Muller Dynamo

[nul-points]

[...]
Thanks nul-points... so many of us missed that.

Ron

i don't think people missed it

when i said "not much was made of it" it was because we then saw Romero's video of the self-run and all other evidence at that time was subsiduary

however, we've since been subjected to a succession of people insisting that there were batteries hidden in Romero's underpants

hence my re-iteration of something else Romero reported early on which supports the view that this wasn't a fake - and which hasn't been pointed out (AFAIK) to all the kind souls who came to cheer at Romero's departure

[neptune]

At some stage during initial testing you will need to drive this with an external motor . It is also quite possible that if you can find an efficient enough drive motor , Looping will be possible . If it is just for testing , transmission losses are not important and a belt drive may suffice .This has the advantage of allowing different speed ratios . Small DC motors can be efficient , but in some applications efficiency has been sacrificed to reduce initial costs . Brushed DC permanent magnet motors are capable of efficiencies between75 and 80% . Brushless DC motors can Be 80 to90% efficient and above , but at the cost of added complexity and expense .They are effectively a 3 phase motor , and have to include a module to covert DC to 3 phase AC .Apparently they can be found inCD and CD Rom drives , some office fans ,laser printers and photo copiers . If you try to obtain them from scrap be sure to get the module as well . Main source -The WIKIpedia article entitled Electric Motor .
@I-ron . Caution . Smoking can seriously damage your drive coils !

[starcruiser]

I play with model aircraft and use similar motors to the Turnigy series. the ESC or Electronic Speed Controller, can be found for less than $50 usd. cost is dependent on the current rating of the ESC. I can locate some at hobbyking.com for like $30, look there for some drives and motors (brushed and brushless) if you are interested.

Most of these brushless motors are really efficient 80+ % and can be run on battery voltages of <4v to over 50v. they usually link them to lithium polymer (LIPO) batteries due to their small footprint and high current sourcing abilities.

[DadHav]

Guys. I can be some help here. It is easy and less expensive than you think to drive an R/C airplane motor or any other three phase motor of that type. You may have to deal with China if you want the best prices. If you check a site like HobbyCity you can find hudreds of motors, and speed controls. Yes, they are three phase and require the speed control. Normally the speed control needs to plug into a receiver for drive control, but you can buy what is called a servo tester for less than $10 and drive the speed control right from that. I have an 80 amp speed control that I only paid $17 for but you can buy something like 20 amp controls for again $10. I'd be surprised if you if you couldnt find a complete setupf for $40-50. Wait. maybe that's to expensive. If you want to see how the setup works without being in an airlplane you can see it on this video. http://www.youtube.com/user/DadHav#p/u/1/e0q8DDtjvMY
Hope this might help
John H (DadHav)

[DadHav]

I play with model aircraft and use similar motors to the Turnigy series. the ESC or Electronic Speed Controller, can be found for less than $50 usd. cost is dependent on the current rating of the ESC. I can locate some at hobbyking.com for like $30, look there for some drives and motors (brushed and brushless) if you are interested.

Most of these brushless motors are really efficient 80+ % and can be run on battery voltages of <4v to over 50v. they usually link them to lithium polymer (LIPO) batteries due to their small footprint and high current sourcing abilities.

Sorry Star. Your post must have went up while I was writing mine. I wouldn't have barged in if I saw yours first. Nice of you to help out if people are interested. You might have to take a close look at the KV rating of the motor right? It looked like Rom's motor wasn't running real high RPM's. Does anyone know about what range the target would be?
John