on: August 05, 2022, 04:21:51 PM »
The full size parts of the bed, due to the size and the technology of the time, would probably have been cast - most likely cast iron.  With all the ribs, those parts probably gave some foundryman nightmares for weeks.

Don

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #29 on: August 05, 2022, 05:47:54 PM »
The full size parts of the bed, due to the size and the technology of the time, would probably have been cast - most likely cast iron.  With all the ribs, those parts probably gave some foundryman nightmares for weeks.

Don
The bed is in four pieces, but its still massive with lots of relatively small sections through the webs, would have been a lot of fun to watch how they did it (from a decent distance anyway! )

 

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