F-4

The HS-635HB servo is listed as "discontinued" on the Hitec web page. However, they are still obtainable from various suppliers. They look like a good servo for the price. Is there a problem resulting in them being discontinued?

John

Ed

They have been breaking teeth on their Karbonite gears. Karbonite looked like a good idea in the beginning, but they have been disappointing.

pilotpete2

John,
Are you sure that you saw that model as discontinued? I just checked, and they are listed as "new" not discontinued.
The Karbonite gears seem only to have been a problem in cases where some have used them in applications where they were not suited, as in situations where a MG servo would be appropriate, such as in large gassers.
Pete

F-4

Pete,

You are correct. The 635 is new. Don't know what I was looking at as can not locate now. However, in reading the numerous comments on Hitec servos, there seems to be an occasional problem concerning compatibility between Futaba receivers and Hitec servos. Any comment? Thanks.

John

pilotpete2

Hi John,
I'm not aware of any compatibility issue with Futaba receivers, I will be able to comment in about a month when I get my Futaba 9C with the 8 ch PPM receiver[8D]
Pete

bcchi

I have 15 airplanes all using hitek servoes and Futaba 9C pcm receivers . All of these airplanes are gas up to Zenoah GT 80 . I have had no problems with this combo. Most of the servoes are 635 with Karbonite gears. I have had no problem with the gears except in a mid air I lost some gears. After reading all of the reports about how bad the 635 servos were I was a little concerned. I tried to strip one of the servos and could not. I really gave it the tough test. I took the output gear from the crash and clamped in a vice,I tried to break a tooth off with a large screwdriver and hitting with my hand could not break a tooth off. I used a hammer and the tooth bent over. I also tried to break the splinde shaft off as this has been reported. I finally twisted it off with pliers after several bends back and forth. These Karbonte gears are not brittle.I do use some of the 645 metal gears and they are fine. I did have a 635 quit on the ground (lucky). But this can happen to any servo.


bcchi

MikeMayberry

My Feedback: (1)

Karbonite servos are fine in applications where you are using one servo per control surface in a model of less than 12lbs. Larger models should use metal gears.

Mike.

F-4

Thanks to all for the input. I will try the 635's.

John