HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 22, 2013, 05:17 PM
as much as I can
beenflying's Avatar
NZ
Joined Jan 2010
4,912 Posts
Mini-Review
New Henge MD752 and HobbyKing HK-752MG Mini Cyclic Servo

The new Henge MD752 and HK-752MG mini cyclic servo:

http://www.hobbyking.com/hobbyking/s...3kg_0_11s.html



Quote:
Features:
Henge MD752 digital servos have following technique characteristics:
1. Use metal gears of high intensity and accuracy, and abrasion resistance to make sure the output deviation of servo veries small after long time running;
2. Use Japanese raw material to produce outer shell, which is more sturdy and durable and can beat 120℃temperature.
3. Use coreless motor of high quality to develop the efficiency and life of servo
4. Use potentiometers imported from Japan, which are of the same quality and type as Futaba servos, and the life can be 2,000,000 times.
5. MD752 applied to 450 and 500 helicopter swash plate

Specifications:
Operating voltage range(V) 4.5~6.0V
Operating temperature range(℃) -20~60
Operating speed 0.13 sec/60°(sec/60° 4.8V) 0.11 sec/60°(sec/60° 6.0V)
Torque 5.1 Kg·cm(Kg·cm 4.8V) 6.3 Kg·cm(Kg·cm 6.0V)
Dead band width(usec) ≤3usec
Midpoint pulse 1520us broadband
Maximum rotation angle ±65°
Motor Five-poles coreless cup
Potentiometer imported from Japan
Size(mm) : 35.0 x 15 x 29.2mm
Weight(g) 28g
Gear 6 Metal Gears
Connecting wire length(cm) 21cm
The Hobbyking version of this servo at USD$14.30 is great value when compared to the price of the Henge and Tarot version of this servo.

As there is very little information about this servo currently, I decided to pull one apart. I was very impressed with the electronics and how nicely the servo is put together. I did note that there was no glue on the servo lead wire where it meets the circuit board, but I'm not sure this is really required anyway, based on how short the distance is to the rubber entry grommet.







The gear set is not as nice as say a DS510M, which uses some titanium gears, but is still near slop free and very smooth. I would imagine the gears for this servo will be much cheaper than the DS510M gears (which costs more than this entire servo does). How they stand up to a crash will be interesting. Hopefully I don't get to find this out.







The gears look very similar to the gears in the DS510M, and as you can see the gears are well greased.

I have to say I really like these servos. They have excellent torque and seem to center well. I like that they have the metal lower case section, which tightly encases the coreless motor. They also have very little slop for a metal gear servo. At 5.5 volts I'm getting around 0.125s on the CX tester/programmer. All three have tested fine and passed a 30 minute continuous run test, at 30%, using the CX-3X1000 programmer/tester.

For the negatives, the servo arms are a little loose on the output gear, and for a 500 heli the servo lead could be a little longer. I'd like to see it 250mm, instead of the current 210mm.

The test flight of these servos in my 500EFL Pro went well. They feel very smooth and very responsive. I also upgraded the tail servo to a MKS DS8910A+, so hopefully no more servo failures for this heli.

P.S. Sorry I should have really put this in the Large Helicopter section, but I realized where I'd created it too late.
beenflying is offline Find More Posts by beenflying
Last edited by beenflying; Feb 24, 2013 at 08:40 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 23, 2013, 11:49 PM
Registered User
United States, NY, New York
Joined Nov 2010
2,347 Posts
Excellent review BF. Always good to have a few reasonably priced options for cyclics on the 500.
ridge_racer is online now Find More Posts by ridge_racer
Reply With Quote
Old Feb 24, 2013, 07:37 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,260 Posts
Quote:
Originally Posted by beenflying View Post
I did note that there was no glue on the servo lead wire where it meets the circuit board, but I'm not sure this is really required anyway, based on how short the distance is to the rubber entry grommet.
You could just put a blob of liquid electrical tape on it.
Atomic Skull is offline Find More Posts by Atomic Skull
Reply With Quote
Old Feb 24, 2013, 07:47 PM
as much as I can
beenflying's Avatar
NZ
Joined Jan 2010
4,912 Posts
Quote:
Originally Posted by ridge_racer View Post
Excellent review BF. Always good to have a few reasonably priced options for cyclics on the 500.
Thanks. Yes, I had a good run with the Henge 922's, so I'm hoping these will be the same.

Quote:
Originally Posted by Atomic Skull View Post
You could just put a blob of liquid electrical tape on it.
I must get some of that. Normally I use E6000, or Shoe goo, but I decided to leave them as is, in this case. I hope that wasn't a mistake. Time will tell...
beenflying is offline Find More Posts by beenflying
Reply With Quote
Old Feb 25, 2013, 01:38 AM
Registered User
Dr.M's Avatar
United States, WA, Issaquah
Joined May 2011
1,523 Posts
How are the plastic mounting tabs? When I was using the 922s I recall the plastic was very brittle.
Dr.M is offline Find More Posts by Dr.M
Reply With Quote
Old Feb 25, 2013, 02:27 AM
as much as I can
beenflying's Avatar
NZ
Joined Jan 2010
4,912 Posts
It's not brittle at all. It's actually quite flexible. According to their spiel, it's a new material that is more sturdy and durable.
beenflying is offline Find More Posts by beenflying
Reply With Quote
Old Feb 25, 2013, 12:33 PM
Team Mulikow 3D
Oxfordshire, UK
Joined Jan 2007
4,118 Posts
David,

I had finally managed to convince myself that I wouldn't bother even looking at cheap servos any more and then you come up with these I'm going to keep an eye on this thread ujst out of interest

Have you managed to find any decent standrad size low-cost servos ???.

Cheers,
Mike.
MikeHRC is online now Find More Posts by MikeHRC
Reply With Quote
Old Feb 25, 2013, 03:10 PM
Looptastic!
sp00fman's Avatar
Enschede, Netherlands
Joined Nov 2009
2,292 Posts
They look might nice for a hurricane 425....
sp00fman is offline Find More Posts by sp00fman
Reply With Quote
Old Feb 25, 2013, 06:42 PM
as much as I can
beenflying's Avatar
NZ
Joined Jan 2010
4,912 Posts
Quote:
Originally Posted by MikeHRC View Post
David,

I had finally managed to convince myself that I wouldn't bother even looking at cheap servos any more and then you come up with these I'm going to keep an eye on this thread ujst out of interest

Have you managed to find any decent standrad size low-cost servos ???.

Cheers,
Mike.
Hehe! Yeah, I have to say I've been feeling the same way myself. I do think Henge have tried to make a good product, so finger crossed with these ones.

I haven't really had to look for a standard servo, as my bigger helis came with them in the combo. I like the look of the VCTRC standard servos, and they now have HV ones, as well. I think they would be the ones I would try if I was going to do a build with standard servos.
beenflying is offline Find More Posts by beenflying
Last edited by beenflying; Feb 25, 2013 at 06:51 PM.
Reply With Quote
Old Feb 25, 2013, 06:48 PM
as much as I can
beenflying's Avatar
NZ
Joined Jan 2010
4,912 Posts
Quote:
Originally Posted by sp00fman View Post
They look might nice for a hurricane 425....
With the adapters, I think they would be excellent, and 28g is a significant saving over a metal gear standard servo, which is usually around 52-58g.
beenflying is offline Find More Posts by beenflying
Reply With Quote
Old Feb 25, 2013, 10:00 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,260 Posts
Quote:
Originally Posted by MikeHRC View Post
David,

I had finally managed to convince myself that I wouldn't bother even looking at cheap servos any more and then you come up with these I'm going to keep an eye on this thread ujst out of interest

Have you managed to find any decent standrad size low-cost servos ???.

Cheers,
Mike.
MKS DS1210's are $35 each and supposedly very good. (and strong, they're meant to be used in offroad cars) I'm planning on using these in an FBL Swift 550 build in a month or so. (or possibly a Radikal E640 if I can't fight the urge)

They are 120hz servos though so if you're using them for FBL or something don't set them higher than that. (anything more than 125hz probably doesn't make a difference on the cyclic anyway, I lowered by 500's cyclics to 125hz without touching anything else and I couldn't tell the difference)
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Feb 25, 2013 at 10:07 PM.
Reply With Quote
Old Feb 25, 2013, 11:44 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,260 Posts
I just noticed that it uses through holes on the board for the wires instead of just soldering them to pads. I'm not sure gluing them would make any difference.
Atomic Skull is offline Find More Posts by Atomic Skull
Reply With Quote
Old Mar 24, 2013, 11:51 AM
Registered User
Canada, BC, Terrace
Joined Feb 2010
333 Posts
How are these holding up? The D-MG16's I normally use on my 500 builds are out of stock.

Thanks

Ryan
FiveZigen is offline Find More Posts by FiveZigen
Reply With Quote
Old Mar 24, 2013, 04:55 PM
as much as I can
beenflying's Avatar
NZ
Joined Jan 2010
4,912 Posts
I put another four packs through my 500 with these servos in the weekend. They fly very smoothly. I checked the temperature at the end of each flight, by touch, and they were cool.

Currently these are the my mini cyclic servos of choice, as they are great value and good quality.
beenflying is offline Find More Posts by beenflying
Reply With Quote
Old Mar 24, 2013, 08:54 PM
Looptastic!
sp00fman's Avatar
Enschede, Netherlands
Joined Nov 2009
2,292 Posts
Nice. I have the 732 type on the tail of my 450 now. 8 packs in, works well. Does warm up quite a bit, 25 degrees over ambient at 5,5V I might see what dropping to 5,0V does.
sp00fman is offline Find More Posts by sp00fman
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! hobbyking new mini osd w/gps abletowinginc FPV Equipment 11 Sep 10, 2013 10:30 PM
Discussion New Henge MD732 and HobbyKing HK-732MG Mini Tail Servo beenflying Mini Helis 43 Apr 26, 2013 02:20 AM
Discussion Multiwii Mini Flight Controller HK Hobbyking alll Mini Multirotors 40 Apr 15, 2013 09:12 AM
For Sale Set of 3 Good Condition Futaba 9451 Coreless Digital Cyclic Servos helinut4ever Aircraft - General - Radio Equipment (FS/W) 0 Jan 04, 2013 06:54 PM
Sold 3x 3x HK-933MG (Henge) Servos - $22 shipped DudeInMyrtleBch Aircraft - General - Radio Equipment (FS/W) 1 Dec 31, 2012 05:44 PM