# 90 degree joint in rotating shafts



## Brian Rupnow (Nov 13, 2016)

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.
[ame]https://www.youtube.com/watch?v=3Xbxp_uZp0E&feature=youtu.be[/ame]


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## Brian Rupnow (Nov 13, 2016)

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!!


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## Herbiev (Nov 13, 2016)

I must agree it's a fascinating motion. We could have a competition amongst the members to find the best practical use for this device.


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## Kwtaylor (Nov 13, 2016)

With the reciprocating motion,  you should have a basin at the bottom and a piston pump to lube the sliding portion.


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## Brian Rupnow (Nov 13, 2016)

Someone on another forum suggested that if the orange plate was made symmetrical about center and had a third lobe added, then there could be two output shafts driven in opposite directions if the blue shaft was the driver.


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## ShopShoe (Nov 14, 2016)

(Tongue in Cheek)

Perhaps as part of another marble machine. I am always mesmerized when you build devices to put your engines to work. 

I like the idea of two outputs with two things happening, perhaps mirroring each others' actions.

Whoa! Sorry. I just turned an easy week's work into something more ambitious. Didn't mean to do that. (Unintended Consequences.)

--ShopShoe


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## Brian Rupnow (Nov 14, 2016)

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.


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## Brian Rupnow (Nov 14, 2016)

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.


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## Charles Lamont (Nov 15, 2016)

Brian, I see no reason why this thing should not work very nicely. There are two points I would watch. The Orange Sliding Thingy needs to slide smoothly and easily on the post, with plenty of bearing length (perhaps relieved in the middle to provide an oil reservoir). There will be lateral and axial forces where the Yellow Knuckle Doofers pivot in the Thingy so I think they could perhaps do with more bearing length and/or broader thrust faces. Oh and thirdly, it will be important to ensure the crank throws are accurately equal. Also, though I am sure you are aware of this one too, don't forget sufficient crankpin length to allow for the 'big ends' to slide axially.


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## Charles Lamont (Nov 15, 2016)

A further thought, probably too late: the Yellow Knuckles would work even better with bearings in the Orange Thingy both above and below the crankpins. Quite a bit more work though.


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## RonGinger (Nov 15, 2016)

There is a commercial version of this at the New England Museum of Wireless and Steam. It was made to go in line shaft operation to turn the shaft around a corner. It As I remember its for about 2" shafts. So these were made and used many years ago.


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## vascon2196 (Nov 15, 2016)

RonGinger said:


> There is a commercial version of this at the New England Museum of Wireless and Steam. It was made to go in line shaft operation to turn the shaft around a corner. It As I remember its for about 2" shafts. So these were made and used many years ago.



Here is my version done a few years back of the Museum's version...Almond Mfg company made the original versions.

https://youtu.be/Am9i0GV8ty0


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## Brian Rupnow (Nov 15, 2016)

I'm almost there. I have two pieces left to make, and have to scare up a pulley. So far I'm happy with what I am seeing, but I need those last two pieces before I can declare a success or a failure.


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## Brian Rupnow (Nov 15, 2016)

So, there we have it, except for a drive pulley. Does it work?--Well, sort of. I grabbed one shaft with my (shudder) vice grips, and turned it. It is very stiff, but is looked as if it wanted to work. The little square bronze parts that have a 5/16" round "extension" on the bottom that passes thru the 1/4" steel plate need to have a retainer on them, or at one position in the sequence they pull straight up out of the plate. I knew it would try and do that, so I had pre-made a pair of bronze "retaining collars" to slip over the ends and trap the plate. I didn't make anything mechanical to do this, just a bit of 620 Loctite retaining compound. I want to give the Loctite a few hours to set up, and during that time I will make a pulley to go on the input shaft.


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## Brian Rupnow (Nov 15, 2016)

YES!!!! IT WORKS!!! I have to put a motor on it and drive it for a while to get any tight spots out of it, but I did find a big V pulley to fit and have been turning it by hand. Video tomorrow.


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## Brian Rupnow (Nov 15, 2016)

Couldn't wait for tomorrow. Here is a video of the beast operating.---Brian
[ame]https://www.youtube.com/watch?v=1FsYYPdO7-I&feature=youtu.be[/ame]


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## Brian Rupnow (Nov 15, 2016)

As promised, here is an up to date set of drawings as pdf files. Please can someone let me know if you are able to download them okay.---Brian
https://www.mediafire.com/?9sgfgicxi5u4p56


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## Cogsy (Nov 15, 2016)

I downloaded them just fine Brian. Thanks!


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## Ghosty (Nov 16, 2016)

Brian, No problem with the down load, Thank You.
Cheers
Andrew


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## Brian Rupnow (Nov 16, 2016)

Good wife and I just returned from the Princess Alexandra theater in Toronto. Seen a musical called 'Come from away', about the 7000 people who's planes were diverted to Gander air base in Newfoundland, Canada, during the 9/11 crisis. Sounds like a strange premise for a live play, particularly a musical. However, it was good. It was really, really good!! Made me laugh, made me cry, touched all the buttons that a good live musical will do. That was my dash of culture for this year.---Now---As for the strange 90 degree shaft joint-----when I first assembled everything, I coated all of the sliding and rotating members with grease. This worked, and did the job for the initial running, as you seen in the video. The longer it ran, though, the harder the drill had to work. It was stiffening up, not loosening up. My next amazing stunt was to reach for the can of spray on WD40 that I use when cutting aluminum in the mill or lathe. I gave everything that moved a liberal shot of WD40, which immediately washed out the grease and made the joint even stiffer. At this point I was wondering what I should do next, so I grabbed my squirt can of #40 automotive lubricating oil and gave everything a good squirt. This immediately fixed things and loosened everything up again.--My forensics on this, are that although the grease provided initial lubrication, it very soon loaded up with microscopic metal particles, as all of the rotating and sliding parts "wore in". All of the metallic particles were then held in suspension in the grease, and instead of a lubricant, the grease itself became a fluid abrasive and was jamming instead of lubricating. the WD 40 then washed out any of the remaining grease, and left basically a metal on metal situation. Then the #40 lubricating oil washed out the remaining metal particles and saved the day. I have sussed this out based on the greasy, gritty residue that has dripped onto the aluminum baseplate from the rotating joints.


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## ShopShoe (Nov 17, 2016)

Downloaded OK.

Thanks for posting

--ShopShoe


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## Brian Rupnow (Nov 17, 2016)

After a half hour of running in, with the big red beast (My 1/2 HP 1750 rpm bale elevator motor) the wonky joint has loosened up remarkably. The "hard spots" it encounters are right at the point where the sliding sleeve on the main-post is at it's very highest and very lowest points. I think this mechanism would benefit greatly from a decent sized flywheel on either the input or the output shaft. You can see in the picture the almost mirror like finish on the main post where the slider travels. I think a linear ball bushing riding on a hardened, ground, and polished shaft would make this thing almost perfect. I'm not going to do that. For what I want to do with it, it will be just fine the way it is. Since I have yet to make a pulley for it, I may incorporate a flywheel into the pulley.


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## Brian Rupnow (Nov 17, 2016)

I believe I may have found my flywheel---maybe even my pulley as well. A gentleman from western Canada was in Barrie last summer, visiting relatives. He has been following my build posts for several years now, and wanted to do something to show his appreciation. He brought me an assortment of cast iron valve handles that he thought I might be able to use on one of my "creations". The offset between the center hub and the rim has kept me from using them on one of my engines, but for this project I think they could be perfect.


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## Brian Rupnow (Nov 19, 2016)

So, as I promised, here is the 90 degree shaft transfer being driven by one of my steam engines. It has been a fun and fast little project, and the transfer mechanism is quite intriguing to see working.---Brian
[ame]https://www.youtube.com/watch?v=c57Hh9E-ovg&feature=youtu.be[/ame]


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## Brian Rupnow (Nov 19, 2016)

Something neat that I hadn't noticed before---there is a tight spot in the mechanism, just as the sliding sleeve on the main-post reaches the top and starts down again. Watch the way the flyball governor reacts to that tight spot. You can see the balls flying in and out, allowing more air flow into the cylinders as the torque demand increases at that tight spot. It isn't in exact synchronization because of the elasticity of the o-ring drive belt, but it is definitely there. The flyball governor is trying it's best to keep a constant rpm at the engine. Ya got to love that old time motion control action!!!


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## Blogwitch (Nov 20, 2016)

You might try the Hobson coupling, which everyone based their elbow engine designs on.
A very, very rough sketch.







It not only can go around corners but the output can swivel through a 180 degree arc with ease if designed correctly.

Imagine the output of this swinging in an arc over the top of the input.

[ame]https://www.youtube.com/watch?v=pVldn35XuXo[/ame]

http://toolmonger.com/2008/05/30/gearless-right-angle-socket-adapter/

I was going to use one of my steam engines to show all sorts of couplings, joints and drives coupled together on one big baseboard, to show to engineering apprentices, but life got in the way.



John


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## Brian Rupnow (Nov 20, 2016)

So, now that it works, and you all have access to the drawings, it's time to offer up a challenge. Who is going to be the first person to put a third "ear" on that orange colored plate and drive a third shaft of the primary driver (blue) shaft?


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