Chain Hook

[Brian Rupnow]

I need a chain hook for the end of the winch cable on my donkey engine. This morning I'm setting in my office, goofing around with ideas. I'm just thinking that if I chucked up a piece of 5/8" steel rod in my lathe, I could probably use a cutting tool and some file work to achieve this without too much trouble.

 

[Brian Rupnow]

Then if I pared away some material from each side and drilled a couple of holes, I could have this---

 

[Brian Rupnow]

Then with either a hacksaw or an endmill I could do this---

 

[Brian Rupnow]

And then with a whole bunch of filework I could have this!!!

 

[ozzie46]

Now that is NEAT!!!! :bow: :bow: :bow: :bow:


Ron

 

[Catminer]

That is neat Brian :bow:, but you know in the real world the hook has to swival in relation to the cable :big:,
you don't want a twist in your hoisting rope Rof}

Peter

 

[Mosey]

And then with a whole bunch of filework I could have this!!!

Brian,
If I may be permitted to suggest a few little enhancements to your drawing in the interest of clarity, please don't be offended. (Please see the dialog about clarity in drawings we are having at "frustrations".)
Make your leader lines polylines, so they are not straight, circular, or any geometric. That way they will easily be distinguished from the parts, especially when in a complex drawing.
Make the dimension extensions NOT touch the part. Leave a little air.
I might like to tie the eyehole dimensions into the overall dimension.
How about lineweights being lighter for the dimensions, notes, etc., Lighter than the part itself, and the very outline of the part being the darkest widest line.
Regards,
Mosey

 

[Ken I]

you don't want a twist in your hoisting rope

Real cables are made with alternating sets of left and right hand twists to avoid the cable twisting under load - that said the lefts and rights almost never cancel out and results in some twisting under load - this degree of twist is sometimes part of the cable spec.

In free hoisting applications its always going to be a problem apart from the obvious need to slew the load.

Just an observation.

Ken

 

[Brian Rupnow]

Let me begin by saying that I had no idea how difficult it is to file a round ball in a lathe. Then let me follow up by saying that its TWICE as hard to file two round balls on a lathe!!!---And they're still not really round. And I've polished them with a variety of emery paper, and its almost impossible to get the file marks out afterwards-----And they still aren't really "round".

 

[Ken I]

Brian,
What I do (in the absence of a ball turning attatchment) is to work out a number of angular flats on CAD which gets you close - this makes the filing much easier and more accurate.

The illustration below is a 30° increments and whatever the tangents are at the cardinal intersects.

The concave radius would defeat my minilathe so I would mill it on my RT with whatever radius cutter I had to hand. (Whilst on the mill you could also work out a bunch of X-Y coordinates to rough mill the balls into shape - then take it back to the lathe for final filing and polishing).

2c

Ken

 

[b.lindsey]

Even so its looking good Brian. Given the closeness of the two balls, I'm not sure even a radius turner would get to the area between them. CNC would probably be the best way but aside from that i think it looks great. Even the real things aren't perfect!

Bill

 

[smfr]

You could cut out a cardboard template based on the plans, and use that to see where you need to remove material.

 

[lazylathe]

How about grinding a profile tool??

Andrew

 

[Brian Rupnow]

Do you remember seeing cars with a bumper sticker that said "Don't follow me----I'm LOST"---Well, I may not be quite that bad off, but this is definitly a "make it up as I go along!!!

 

[Ken I]

What the hell Brian, like Bill said its looking good anyway.

Ken

 

[Brian Rupnow]

Well there!!! Thats as good as it has to be untill I get a little black paint on it.

 

[kvom]

How about drilling a ball bearing and making the other two parts separately?

 

[Brian Rupnow]

How about I be satisfied with what I've just made??? For a piece of scrap steel and a couple of hours on a boring Sunday, it doesn't get any better than this!!! The shine on that ball will die back in a couple of hours to the same semi gloss finish as the boiler. The ugly knot holding the ball in place for now will be finished with some black thread reaving put on with fly tying dope when I get around to it.

 

[idahoan]

I have this handy little book that I purchased from Guy Lautard Years ago ( I believe that it is still available); it works quite well and I have use it many times over the years. I think Marv also has someting similar on his site. This works really well for radii that are not super critical and more visual in appearance.

http://lautard.com/ballbook.htm


PS Nice job on your Donkey engine; I started on the W.M. Harris version but never got it finished. It is still in a box on the shelf waiting for me.

 

[Herbiev]

Hi Brian. Excellent job on both engine and ball hook. Just a thought but if you wished to add a swivel, the local fishing tackle shop might have something to foot the bill if you find the cable twist a problem.