Author Topic: Chris's Build of Battleship Ohio Engine  (Read 117301 times)

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #705 on: March 26, 2023, 02:56:08 PM »
Here is the setup for boring the holes in the crank webs. The screws to hold the crossbars on were added, as was a brass weight plus some stick on wheel weights to balance it all. Started with drilling a hole through the webs - there is one pair of webs in the fixture, they are all number stamped to keep the pairs together from now on.


Then bored out the hole to size. The first hole is the outer end for the crank pin, i'm taking these to 1/2" diameter. The crank pins are 3/4" OD, and I'll turn a post on either end to fit these holes. The shoulder that leaves will serve to set the spacing between the two webs.

First pair with crank pin hole done

and the rest with first hole done

I cut a short length of 1/2" rod to use as an alignment tool, short enough not to stick out either side. This will ensure that the two holes in each pair line up properly

With the short rod in the hole, the pair was run into the fixture to drill/bore the crankshaft hole. You can just see the short rod behind the cross bar

Drilled and bored the crankshaft hole to 3/4"

The final passes were light cuts to sneak up on the close fit on the shaft, I'm using a piece of the shaft material as a gauge:

Taken out of the fixture, thats one pair of webs with the holes done. The ends of the webs still need to get rounded off, both concentric to the crankshaft. This is not the final spacing of the webs, the upper pin is too short to reach if I move the webs farther apart. Final spacing is about double this.


As you can see better here, the crankshaft hole gets close to the edges of the web. To join them later, I'll use loctite retaining compound first to get them positioned, wait for that to cure, then put in taper pins. I am figuring two pins at each shaft, one from the end, the other crosswise. The webs are thick enough to let the pins be spaced along the shaft axis.

So, three more crankshaft holes to bore!

Offline kvom

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Re: Chris's Build of Battleship Ohio Engine
« Reply #706 on: March 26, 2023, 03:20:39 PM »
CAD model seems to show holes through the web are smaller than the shafts.  Looks like you chose not to make it that way.

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #707 on: March 26, 2023, 03:46:10 PM »
CAD model seems to show holes through the web are smaller than the shafts.  Looks like you chose not to make it that way.
The circles shown in the cad model are actually the  holes through the middle of the shafts, which are hollow in the original.  I don't know how  the originals  were fabricated, what size holes they bored or how they were forged on.

Offline cnr6400

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Re: Chris's Build of Battleship Ohio Engine
« Reply #708 on: March 26, 2023, 05:39:40 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:

Crank parts are looking great Chris!
"I've cut that stock three times, and it's still too short!"

Offline Kim

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Re: Chris's Build of Battleship Ohio Engine
« Reply #709 on: March 26, 2023, 06:52:50 PM »
Nice work on the crank webs, Chris!  Good use of that jig too!

Kim

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #710 on: March 26, 2023, 07:11:17 PM »
The jig is working  great, just slide in the parts and everything is  aligned, no need for  adjustments or  measurements. 


 :cheers:

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #711 on: March 27, 2023, 03:42:03 PM »
All the crank webs have been bored out for the shaft/pins:

They still need to have the ends rounded. While I was on a roll (spin?) on the lathe, I decided to turn up the flanges for the ends of each crankshaft section. Got the middle three turned to shape so far - these will represent the joints between the sections. I still need to turn the two for the outer ends, which are half as wide. Those would connect to the turning engine at the front end and the prop shaft at the aft end. To make them look like they were fabricated on the shaft and blended in, I left a little flare at the hole on each side:

They still need to have the bolt holes drilled around the perimeter.

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #712 on: March 27, 2023, 05:33:00 PM »
Turned the rest of the flange rings after lunch. Here are all the webs and flanges slid onto the bar stock for the crankshaft - all close together to fit in the camera view without having to back away as far.


Yesterday I 3D printed the figure behind the crankshaft - he is to scale (1:20) for the model. Really shows how massive this engine was in real life!

Offline sid pileski

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Re: Chris's Build of Battleship Ohio Engine
« Reply #713 on: March 27, 2023, 05:40:47 PM »
Hey! where'd you get my likeness to print???

 :lolb:

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #714 on: March 27, 2023, 05:45:29 PM »
Hey! where'd you get my likeness to print???

 :lolb:
You got scanned by Superheroes-R-Us!    :ROFL:     Careful, or I'll print a miniature seagull to sit on your shoulder...   :LittleDevil:

Online tghs

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Re: Chris's Build of Battleship Ohio Engine
« Reply #715 on: March 27, 2023, 06:38:22 PM »
you forgot to add the period correct mustache :stickpoke:
what the @#&% over

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #716 on: March 27, 2023, 06:50:37 PM »
you forgot to add the period correct mustache :stickpoke:


Um, he got it ripped off by the gears. Yeah, thats it!   :Lol:

Offline cnr6400

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Re: Chris's Build of Battleship Ohio Engine
« Reply #717 on: March 27, 2023, 06:55:43 PM »
That guy'll be able to give you a hand shifting the heavy parts around, anyway.....seagull or not   :Lol:     :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline ddmckee54

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Re: Chris's Build of Battleship Ohio Engine
« Reply #718 on: March 27, 2023, 07:07:51 PM »
Careful, or I'll print a miniature seagull to sit on your shoulder...   :LittleDevil:

Fire Control stands ready to repel all boarders, Sir!

Offline crueby

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Re: Chris's Build of Battleship Ohio Engine
« Reply #719 on: March 27, 2023, 07:25:32 PM »
Careful, or I'll print a miniature seagull to sit on your shoulder...   :LittleDevil:

Fire Control stands ready to repel all boarders, Sir!



 :lolb:


I never thought to put a CIWS turret on my rc tugboat. Hmmm...

 

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