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Dear All,
Thanks for very good support. I already found solution to my problem. This Turnigy ECS dlux 40A SBEC Brushless Speed ...Realy have problem with my walkera gyro. But what i did i turn around the my walkera V450D01 v2 RX-2703H-D just to make gyro works. Bcoz even i set my tx DEVO10 to reverse the RX-2703H-D gyro is not good. And it just come up to my mind if i will just turn it around the position of my RX-2703H-D to have a try. Jesus answer my prayer and it works. The 2 Turnigy ECS dlux 40A SBEC Brushless Speed ... is working with this 3 DS939MG very good for my cyclick and i can fly again.
Hey guys!
I'm building a Hexapod, and just wondering, how would these servos hold up? (I need 20 of them so looking at relatively cheap but still good ones)
Thank's in advance!
Basically a digital servo is stronger and more accurate size for size. Digital servos provide constant torque over their whole travel range, better 'holding' power when not moving, faster reaction times and better positioning. This is all to do with how the electronics deliver the power pulses to the servomotor. Analog servos deliver at 50pulse/sec whereas digital ones deliver at 300pulses/sec.
There is more to it than this of course, but generally a digital servo has no disadvantages - apart from they use a little more power than the analogue equivalent.
I would not do it, it has a metal gear and is a little bit slow. For yaw i would use a high quality digital servo with plastic gears for lowest play. If you wanna buy on HK i would suggest the Power HD 3688 if it will fit.
Hi, Can I use Corona 939MG digital servo with HK401B Gyro with DS switch in ON position in T-Rex 450 SE V1 as rudder control. Will it help with the tail wag. I was using GWS PG-03 with analog servo HS-81 and there was no tail wag. I just changed the gyro and there is enormous tail wag now. Tried different setting but no avail. Thinking of switching to digital servo. Thanks.
You need to adjust the gains on your transmitter gyro rate/channel. The HK401 is very sensative to this. I had the same with the newer type 401 and on my JR radio at the time I used 32% and 73% gains. Even then there was a tiny bit of wag.
You can use the 939, but it is a little slow for tails, but Would better off using a DS9257 servo on the tail. Much better option, but leave the gyro in analogue mode in either case to keep servo running cooler.
I managed to adjust the gains to 35% and 75% and get rid of the tail wag and used 939 as I had one spare. DS9257 is HKS-9257, right? It's mounting was different, so I was not sure if it'll fit on 450 or not. Again can I still use 939 and 9257 with gyro in digital, will there be noticeable difference?
Ideal - the HKS-9257 which fits fine on 459 helis is the better option as it is faster and stronger than the 939. Use either by by all means, but for longer life and slightly better performance the 9257 wins.
Using the gyro in digital mode shows no appreciable difference apart from increased heating of the servos, leading to shorter lives.
Thanks. Will keep it in analog then and will get HKS-9257. Would like to upgrade my t-rex 450 SE V1 to 4S1P Lipo. Any suggestions (ESC, motor, servos)?
Good move to 4S. I ran a 450 pro flybarless with Scorpion 2221-8 motor and I think 11 tooth pinion. Gyro was an Align 3G. ESC was a HobbyWing 60A in governor mode, and I had quite a mild throttle curve. Recall flights of about 4 mins or so on 1800mAh. Was a while ago now and I no longer have it or the setting sheet.
Ran the thing on 929mg and 9257 servos. Seperate 5A bec as well.
Thanks. I think I read your post somewhere with this setup. Wouldn't 939MG digital be more precise than 929MG at the cost of speed, or is there no advantage of digital?
Ah - a typo! I meant 939mg's - was typing on iPhone! apologies. Only thing with fitting the Corona servos to the Pro is you need to carefully remove the little servo mount tab reinforcements. Other than that they are fine. However, they will fit the SE versions with no modifications at all and are my preferred servo for cyclics. Never had a problem with them even after having crashed very hard once or twice! heh heh!
I don't speak your language, but with the power of google translate I can say you that this servo can replace a 410m but I don't think that it will be better. It works without any problems and on the paper it is as strong as a 410m, but also it is a little bit slower. But that are only paper figures. So if you want to use it as a replacement for a 410m, sure, you can, but I would not use it as an upgrade.
Eu preferiria usar XGD-10 ou XGD-11MB, porque eles nã*o sã*o tã*o altos. O 939MG vai impedir que você* montar o dossel se você* montar o servo arremesso de fora, só* para você* saber. Boa sorte!
They are digital. It makes no odds what the mechanics are - pots included. The difference is down to how its signals are processed.
Analog signals are processed at say 50cps and digitals are anything from 300cps and up.
Go google the difference between analogue and digital rc servos ...
Never had a problem with these in over a year of different batches. Only one fried and that was deliberate to see how it withstood abuse. Gears and casing all fine.
What Size Metal Servo Arms fits Output Teeth. What Are They? I Tried Futaba and way to BIG !!! Love these Servos and Want Better Servo Arms to get Max Solid Contol on Precision Aerobatics Planes. richgrow
Dunno what the HS-55's are like but,I use these and the slightly quicker 2.2kg model on most of my planes.I haven't had a single problem with any of them.They all centre well and are strong.A veritable bargain.
These servos are digital and slightly faster as the HS-55MG 0.14sec my opinion, These are more reliable and have better centering. Either the 9306MG Metal Gear Servo or the BMS-373 Micro Servo 1.5kg. But price wise I would stick with the carona they are good servos
Search 939MG and get the hobbyking version,work well just as good,in my opinion.Used on Nitro and electric.No jittering, centers fine.Cheaper too but on backorder at the moment.Dont also dont jitter with 1.2ghz video transmitter on board used for fpv(first person view)flying.
yes, very nice little servo, work very well on my HK 450 pro
problem I have is the securing tags are very weak, and now I need 4 cases, any one know where I can get some??
Size is similar but performance is a little different, these are a bit slower but more TORQUE, means it can push/pull more weight than the servo you mentioned.
These are great little servos for the very affordable price!
I do not believe these servos have very much (if any) play at all. Smooth too. Im using these in my Funjet Ultra and T-50 EDF jet. I'm very happy with them so far. the HK 939MG's are also pretty good.
I have to agree, i am using 4 on a epp 3d with servo arm extensions for greater travel and they are strong and reliable with no play. Try them, you will be impressed. Excellent value for money, as usual, from Hobby King.
when i get metal gear servos i open them and put a tooth pick point full of Vaseline on the gears and friction treatment then the servos are smooth and no slop and also dead quiet as well
Dont hesitate to use it. It is very strong. The description says metal gear, the box says resing gear. By inspecting it, it has the first two gears resin, and all the other metal! The bearing is pretty big too....over all a great servo.
As far as I know it should have came with a set of arms, but if you are looking for more arms then any micro gear servo arms should work just fine. You can purchase extras here at Hobby King.
Hi KodaMan,
Thank's for your reply but Hobby King sells arms for Futaba, arms for JR and arms for Hitec, and I don't think that they are the same and that they will all fit on this Corona Servo...
I tried my collection of arms & couldn't find any Futaba. JR or Hitec arms that fit. Also tried Bluebird & Tamazo. What does fit is the SG90 arms & I presume that includes SD90 as well.
Hi, I have 10 of these servos with 2 still in the box. The 0.24mA spec is the stall current at 6V. There's no idle current info on the box, so I ran a quick check with my Fluke multimeter just to satisfy my curiosity (and yours). Got a 6mA reading on a freestanding servo and around 8-10mA on an in-plane servo loaded with weight of aileron. Cheers!
There are a lot bigger than the "Efright" & Esky servos. Helluva bitch getting 'em installed, which I had shopped for smaller! Or even the carbon geared type! On a Kong 4, they bang on the top of the outrunner drum and when that spun up, it bit off the output arm. CCPM helis have no extra room for servos, they pretty much locked us into the 7.5gram class.
See they sold out on 'em again, confirming my opinion it's better to not review any items on this site if you think you may want more. No matter, I want smaller.
Too bad I can't edit my typos above. Bottomline is these are a bit too large for most micro helis on the mkt. with CCPM heads. The cases are too big for the mounts and you'll have to do bodywork!
Is anybody using these as swashplate servos with a beastx/microbeast? What are the correct settings for the frequency and the center-position pulse-length?
The microbeast is one of the cheapest FBL-systems you can buy in Germany (besides an unbundled Align 3G), so I don't see a contradiction here. Why pay more than you have to?
it is calm that fits in the receiver Futaba! Standard connector Futaba JR, I didn't find the gears, it can entrust that that servant is excellent. for the price it is worthwhile. any thing nor it is worth the feather substutir the gear. if he/she gives problem he/she buys other. good purchases
no gear kit.the corona and hobbyking 939's are not showing a replacement gear set on this site, I checked in servo accessories, servo parts and also did searches on Servo Gear, and on Servo Gear Set. Also note...metal gear servo won't break a gear very easy. Replacing a nylon equiped servo with metal is not available, the sets are not listed yet. A 'universal' plug, works on all adaptors, a Futaba plug is proprietary to Fubaba adaptors (receivers and extension females) Ed
it is calm that fits in the receiver Futaba! Standard connector Futaba JR, I didn't find the gears, it can entrust that that servant is excellent. for the price it is worthwhile. any thing nor it is worth the feather substutir the gear. if he/she gives problem he/she buys other. good purchases
Unsoder the 2 metal connectors on the motor, pull the motor out, then swap the 2 outside wires on the pot, Then put the motor back in opisite direction, and your done.
Its just a little odd becouse there are no wires to the motor.
I don't advise you to change the threads of entrance of the motor, very bad to weld later. it is better to buy a reverse adapter, or to use the rev option. of yours I radiate. good purchases.
HobbyKing sells a specific servo reverser, there is also a 3-channel servo rate controller whre one of the channels is a reversing channel. That will resolve your issue. $pektrum suggest not using servo amplified Y-cables, servo reversers are fine.
Customer Reviews
Overall Rating
Martin0107
39 likes
Value
UNRATED
Quality
UNRATED
10 thumbs up!
I purchased two of these servo's for a Windrider F-35, perfect specs for the application. They seemed to work fine out of the box, but when they were installed in the plane I had a huge problem. The one servo works 100pcnt, but the other one has huge movement on the output gear. I removed the servo and opened it up. There was no bearing to support the output gear! I fixed it by fitting the bearing from a GWS Naro servo, works fine now. Quality control must have gone on holiday the day mine was made.
1 comment. Reply..
Overall Rating
fullrespect
121 likes
Value
Quality
9 thumbs up!
I bought 4 of these servos - and have had the same - but hopefully before test flight, 3 servos has been self-broken after few minutes of playing with my swash-plate. Peace of nothing - I will never buy any corona servo! Strongly NOT RECOMMENDED
No comments. Reply..
Overall Rating
Dale.E
156 likes
Value
UNRATED
Quality
UNRATED
8 thumbs up!
Pro's: Centers very well, good torque nice weight, good mounting real bearing on output, can shorten leads by soldering. Con's: Noisey as in loud, 1 of the 4 I got was bad, not all metal gears.
Overall an ok MG replacement for HXT900 but the HXT900 just feels better. I cannot really recomend this. I have found reports of bad PCB failure after 15 hours or so.
5 comments. Reply..
Overall Rating
3D maker
13 likes
Value
UNRATED
Quality
UNRATED
7 thumbs up!
I can't recommend this servo for use 3D airplane. My airplane weight is 700g. Because of the weaknesses were found in the servo. Takes an overload on the servo, the servo does not work at all. If the situation continues to deteriorate, pcb board will fire. Another brand servo simply stop the work, Itself takes an overload. I am a little disappointed, but agreed to use only two aileron. but not use to elevator and rudder.
No comments. Reply..
Overall Rating
Dale.E
156 likes
Value
UNRATED
Quality
UNRATED
6 thumbs up!
Two out of four bad, all work but the two lock up under load! center fine look ok other than that, if you get lucky enough to get a good set then fine.
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