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1967250s
Apr 11, 2009, 02:48 PM
Has anyone any experience with this servo?
http://www.chiefaircraft.com/rcmsec/Models/RadioControl/JR/JRPS8711HV.html
It looks like a lot of torque-480 in.lbs. but it is 180 bucks! And what does 2S lipo translate to in volts/amps? Can it be used for sailing?
martin richards
Apr 11, 2009, 03:05 PM
A 2S lipo is nominally 7.2 V, freshly charged a bit more. Based on that, at 6 V it should give about 400 oz/inch.
JayDee1
Apr 11, 2009, 03:59 PM
Hello
tigerbay
Apr 12, 2009, 12:59 AM
Hello,

I hope the stated time for it to travel 60 degrees is wrong!!.
Because 60degrees in 12 seconds is really slow.
Maybe the time should read "1.2 secs/60 degrees".

John.

Edit** the time should be "0.12 secs".

That is very fast for a big servo.
Hence the price.

Anybody and idea what the Metric conversion of 480 inch lbs torque is in Kg/cm?
nick_75au
Apr 12, 2009, 02:52 AM
34.6Kg/cm
Ive got a little free program called Convert
http://www.joshmadison.com/software
Nick
hew565
Apr 12, 2009, 10:48 AM
HiTech's HS-7950TG is due out anytime, and $$ cheaper too.
1967250s
Apr 12, 2009, 01:02 PM
Great info, guys, thanks!
JayDee1
Apr 12, 2009, 02:00 PM
Hello,
1967250s
Apr 12, 2009, 02:18 PM
Drums certainly have their place but some of us prefer a simpler system with out double pulleys and a closed loop system. Simple works and is less likely to screw up. Also at the ends of the arms arc you are getting more torque as you are at a reduced angle of pull, correct? Not knocking the drums with their better resolution for racing, this was just a question of who knows what about this servo that is available and someone, like me, who may be interested in it has not heard about it.
JayDee1
Apr 12, 2009, 02:37 PM
Hello
VO70
Apr 12, 2009, 02:44 PM
Just a quick point, the torque of a servo remains constant, it is the force that changes with the length of the arm.

Richard
1967250s
Apr 13, 2009, 12:29 PM
Jaydee1, Sorry to upset anyone, I was just curious about a servo. Mea Culpa
Richard, good point, do you have a formula for that? I'd be curious about one for an arc, like an arm winch vs a drum.....
VO70
Apr 13, 2009, 01:51 PM
Some excellent info on the OneMetre.net site.

Arm winches here (http://www.onemetre.net/Build/Armwinch/armwinch.htm)

Winch torque/speed here (http://www.onemetre.net/Build/Servo/Servo.htm) I found this info really helpful.

Richard
1967250s
Apr 14, 2009, 10:22 AM
Doh! I knew that, just too lazy to look, Thanks