Bicycle Dynamo powered by model I.C. engine

[Brian Rupnow]

Today I tested the bicycle generator (dynamo) that was sent to me by a fellow member. Not knowing what voltage this thing produces, and not having a voltmeter, I robbed a 2.9 volt rated battery out of a flashlight and jerry rigged a pigtail and alligator clamp to the bulb and the output terminal of the dynamo. I have a small cogged drive belt that I salvaged off something, and holding a 1" pulley in the milling machine chuck and pulling the belt tight I was able to light the flashlight bulb. This satisfies me that the dynamo does indeed produce electricity. It did need to be rotating at a pretty respectable rpm to light the bulb, but I don't have actual figures on the rpm. I intend to machine a 0.8" diameter flat pulley with side flanges on it to press fit onto the knurled end of the dynamo, and use the same belt that is in the picture to drive the dynamo from the 2" diameter starter hub on my side valve engine. This will give me a ratio of 2.5:1, so if the engine is rotating at 1500 rpm, the dynamo will be revolving at 3750 rpm. I have to design and fabricate a mounting base for the dynamo and a belt tightening mechanism, as I want the dynamo and its base to be a "composite unit" separate from the engine.--Stay Tuned!!!

 

[///]

The sight of this thing has caused an involuntary twitch in my left eye.

Memories of my youth and how damned inefficient these things are.

I can't find an english version, but this video is exactly how I remember it:
www.youtube.com/watch?v=i7kgzgcqe5s

 

[Swifty]

That's exactly how I remember mine as well, I longed for one as a kid and eventually got a secondhand one.

Paul.

 

[Brian Rupnow]

I think I have most of this sussed out now. I have a short length of 24DP rack left over from when I built the sawmill, and I will build the mounting plates from 3/4" aluminum. The sprag will be a bit of 1/4" square steel key stock. I want to be able to start the engine with the belt loose under "no load" conditions, then tighten the belt gradually until the revs come up on the dynamo. The sprag will hold the belt tight. I haven't modeled the release mechanism yet. I have to go out and buy a bulb and holder yet.

 

[Brian Rupnow]

I made the pulley and pressed it on. That went well, but the pulley was so smooth the belt slipped badly. Next trick was to go all around the pulley with my automatic punch and "upset" the metal to give a little something for the belt to grip. If I was smart instead of good looking, I would have knurled it while it was still in the lathe.---Nah, that wouldn't have worked. I just checked and the knurling tool is too wide to fit between the flanges.

 

[Toolguy]

How about some skateboard tape on the pulley?

 

[gus]

Hi Brian,

You have justed started a ''Bicycle Genset'' Trend and we expect more such Gensets will appear powered by IC Engine.th_wav .

 

[Hopper]

Have you thought about using an old "Dyno-Hub"? It was a generator built into a small hub like a small brake hub on the front wheel. Unlike the type of dynamo that rubbed on the tire, the Dyno-Hub required no extra noticeable pedalling effort to turn it over.
From what I remember they were made by Sturmey Archer in the UK. But apparently more powerful models are available today from the Japanese manufacturers.such as Shimano.

 

[offchopdarwin]

that out put is around 3.5 volts

 

[Brian Rupnow]

I like the sound of the skateboard tape Toolguy. I may buy some if I need it.--Brian

 

[Brian Rupnow]

There was a bit of method to my madness!!! By building and installing the pulley first, I was able to start the engine this morning and drive the dynamo via drive belt from my engine itself. Remember, the only test done previous to this was to drive the dynamo from my milling machine arbor. At any rate, even at half throttle the engine doesn't even grunt, and the lightbulb lights up like the lighthouse at Rhodes!!!---A very positive result!!! I needed to check this out before I wasted time building any of the other parts. Now that I know the engine drives the dynamo with no problem, I can proceed.

 

[goldstar31]

It's all very ancient stuff but interesting. It was the English firm Raleigh that sold the Raleigh Sturmey Archer Dynohub. There is lots on the 'net at least from the Brits. I recall vaguely the dynamo which knackered the side walls of already pretty knackered push bike tyres(tires) during the war.
There were no replacements when the Far East was overun for tyres and tubes! I recall that some aspiring guys wound cycle tubing around the milled edge to minimise wear.

Matron let me out of the asylum for a couple of hours and I visited a sort of Aunty Wainwright of Last of the Summer Wine junk shop- and found a Winged Wheel thing. I guess that Ned Westbury built the Busy Bee motor to do much the same.

One of my old 'dearies' in her near nineties has a NSU Quickly in the cellar. Never been run for perhaps 50 years- and she is playing 'sticky- to it

Cheers

Norman

 

[canadianhorsepower]

Brian
your motor is running so slow we can read the part number
on the belt, and the fan is almost stopRof}Rof}Rof}

 

[tornitore45]

Light bulb? Have you considered LED's, they consume very little and place a corresponding minimal load.

Since the "dynamo" generate AC, LED's need to be place "back to back".
LED's will flicker, perhaps not visibly but enough to strobe any part of the engine.

 

[Brian Rupnow]

I believe everything that has been said about the effort to pedal a bicycle with one of these installed on it. I used to own one many years ago. Fortunately, the engine seems to run it with no problem. I did consider LED units, but I'm not an electricky sort of person. A bulb will do fine for me.

 

[Lathejack]

I have been reading this thread with interest. Amongst several projects I have on the go at the moment is one of the 1/4 scale hopper cooled horizontal open crank Red Wing engines.

A year or two ago I rescued a dynamo from the front wheel hub of an old bike thrown in the big skip at work, with the intention of driving it with the Red Wing engine, when I finally finish it.

This dynamo is also a Sturmey Archer and although in good external condition it is in need of a strip and rebuild. I think it dates from the late 1950's or early 60's, it's stamped on it somewhere. A special keep plate is required when dismantling to prevent loss of magnetism.

When I was a teenager I had a speedometer on my bike and this, like your dynamo, was also driven off the front tyre. So while eagerly seeing how fast I was going it was actually slowing me down. I remember crashing into the front of a parked car while concentrating on the speedo as I frantically tried to break the 15 MPH barrier! Spectacularly bent front forks were the result.

I also remember fitting a small mileometer, this was mounted on the front wheel spindle and was driven off a small lug clamped to one of the spokes. I am sure I also crashed into another stationary solid object while squinting to make out the vast distance I was sure I had travelled, bloody hell!

Anyway, this thread has renewed my interest so I will take a closer look at that old dynamo. I suspect the hub type do not need to rotate as fast as the tyre driven type.

 

[gus]

I bought a lot of five bicycle dynamo from Ebay. I have four to give away as Christmas Presents. Any taker??. DHL from Singapore will be expensive.

 

[ShopShoe]

Brian,

I vote in favor of the light bulb. To me it seems in character with the rest of the setup. You may be able to use a suitable socket and find bulbs of different voltages to play with for your final effect.

--ShopShoe

 

[jj-smith]

that out put is around 3.5 volts

Seems to me that that's right, I remember something like 2.9v through the cob webs in my mind.

I think I played with six volt lights. J.

 

[jj-smith]

There was a bit of method to my madness!!! By building and installing the pulley first, I was able to start the engine this morning and drive the dynamo via drive belt from my engine itself. Remember, the only test done previous to this was to drive the dynamo from my milling machine arbor. At any rate, even at half throttle the engine doesn't even grunt, and the lightbulb lights up like the lighthouse at Rhodes!!!---A very positive result!!! I needed to check this out before I wasted time building any of the other parts. Now that I know the engine drives the dynamo with no problem, I can proceed.

Don't you just love it when things work better than you thought they would?