BMS-385DMAX Digital Servo (Metal Gear) 4.2kg / .15sec / 16.5g

• Overall
• Quality
• Value

Weak Plastic Case

Apr 05, 2018

I have used more than seven of these servos in my experience they are quite strong for the size and make a good replacement for the HC-5085. They have been more consistent than the TGY-210DH or the BMS-390DMH. But I gave up on the 385-Dmax finally because of the weak top case. The case cannot hold the bearing in place to prevent output wheel side to side rocking motion that comes from normal servo operation. After about an hour of operation the servo loses the ability to center accurately. I tried tightening the case screws but no good. The feedback pot must be worn out due to the shaft rocking. Too bad for the poor case design because otherwise it was a good servo.

• Overall
• Quality
• Value

good

Nov 25, 2017

I am using it on my David Windestal style tricopter and it does the job perfectly.

• Overall
• Quality
• Value

Certified Buyer Rated

Apr 11, 2015

Used this for my tricopter since its a fairly strong servo with replacement gears available. Its held up well in a few crashes, haven't needed to replace any gears yet.

• Overall
• Quality
• Value

Customer Rated

Mar 26, 2015

My first negative review. Brought a while back for a tricopter. Had a few minor spill, nothing major. Went to fly it yesterday now that it is warm and the gears must be stripped. Not replacing it with one of these.

• Overall
• Quality
• Value

Certified Buyer Rated

Mar 23, 2015

Came well packed and worked out of the box! Little noisy but pretty precise. Using it on a DIY RCExplorer TriCopter and works flawlessly. Doesn't heat up or lose it's sync! Feels very robust too. Recommended.

• Overall
• Quality
• Value

Customer Rated

Dec 21, 2014

I just posted a review where I state that the top gear on this servo is silver-colored plastic. I was wrong, it is made of aluminum (which is pliable and therefore, when I tore it apart, initially looked like it was plastic). Mea culpa.

• Overall
• Quality
• Value

Customer Rated

Dec 21, 2014

I am using this servo in my Talon Tricopter. It worked perfectly until I had a bad crash and stripped some gears. Not the servo's fault. However, when I bought the replacement gear set, I discovered that a replacement ball bearing set is not included in the bag. If you happen to damage the top gear, where the ball bearing set seats, you will find it is almost impossible to remove the ball bearing set without destroying it. Therefore, if you damage the top gear (which is silver and looks metal but is in reality silver-colored plastic), you cannot replace it because you can't remove the ball bearing set to install it on the replacement gear. The gears that get stressed lots are metal; two other gears are plastic (one black plastic and one silver-colored plastic). I liked this servo a lot, but would love it if HK would include a replacement ball bearing set with the replacement gear set. As I understand it, usually people only strip that one black plastic gear, which is very easy to replace. I ended up buying an identical servo to replace the old one, simply for the lack of a replacement ball bearing set.

• Overall
• Quality
• Value

Certified Buyer Rated

Jul 10, 2013

Good servo, although thought it might be a bit slow.

• Overall
• Quality
• Value

Certified Buyer Rated

Jun 09, 2013

Worked well with my 2nd rcexplorer.se tricopter build...had some problems with other servo before (from another online seller), but this one has been working well for a while now!!! bought some more for spares, and i think they will be in the shelve for a while until the next build...

• Overall
• Quality
• Value

Customer Rated

May 11, 2013

I am really impressed with these BMS 385D-Max servos. They are my default option for flaps on my homebuilt "Scratcho" moulded 64" gliders used for slope soaring and dynamic soaring. I've used more than 14 of them and had great success. I don't think I've ever had one fail, except after a huge crash and many of them have survived enormous crashes and are still being re-used. I put a lot of hours into flying these planes and fly them hard so it's a pretty good test. I actually can't believe how solid and strong they are for the price. I've even fitted them into a 3.3m heavy slope glider with huge flaps, DSed it and they were perfect. I try to convince other guys to give them a try but I think they're a bit suspicious that they must be crap for such a good price, but they're not - they're tough, long lasting, reliable, perfect centring, fast enough and have plenty of grunt. Excellent. My standard setup for every Scratcho except the very lightest and the very heaviest ones is BMS385's on flaps and Bluebird 555's on ailerons. The 385's are good for rudder/ elevator on big mouldies too.