Servo details

[zoombolt]

I'm quite confused with the huge range of servo choice out there & wondered if there was a link, thread, site, somewhere that explains (in laymans terms) what all the differencies are, from the low end of the scale to the high end.

Do the digits acually mean anything? Some go up indicating a better servo & some go down? Ball, Digital or gimball?

So do I want a HS-5245, Futaba-9254, 9650, S3152 or a D510 or D610??????????

Just trying to leap one of my last few hurdles & it's not sinking in!

[trillian]

Last year when I was researching servos for a few helis it drove me mad (I am still mad in fact). I concluded that Futaba makes waaaaaaaaay too many different servos.

[Richard H]

Nice post zoombolt! They confuse the hell out of me too so will watch this thread with interest.

[SadSack]

digi's center better than anolog. They make a lot more noise but thats normal.

which digi to buy million dollor Q:

DS610's they first appeared people where like 'its re-labled servox' rubbish !?? Now they been out a while there very good for money. I got them last year and very cheap.

Give you idea my first t rex 600 np had cheap hitek car servos/metal geared but i thought they where great till relaced with 610. But only hovering/FF both worked well. As you spend more on servos you'll see why. Even if you could afford HV 8717's you'd be a unwise to get them just learn to hover still people do and have one for throttle (please don't slate me for sayin that. if you have one installed)

Futaba/JR make very good servos very! They have a large range because they have a servo for just about every model type going

[scallybert]

Spartan Say..:

The ultimate helicopter servo resource:

Spartan RC

[This is for tail servos, for use with the DS760, but is interesting in general.]

Ino-Lab are interesting. Seem to be better & cheaper than certain leading brands. May be worth a look, or asking someone better qualified than me.

[I've got HS65MGs & an S9257 on one G5, and Ino-Labs on the other (can't remember the models).

IL tail was cheaper and lighter than S9257 and scores slightly better on Spartan sheet.

The IL swash servos are digital, whereas HS65MGs aren't. Same price from Blink. Debatable whether this matters to me in itself. However, during set-up the IL servos kept the swash level throughout the collective range (without tinkering), whereas the HS65MGs didn't. IL servos had slightly shorter horns, though. (1mm less than G5 manual expetcs, IIRC.)]

[Hangar-7]

I'm quite confused with the huge range of servo choice out there & wondered if there was a link, thread, site, somewhere that explains (in laymans terms) what all the differencies are, from the low end of the scale to the high end.

Do the digits acually mean anything? Some go up indicating a better servo & some go down? Ball, Digital or gimball?

So do I want a HS-5245, Futaba-9254, 9650, S3152 or a D510 or D610??????????

Just trying to leap one of my last few hurdles & it's not sinking in!

Which servo?

I ask myself a few simple questions and then decide which one to buy. Thought I share it with you

a. Servo weight? For a mini ‘copter less than 9 grams but 20-30 grams OK for 400 and 40 grams+ for 500 sizes or bigger. A small weight servo may not have all the features you’re looking for so make sure it will do the job.

b. Does size matter? Yes it does and depends on the make of heli and position where it goes. Double check that the servo will fit in that location. Measure it with a vernier calliper unless you have the exact size from heli manufacturer. Ask your model shop - they should be able to help you.

b. Digital or non-digital (analogue)? Digital gives you full power at all times. It is either on or off no half way home. Whereas, non-digital gives changeable power eg, for rudder, it is best to use digital. Digital are expensive but if you can afford it then go for it.

c. Speed very important for helis – you need faster servos. Speed less than 0.11 sec/ 60 degree at 4.8V is slow and not suitable for helis IMO. Remember higher speed = more £££.

d. Torque basically this means how much force applied to the control surface eg, rudder you need high torque. A torque value less than 1.3 kg/cm at 4.8V is acceptable for mini copter but anything 400 or above you’ll need higher torque servo. Again, higher torque = £££

e. Metal or non-metal gears? Metal gears, if you can afford it. Most popular brand servos allow you to upgrade to metal gears. But good quality plastic gears are not bad, if you’re on a limited budget.

f. Which Brand? This really depends on your budget and preference. Futaba, Multiplex, Align are all good quality which comes at a price. Next best is probably Hitec – they are good, reliable and not expensive. IMO, Futaba servos are unnecessarily expensive- you get diminished return for your money.

MG as prefix in servo = metal gears and if it does not say that then it is plastic gears

If in doubt, ask in the appropriate forum and you will get good answers.

Hope it demistfy servos for you.

[scallybert]

c. Speed very important for helis – you need faster servos. Speed less than 0.11 sec/ 60 degree at 4.8V is slow and not suitable for helis IMO. Remember higher speed = more £££.

There's an argument that it's fairly pointless having servos faster than whatever is driving them.

eg a tail servo is driven by a gyro that reacts really fast - so you want a really fast servo.

OTOH, the swash servos are driven by your thumbs - so there's no point in the servos being much faster than you are. [This doesn't apply if you have a flybarless system with a gyro stabiliser driving the swash servos.]

Having said that, much better pilots than me claim to notice the difference that a faster Tx makes (DX7SE vs DX7).

An HS65MG is a pretty common swash servo and its speed is quoted as: "Operating Speed (4.8V): 0.14sec/60° at no load".

Maybe accuracy is more imporant than speed on swash servos ?

[Hangar-7]

There's an argument that it's fairly pointless having servos faster than whatever is driving them....

.......Maybe accuracy is more imporant than speed on swash servos ?

I agree with your points .. but I think many of the 3D pilots will not touch a HS65 MG servo - too slow for them... but for a beginner or an intermediate pilot HS65 is fine. Why buy something which you may not be needing for another 12 months.

IMO, as in politics, a year is a long time in our hobby... so a dog's b*****s servo in the year 2009 may not be worth much in Yr 2010.

So perhaps I should add another box in the check list - Do I need it at the moment or I want it NOW!!! coz my mate got one.