View Full Version : Gear ratio problems.....any suggestion?
oysifly
11-28-2007, 10:37 PM
I need a 93 tooth main gear and a 11 tooth pinion. This is for a 46 graphite with a Hyper 50.
DavidH
11-29-2007, 10:19 AM
The 11 tooth pinions screw into the clutch bell.
Does your clutch bell have threads in it, or is the pinion in it now pressed and held by two set screws?
David
oysifly
11-29-2007, 03:09 PM
I see 2 set screws on it. How can I get to a 8.5:1 ratio? I'm not sure what my options are with this setup. 46 graphite with a 60 head,extended tail boom and a Hyper 50 running 600's
DavidH
11-29-2007, 07:22 PM
You will need to use the 60 size clutch bell and clutch. You will have to use the fan hub for the 60 also. Then you can screw a 11 tooth pinion into the clutch bell and use a 93 tooth main gear and have 8.45 to 1
http://www.miniatureaircraftusa.com/Store/proddetail.asp?prod=0864%2D10
http://www.miniatureaircraftusa.com/Store/proddetail.asp?prod=0546
I am guess that these collets might work on the OS 50. You would have to measure the diameter of the crankshaft.
http://www.miniatureaircraftusa.com/Store/proddetail.asp?prod=0546%2D7
David
oysifly
11-29-2007, 08:08 PM
Ouch, didn't think it would be that much to get this hyper 50 in this older bird. Maybe I should just go back to my OS 46 and just use it as a auto bird. Just painted the canopy on it and got excited about getting it back in the air. Thanks for the help.......
You can run a 90/10 for a 9.0 gear ratio and just use the throttle curve or a GV-1/revmax/etc. to limit head speed. We did it with an OS 50 and it worked pretty well as long as you didn't do extended vertical descents in idle up. If you have a new style auto hub, you can get an 87 tooth main gear and go as low as 8.7 but that's with the new style hub and the white gears.
Gordie