90 degree joint in rotating shafts

[Brian Rupnow]

I think I may make this next. Not because it has any real practical purpose, more just because it is such a neat mechanical motion.
<a href="https://www.youtube.com/watch?v=3Xbxp_uZp0E" target="_blank">http://www.youtube.com/watch?v=3Xbxp_uZp0E</a>

[Dave Otto]

<a href="https://www.youtube.com/watch?v=_ra7T4WRG48" target="_blank">http://www.youtube.com/watch?v=_ra7T4WRG48</a>

[philjoe5]

Brian,
I like it, hope you go for it

Cheers,
Phil

[crueby]

That is one of those things that is so simple that it is brilliant.

[b.lindsey]

 Very neat Brian, and as Dave's video clip shows maybe it could be applied as other than just a proof of concept. I had done an engine years ago using a similar concept though the second shaft (piston in the case of the engine) only oscillated and didn't rotate completely. Couple of pictures at the following link and a video link at the bottom of the page. http://www.workbench-miniatures.com/opv.htm

Bill

[Roger B]

Interesting  Does it give a constant speed of rotation or does it vary like a Hookes  coupling (basic universal joint) 

[Brian Rupnow]

Okay--From concept to reality. Now it is modelled as I would actually build it, and detail drawings are finished. If I don't have any "real work" this coming week, at least I have an interesting project!! The ratio is 1:1

[Brian Rupnow]

I spent most of the day working in a factory across town that uses me for engineering work they need done. Then I came home and played. I have a most wonderful collection of "bits and bobs" that all have a home on the wonky joint. I had a change of heart at the last minute and made the base from 1/2" aluminum plate and the vertical 3/4" upright is made from 1045 steel with a 5/16"-18 thread in the bottom. Initially I was going to go with a steel base and weld the upright to it, but decided I had a better chance of everything staying "true and square" if I bolted the 3/4" diameter upright in place with a 5/16" socket head capscrew. The square bits with the round extension on them are made from some grade of bronze. I'm still using up scraps from that big bronze weight that I reclaimed from the dump. I might finish this thing tomorrow.

[crueby]

Looking forward to seeing how this one behaves, it will be interesting to see how it compares to a miter gear arrangement.

[philjoe5]

Brian,
Looking to see how this turns out.  If you post plans I'll give it a try sometime

Cheers,
Phil

[Art K]

Brian,
I have to say this is a cool project. Correct me If I'm wrong, It has to be a 1 to 1 ratio , wouldn't it lock up or something because of the unequal ratio for the crank turn. Want a different ratio change the pulley.
Art

[PStechPaul]

It looks like this mechanism would work for shafts at any angle, and also for shafts at different heights, as long as they are on parallel planes. And even with multiple output shafts, with both clockwise and CCW rotation, something like a differential.

[I hope this posts OK - got a "forbidden" error message that wiped my previous post) 

[Brian Rupnow]

There is far more that I don't know about this mechanism than there are things that I do know. It is a straight 1:1 ratio. Yes, with minimal tweaking there could be two output shafts. I first seen it on a "mechanisms" website, then modelled it in 3D cad and animated it. It appears that it will work, but I will hold my final opinion of this until I see this one running. In all of my 70 years I have never seen a mechanism like this on anything, which leads me to believe that either it doesn't work all that well, or else is too expensive to make compared to miter gears. I am building it more for the "Neat eye candy effect", not as an potential replacement for gears.  If it does work well, I'm going to do something a bit different, and drive it with one of my steam engines. I have been so rapped up in i.c. engines for the last few years that my collection of various steam engines have only been holding down shelves in my office. And yes, when I have it working properly, I will post a link to a download of the drawings, for anyone daring enough to build one for themselves.

[Ian S C]

When I saw the heading to this thread, I thought maybe a Hobson Coupling, also known in the modeling fraternity as the Elbow Engine, but this one looks interesting.  I'm just wondering if it will start in all positions, or will it tend to jamb up starting ? We'll see soon.
Ian S C

[philjoe5]

Brian,
I saw this at a model show some time ago.  Same principle with ball and stick components


We also have an antique full size working example of this drive at the Rough & Tumble museum.  I have several pictures of it because it really caught my attention.  So far, no luck finding those pictures but IIRC the name of the drive was on the casting.

Cheers,
Phil