The Contraption 2009

[fciron]

Sloss furnaces is on my to-see list too. Let's have a road trip. Maybe when we gotta escape the wet Kentucky winter.

[LeChatNoir]

Hey, now there's an idea!!

[Dusza Beben]

Do you get there via the Slossen cuttoff?

DB

[Elliot]

A while back, there was mention of a possible transmission for the Contraption -- maybe a chain gang. And more recently, I mentioned that I saw a chain gang at a Kinetic Sculpture Race.

Well, this picture just happened to land on my computer screen today:



It’s the KSR machine I mentioned. Both chains always turn with the wheel. But only one of them is connected to the power at any given time. Follow the chains to the small pair of sprockets at the far left. Although the shift mechanism is not visible in this picture, that’s where the magic happens. The two small sprockets are mounted on a hollow shaft with a slot in it, and a shift pawl slides back and forth in that slot. Thus you can choose which chain is transferring power.

[Elliot]

All right.

We were talking about building a chain gang transmission.



Here is the lawn tractor guts:



This is the shaft with the five selectable gears. These gears spin freely on the shaft - except the one that is "in gear". They are all engaged with their counterparts on the other shaft, and those gears are all fixed to that shaft. Thus, the “magicâ€

[LeChatNoir]

This is close to what I was imagining, but I was thinking of a sliding coupling that was slid over a fixed key in a shaft, engaging the desired gear. Doing it with a hollow, heavy wall tube and moving the key itself might be an easier approach, actually.

I’d fancied the idea of making it able to shift while in motion, but I’ve got to study on this a bit more. I suspect that would require some sort of clutch between the engine and sprockets. Perhaps its best (and really more appropriate) to just keep it as a tractor type of set up… stop, select a gear, engage and go.

[LeChatNoir]

Good God, man…

You posted again while I was composing!!

Yes, I do think this could work. I’d love to scrounge one of those gear assemblies and axle, but even if that doesn’t happen, the machine work could be done pretty easily. And!!! There is one of the driver accessible levers on the Old Egg Crate that has several positive stop points on it and nothing to do at the moment. Can you say gear shifter?

And that is a brilliant positive lock setup… simple elegance.

Now I have something to think about in my amazing free time.

[Elliot]

A chain gang could be built with parts from Tractor Supply Co. and such stores.



From the top: sprocket, plain hub for said sprocket, pair of jaw couplings, splined hub, splined shaft. This spline is a common agricultural “Six Splineâ€

[Toolmaker]

Heres a couple places to window shop and brainstorm

http://www.rushgears.com/
http://www.magnaloy.com/
http://www.hayescouplings.com/
http://www.lovejoy-inc.com/

Rush gears is especially handy.. calculators and 2d / 3d cad files for free

I've used hayes and lovejoy in the past with good results when I didn't have time to machine something. I have heard that magnaloy is good too.

[Elliot]

You guys who are machinists and tool-and-die-makers must have had a good laugh when you saw my crude mock-ups! (At least I hope so. )

I took some machine shop in vocational school 40 years ago, and I often wish I had pursued that field.

Looking at their web site, firms like Rush Gears are what made America great. A can-do attitude with the skills to back it up.

I expect Le Chat Noir can and will fabricate a nice tranny, chain gang or otherwise, for The Contraption. Myself, I would like to track down suitable junk and off-the-shelf parts to assemble a number of chain gangs for my Kinetic Kontraptions -- cheaply. How many? I could install nine of them right now, and more in the future. Two ratios would be a good thing, but three or four would be much better. In Kinetics, we need as much as a 20:1 range of gear ratios, so some intermediate ratios are kind'a needed.

Some years ago I found a source of industrial gear boxes that could probably do the job. But they are built to order and cost thousands.

I have a setup on a single-seater that gives me a 12.25:1 range, and it was plenty at the Ventura race. But Ventura is an easy course.

Hmmm.... I'm just Train-Of-Thought Brainstorming here. (Sunday morning and frost on the ground.) And a lightning bolt just struck....

It's about that 12.25:1 setup I just mentioned. That thing is at least $650 worth of parts, and it cannot take much torque, but it is a stepless transmission. Yep, a Continuously Variable Transmission. It's actually two trannies in series -- one unit has a 3.5:1 range. It’s a bicycle wheel hub called NuVinci. Take a look at this, if you wish: http://www.fallbrooktech.com/

Looking at the animation, it is not difficult to understand how the ratios are changed. Pretty clever. It took me longer to understand how the force is actually transmitted, but I believe it boils down to friction. There must be a bit of preload on the balls, and then the “secret recipeâ€

[gyre]

I have some machine transmissions with a shift lever that are direct and a higher or lower gear.
They have a handle shift on the side.
I don't know how tough they are but they look heavy.
No idea where they were originally used.
They look suitable for a lighter vehicle without question.
I don't know how they would handle a heavier vehicle.

They have a shaft in and out.

[Elliot]

Sounds interesting. There is so much hardware out there that generally goes unseen. A big part of building Kinetic vehicles is in discovering Stuff that can be used.

If these are lawn mower trannies, then the ratio range is probably only 3 or 4. Same with motorcycles and cars. Or even less -- the 2-speed GM PowerGlide has only 1.75. But if they are industrial, then anything is possible. I'd love to see a picture. You could e-mail me a .jpg instead of taking time to post it.
And can you spin it by hand and get a rough idea of the ratio? And roughly dimentions and weight?
It's a long shot, but it is always possible that a Major Solution has been hiding in your shed!

[gyre]

They appear to be for machine tools, gray finish.
They might be some sort of part for factory equipment.
I think a half inch shaft.
The ratios are labeled.
I just can't remember them right now.
They are at my friend's shop now so I can't check.
I'm not set up to send pictures yet.
I think one of the ratios was pretty radical, but I can't be sure.
They are all two speed with mounting flanges to bolt them to a surface.
They are quite solid for their size, ten to twenty pounds, guessing.

[Elliot]

This sound VERRRY interesting. Specially the "radical" ratio. All the rest of it also. One good-and-wide 2-speed could be combined with a more common mechanism to "split" it -- a Nuvinci hub, for instance. Or even a bicycle derailer, although I do loathe those.

And 20 pounds would be agreeable.

An other approach: So far, I've been talking about each Kinetinut having his own transmission. That is preferred. But it is also possible to collect the power from several riders into one chain, and then run that thru the tranny. So if we come up with a tranny that is "too big" but with a huge range, we could use it that way.

Of course, if they weigh ten pounds and have a huge range, I want 20 of them! I might be willing to set one aside for whatshisname with the big rusty thing.

Would you keep this in mind, and take a look at these treasures next time you are at your friend's shop?

[gyre]

I'll take a look at them.
He has visions of using them on a small electric car, but I think he may be overly ambitious as to their torque tolerances.
I wish I could figure out where they came from or even what they are called.
They look like a universal part to be added to anything, but they may be specific to something.

I found references to machine tool gearboxes and transmissions.
May be relevant.

And I found a discussion board that may be of some use.
he Home Shop Machinist & Machinist's Workshop BBS
http://bbs.homeshopmachinist.net/index. ... f75c1b75eb
Seems to be connected to some Machinist magazines.

[Elliot]

Marvellous. I'll take a look at that web site tonight. Working on my bus today -- installing an interior door. Very strange to work with... wood.
There are definitely such magazines. I have here copies of The Home Shop Machinist and Machinist's Workshop, same publisher.

Electric motors deliver max torque at zero RPM (as you seem to be aware of). And they have a wider span of usable RPMs than piston engines -- zero to centrifugal detonation. Thus, a "real" electric car does not need to change gears. I test drove a GM Impact (EV1) and it was like an airplane -- kick the chocks out from the wheels and hang on straight thru to cruising altitude.

Admittedly, home built conversions are usually different. They often use the original transmission and even clutch. And I was astonished to learn of a commercial conversion that had the electric motor spinning even when the car was stopped -- to keep the accessories functioning.

I ramble. Back to the bus project.

[gyre]

I have to disagree about transmissions not being a good idea for electrics.
They used to say the same thing about cars.
I think they need them for the same reasons, to keep everything at maximum efficiency, have torque multiplication when needed and not waste the power when it is not.

Most of the bike hubmotors sadly need gearing as evidenced by all the fixes out there.
The better ones use a controller to artificially limit power except when needed and will burn up on wide open power.
But this doesn't address friction losses or sizing issues.

My big V8 has a wider torque band than my big electric motor which is supposed to be limited to 3600 rpm.
If I use it on a bike I will probably use it without a transmission to solve complexity issues and I will use belt drive to change ratios when I need to.
And the Curtis controller should be able to limit waste.
But it is vastly oversized for normal cruising.
It should be capable of handling hills and heavy loads too.
If it was sized for max efficiency, it would need gears to be adequate.
The first version of the bike it came from wouldn't climb the drive going home, without gears.
This motor would.

[gyre]

I have found a supplier for custom toothed belts if anyone needs any.

[Elliot]

Hmmm.... Well, I said I was rambling, and now it turns out I was rambling all the way outside my (limited) expertise. Apparently, there is more to electric motors than I was aware of. I humbly accept the correction, with thanks.

While we are on the subject, I have a rather large A/C motor that came out of an experimental automobile. But I have no controller. I'm willing to let the thing become a boat anchor, but it does seem a shame. The biggest obstacle seems to be that it is an A/C motor, so it needs some sort of inverter to run off batteries. (But I'm pretty sure I have read that A/C motors are more efficient, even with the inverter loss.) I have no plans for this motor. It was earmarked for educational purposes, and perhaps I should disassemble it and make a tabletop display, then offer it to the local high school. Ideas welcome.

[gyre]

It's a debatable question, but that's my opinion.

If you have a controller that outputs in ac, you wouldn't need a separate inverter.
You might want to save that motor for you or someone else that can use it.
You can always find a burned out one for a display.

It's hard to compare motors unless they are very distinct or almost identical, except for one thing.
I can tell you that already having a motor around is hard to beat for cost, though it does happen sometimes.
If it's a well made motor, it may very well be worth using.

Heinzmann believes in brushed motors.
Others prefer brushless.
And of course, construction quality counts.

Electric motors are out of my area, but I know some real experts when I need help.

[Elliot]

This one is a Hyundai, and it came from their automotive Fuel Cell development program. You are right, or course, it is too good to toss. Water cooled, even. Max RPM 9.500. Of course, it could be defective -- I have no way of knowing. But it seems likely that it was simply replaced with a new model. It was donated to a school teacher friend of mine "in case he could find some educational purpose for it", but gave up on that. I'll just let it sit here and mention it around. It doesn't eat much.

[gyre]

That sounds like a good one.
A friend had a chance to pick up a huge low voltage dc motor from an mri machine and didn't get around to it.
Probably cost thousands and got thrown away.

[gyre]

Can you post a wide angle photo of the contraption like this?
Interesting overhead too.
Wide Angle Photo

[MozyBonz]

Public transportation for Black Rock City?


[youtube]http://www.youtube.com/watch?v=QYROHF4VjTw[/youtube]

[youtube]http://www.youtube.com/watch?v=IC2BZp-25xQ[/youtube]

[youtube]http://www.youtube.com/watch?v=UzRwgdqcXUw[/youtube]

[jkisha]

How cool is that!

JK

[karine]

We actually don't have any wide angles.. good idea, though!

[LeChatNoir]

Cool find, Mozy!!

[LeChatNoir]

Can you post a wide angle photo of the contraption like this?
Interesting overhead too.
Wide Angle Photo

And nice wide angle of the Ferrari. Makes me think of Top Gear. I love that show.

[theCryptofishist]

Now you guys are making me feel stupid. And you're immune to my snark so I'll never get rid of you!

[LeChatNoir]

You couldn't get rid of us if you tried.

Even throwing rocks at us wouldn't make a difference.