Looking for a clutch solution for a human powered drive shaft

[cogzoid]

Alright, this one is kind of hard to explain. I hope it comes across. Basically I'm building a pedal powered bar. Bar drinkers will sit on a bicycle seat with set of pedals to put their feet on. The pedals will drive a main driveshaft that they can add power to. The driveshaft will be used to power an assortment of bar appliances: a blender, a juicer, a shaker, etc. This project is a functional art piece. The bartender will be able to "turn on" the juicer, get some fresh lime juice, and "turn on" the blender to mix up a delicious margarita. Sounds like fun doesn't it? Here's the problem: I need a simple clutch mechanism that the bartender can use to "turn on" and "turn off" the appliances without everyone having to stop pedaling.

My first thought was just let him grind the gears a bit, but I really don't like that. I was thinking about it, I realize that my South Bend lathe has a clutch that allows for engaging and disengaging without the drive shaft needing to stop. I might have to design up something that solves the problem in a similar way. I've got access to a CNC mill so I can crank out a few pieces if I need to.

Anyone have any better ideas for a clutch system? Ideally it will be simple for a bartender to utilize in a hurry. It'll have to be easily cleanable and hopefully not require too much oil. The gears can hide under the bench top (glass so everyone can see what's going on!) but it'll need a method that the bartender can grab. Big points for things that look awesome. This is an art piece after all. Rubber drivewheels might also be a solution, but it seems like cheating to me, and I don't really like that aesthetic.

Thanks for suggestions or advice. It's going to be a fun project.

 

[Hybridss]

Just use what they used to use back in the day. Pulley and belt systems. Same thing can be found on modern lawnmowers to engage the deck belts. The belt routed around the drive pulley and the thing you want to power....but not engaged until you move the lever, preferably to an over center position which then tightens the belt.
In old workshops saws and grinders and lathes used to run off one steam powered engine with a seies of shafts and belts and pulleys.

 

[kerrynzl]

Sprag Bearings on the pedals [just in case one will get lazy]

And a 12Volt Clutch off a Car AC Compressor

Also look at clutches on a Sewing Machine Motor [pedal operated]

 

[theoldwizard1]

Just use what they used to use back in the day. Pulley and belt systems. Same thing can be found on modern lawnmowers to engage the deck belts. The belt routed around the drive pulley and the thing you want to power....but not engaged until you move the lever, preferably to an over center position which then tightens the belt.
In old workshops saws and grinders and lathes used to run off one steam powered engine with a seies of shafts and belts and pulleys.

Those are called "line shaft" systems. They did not use a clutch. The flat belt was slipped on/off the "line" to power the device. Google it for pictures.

 

[Hybridss]

Those are called "line shaft" systems. They did not use a clutch. The flat belt was slipped on/off the "line" to power the device. Google it for pictures.

In Sarasota Fl Edison had his "winter shop" and residence. You can tour his workshop and the ceiling is nothing but a series of shafts and pulleys, oilers and long flat belts. Its really something.

 

[larry_g]

http://www.tinyclutch.com/spring-clutches.htm

We used to use spring clutches in office machines. Some mechanical and some electrical. A mechanical one would do your job.

lg
no neat sig line

 

[DenisG]

Older industrial sewing machines use motors that constantly run. A friction clutch is engaged when the operator presses on a foot pedal that is connected to the clutch lever.

 

[EdT]

If you take the power off of the low speed pedal shaft, a simple dog clutch would work fine. You will have to gear things up A LOT to run a blender at any reasonable blending speed and, after all the losses in the drive train, it'll take two people pedaling furiously just to run the blender. You might want to consider running a generator off the main drive to charge a battery bank and run the appliances off an inverter. That way you can store some energy and not bring the whole thing to a grinding halt when you turn on the blender or something. This is the kind of thing where it makes sense, to me at least, to test some of the elements separately and get a feel for what you're up against before you worry about integrating the whole thing together. For example, hook a bike up to a blender and see how that feels. I think a modern blender turning 20K rpm is making something more than 1/2 horsepower and, IIR, a good pedaler is good for about 1/4 HP on a continuous basis. So a big chunk of ice in the blender will be a challenge. Ever have a bicycle with a generator on the wheel? That was only running a 6 watt bulb.

 

[cogzoid]

Great ideas!

I think a idler pulley system might get too complicated. This will be a functioning bar and things might get messy. Belts sound like they'd be tough to clean. But, I do agree that done well they'd look really awesome.

One of my favorite Youtube channels is the Old Steam Powered Machine Shop. The aesthetic might be a little big and frankly possibly dangerous for a customer serving bar. But if it was up to me...

kerrynzl, great idea on the sprag clutches. I definitely will put them on each input. Not only is it a "lazy" feature, but it's a necessary safety one. I've built an 8 person bicycle before, and I used the existing bicycle ratchets to solve the "lazy pedaler" problem. However, for this application I want a cleaner look, so all of the parts will be purpose built. I finally have the tools to do this right, so I'm going to take advantage of that. One-way bearings are so compact and clean that it's a no-brainer. Thanks for the suggestion!

larry_g, thanks for the link! Spring clutches might be just the ticket. I'm going to read up on them and order one or two to play around with them. They look like just the solution I had in mind. Thanks!

Friction clutches like on that sewing machine might be a good solution as well.
They certainly look cool. My only problem might be the size of them. If the tiny clutches don't work out, I'll have to think about them...

And to do a little bragging about my previous pedal powered project, you can check out this video we did for a local tv show: A Moveable Feast

Once this project gets the green light from the powers that be (and I bet it will) I'll start documenting the process with pictures and possibly some video. It'll take months to do this right, but it looks like a heck of a lot of fun!

 

[texasranger]

EdT brings up a good point about the gear reduction (or increase as it were) to drive a blender from your patrons pedaling at 60-80 RPM. Do you plan to use a gear box or sequential sprocket/chains or pulleys to get up to 20k RPM?

Thinking out loud, you could make it a game and have the peddlers only power the blender or the traction drive. When you are stopped at a light or something, switch to the blender and everyone must pedal their **** off before the light turns green.

Sounds like an interesting project.

 

[cogzoid]

So the plan is to have seats for 8-12 people to pedal. I think we can get the HP necessary. What I've found is that people love to pedal with a purpose, especially if that purpose is to help someone get their drink poured. With a little motivation from the bartender, a lot is possible.

The "art" of the project is to keep the gear train visible. People love to look at spinning things. Having the power go through a generator and battery bank seems like cheating. Some of the elements are kinetic sculpture elements which will give everyone some resistance to push against. Just as it's difficult to pedal against a heavy load, it's annoying to pedal against no load.

You guys are spot on with the difficulty of getting the speed of the blender up nice and high. I've got some sketches on using a gear train to do just that. I just bought some gear cutting tools, so I'm looking forward to making my own spur gears. This project will definitely increase my machining skills, but I truly love this stuff.

The other appliances/elements will work fine off of the lower speed. I haven't designed them all yet, but I'm working on them. My workbench right now is a mess of bar tools and implements. It could be worse...

 

[Gotcha640]

Couldn't you use the gears already on the back wheel? As long as you don't go fixed gear, the riders can "coast" if they want, and the driveshaft is as long as you need. Gearbox up to the bottom of the blender, and you're set.

Gearing on a road bike goes up to about 4.5:1. The rest of my math seems to have gone wrong, because it suggests I can pedal 200mph, but you'd be getting something like 300rpm before the patrons gave up and went home.

With 10 pedallers you might be able to turn a small differential. That would give you gear advantage and change horizontal to vertical rotation.

How fast does a kitchenaid spin? Might be more realistic to spin than a blender.

 

[alfazer]

A cone clutch would be a pretty simple way of engaging and disengaging the drive to a blender. It can slide on a splined shaft and use a lever to move it in and out.

Or a belt drive with moving tension pulley like you see on lawn tractors and mowers.

 

[CNGsaves]

What about rear axles from 3- or 5-speed bicycles that free-wheel when not pedaling ??? Would be cool to have the shifter so each barstool could change their own RPM of pedaling.

Think you should have one of the decorative "art machines" that always turn when someone is pedaling. Thus, even if no juicer or other useful machine is being used, patrons can still pedal and at least turn something.

 

[kerrynzl]

You can run a whole row of juicers off one shaft.

Make them from old hand drills [the crank variety] with the blender in the chuck.

Replace the handcrank with spur gears [one on the shaft/one replacing the crank] and mount the drill/juicer to a pivot bracket so it disengages when you lift it up

It'll look cool like some invention from a "mad scientist"

 

[will gilmore]

What about rear axles from 3- or 5-speed bicycles that free-wheel when not pedaling ??? Would be cool to have the shifter so each barstool could change their own RPM of pedaling.

Think you should have one of the decorative "art machines" that always turn when someone is pedaling. Thus, even if no juicer or other useful machine is being used, patrons can still pedal and at least turn something.

You're also going to want a flywheel somewhere so it doesn't bog when you power up an appliance.

Sent from my SM-G900V using Tapatalk

 

[kbs2244]

I would suggest a good sized flywheel somewhere in the driveline.
One of the old spoked style.
Keep it where I can be seen.

 

[cogzoid]

You're also going to want a flywheel somewhere so it doesn't bog when you power up an appliance.

Sent from my SM-G900V using Tapatalk

A flywheel isn't a bad idea. I might have to leave room for one and then add one of the right size once I get things tested.

You can run a whole row of juicers off one shaft.

Make them from old hand drills [the crank variety] with the blender in the chuck.

Replace the handcrank with spur gears [one on the shaft/one replacing the crank] and mount the drill/juicer to a pivot bracket so it disengages when you lift it up

It'll look cool like some invention from a "mad scientist"

I like what you're thinking.

What about rear axles from 3- or 5-speed bicycles that free-wheel when not pedaling ??? Would be cool to have the shifter so each barstool could change their own RPM of pedaling.

Think you should have one of the decorative "art machines" that always turn when someone is pedaling. Thus, even if no juicer or other useful machine is being used, patrons can still pedal and at least turn something.

I'm not sure how important changing gears will be. It's probably not worth the complications. With my pedal powered dining table people don't really care and pedal at a comfortable speed/power level. As for the art machines, you're spot on. There will be plenty of things running so people will always have something to entertain themselves.

A cone clutch would be a pretty simple way of engaging and disengaging the drive to a blender. It can slide on a splined shaft and use a lever to move it in and out.

Or a belt drive with moving tension pulley like you see on lawn tractors and mowers.

I think belt drives might have a cleanliness problem. The cone clutch looks great, but I think it might get complicated to have multiple cone clutches on the same drive shaft. I don't know, it seems bigger than I want it to be...

Couldn't you use the gears already on the back wheel? As long as you don't go fixed gear, the riders can "coast" if they want, and the driveshaft is as long as you need. Gearbox up to the bottom of the blender, and you're set.

One way bearings aren't expensive, and are a great way to have everyone tie into the same driveshaft.

 

[bluebolt]

Cogzoid, I just watched the video, that Moveable Feast is awesome! Really looking forward to the Moveable Bar!

 

[JamieK]

Older industrial sewing machines use motors that constantly run. A friction clutch is engaged when the operator presses on a foot pedal that is connected to the clutch lever.

A simple friction clutch with an oversize actuating lever that the bartender could throw.

 

[DenisG]

A simple friction clutch with an oversize actuating lever that the bartender could throw.

Here's a different friction clutch/drive used with a lever that is thrown:
https://simanaitissays.com/2013/08/30/continuously-variable-transmissions/

... similar to the drive on my old Ariens snowblower.

 

[kerrynzl]

Put a centrifugal clutch on it [make the patrons earn their drink]

 

[rsanter]

Cheaper than dirt.com has thenold ex military hand crank power generators.
Buy one, convert to bed all power. Charge a battery and then you can use an inverter to power whatever appliances off of that....

Bob

 

[Brian_WK]

If you only plan on one device running at a time, Blender, Pump, Shaker, etc. A magnetic clutch (like a cars AC compressor) is going to be the quietest and easy to operate as each device would have a switch to activate it. A flywheel on the common drive shaft would be ideal as it would keep the patrons from pedaling up hill so to say when the you pulse the blender for that perfect ice blend. I don't think RPMS are going to be a issue as you can individually gear each device for its needs pre-cluch and just use the magnetic clutch as the final connection to your device.

Lots of Glass or acrylic and seeing this thing work would definitely be awesome. Look forward to seeing this progress.

Brian

 

[hh76]

My lathe head sounds about right for your idea.

Motor and pulley below, leather belt to the head, gearing to adjust speed. There's a lever to drop the motor pulley down to engage.

I'll snap a few pictures tonight.

 

[Bronson]

I would hate to have pedaling interfere with my drinking.
A man has to have priorities!

 

[Robert Haas]

why a clutch at all?

Why not a simple freewheel?

Several silent designs used in the cycling industry

 

[cogzoid]

why a clutch at all?

Why not a simple freewheel?

Several silent designs used in the cycling industry

The clutch is between the common driveshaft and each individual appliance, or kinetic art element. I'm not sure how a freewheel would solve the problem.

I would hate to have pedaling interfere with my drinking.
A man has to have priorities!

Don't worry, you can still order a drink and give the pedalers something to work for. They'd love you for it.

My lathe head sounds about right for your idea.

Motor and pulley below, leather belt to the head, gearing to adjust speed. There's a lever to drop the motor pulley down to engage.

I'll snap a few pictures tonight.

I have a similar lathe head, but the problem is I can't move the common driveshaft, and the appliances should stay on the shelf. I think belts aren't the best idea for this solution.

If you only plan on one device running at a time, Blender, Pump, Shaker, etc. A magnetic clutch (like a cars AC compressor) is going to be the quietest and easy to operate as each device would have a switch to activate it. A flywheel on the common drive shaft would be ideal as it would keep the patrons from pedaling up hill so to say when the you pulse the blender for that perfect ice blend. I don't think RPMS are going to be a issue as you can individually gear each device for its needs pre-cluch and just use the magnetic clutch as the final connection to your device.

Lots of Glass or acrylic and seeing this thing work would definitely be awesome. Look forward to seeing this progress.

Brian

Magnetic clutches are close, but I think I found a mechanical clutch that fits the bill, more on that...

Cheaper than dirt.com has thenold ex military hand crank power generators.
Buy one, convert to bed all power. Charge a battery and then you can use an inverter to power whatever appliances off of that....

Bob

If I wanted an easy solution using electricity I'd just buy a $40 blender and plug it in. The goal is to keep this thing mechanical so people can watch the chains and gears move. People are crazy for that stuff!

Put a centrifugal clutch on it [make the patrons earn their drink]

A centrifugal clutch doesn't work for multiple outputs that need to be turned on and off individually. But they will earn their drink...

Here's a different friction clutch/drive used with a lever that is thrown:
https://simanaitissays.com/2013/08/30/continuously-variable-transmissions/

... similar to the drive on my old Ariens snowblower.

I like the idea of the friction clutch/variable transmission. The pictures help a lot. If my other plan doesn't work in testing I'll give this one a go.

So I looked into larry_g's link to tinyclutch.com and gave them a call to have a talk with an engineer. They seem to be an almost perfect solution. They're small, not too expensive, and are made for exactly this situation: having one driveshaft with lots of power take-off elements that need to be turned on or off.

This afternoon I'm giving a quick presentation to those that hold the purse strings. If I get a green light I'll start ordering some of these parts to test the mechanisms. I've been messing around with some scrap in the shop, getting ready to put together my own step up gearing for the blender. So far everyone that I've mentioned this too in the company is excited about the project, so it'll likely get a thumbs up.

Thanks everyone for the ideas!

 

[greenlizard]

Seems like a dry motorcycle clutch from a bone yard would work for a fairly low power system. Something with a chain drive primary would be easiest. It would also be the mechanical look mentioned.

 

[ndnchf]

I have a heavy duty belt driven clutch assembly removed from a very old industrial sewing machine. It does not have an integral motor. It has a input pulley at one end and an output pulley at the other. A foot operated clutch is between them. It's heavy, old school steampunk iron. I don't have need for it. PM you email address and i'll send a photo if you are interested.