Author Topic: 90 degree joint in rotating shafts (Read 11632 times)

Brian Rupnow · « **on:** November 13, 2016, 04:06:03 PM »

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 · « **Reply #1 on:** November 13, 2016, 04:18:49 PM »

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

philjoe5 · « **Reply #2 on:** November 13, 2016, 04:19:22 PM »

Brian,
I like it, hope you go for it

Cheers,
Phil

crueby · « **Reply #3 on:** November 13, 2016, 04:50:31 PM »

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

b.lindsey · « **Reply #4 on:** November 13, 2016, 06:11:09 PM »

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 · « **Reply #5 on:** November 13, 2016, 07:46:12 PM »

Interesting

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

Brian Rupnow · « **Reply #6 on:** November 13, 2016, 07:55:34 PM »

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 · « **Reply #7 on:** November 14, 2016, 11:53:18 PM »

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 · « **Reply #8 on:** November 15, 2016, 12:06:15 AM »

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

philjoe5 · « **Reply #9 on:** November 15, 2016, 12:11:07 AM »

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

Cheers,
Phil

Art K · « **Reply #10 on:** November 15, 2016, 12:45:13 AM »

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 · « **Reply #11 on:** November 15, 2016, 12:55:09 AM »

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 · « **Reply #12 on:** November 15, 2016, 02:09:38 AM »

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 · « **Reply #13 on:** November 15, 2016, 01:00:19 PM »

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 · « **Reply #14 on:** November 15, 2016, 02:52:24 PM »

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

steam guy willy · « **Reply #15 on:** November 15, 2016, 03:41:50 PM »

Clever stuff, and i suppose there is not much backlash ??
wilbert,

Brian Rupnow · « **Reply #16 on:** November 15, 2016, 07:12:03 PM »

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.

philjoe5 · « **Reply #17 on:** November 15, 2016, 08:18:34 PM »

I like it

Cheers,
Phil

Brian Rupnow · « **Reply #18 on:** November 15, 2016, 10:30:42 PM »

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.

Brian Rupnow · « **Reply #19 on:** November 15, 2016, 11:01:28 PM »

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.

crueby · « **Reply #20 on:** November 15, 2016, 11:10:45 PM »

Neat! Looking forward to see it go, and see how it behaves. Now it needs a motor, and a conveyor system to drive at right angles...

Brian Rupnow · « **Reply #21 on:** November 16, 2016, 12:02:33 AM »

Couldn't wait for tomorrow. Here is a video of the beast operating.---Brian

<a href="https://www.youtube.com/watch?v=1FsYYPdO7-I" target="_blank">http://www.youtube.com/watch?v=1FsYYPdO7-I</a>

crueby · « **Reply #22 on:** November 16, 2016, 12:26:00 AM »

That's fantastic!

Looks like a very even motion on the output shaft. As Paul mentioned, it would most likely work on other angles too, not just 90, and at other heights which would be harder to do with gears. Very clever.

b.lindsey · « **Reply #23 on:** November 16, 2016, 12:47:50 AM »

Very cool Brian and interesting to watch just on its own. Well done

Bill

Brian Rupnow · « **Reply #24 on:** November 16, 2016, 01:37:13 AM »

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

philjoe5 · « **Reply #25 on:** November 16, 2016, 03:31:57 AM »

Very cool machine Brian. Plans downloaded just fine

Cheers,
Phil

Roger B · « **Reply #26 on:** November 16, 2016, 11:19:06 AM »

Very nice

philjoe5 · « **Reply #27 on:** November 16, 2016, 05:42:55 PM »

The right angle drive that we have at Rough & Tumble is called an "Almond Drive".

I always wanted to make one but capturing the ball in the casting was something I hadn't figured out. Brian's design looks doable by me so I'll try making it

Cheers,
Phil

Tennessee Whiskey · « **Reply #28 on:** November 16, 2016, 06:49:37 PM »

Apologies if needed Brian, but, how do they do that ball in a casting thing anyhoo? BTW Brian, that mechanism is neater than blue dot tail lights

Cletus

Brian Rupnow · « **Reply #29 on:** November 17, 2016, 12:28:11 AM »

No apology needed Cletus. I don't know how they do that either. that was Philjoe's post.---Brian

Brian Rupnow · « **Reply #30 on:** November 17, 2016, 01:28:44 AM »

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.

crueby · « **Reply #31 on:** November 17, 2016, 02:28:53 AM »

Are the sliding tubes also made from steel? Would it be better if they had a sleeve of bronze maybe? Hard to tell on the pics of the antique R&T one, looks like it may have a sleeve of some sort. Or maybe that is just grease.

philjoe5 · « **Reply #32 on:** November 17, 2016, 02:36:21 AM »

Quote

how do they do that ball in a casting thing anyhoo?

Someone told me a while back that the ball is cast in the sleeve, then the connection is cut and the flash or whatever its called is ground off. Since I know little about casting I don't know if they were "selling me a left handed screwdriver" or not.

Cheers,
Phil

Brian Rupnow · « **Reply #33 on:** November 17, 2016, 12:58:17 PM »

Quote from: crueby on November 17, 2016, 02:28:53 AM

Are the sliding tubes also made from steel? Would it be better if they had a sleeve of bronze maybe? Hard to tell on the pics of the antique R&T one, looks like it may have a sleeve of some sort. Or maybe that is just grease.

It should have a bushing in there on a real working full size unit. I didn't sleeve mine, because it was just a "what if" model.

Brian Rupnow · « **Reply #34 on:** November 17, 2016, 11:43:09 PM »

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.

crueby · « **Reply #35 on:** November 18, 2016, 12:46:18 AM »

On the antique one from the R&T museum, it looks like the cranks they used are heavy enough to act like flywheels, maybe they saw the same action you did. Neat stuff!

Brian Rupnow · « **Reply #36 on:** November 18, 2016, 01:17:38 AM »

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.

Brian Rupnow · « **Reply #37 on:** November 19, 2016, 02:50:27 PM »

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

<a href="https://www.youtube.com/watch?v=c57Hh9E-ovg" target="_blank">http://www.youtube.com/watch?v=c57Hh9E-ovg</a>

philjoe5 · « **Reply #38 on:** November 19, 2016, 10:42:31 PM »

Nicely done Brian. I do remember your build log of that twin cylinder steam engine.

Cheers,
Phil

PStechPaul · « **Reply #39 on:** November 19, 2016, 11:17:39 PM »

Very interesting and well done! If you think about it, this converts linear oscillatory motion to rotary, then back to linear, and finally once again to rotary. The linear motion of the right-angle drive could be used for other purposes, such as a valve, or maybe something like a trip hammer. But cool enough as it is!

gerritv · « **Reply #40 on:** November 19, 2016, 11:24:47 PM »

An interesting puzzler to mesmerize people.

Art K · « **Reply #41 on:** November 20, 2016, 12:59:24 AM »

Brian,
You just keep finding cool things to build, love it. Cant wait to see whats next.
Art

Brian Rupnow · « **Reply #42 on:** November 20, 2016, 01:27:25 AM »

Thanks guys. The action on that mechanism was still a bit "herky-jerky" when I made that video with the steam engine, so I set the mechanism up with the old bale elevator motor again, covered it all with oil, and let it run for an hour. It is as smooth as silk now.

b.lindsey · « **Reply #43 on:** November 20, 2016, 03:29:39 AM »

Brian, the pulley/flywheel thingy's add a lot to the visual of watching it run. Should play well at shows and generate lots of interest for sure. Very neat mechanism and well executed also!!

Bill

Brian Rupnow · « **Reply #44 on:** November 20, 2016, 03:45:56 AM »

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!!!

crueby · « **Reply #45 on:** November 20, 2016, 03:56:05 AM »

Quote from: Brian Rupnow on November 20, 2016, 03:45:56 AM

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!!!

So its a right angle drive AND a governor testing device!

Brian Rupnow · « **Reply #46 on:** November 20, 2016, 04:08:07 AM »

Yes Chris, it wasn't intended to be a governor testing device, but it is. That governor is such a neat thing. I designed that based on old drawings in "500 Mechanical Movements" about 6 or 7 years ago, just after I had built the engine, and was fascinated the way it responds to loads imposed on the engine. Some of that old time "mechanica" is just so darn neat to watch working. Sometimes I almost feel as if I was born a hundred years to late.---You are doing amazing work on you timber hauler tracks. You have more patience than I do.---Brian

BillTodd · « **Reply #47 on:** November 20, 2016, 07:13:50 PM »

The interesting thing about this mechanism for me is that it translates the rotation without reversal and could be used to change any angle or height . Very neat.

Congratulations Brain, another wonderful model :-)

Brian Rupnow · « **Reply #48 on:** November 20, 2016, 07:19:39 PM »

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?

10KPete · « **Reply #49 on:** November 20, 2016, 08:00:10 PM »

Brian, the neat thing about that gizzie is that if the sliding tube were long enough one could put any number of connections on it, either driving or driven. A real communal hook-up!!

Pete

Kim · « **Reply #50 on:** November 21, 2016, 07:22:59 AM »

That is just pretty cool Brian!
Kim

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Author Topic: 90 degree joint in rotating shafts (Read 11632 times)