How to Make an Impeller Rotate at a Constant Speed

Cheap may not be easy.

Mechanical governor.

Dear Lyn when you make a suggestion you should go to the end. A mechanical governor should be used to control a variable link, where is the one you suggest ? For so small powers as the human being can deliver (about max 120...160 W a longer time) a variator with V- belts can be used. The change in the running diameter on one side combined with the constant belt length leads to a transmission variation which can be controlled by the governor you propose.If the OP wants more input he can contact e on the private channel.

The mechanical governor was intended to be just a seed for thought, not a solution.

These villages have almost no resources on which to draw, and surely will not have "variators with V-belts" to work with.

Some form of centrifugal governor fashioned from materials at hand was what I was proposing.

I repeat my question: what will you govern with it? If it is a seed you should pour some water on it to make it grow up and become an idea and even a solution.

As for the "variator with V-belts" it is so simple that I am surprised that you do not see it. It can be build in ANY shop where there is a lathe and one without any precision. The wheels can be made of wood for so small power or from a piece of thin metal sheet pushed on a wood model. Do not depreciate what you do not know.

V-belts are every where as they are used in many engines to drive the fan. It is possible to use even a rope to build it up.

It is a pity since you (sorry I wanted to write "idea") seed for thoughts is a very good one.

That's what I am going to say too. A fly wheel would do the job and the cheapest resort.

The problem is that the "operator" is NOT able to bring same speed all time even if is informed that he is out of range. The optimal solution is to make an automated system to maintain the output speed constant when the input varies within normal human limits.

The problem is to make it simple so that even a simple shop can make it.

An automated transmision system would have little use when the operator is becoming tired and starts pedaling too slow. The system would demand more torque at this time and the operator would not whitstand it for long (power = torque x angular speed).

When the operator is starting his turn he will tend to go too fast. Using a governor with a centrifugal brake means wasting power. A centrifugally actuated CVT or similar will have too much loss.

This is why I have suggested a simple centrifugal ringer. It has virtually no losses and will help the operator saving his muscle power for later, by keeping a speed just at the onset of the ringing noise.

The operator will be able to talk to other people, look around and so on. Keeping an eye on a speedometer is boring when the landscape doesn't change.

Get a small bicycle light generator (the type that runs on the tire) and figure out what voltage it needs to puts out that matches your speed requirement. Hook it up to a cheap volt meter and have the pedaler watch the meter.

Heck just get a DC motor and hook it to a 12v battery, and charge it using the bike...simple way to have a constant speed...until the battery dies!

The best way to regulate speed is to over power and gear down....without a constant power torque being applied this becomes even more problematic....of course you could just include a metronome that would keep time with the ideal pedal speed...

and Acmhed

Make the pedaler sing and crank to a tune of the right tempo. Hava Nagila would be too fast; Adagio for Strings too slow.

Maybe a bicycle bank....? Now all together!... I've been workin' on the railroad,,,all the live long day....

These guys have extra motivation.

S.E. your such a joker.

then send me some music CDs

Feel free to sing along....

https://www.youtube.com/watch?v=a6bRENou_ZE

..... but if that speed is exceeded the % separation is only 50 to 60%. Is the reason we want Royalties for our design!Good Luck with that one

Is it your intent to maintain a bicycle device powered by pedalling?

Do you wish to make the device electric?

People are not machines, they slow down and speed up (sometimes based on a good football game, smooth music, short skirt....you get where I'm going...).

There is no electricity available at many villages then how can be that made electric. So we want it manually controlled.

Batteries = electric.

Then what's running your computer?

speedometer and metronome, definetly.

Or tape a whistle to the spokes so that it starts to make noise at just the right speed.

or all three...

Or hook the bicycle to a water pump, pump water up into a cistern, turn the husker with water power.

Get a bicycle cadence meter.

www.rei.com/products/751831/cateye-strada-cadence-bike-computer

this will give a readout of the rpm of the crank. the pedaller just has to keep the speed constant. One could try a digital bicycle speedometer, by putting a magnet on the crank to trigger the pickup, not as good, but cheaper and easier to find. search out "very easy cadence meter for your bike"

I think it's been done already.

Go on ebay or to a bike shop and buy a digital speed indicator. There are wired versions and radio versions for less than US$10. See here for example:-

WIRELESS-WATERPROOF-LCD-BICYCLE-BIKE-CYCLE-COMPUTER-SPEEDO-ODOMETER

Use a multi speed bicycle and match the right gear to the rider to obtain final results.

Use a motorcycle speedometer to watch and maintain the speed. You will also need the flexible cable and construct a proper gear with the needed ratio.

It can be done adjustable with a round (rotating)plate and a wheel with rubber tyres driving the speedometer cable.

For adjustment, you have to change the radius at which the rubber wheel touches onto the disk.

Also use a flywheel as suggested, for small variation.

Gajanan Phadte

I will not wonder on the rating...

But do you know that this is the only possible solution for the OP, due to the non-availability in his region, of the other good solutions suggested above.

You don't know the markets here more than me.

No wonder this forum is loosing members.

Gajanan Phadte

Try attaching a small weight to the last pulley. The link must be elastic (coil spring, rubber band) so the weight will start hitting a small bell above a certain speed. The bell (from a bike ringer) will be fixed to the static part of your equipment.

brgds

Snel

Lot's of inane ideas on offer here and I doubt that there is a simple and inexpensive solution if you really need to keep the speed within critical constraints.

Rixter's flywheel (#2) will be mandatory as will Lyn's Governor (#1)

You will likely need to couple those to a variable speed belt drive so that the governor alters the pulley ratios in line with detected speed changes, with the flywheel smoothing out the spikes in torque when this occurs.

"At a certain speed of pedalling we get 90% separation of husk, but if that speed is exceeded the % separation is only 50 to 60%." (OP)

Our main goal is not to exceed the ideal speed.

The device as shown above will give the operator an accoustic feedback whenever he is pedalling at [more than] ideal speed.

A coil spring is shown, but a flat spring may be better. And the whole things costs close to nothing.

brgds

Snel

Thank you to support my suggestion which was refused by Lyn. It is good to feel not alone.

In fact I doubt that they will have the money to buy it. What is usually proposed are devices for higher powers and for industrial use thus more expensive than what they need. In fact it is a simple mechanical system which can be manufactured in normal shops provided the drawings are made to respect simple, basic, manufacturing technology.