throttle and choke???
10-03-2005, 07:02 PM
#1
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throttle and choke???
for my carden 35% extra, i think i went overboard and used futaba 9405's for the throttle and choke servos. these servos have a speed of .11 sec and a torque of 100oz-in.
for my new plane i am think of using a futaba 9001 for throttle and i'm not sure what i can use for choke. the 9001 is also a coreless servo with a speed of .18 sec and a torque of 72oz-in.
i do undo the throttle spring to take away any additional torque from the throttle servo.
how much torque do you need for the choke servo??
does it need to be coreless too??
how fast does the throttle need to be???
the plane these are for is a 34% planes plus extra that will be used for 3D.
thanks guys,
tony
for my new plane i am think of using a futaba 9001 for throttle and i'm not sure what i can use for choke. the 9001 is also a coreless servo with a speed of .18 sec and a torque of 72oz-in.
i do undo the throttle spring to take away any additional torque from the throttle servo.
how much torque do you need for the choke servo??
does it need to be coreless too??
how fast does the throttle need to be???
the plane these are for is a 34% planes plus extra that will be used for 3D.
thanks guys,
tony
10-03-2005, 07:10 PM
#2
RE: throttle and choke???
My experience has been that a standard servo kinda struggles to work the choke. I usually go for an 80oz or better servo on the choke.
Having too fast of a servo on the throttle deosn't help much IMO. It will actually move the butterfly faster than the engine can keep up with.
I usually just use a servo with standard SPEED, but always at least a coreless motor for the precision. Sometimes--I'll use a digital servo on the throttle--if I have one extra lying around and I know it's in good shape.
Of course--this only applies to the big and expensive planes. On my little planes--any servo will do the job for throttle.
Having too fast of a servo on the throttle deosn't help much IMO. It will actually move the butterfly faster than the engine can keep up with.
I usually just use a servo with standard SPEED, but always at least a coreless motor for the precision. Sometimes--I'll use a digital servo on the throttle--if I have one extra lying around and I know it's in good shape.
Of course--this only applies to the big and expensive planes. On my little planes--any servo will do the job for throttle.
10-03-2005, 08:32 PM
#3
My Feedback: (31)
RE: throttle and choke???
I use standard servos on choke all the way to the big ones.
Throttle servos should be capable of precision and or repeatable results. Digital coreless servos are best IMO. Speed is not real important but generally a good precision servo is rated around 0.15sec. I like the nylon or Karbonite geared servos verses metal gears for long term precision without worry of gear-train wear.
I have several 40% models with Hitec's 5975 or 6965 on throttle; these are fast and accurate with the Karbonite gears.
A very important consideration is the linkage and or linkage ratio. Ideally you want to move the servo nearly 120* degrees and the throttle arm 80*. Anything less requires exponential and extensive use of throttle curves to obtain linear throttle response.
My experience suggests 3/4" servo arm together with a 1" carb arm works best.
Throttle servos should be capable of precision and or repeatable results. Digital coreless servos are best IMO. Speed is not real important but generally a good precision servo is rated around 0.15sec. I like the nylon or Karbonite geared servos verses metal gears for long term precision without worry of gear-train wear.
I have several 40% models with Hitec's 5975 or 6965 on throttle; these are fast and accurate with the Karbonite gears.
A very important consideration is the linkage and or linkage ratio. Ideally you want to move the servo nearly 120* degrees and the throttle arm 80*. Anything less requires exponential and extensive use of throttle curves to obtain linear throttle response.
My experience suggests 3/4" servo arm together with a 1" carb arm works best.
