Bicycle Dynamo powered by model I.C. engine

[Brian Rupnow]

So, here we have a view from the rear, with everything wired up. I just tested it on the mill spindle, and it seems to work the way I intended it to (the bulb does indeed light up). One of the things you see from this side is the tapped #5-40 hole in the side of the socket which holds the bulb in place. It has a set screw in there with a very light pressure against the base of the bulb, just to ensure that I have a good path for the electricity to flow. What you don't see is the wooden insulator that sets inside the bulb socket to keep the electricity from shorting out and finding a path to ground through the aluminum holder. The bulb holder is press fitted into the 1" x 3/16" flatbar which bolts to the top of the dynamo bracket. At this point all that is left to do is make a video of the engine driving the dynamo and lighting the light.

 

[Brian Rupnow]

And away we go!! Everything went very well on this project, except for one surprise. If the dynamo turns one direction, it runs fine and freely. If it turns in the opposite direction, it tightens up inside and becomes very stiff to turn. My original plan was to have the engine setting on the left hand side of the engine with the pulley facing out. The result was that the dynamo would tighten up to the point where it stalled the engine. So---I turned the dynamo 180 degrees and put it on the right side of the engine. That reversed the rotation and fixed the problem, and it works like a charm. The bulb I have in there is only rated at 2.9 volts, so I bought two "back-up" bulbs for a 6 volt light in case I need them.
[ame]https://www.youtube.com/watch?v=xP1bOhvse8Q&feature=youtu.be[/ame]

 

[Herbiev]

Cool project. Thanks for sharing Brian

 

[Brian Rupnow]

I may have learned something here about the Chuck Fellows carburetor which I built and installed on this engine. The carb works great, and I recommend it to anyone looking for a simple, easy to build carburetor with a "throttle" on it. The carb I built is from one of Chuck's early designs, with a #8-32 screw acting as the throttle. By turning the screw in, it closes off the 1/8" diameter main air passage, and by unscrewing it, the air passage is opened, thus letting more air (and venturi induced fuel flow) into the engine. I took matters a step farther, and made up a little handle to clamp on the head of the #8-32 socket head cap screw, so that with an arc of about 180 degrees swing I can go from idle speed up to a much higher engine speed.---And that works fine, as long as there is NO LOAD on the engine. However, when the engine is under a load, it doesn't want to rev very high. I thought about this for a while, and come up with the following theory---An 8-32 thread only advances (or retracts) 1/32" for a full 360 degrees of turn. The 180 degrees of arc I am limited to with my "throttle handle" only advances (or retracts) the screw 1/64". Now on an engine running under "no load" conditions, that 1/64" is enough to go from idle to quite a respectable "high" rpm. However, in an engine running under a load, that 1/64" simply isn't enough to feed the fuel and air the engine requires to overcome the "load" and rev higher. The main air passage on the carburetor I built is 1/8" diameter. To really feed the engine the fuel and air it needs to rev higher under a load would require that the screw be unwound possibly a full turn or even 2 or 3 turns. This is all just theory at the moment, but tomorrow I will do a practical test and remove my "throttle handle" and see what happens when the engine is running under the load of the generator and I unwind the screw more than the 1/2 turn I am currently limited to. In the video I posted, the engine is running with the throttle "wide open" within the limits imposed by the swing of my throttle handle.

 

[jj-smith]

Good theory and good thinking Brian,

It makes me think also, as I wanted to build my own mini micro carb some time in the near future.

I am playing with thoughts of a primary and secondary equipped throttle system where you use the secondary supply to partly control the primary supply, basically controlling what the primary throttle can deliver.

Think of a screw control like you have with an additional screw control within it, and a fuel supply large enough to feed both full open.
Work with the first (no load), and open the second if demand dictates more fuel.
The idea in my head is to keep it verrry simple and that makes it harder, but I'll think of something.

Should the time come for bigger coal, you can then simply open up the primary control in addition to the secondary or control the amount of extra flow to the primary, and in this way feed double or some proportion thereof bigger than the secondary can deliver by its lonesome.

If this is confusing, think of how a carburetor has primary and secondary jets, or idling, intermediate and running feed passages in the smaller ones to overcome the dead spots or starvation at a higher required flow.
The big problem has always been the smooth transition from one to the other in order to keep the engine fat dumb and happy.

Carburation is still a big thing in my vocabulary of things to invent as I have slugged and toiled with the rather crude and inefficient early designs (I know..."old School") in my youth.
The Harley "linkert carburator" comes to mind lol, basically a bronze tube with a needle valve, a jet and a fuel feed

I am not intending to break any barriers here, but rather want to come up with something to, lets say, enhance the way fuel gets delivered for the demand, and not that demand should suffer because of inefficient delivery in more than one way, and still keep it simple, that's the thing. (and mini.)

If all else fails use a BIGass screw!

In the aircraft business where I was an apprentice AME for a bit (hated the job, but still like aircraft and flying.) there is a saying that everything is a compromise in aviation.
I always thought that that was the dumbest saying and attitude.

If there IS a way, let's find it! ( Me..., the Einstein who's going to change the world lol.) :hDe:

Just saying!

Beers...., er...., Cheers, J.

 

[Brian Rupnow]

For what it's worth--after spending some time adjusting the carburetor, I ended up with the following results. The top engine rpm with no load on it is 1900 rpm. When the slack belt is in place, it puts enough frictional load on the engine that the rpm drops to 1780 rpm. When the belt is fully tightened and the generator is lighting the light very brightly (2.9 Volt bulb), the rpm drops off to 1467 rpm. The finished diameter of the driving and driven pulleys is 2.0" and 0.845", giving a ratio of 2.367:1----So, the dynamo is turning at 3472 rpm. That is without factoring in any belt slippage. If we allow 5% for belt slippage then the dynamo is turning at 3300 rpm, and that gets pretty darn close to the "best guess" calculation I had made originally, that based on a 28" diameter bicycle tire, with the "rub contact" diameter at 26" , the dynamo with a 1" friction wheel on it would be turning 3000 rpm. when the bicycle was going 10 miles per hour.

 

[Brian Rupnow]

JJ Smith---Back when I was a kid, a neighbor had a "wind charger" mounted on his garage. As I remember, it had 4 or 6 "blades" made out of old car license plates, and was about 30" overall diameter. The "blades" were attached to a center hub that was mounted on a car generator, and he must have had a voltage regulator wired into it somewhere. He used it to keep a spare battery charged up. That would have been in the 1950's. Then in the 1960's when they ran the hydro line into Kaminiskeg Lake near Barrys Bay I was in high school in Bancroft. I got a part time job with Ernie Byers, a local electrician, wiring and doing some plumbing in cottages in on the Lake. One place sticks in my mind, because it had a fast flowing stream coming down the hill from the northwest side, right beside his cottage. He must have been a pretty resourceful guy, because he had a Pelton wheel in the stream, hooked up to a car alternator and had the whole cottage wired for 12 volt electric lights. One of the funny/crazy memories I have from that time---Ernie had a little wee car, I think it was a Mini Cooper or an Austin Mini. We went to the hardware store in Bancroft and picked up six 10 foot lengths of 1/2" copper pipe to take up to Kaminiskeg. He didn't have any roof racks, so he had me roll down the passenger window and stick my arm out the window and hang onto the pipes. They didn't weigh very much, and he taped the ends together so they wouldn't all come apart while we were driving. About half way up to the lake, we ran into an absolutely ferocious thunder and lightning storm. i was scared right to death that I was going to become a human lightning rod, hanging onto all that copper pipe, but Ernie said "Don't worry Brian, we are up on 4 rubber tires, the lightning won't bother us!!!" I don't know if he was right or not, but I didn't get struck by lightning. I was awful damn glad to get to the end of that trip, anyways.

 

[Cogsy]

but Ernie said "Don't worry Brian, we are up on 4 rubber tires, the lightning won't bother us!!!"

So his theory was - even though the lightning jumps a spark through several miles of air, it wouldn't go through the metal car then jump a foot or so to the ground .

I'm glad you got lucky that day Brian.

 

[Brian Rupnow]

Cogsy---I don't think I have ever heard of a car being struck by lightning---Have you? Airplanes, yes, boats, definitely yes, but not cars that I know of.

 

[Toolguy]

They have videos on YouTube of cars being hit or have been hit by lightning. Lots of damage.

 

[Brian Rupnow]

They have videos on YouTube of cars being hit or have been hit by lightning. Lots of damage.

Do you have a link?

 

[Cogsy]

I have certainly heard of it, it generally makes the local news when it happens here. Usually though, the occupants are safe as the charge runs through the metal of the car then to ground and they are untouched inside - kind of like a faraday cage. In your case, holding on to the copper pipe (which is likely what the lightning would have hit) I think you would have had some nasty burns at the very least.

 

[Cogsy]

Here's a video I just found of it happening (in Canada too).

[ame]https://www.youtube.com/watch?v=k4WL0s09Z9c[/ame]

 

[Cogsy]

Sorry to triple post but here's a link to an interesting story as well.

 

[///]

A car was struck by lightning in New South Wales late last year, just one of the many news articles with video and story at the following link:
http://www.smh.com.au/environment/w...htning-in-newcastle-video-20131123-2y29y.html

An excerpt:

''I was filming for like 30 seconds and then BANG!'' he said.

''It hit the aerial of a car about 30 or 40 metres in front of me and just kind of exploded and orange sparks shot out everywhere.

''I was just in shock and ducked down in the car because it was just so loud.

''The guy got out of his car and checked his aerial, he looked a bit rattled but otherwise he was OK.

''Luckily an ambulance was driving past and it just ducked straight to him, it pulled up next to him and the officers spoke to him and he didn't appear hurt or anything.

''It was pretty miraculous to have that happen and walk away.''

Storm-chasing is one of my pastimes (lightning photography). I've had some pretty close calls over the years tho never had a direct hit! Phew!
One of my images (much reduced) attached, full size view here: http://www.pbase.com/mrb/image/144604924

 

[Brian Rupnow]

Well!!--I'm luckier than I thought!!!

 

[Herbiev]

You could build a Van de graaff generator powered by that engine and make your own lightening :hDe:

 

[gus]

Playing golf can be very hazardous in Singapore. Colleague was struck and saved due to persistent efforts of my junior to revive him. Ambulance came but gave warning he may not survive but they will continue life saving efforts all the way to A&E. They were about to give up but he did revive in due time. Took three years to recover.

When lightning strikes about 500 meters away from my boat,I do get very weak shocks on the helm. When lightning hazard is bad,all carbon fibre fishing rods are removed from rod holders. There are warning labels on the rods.

Take Care.

 

[Swifty]

Hi Gus, also no flyfishing with graphite rods when there is lightening about. It's like waving a lightening conductor around.

Paul.

 

[tornitore45]

He didn't have any roof racks, so he had me roll down the passenger window and stick my arm out the window and hang onto the pipes.

Which remind me... when I was 15 or so I flew U control aerobatic planes.
Friends ad I used to go competition in a 50 miles radius, I had no vehicle but an older friend had a scooter so I sat in the back holding my plane and his plane along the sides with the wings vertical. The models had a wingspan of 5 feet and it was mandatory to keep the wings "toed in" otherwise the lift would have been very difficult to control motoring around 50 mph.

The crazy things you do when young.