Tail boom servo constant replacement issue

[Marty]

I have built David’s tricopter and have really enjoyed learning how to fly it. I would like to post an issue that I am having with the tail boom servo just to see if my experience is commonplace or not. I am using the DT750 750kv motors and the BMS-385DMAX digital metal gear servo.

My question is how often has everyone had to change out their servo due to stripping out the gears (I guess this is what has happened). In less that 3-4 months of occasional flying I have had to change out mine 3 times. It appears that with each less than totally gentle landing (and this could be as little as a 3-5 foot drop) something happens to the servo and then from that point forward the copter just wants to go around in circles. This is corrected by replacing the servo. Not a bad fix but at $20+ a pop it does get expensive.

Does this sound like a stripped servo gear? Is it due to the torque of that heavy motor setting up somewhat high on its perch when the bump happens? I am still relatively new to RC and have just had experience with the little cheap $4 HXT all plastic servos and assumed that when one pays 5X’s the amount for “metal” gears there would be better durability? Is there another servo out there among the millions that you all have had better experience with in this setting? I look forward to your experiences.

Granted,,,,,in time,,,,I will become a better flyer and bumpy landings will become fewer and fewer,,,,,but I would like to hear from you about the above. Thanks folks! ! !

[phlakvest]

Are you using the newer style tilt mechanism connected with small zip ties?

Any chance you can take one of the dead servos apart and see if the gears are stripped? According to the description it’s a hybrid of metal and nylon gears which may make for a weak point.

My BMS-210 has taken much more abuse than 5-6ft drops without damage. I did manage to kill one by crashing into a parked truck. It was enough force to break the rear boom. It still functions and none of the gears were stripped. It actually bent the servo shaft.

You may see if one of those fairs better than a 385.

[LeoTheHuman]

Well, I crashed my tricopter multiple times while occasionally flying for almost 6 months and I still have to break the servo I bought from David… I do have a few spares, though, as I expected it to break more frequently.

[biggestRCEfan]

Plenty of crashes on FT electrohub, RCE V3 and RCE Mini. Those fitted with the servo from RCE held up well (I only damaged one after many hours of flying). On the other hand, the expensive servos bought from HK (not the equivalent of the one in RCE store) kept breaking as you mentioned. I’m very happy with the robustness of the RCE-offered servo! True, as we get better at flying we break less and less things. So much fun, this hobby!!

[rue]

Not so happy with the BMS-390s (due to local availability, David did not offer the 210s back then) – even though they have an all metal gear they became sloppy soon so I ran through 3 of them rather quickly. As I have this strange habbit of trying out things and crashing the poor V3 I might have given them just too much abuse.

Using Davids 210 now on the Mini and hope it turns out to be more resilient.

[Marty]

Thanks so much to all of your responses. I guess I did not get the memo when David switched servos. ha ha I followed the original V2.5 design. I guess it would have paid to keep up with the Tricopter forums. Anywho,,,,,thanks again. I look forward to upgrading to the BMS-210. Learning is a process,,,,,but I love it.

With my question answered I come up with another. On looking into the 210 I see that Hobby King has their own Turnigy knockoff (TGY-210MH). Has anyone used this one and if so what has been your experience? I do have a HK order about ready to make and could add it. And while I am at it,,,,,being a bit of a newbee,,,,I would be interested to hear your impression(s) about HK generics. I am not trying to open a can of worms but am still learning. After three years in the hobby I have gotten 90+% of my goods from HK learning the ins and outs of their grueling website, etc. I am open to any directions you would like to pass on to me for my growing RC interests.

Thanks again all,,,,,I appreciate your comments and help!

[Author]

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