Latest Experiments

Dynohub neodymium conversion

 

I wanted to increase the output of my Dynohub, I decided to purchase 13 Neodymium super strong rare earth magnets
and replace the old ring magnet with them. This would give me a super high flux 13 pole alternator.
I decided to ask an expert for his opinion before commencing, so I emailed Hugh Piggott, who kindly replied :
"I doubt if that would work. The number and spacing of poles needs to be suitable for the stator. 
 Also it might become very difficult to start with such high flux."
As Hugh Piggott advised, the Neodymium conversion did not work, I lined the inner hub with 13 magnets
and to my surprise I barely got any output!


 


The Monoblade experiment

monoblade

The Monoblade was a bit of fun, that surprised me at how well it worked, once I had accurately balanced the

rotor, the use of a length of 6mm studding connecting a 3/4" socket was ideal for fine tuning.

      

See the Video of my monoblade design (767 kb) .wmv format


 LTD Stirling engine

stirling_engine

This is a bit of a diversion but worthy of the site, The LTD (Low Temperature Differential) Stirling Engine is an excellent demonstration of a heat engine, showing with one spin of the flywheel a clean and simple way of converting thermal energy into motion .The KS90 model was purchased from www.stirlingengine.co.uk

I was very impressed at how lower temperature the engine runs, I leave mine on top of my stereo

and it runs at approximately 200rpm - continuously. A superb piece of quality engineering.

See the Video of my Stirling Engine (462Kb) .wmv format


Rotary sign

This was an idea to maximise the visibility of outdoor signs - according to statistics a moving sign has 60% more impact

over a stationary one - 'For sale' signs seemed like the most appropriate use - in the right location of course.

Made of Corex (fluted polypropolene) and mounted on a bicycle wheel hub inserted into an aluminium tube.

See the Video of my Rotary Sign (1.6Mb) .wmv format


The DIY Slip ring design

Rather than purchasing expensive slip rings to transfer electrical power from the wind generator down to the tower base

I used a standard 1/4" mono jack plug and socket. The hub spindle was drilled through to allow the cable to be inserted.

The jack socket was then retained inside the mounting tube by means of a spring clip. A piece of rubber tube could

be used to connect the jack plug to the threaded spindle. this allows for any misalignment.


The 3 Speed Dynohub Design

   

This 3 speed dynohub utilises the gearbox's epicyclic principle, and a 1.33:1 increase in speed is achieved

i.e. one revolution of the sprocket, rotates the hub 1.33 revolutions. an increase of 33.3%

An aluminium mounting plate was fabricated, using the existing sprocket as a template.

There is some additional drag using this hub, but not excessive. The only downside is the annoying clicking that is produced

with this type of hub - fine if generator is well out of earshot.


 

The rewired hand cranked generator

 

 

 

This was a small 60v hand cranking AC generator for use with old telephones, I believe.

The 60v AC would give you shock, and was not of much use to me so I rewired the armature with thicker 22 swg wire.

This gave me a resistance of  6 ohms and 12 volts - about 4.5 watts of power.

The unit incorporates a 5:1 gear, a large low speed propeller could be attached for wind generating purposes.

 


 

The Soil Pipe with Dynohub

 

 

I decided to try the soil pipe propeller coupled to the dynohub generator.

The generator would spin, but only in a real gale, there was too much resistance from the generator

even with no load attached. the six blade propeller is the best option.


 

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