Brian's Donkey Engine

[AussieJimG]

A karma to you for the journey. I won't download the drawings as the project is beyond my skill level at present. But following has increased my knowledge level greatly. Thanks
Jim

 

[Ken I]

design engineering is a strange business, and sometimes errors do slip through.

Tell me about it - I worked for a company that had been maunfacturing a particular (shockabsorber) part for over 30 years when someone discovered that a cardinal dimension was missing from the drawing - how had it been made all these years - Who Knows !

Ken

 

[Brian Rupnow]

As I said in an earlier post----I like Captain Jerry's idea about an A-Frame boom---Might go here next!!!

 

[Don1966]

Brian you are by far a great craftsman, that is a superb built and thread. I have loved reading your progress :bow: I am looking forward to your next built. You are a superb teacher.

Regards Don

 

[ShopShoe]

Brian,

Yours and Jerry's donkey projects are addictive reading. Were I to be able to build one of these (Maybe someday...), I know I would spend a lot of time running it and lifting things and all that.

I have never seen one of the full-size hoists in operation, but I have seen winches that are similar being used to assist pulling ropes to move things around. (with a team of men pulling on the ropes.) Perhaps you could make some small snatch blocks as accessories.

I don't mean to add work, I just saw it in my mind's eye and couldn't resist posting.

Congratulations again.

--ShopShoe

 

[Ken I]

Brian,
Thanks for the free download - much appreciated - definitely worth more than one KP.

That's quite a haul of KP points you've got yourself there.

Regards,
Ken

 

[moconnor]

Hello Brian,

When ShopShoe mentioned making snatch blocks in his last post, I remembered an article in Guy Lautard's 'The MACHINIST'S THIRD BEDSIDE READER' about his friend Bill Fenton and the steam operated, two-drum donkey engine that he built. In the article, Guy describes in great detail (with drawings) no less than four different blocks that he dubbed "Bill Fenton's Jewelry". The donkey engine is also shown in 'A Video Visit with Guy Lautard and Bill Fenton' as well as both of their workshops.

http://www.lautard.com/

Guy's books are very informative and interesting reading and and I would highly recommend them to all here. He writes in a style that is unique among the usually cut and dry world of machining and model making treatises. It is quite addicting, because Guy manages to describe a project or technique in a way that makes the reader feel as if he his sitting on a stool in his shop and being told exactly how he went about the job. He can also tell a great story.

Great work Brian on the engine and the documentation. As always, very interesting to follow along with you as you design and evolve your projects. Can't wait to see what you come up with next.

Kind regards,
Mike

 

[Brian Rupnow]

Found a little spare time and a piece of scrap aluminum yesterday, to start the A-frame hoist.

 

[vcutajar]

Brian

You never rest. Thanks for the plans. I will not be downloading them as I think it's a bit above my skill level but still a karma point to you for your dedication and unselfishness.

Vince

 

[Brian Rupnow]

And some time this afternoon to finish cutting it out, profile the edges, and chase down a couple of stainless rods to become the legs. Hand bombing the radius around the edges is very finicky business, but when done right, it adds a lot to a part.

 

[jonesie]

thanks brian a karma sent your way jonesie

 

[Brian Rupnow]

And a little tad of mig welding----

 

[Brian Rupnow]

The fun just never stops around here-------------

 

[miner49r]

Looking good Brian. You are getting close to making a turret and mounting it to a rail car.
Alan

 

[Brian Rupnow]

Things have kind of lurched to a stop here. I can't find any round 1/8" or 5/32" diameter, black, rope/cord nor twine that looks like a cable for my winch drum. The local hardware store has the perfect size and shape in a white polynylon cord, but as far as I know you can't die that stuff black. Fishing tackle doesn't come that big around (at least not 1500 miles inland where I am). I am going to call the drapery companys in town after I finish this post and ask about black sash cord. I already went to the shoe repair shop hoping they sold work boot laces by the linear foot, but no joy there. Does anybody have any suggestions?----Brian

 

[Jasonb]

Those sound a bit thick to me and would look overscale, something more like 1/16" would be more in proportion.

Why don't you use steel cable its readily available in a whole range of diameters, as an example the winch drum on the traction engine in my avitar is a similar dia and 1/16" steel cable wraps round that with no problem, just add a thimble and crimp to the end and it will look like the real thing rather than string.


http://www.tecni-cable.co.uk/Products/Galvanised-Wire-Rope-7x7-Flexible

Are you going to add any straining wires or rods to the boom as most small jibs have them.
J

 

[Brian Rupnow]

Never underestimate you local fabric shop!!!! They have all kinds of winch cable looking stuff, in a host of colors and diameters!!! This stuff happens to be satin, but its strong enough that I can't break it. (And if it doesn't work as winch cable, I can knit myself some unmentionables.)

 

[Brian Rupnow]

Aha, by God!!! Slick as a tin whistle!! Of course I have yet to replace the drill which is currently acting as the shaft for my brass pulley at the top of the boom, and organize something a bit nicer looking than that lump of steel hanging on the end of the winch cable, but I think the "winch cable" looks just right.

 

[Brian Rupnow]

"Are you going to add any straining wires or rods to the boom as most small jibs have them."---I really don't know what I'm going to do. The boom was just a last minute thought, inspired by Captain Jerry. It didn't require a lot of thought nor effort to build, and it does give me a way to end off the winch cable, which I hadn't figured out before. The machine was never designed to work with an A frame boom, and consequently there are no good places to run stay rods to. I may just leave it as is.

 

[Captain Jerry]

Brian

I like the A-frame boom (of course) but there is one thing that bothers me. In twenty five years in the construction equipment business, I never saw a boom rigidly attached at it base. To do so invites catastrophic failure as the boom will deflect under load and all of the stress is focused on that point. I realize that this design was a quick response to an impulse but don't allow anyone to stand under it. It is a hazard.

It should be pivoted at the boom foot and supported by some kind of back stay rig. Draglines and clamshell excavators, which typically carry their boom at a low angle and subject it to high cycle loading commonly use a gantry arrangement to increase the effective angle of the backstay. I have attached a very crude diagram of a possible arrangement.

The gantry frame is pivot mounted (for the same reason as the boom) to the A-frame. The backstay is of fixed length as is the guy which transfers the load to the main frame. I realize there is no historic precedent or example of a donkey so configured but it is based on common practice. And it would look pretty cool.

Jerry