Neil Rabara

I just completed putting together a Serpent 705. I need ideas on the type of servos required for steering and throttle/brake. I run an Airtronics M8. Any type of servo specs would be great.

skibum989

A pair of Airtronics 94757's would make a good choice, I have one for steering in my V1R and it rocks. Would make a good throttle servo too.

InitialD

Like I mentioned previously, if money was no object, the KO 2143 digital servo will be the fastest servo for steering at 0.08 seconds / 8 kg torque.

For braking / throttling service, the baddest servo is the 13 kg torque / 0.13 seconds KO 2144 digital servo. If you dislike digital servo on the throttle for power consumption considerations, then you can go with KO 2174 which has 12 kg torque / 0.13 seconds.

Futaba 9450 and 9451 digital servos are also good. 0.1 seconds / 8 kg torque if I'm not mistaken.

Boomer

Get a strong fast servo for your steering. If you're a beginner, go for strength and not as much for speed (although don't go for a slow one. . .get speed, but don't focus AS MUCH on speed) - you're going to be throwing a lot of weight around and you need a strong servo to keep the wheels pointed where you want them.

For your throttle, you don't need strength. Not really. Think about it. It doesn't take ANY strength to move the throttle. It doesn't take much torque to push/pull the brake lever. Don't get a wimp-ass Airtronics 102 (stock servo. . .any brand) but something like a 737 (mid-range, good torque, good speed) is going to do quite well and be more cost effective. HiTec 625 is also good. . .

Hope that helps.

Neil Rabara

Thanks everyone, I'll look into it.

jason102276

i am planning on replacing my servos with the futaba digitals

i have also heard KO and JR servos are good

i have hitec digital 5925 servos really fast and strong but occasionally fail

Darkseid

iTrader: (9)

I use the KO 2173 as the steering servo in my ReflexNT. Its not digital, but its constantly centering itself(just not as rapidly as digital) and carries with it specs like these: .08sec @ 116oz/in.

All for $20-$30 less than most digital servos. And with less power consumption.

For throttle, I use a standard Air/Sanwa 94102 .22sec @ 55oz/in. All you need it to do is stop the car, not rip the brake arm off! At the most I would say go up to the new JR Z590:.15sec @ 85oz/in. Save the 100+ oz/in. throttle/brake servos for stopping 1/8 scale buggies. Sedans simply don't require all that power on throttle/brake.

Now, if you have the extra money to spend....then go for it!

Corse-R

My advice of servos goes to Futaba, on all my cars (quite some) for steering use a trusty Futaba 9450 model (110oz 0.10 sec) digital model who resists anything you knock. Service of them is cheap and fast (sorry prefeer to not talk about the nasty and hedious service of Ko Propo on Europe) a repair for a 9450 servo elapsed 2 weeks and a half the price.

For thottle, go with a 9402 model (the same as the 9450 but not digital). Futaba servos are rugged, trusty, reliable and quite cheap.

My case about: Ko Propo UK retained for 'repair' 5 (five) months a receiver that 2 weeks (15th of September) after sending to repair (a brand Mars-R with 2 weeks of use) they said that a new receiver in replacement of the broken. About 15th of January, KO Propo UK sent to my importer a replacement receiver in swap for the defective one (5 months ago... KO Propo UK: The receiver went from Japan swimming or walking?).

I've been a loyal customer of KO since 1988 (yes, 15 years, my first KO radio was a KO EX1 gray/black model on AM). The day that my KO radio wents bad and need service, these day I'll switch to another brand, let's say Futaba for example.

jason102276

that sucks that ko propo has such bad service

i emailed them along time ago with some questions and got no response

Neil Rabara

I hear using a digital servo on the throttle is best. Why is that?

jason102276

actually ive heard the opposite is true because digital servos will sometimes burn up especially if endpoints arent set perfectly

i use them anyway and i havent had too much trouble but i have had some fail but they were hitec servos which are known to fail no matter what

i really like the speed and they center much better than regular servos

i plan to buy futaba servos to replace my hitecs i have heard futaba servos last along time

for now though my hitecs are under warranty for another year and the lhs just swaps them out for me

but alot of people will say its best to use a regular servo for throttle something fast and torque isnt very important unless you run a 1/8 buggy or monster truck that needs a strong servo to brake well

patelladragger

conventional wisdom from a lot of the 1/8 guys say don't put digital servo on the throttle - use a strong analog.

Corse-R

The unique for not putting a digital servo on the throttle is that you need to avoid the high power drawn by to digital servos or much probably your battery don't last a 45 minute final.

Use digital on the steering and analog on the trottle/brake.

Neil Rabara

But using a decent analog servo on the throttle/brake, doesn't that prevent the throttle return spring, or rubber band, from actually closing the carb?

Boomer

Any servo is going to prevent a throttle return spring from doing its job if there's power to it. Personally, I think they're pretty stupid things and if they had cost very much I wouldn't invest in one (only reason I do is so I can race. . .) - better investment is a failsafe.

If you're not a high-end racer (and I don't count myself as one) then I really don't think a digital servo is going to make that much difference. They're a TON more expensive than an analog servo and there's not a huge benefit.

If you're new at racing, invest in a GOOD servo for steering and a DECENT servo for throttle. You can get away with a SUCKY servo for throttle but not for steering.

Just use common sense - we've all stated why the steering needs to be stronger and faster than a throttle servo. Work from there and purchase what you can afford.