# My Mine Engine



## DavesWimshurst (Feb 28, 2010)

Hi,
I liked the look of Elmer's mine engine but wanted to add some extra details:







I added fluted columns and finials:






I used a milling spindle to do the fluting:






I wanted a fancier flywheel than the plans showed. I had some 4 inch copper pipe to use for the rim. The base parts were made thicker to accommodate the larger size. The core of the flywheel was made as an aluminum disk about 0.005 inch larger than the ID of the pipe. The disk was placed in a polypropylene dish filled with liquid nitrogen left over from a science show. When the bubbling stops the disk was about 325 deg F below zero. It fit easily into the copper pipe, sorry no pictures of this step.
I wanted a design with five curved spokes but didn't fancy the elaborate setups some have used for such tasks so I proceeded as follows. First I drilled the corner holes for the cutouts between the spokes:






A pattern disk shown on the right was made by drawing the cutout shape on paper and gluing it to the disk. The corner holes for one space and one in the next space were drilled using the rotary table the pattern was glued on and the opening was cut out:






This disk was then used to scribe the outlines for each opening. The flywheel was returned to the rotary table and the waste cut out using a short pass in each opening indexing to make the same cut in the other spaces with the same setup. It took about 2 hours to get the flywheel roughed out and another 2 hours to file to the lines. It takes some time but is not difficult if no visitors are around. :






I wanted to use a slip eccentric reverse and I also wanted the flywheel position to be adjustable to set the timing. For this I used a collet mounting for the flywheel and cut a semicircular groove in the eccentric:






A pin in the collet engages the groove to allow the eccentric to be in the correct position for each direction (ignore the extra hole :-[ ) :






I made a short video showing the action, the engine is running on 3 psi:





I know I have been brief so feel free to ask.

Dave


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## zeeprogrammer (Feb 28, 2010)

Nice looking engine!
Maybe it's the brass or the action...but it looks very 'clock-ish' to me. Neat.


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## Metal Butcher (Feb 28, 2010)

Congratulations on your successful build! Beautiful workmanship. I like the eye catching color combination you used on the flywheel.

I just happened to have started a thread today asking members to show pictures of this very same model. I'm seriously considering the #29 Mine Engine for my next project.

I see how that eccentric operates, and how the rotational direction is set by adjusting the flywheel/ crank position in relation to the eccentric. Its really quite simple, but aneffective system for a demonstration model.

Thanks for sharing by posting a very inspirational video along with your pictures.

-MB


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## Philjoe5 (Feb 28, 2010)

Dave,
Great pictures of a very fine looking engine. I'm currently building a Mine engine also, though not of Elmer's plans. It looks quite similar. I love the action on this engine.
Thanks for posting.

Cheers,
Phil


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## ksouers (Feb 28, 2010)

Dave,
That's a very beautiful example of dressing up Elmer's engines. I love the way it runs, very smooth and precise.
I had the mine engine on my list, perhaps it just moved up a bit.

Thanks for sharing.


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## 4156df (Mar 1, 2010)

Dave,
Very nice job. Really a joy to watch it run.
Dennis


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## gbritnell (Mar 1, 2010)

Dave, 
Excellent work on your engine. The extra detailing really sets it of, the fluting, the copper band on the flywheel. I have seen similar setups with the tapered attachment of the flywheel but not with a collet style like yours.
gbritnell


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## DavesWimshurst (Mar 1, 2010)

Thanks guys for the kind comments. You guys rock!
Dave


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## JimN (Mar 1, 2010)

Very nice.

JimN


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## cfellows (Mar 1, 2010)

That's a beautiful build, Dave. I'm really impressed with the simplicity of the reversing mechanism. Great job!

Chuck


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## SAM in LA (Mar 1, 2010)

Dave,

I like how you dressed up your engine. Thm:

The copper and spokes really make the flywheel interesting. :idea:

SAM


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## kustomkb (Mar 1, 2010)

Beautiful engine!

very smooth too.


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## rake60 (Mar 1, 2010)

Great build Dave! :bow:

Rick


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## GailInNM (Mar 1, 2010)

Very Nice, Dave.  Thm: Thm:
Gail in NM


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## hobby (Mar 1, 2010)

Beautiful work.

Nice idea with your emplate for marking out your flywheel.

Flywheel looks really good...


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## JMI (Mar 2, 2010)

Simply beautiful! Was unfamiliar with the slip eccentric reverse and a very clever device it is. A quick "Google" search reveals it has been around for quite a while.
Been thinking of doing Elmer's Mine Engine for quite some time. What a great modification to incorporate into it. Would you mind elaborating a little more about the design and maybe a little more about the collet mounting?

Thanks

Jim


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## Blogwitch (Mar 2, 2010)

Jim

This one bit of a post shows mine, plus there is a link in it about slip eccentrics.

http://www.homemodelenginemachinist.com/index.php?topic=389.msg2792#msg2792

And this part of a post shows how a taperlock was made.

http://madmodder.net/index.php?topic=871.msg6640#msg6640

I think Dave incorporates his all into one, so it might be best to wait for his design. I was just showing how I achieved it.

Blogs


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