1st time head speed setting

[Shaprap]

I'm still building the Hurri, and I noticed the Flying Hobby kit came without a Pinion.
Maybe that's a good thing - I used the Head Speed Calc (http://www.helifreak.com/showthread.php?t=71718&highlight=hobbyworld). and found that by running all my components I'll get no less than 2350 RPM on 95% efficiency (w/ 13T pinion).

I want to make it around 1900.

My pile of plastics includes: 61T rear gear, 42T front gear, 20T one-way gear, No Pinion, Z30 1100kv, and 22.2V on two Lipos.

I found that if I get a 60T rear gear, and a 15T pinion - I'll get 1902 RPM on 95% or 2002 RPM on 100%.

Am I correct, or am I missing something?

p.s - what does the "Efficiency" percentage mean?

[Mikej]

I'm still building the Hurri, and I noticed the Flying Hobby kit came without a Pinion.
Maybe that's a good thing - I used the Head Speed Calc (http://www.helifreak.com/showthread.php?t=71718&highlight=hobbyworld). and found that by running all my components I'll get no less than 2350 RPM on 95% efficiency (w/ 13T pinion).

I want to make it around 1900.

My pile of plastics includes: 61T rear gear, 42T front gear, 20T one-way gear, No Pinion, Z30 1100kv, and 22.2V on two Lipos.

I found that if I get a 60T rear gear, and a 15T pinion - I'll get 1902 RPM on 95% or 2002 RPM on 100%.

Am I correct, or am I missing something?



p.s - what does the "Efficiency" percentage mean?


You mean 60T front gear not rear gear don't you ??? - if you go 15 / 60 / 20 / 61 then you should get the figures that you mention

Mike.

[mysticmead]

the efficiency % is how close to the true RPM/V you really get. no electric motor gives you 100% since there is friction involved. a good point to look at is the 90-95% range..the motors won't really give you that much efficiency but the RPM numbers in the calc are based off of 22.2v... a fully charged 6s LiPo is closer to 25v so increasing the % to 90-95% gives a closer estimate..

[Shaprap]

60T front of course,

1. Is the whole gear-wheel-thing universaly structured, or do I need a specific Hurrican 550 60T wheels?
2. What about the Pinion - can I just stick any 15T on it?
3. Any reccommeded materials, or brands?

Thnx

[Mikej]

60T front of course,

1. Is the whole gear-wheel-thing universaly structured, or do I need a specific Hurrican 550 60T wheels?
2. What about the Pinion - can I just stick any 15T on it?
3. Any reccommeded materials, or brands?

Thnx

No, you MUST buy the Gaui 60T and pinion ...

http://www.readyheli.com/204622_Front_Main_Gear_60T_Gaui_Hurricane_550_p/204622.htm

http://www.readyheli.com/901501_Pinion_Gear_Pack_15T_Gaui_Hurricane_550_p/901501.htm

[bobbybe]

also, you can use different motor pinions but they must be a mod 6 i think... i used a 17t pinion for a while that i got from a rc car website

[wis1]

The Gaui gears are mod 8. Tower has 12 thru 25 mod 8 pinions.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXVCX0&P=M

wis1

[Shaprap]

Only Hurricane gears... Well that's another two weeks of waiting.
I'll order it from Flying-Hobby, cuz that's where I got the kit from, and maybe they'll send me the missing pinion for free...
I also found one L45 and one L35 links with a cracked ring. I know I didn't crack it because it popped off before I even got to assembly the head.


One big question though - I feel like the rotor spins less freely when I tighten the body bolts. Is that normal? I don't want to leave the bolts half open just to get a free rotation, but on the other hand I don't want the motor to work harder for no reason.

[MartinS819]

Yeah I found that too. Have you watched the Finless vids? Just work your way from the inside of the frame towards the outside. You can slide in the main shaft and check to see if it moves freely while you're tightening the screws. I found that I had to really control how tight/loose I turned the screws since the plastic tends to warp and the bearings come out of alignment. Don't forget to use threadlock!

Good luck with the build!
~Marty