Hitec HS-55 Servos in an LMH Corona? - RC Groups
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Nov 13, 2001, 09:15 PM
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Hitec HS-55 Servos in an LMH Corona?

I'm starting the assembly on my Corona. The radio I was going to use has HS 55 Servos. They're plenty small, but it occured to me that they have a lot less torque (13 oz/in) than the HS 81s (32 oz/in) that the manual shows in its "typical installation".

Any opinions on whether or not the HS 55s will be up to the task? Thanks!

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Nov 13, 2001, 10:00 PM
Our Daddy and Heli Junkie
Fred Bronk's Avatar
They may have enough torque, but the gear train is not up to any rough stuff.

Go with the 81's, they work in the LMH fine and the bigger Corona will load them alittle more.
Nov 14, 2001, 12:06 AM
Registered User
I totally agree with Fred... HS-55's are too small for your LMH. I started with HS-80's in mine and later went to JR 241s. The 241s are about the smallest and lightest servo that I'd put in the LMH... while they are rated about the same as the HS-55, but have a sturdier gear train. That's the limitation of these servos... the HS-55's will probably move the cyclic 95% of the time, but a hard landing or minor blade strike or even a hard pullup can strip the gears... a bad thing to have happen, a really bad thing to have happen in the air.

The HS-81s are VERY good servos here!

Greg Stewart (Minneapolis, MN, USA)
Nov 14, 2001, 01:30 AM
-Flight enthusiast_
gpeden's Avatar
I used JR241s in mine and they stood up to hard fast flying including loops. In the few crashes they endured I had to replace a couple of gear sets, no worse than the stock HS-80 servos originally used. I would not have used HS-55s though. If you are a beginner and might be crashing more than the odd time, then the HS-81s are probably a good idea


Nov 14, 2001, 10:25 AM
Registered User

Just a thought

The MX-50HP servos' have a weight of 9grams and 23in/oz torque, speed 0.078sec/60, and ball bearing on top. Not the same as HS-81 but not bad for a micro and weight. Would these be okay for the Corona.I have used them in electric planes and so far been really good. Is it true every gram you save is 1 more sec of flight time!

The JR241 have 17oz torque and .23sec/60, 9 grams

Nov 14, 2001, 12:37 PM
Registered User
Dave sell the HES servos at really good price. I would go with either HES-588P or HES-688P upgraded to metal gear. I never had a stripped gear ever.

Nov 14, 2001, 09:00 PM
Our Daddy and Heli Junkie
Fred Bronk's Avatar
Tony, those are the same wieght as the HS-81 with the same power, but MUCH slower.

I would still go for the 81's, or 81 MG. They are strong and go for well under $20 almost everywhere.

I on the other hand am setting up a light LMH and got some CS 21's for it. A little less power than the 81's, but 1/2 the wieght.
Nov 15, 2001, 03:15 AM
Registered User
You are right on BOTH count.
Last edited by rcdude; Nov 15, 2001 at 03:41 AM.
Nov 15, 2001, 02:50 PM
Registered User
I've been using HS55's on my eLMH all along and have had to replace 4 gearsets - thats a lot of flying. After I made it an ultralight I've had no more gear problems. The 55's are fragile though but the torque is fine for the eLMH.
Nov 19, 2001, 08:12 PM
Registered User
Thanks to everyone for the advice. New HS-81s are on the way!