Alternatives for Speed 280 / G-295

[dschim]

Does anybody knows any alternative engines
with a better eta for the Piccolo?
According to Graupner's catalogue efficiency of Speed 280 is only at about 54%, so the rest of the power is converted into heat :-(((.

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Dschim

[pgoelz]

Look back through the postings here. There has been some traffic about the Astro brushless 010, and apparantly the new "310 tuning motor" is pretty good. I have one on the way (hi Bernie!) and I'll let you know how it goes.

The other possibility is the ball bearing version of the S280, but it is a MUCH hotter wind and you need a much higher gear ratio to get it into the speed range where it is efficient.



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Paul Goelz
pgoelz (at) eaglequest (dot) com
Piccolo web page: http://www.eaglequest.com/~pgoelz/piccolo1.html

[dschim]

does the 310 have a better eta or "only" more torque/power? i think if using nimh's it's better to decrease current.
Have you ever tested J's runing in treatment with a bath in WD40?

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Dschim


[This message has been edited by dschim (edited 01-31-2001).]

My Huey kit arrived yesterday but I didn't get a chance to open it yet. (thank Bernie!)

I guess I too will be playing with the 310 motor tonight

gnorbury

[pgoelz]

Sounds like the 310 is more efficient and runs cooler, but may have a different max efficiency RPM?

I have seen reports that it gives better power, better duration, lower duration but better power.... I'll have to see for myself when it arrives!



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Paul Goelz
pgoelz (at) eaglequest (dot) com
Piccolo web page: http://www.eaglequest.com/~pgoelz/piccolo1.html

So far I have tried my 310 in my Huey with the 10 tooth and 9 tooth pinions. 8 x Sanyo Twicell NMh packs. Only about a minute or so out of GE, and a hot motor. Standard blades fitted. With cut blades it wouldn't lift off, which is why I tried the 10 tooth for a higher head RPM. This may have been the wrong move, and this weekend I will be experimenting with some CF specials Robert has made for me and the eight tooth pinion. Robert and I will be reporting....
J and Koen have advised me I may be better with a higher motor RPM. I may also be cutting a cooling hole in the bottom of the fuselage.

I think the 310, is not a "better" motor but it is bigger. It uses more power and gives more power! And it is heavier. A 400 would give allot of power for maybe a minute. If you have it you should try it. But if you need a motor for a stock piccolo and do not need more power get a stock motor (295)

I have not tried with 7 teeth pinion yet so I could be wrong (or maybe you could fly with 6cells)

If someone tries this I would like to know how it works.

[Robin]

Hi J
getting confused again (me) whyif you reduce the teeth on the pinion do you get longer flights, (when your kit arrives im gonna do a refit all over inc the 8 tooth pinion as u advise....surely more teeth, less turns on the motor .....but high head speed is good???

why did i not learn at school...ps i just got a book "The principles of AC DC circuits" the opening chapter discusses atomic/molecular structure....I reckon to get 7.5 plus your piccolo is made of .....i havnt reaD THAT bit yet but its definatelt loosing electrons (apparently slower than the restof us) what i want to know is where else are they coming from....emmm have you got a bag of em in your pocket??? if so do you and willp get them from the same shop


regards robin

I hope the intended humour is understood)

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http://albums.photopoint.com/j/Album...529&a=11121098

hey i was thinking i have the huey fuselage and manytimes i have been reading that the engines gets hot . i was wondering if you could shape little winglets or something to turn the large main gear into a kinda fan to circulate the engines heat in the fuselage. i will try it but for me work and school have taken over for no wbut i wil try it a soon as i can. i am sorry graham that you havent had good flight with the new huey body . i have gooten mine but not yet assembled it . any pionters on lightening it up any ?
thanks
travis

As I understand it, the lower the gear the faster the motor has to turn to spin the rotors enough to fly. The rotor speed for flight will be the same no mater what gear you use, unless you change pitch, blades or weight. therefor the only thing that changes is motor speed. electric motors become more effecient as they spin faster, and produce less waste in the form of heat. that is up to a point. if you load a motor down so it cant spin, and apply power you get heat very fast. if you let it spin freely it runs fast and stays cool (and does no work). so you want to run a gear that gets the motor spinning fast enouigh to be efficient and slow enough to still have some power reserve. To slow and you won't have any power either, the motor will simply get to hot. correct me if i'm wrong but, I seem to remember optimum speed on brush type motors is usually 60-70% of their no load RPM.

so, if you are running at optimum and you change the rotor speed for some reason (more weight, cut blades etc.)you will probably need to change the gear to keep the motor at its optimum speed.

And reducing the gear from standard will make the motor more efficient,and thus give you longer flight times but may reduce your available power.