Current servo choice

[Jim Hearnden 1]

OK a model I have just bought has cutouts for standard servos. nominal 40 x 20mm. I have a JR NES 591 which fits the 'ole perfectly. 

But I need more than I have. So looking at say Servo shop there is a LOT of choice. Both of manufacturers & models. I used to use HiTec with the JR gear years ago.

Any advice on standard servo choice before I just take pot luck and choose something I may have heard of! 

E Tronix comes up & I use their 3 channel kit in my boats, albeit with a strange chinese sail winch & a Futaba rudder servo.

[Bruce Collinson]

Jim,

 

If these are going in the same plane as the YS 140, get something high end, Savox eg, because it will be big, as Peter J has said, and it will vibrate.

 

BTC

[Jim Hearnden 1]

Bruce no these servos are for a 46 low winger I have bought. Will have a TT46 in it.

[Paul De Tourtoulon]

Any futaba, hitec Jr or Graupner 3kilo servo will do.

[Brian Cooper]

As has been highlighted, "standard" only refers to the physical size of the servo. 

The internals - and power outputs - can vary widely inside a "standard" servo.

 

However, for a relatively simple model with a .46 glow engine up front, any of the basic 3Kg servos will do the job. 

Ideally, for a bit of extra precision and longevity, go for servos with a ballraced output shaft. 

[Jim Hearnden 1]

After ploughing my way through the specs looks like it'll be Hitec HS-422 as that seems to be the equivalent of the Hitec I used before (311?) They were always OK when I used them on the JR X347.

I was really looking for names to avoid as there seems to be lots of manufacturers playing in this space. 

[Jon H]

Check out the savox 351. Similar price and marginally better spec as its digital. I use them all the time in my WWII stuff on ailerons/rudder up to 90 inch

[Paul De Tourtoulon]

5 minutes ago, Jim Hearnden 1 said:

After ploughing my way through the specs looks like it'll be Hitec HS-422 as that seems to be the equivalent of the Hitec I used before (311?) They were always OK when I used them on the JR X347.

I was really looking for names to avoid as there seems to be lots of manufacturers playing in this space. 

HS 422 Perfect 😇

[Jim Hearnden 1]

Just now, Jon - Laser Engines said:

Check out the savox 351. Similar price and marginally better spec as its digital. I use them all the time in my WWII stuff on ailerons/rudder up to 90 inch

Thanks Jon & all. Don't digital use significantly more power? There is a a reasonably priced  MacGregor one which looks OK but that's digital.

[Shaun Walsh]

https://www.4-max.co.uk/servo-hitec-HS-311.html

 

[Jon H]

digital servos hold slightly better, are slightly more accurate etc so can give a slightly more crisp feel. Its pretty subjective mind you and i only use them as they happen to be good on the price/performance ratio while still being a known brand rather than a no name from ali express. 

 

Using 4, 5, 6.5, 9 and 11kg analogue and digital servos over the years i cant tell the difference in the air. The models i fly, my flying style etc. Generally i just dont notice the difference. Admittedly my acrowot xl with savox 352 digitals is noticeably crisp and responsive, but as i have never flown it with other servos i cant tell if its better/worse. On the power useage, its not a concern in a model like this. If you had 10 high power (10kg plus) digi's and were slapping the controls about like an animal it would matter, but i use 6v nimh batteries and have no issues. 

 

For the model you have digital is no advantage, but if you are buying 4 servos for X cost and you can get digital then i would do so as you can use them later. The savox also share output splines with Futaba and have the uneven number so you can mechanically centre the arms with ease. Hitec do not have this and i have stopped using their servos because of it. I had 4 hitec servos going in a model and they all had wonkey arms which required a bunch of sub trimming and faffing about. This was impossible for the ailerons as i wass using a y lead, so i swapped in some futaba's instead. 

Edited March 4 by Jon - Laser Engines

[Jon H]

4 minutes ago, Shaun Walsh said:

https://www.4-max.co.uk/servo-hitec-HS-311.html

 

 

https://www.kingslynnmodelshop.co.uk/savox-sg-0351-standard-size-digital-4-1kg0-17s/

 

Same price, better servo. Normally i would agree the 311 is fine, but they arent £5.99 any more and do not offer great value. 

[Jim Hearnden 1]

What about:- I've used 4Max for motors & ESCs. https://www.4-max.co.uk/servo-4max-4M-455AH-033.html

[Brian Cooper]

10 minutes ago, Jim Hearnden 1 said:

What about:- I've used 4Max for motors & ESCs. https://www.4-max.co.uk/servo-4max-4M-455AH-033.html

This one would be slightly better.... it has a ballraced output shaft. 

https://www.4-max.co.uk/servo-emax-ES3001.html

[Cuban8]

The old go-to Futaba 3001 looks to be pretty much unobtainable now (not including the Ebay offerings that I wouldn't trust). Looks like 3001/3/4 etc have been replaced with their new standard digital offering the S-U300. Not clear in the adverts whether it's a ballraced output though - anyone know?

Good spec and price for non crazy performance sports models and usual Futaba quality I'd have thought. Need to finish a couple of projects myself and am short of a few standard type servos.

 

I know I shouldn't temp fate but in getting on for 50 years of R/C modelling I've only had one servo actually fail in flight. One of the old Futaba 128s with the hard wired feedback potentiometer. A broken solder joint that was only just making contact gave an intermittent connection at about half throttle and caused uncommanded aileron movement - all other throttle positions it worked ok, so managed to  get the model down. Picked up a few dodgy servos during preflight checks and testing though over the years.

Edited March 4 by Cuban8

[GaryW]

1 hour ago, Cuban8 said:

The old go-to Futaba 3001 looks to be pretty much unobtainable now (not including the Ebay

 

I get hold of 3001's no problem even on ebay,, got half a dozen on way as we speak as it happens.. ok they are second hand/reconditioned but still perfectly sound

Edited March 4 by GaryW

[Nigel R]

 

3 hours ago, Jim Hearnden 1 said:

Thanks Jon & all. Don't digital use significantly more power? There is a a reasonably priced  MacGregor one which looks OK but that's digital.

 

Savox 351 have very similar torque to the 422. In fact their quoted stall current (800mA) is the same as Hitec's quoted stall current for the 422 (and most of their other analogue standards).

 

 

1 hour ago, Cuban8 said:

Not clear in the adverts whether it's a ballraced output though - anyone know?

 

Usually it's a selling point... I'd have to assume not.

 

[Engine Doctor]

Jim . Go and speak with Justin at Rapid RC . Analouge servos will be fine . If you do go for digital make sure to up the battery capacity to cope with the higher current draw.

Dont trust any servos offered at bargain prices on ebay and be careful of any others on the net unless from well known suppliers

ps your JR servos arw only ok on 4 cell Ninms..Any higher voltage can let out the  Magic Smoke .

Edited March 4 by Engine Doctor

[Paul De Tourtoulon]

4 hours ago, GaryW said:

 

I get hold of 3001's no problem even on ebay,, got half a dozen on way as we speak as it happens.. ok they are second hand/reconditioned but still perfectly sound

DON'T !, I have seen a few open them up and see if they are real Futaba servos, most aren't !.

 Futaba U-300 no bearings

U-400 bearings.

[Nigel R]

Ebay fakes and scammers, there's a different rant for a different day.

[GaryW]

43 minutes ago, Paul De Tourtoulon said:

DON'T !, I have seen a few open them up and see if they are real Futaba servos, most aren't !.

 Futaba U-300 no bearings

U-400 bearings.

 

Oh no fear there Paul... I have a couple of guys that I've been dealing with for 20+ years one of which does sell on ebay and they wud never sell anything less that Genuine Radio Gear, Engines and other RC Accessories and they wud never entertaining selling dodgy fake anything.. And yes I do know there difference between genuine and fake not just with fake futaba but other fake ripoffs aswell

Edited March 4 by GaryW

[Jim Hearnden 1]

5 hours ago, Engine Doctor said:

Jim . Go and speak with Justin at Rapid RC . Analogue servos will be fine . If you do go for digital make sure to up the battery capacity to cope with the higher current draw.

Don't trust any servos offered at bargain prices on Ebay and be careful of any others on the net unless from well known suppliers

PS your JR servos are only ok on 4 cell NiMhs. Any higher voltage can let out the  Magic Smoke .

Thanks will do, I need a trip over there anyway. They sell Corona, a new name to me coming back to modelling after cough... lots of years cough. They are the only ones I have seen someone saying avoid? Any experience, good or bad?

I have only had issues with one servo where the elevator came off of one of my OD model at 200ft! It came into a farm road vertical. The aileron servo was "beheaded" by the wing sliding off of the fuse. MacGregors laughed and just swapped it. New crystal in the RX & was all OK. The engine, my beloved HGK 46 sheared the stud hold in the prop on. New stud & all was well. This model is still flyable today. 

[Cuban8]

3 hours ago, Paul De Tourtoulon said:

DON'T !, I have seen a few open them up and see if they are real Futaba servos, most aren't !.

 Futaba U-300 no bearings

U-400 bearings.

No way would I go back to a non ball raced servo. The U-400 looks good but for over a hundred quid for four they are a tad expensive compared to the perfectly acceptable 3001s

Ebay and second hand servos I steer clear of.

 

[Jon H]

13 hours ago, Jim Hearnden 1 said:

They sell Corona

 

I wouldnt touch them with a 10 foot pole. 

 

Obviously no brand is 100% perfect when it comes to reliability, but you are stacking the deck in your favour sticking with known brands like Futaba, Savox and hitec. As there appears to be no significant saving when it comes to cost either i would simply walk away. 

 

[extra slim]

2 hours ago, Jon - Laser Engines said:

 

I wouldnt touch them with a 10 foot pole. 

 

Obviously no brand is 100% perfect when it comes to reliability, but you are stacking the deck in your favour sticking with known brands like Futaba, Savox and hitec. As there appears to be no significant saving when it comes to cost either i would simply walk away. 

 

In this situation, I think Jon's advice is sensible, in terms of giving yourself the best odds to succeed. I have many corona servos operating fine in smaller models, mostly midi mini, and micro size, aswell as many many futaba, Savox, Hitec..hyperion, sanwa, Emax JR etc.. but then again, I have built up some experience and know what has worked for me in which application.

It is true when the "Chinese" type brands entered the market there lots of reports of quality control, more so than the more regular brands, but nowadays if they are legit and not copies, then the news of servo issues, tends to be somewhat similar across the board, with some notable exceptions. Given personal experience I dont use Towerpro, and NewPower, I'm sure there are good ones out there, but for me, I saw poor quality, poor centering etc, so given the wealth of choice, I have no need to go back there.

 

Stick to the less risk brands given you are a returner.. and then go from there.