RunRyder RC
 3  Topic Subscribe
WATCH
 1 page 560 views
Scorpion Power Scorpion Power
HelicopterAerial Photography and Video › Calculating gear ratio - Futura
08-10-2007 02:10 AM  10 years agoPost 1
ben1101

rrApprentice

Australia

My Posts: All  Forum  Topic

Hi,

Im setting up a futura SE for AP and dont know how to calculate the gear ratio for the 4 gears, could someone help me out?

Thanks!

ben

PM  EMAIL  GALLERY  Attn:RR  Quote
08-10-2007 02:28 AM  10 years agoPost 2
kima

rrApprentice

Wellington, New​Zealand

My Posts: All  Forum  Topic

Hi Ben,

Here are all the gear ratios already worked out with the different options available for the Robbe Cuatro, Nova and SE.

http://robbeusa.com/Belt.drive.worksheet.htm

Did you get my last e-mail?

K R Attwell
www.PhotoHigher.co.nz

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
08-10-2007 02:38 AM  10 years agoPost 3
bell-230

rrKey Veteran

sonoma, ca​(currently milano​italy)

My Posts: All  Forum  Topic

find the ratio between each set of gears and then times the ratios by each other.

so lets say you have a 60 tooth, 45 tooth, 30 tooth, and 15 tooth gear system.

60/45= 1.33
45/30=1.5
30/15=2

total = 3.99

to confirm that you can also just figure out what the rpm will be at each gear by doing one ratio at a time, this helps to confirm that simply multiplying the ratios will also work.

so with an rpm of 25,000 we can figure;
1.33= 18754rpm
1.5 = 12503rpm
2 = 6251rpm

and if we just do 25,000/3.99 we get 6265rpm(the numbers are different due to rounding errors)

so it seems to make sense! i just came up with this off the top of my head, so hopefully it actually works.(i did fail algebra freshmen year though so keep your doubts)

edit* or what Kimberley linked you works too(just goes to show how long it took me to figure it out)

ian brooke
k2shots.com

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
08-10-2007 03:26 AM  10 years agoPost 4
z11355

rrMaster

New England

My Posts: All  Forum  Topic

take the # of teeth on the clutch bell and divide 204.4 by that.

the 204.4 is the calculated ratio of the other 3 gears/pulley.

example: 204.4/25 = 8.18 ratio for the 25t clutch bell.

PM  EMAIL  GALLERY  Attn:RR  Quote
08-10-2007 03:48 AM  10 years agoPost 5
ben1101

rrApprentice

Australia

My Posts: All  Forum  Topic

Thanks Heaps guys, that makes life easy!

Hi Kima,

I just sent you a reply, will email later today hopefully everything is AOK!

Ben

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 560 views
Scorpion Power Scorpion Power
HelicopterAerial Photography and Video › Calculating gear ratio - Futura
 Print TOPIC  Make Suggestion 

 3  Topic Subscribe

Sunday, November 19 - 12:38 pm - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online