Servo: What's enough for RC cars?

[TB-EVO 1]

I read many of the servo posts and many people are recommanding high-end servo or high-performance servo most of the time. I just wonder what's enough for RC car application? I am using the Futaba S3003 servo came with my 3PDF and it has not failed me once or glitch on my once. It's a pretty good servo but it's way on the lower end. Is it necessary to buy high-torque/high speed/high end servo? Does it make huge difference in races? What's a good number for a servo for its torque/speed? I want to get a good servo myself, but just don't know if it's necessary. My S3003 servos works fine. What do you all think? Is it necessary to get a performance servo? Also, for those of you who has multiple cars do you buy a high-end servo and switch between your cars when you are running that particular car? Or do you buy multiple servos for each car? Thanks

[Big Wig]

I use a Hitec digital servo #5925 for steering in my RC10 GT. Now that I'm used to this I will never go back to a cheap servo again. It's very fast (I think .08 transit time) and has a lot of torque (128 oz/in).

These numbers are for 6v operation.

I chose this servo for throttle in my 1/8 buggy and I went with a #5945 for steering which gives a whopping 180 in/oz of torque!

I don't swap servos from vehicle to vehicle. I build up a car the way I want it then leave it. These servos might be overkill but they do make a huge difference.

My brother in-law runs a JR Z550 for steering and throttle in his GT and he sees no reason to switch to a faster, more powerful servo,... go figure ;) I know that I don't like driving his car.

Which vehicle are you running? Do you race seriously? On an RC10 GT for example, the car is so light that I honestly don't think a high end servo is necessary to have a lot of fun. A 1/8 buggy is so heavy, though, that I think a standard servo would seriously limit the fun factor.

I guess, to answer your question, high end servos aren't needed, they're just nice :D

good luck

[sniper-8]

bigwig, i use 4 batteries that are alkaline, (6volts) and two servos, but my servos are 4.8volts, so im confused? does the crystal restrict some of the power? :confused:

[TB-EVO 1]

BigWig,

I'm running Touring car: Tamiya TB-Evolution. Touring cars are not too heavy at all. Maybe that's why I got enough torque/speed from my cheap servo. But I always see people recommand better servo (not necessarily the best) for steering. Why? I am just getting into racing recently. Nothing serious; just Novice racing. And sometimes I wonder for such a short responds time for the servo(speed of the servo) won't it make the car out of control very easily? Just wonder.

[Railman]

Big Whig said it all quite well & I totally agree. What happens with a slow servo is that you learn to anticipate the short comings of the servo, but if you make a mistake the slow speed will not allow you to make the proper connection in time. Too much speed on an on road car would probably be a misrake though, because it would be too twitchy. The faster the car speeds is the less servo speed you want. This can be adjusted with a good radio, so that you can have the best of both worlds though. Off road the faster the servo the better, due to the loose condition which makes for constant corrections. Just my$.02

[marvi]

upgrading your servo is just a matter of preference. if your car handles great and youre winning races with your current servo, just stick to it. if you plan to upgrade, digital servos are the way to go. i currently have a 9402 but i plan to get a 9450.

[TB-EVO 1]

Marvi,

How much did you pay for your S9402?? It's a Coreless isn't it? That's the servo I'm looking in getting. How is it that Digital servo are better?

[TB-EVO 1]

Marvi,

I just checked Futaba's website. I don't see the 9450 servo you are talking about their digital servo are 9200-series.

[gubbs3]

I'd say that untill you try a high power servo you really don't know what they can really do for your car. When I got my first high end servo I didn't notice too much difference but when I switched back to the standard, whoa! there is really a difference. For a TC you don't need a servo with any more than 60 oz. for perfect control but you want the fastest servo you can afford. A Hitec 525 would be a perfect choice for your TC. It has 52 oz. of torque at .12 sec transit time so it's by far fast enough. It runs at around $30.

[qua77ro]

I'm running in my NRS4 JR 550 servo for the throttle and a KO PROPO 2143 FET 6v Servo for steering. The transit time on the KO servo is 0.08 which you DO notice when you go from one that was .2 seconds transit. Torque is 111oz. It's a pricey servo, 120 at my LHS, and 110 from Stormers I believe.

[marvi]

tb-evo: the 9402 servos were included when i bought a 3PJ. i saw the 9450 specs in rc car action's 2000 buyers guide as: 1.59x0.79x1.48 inches, 1.94 oz weight, 111.1 oz.-in. torque. i dont know the speed, but i think it is fast, since its a digital servo.

the 9402 has a coreless motor, ball bearings, and brass gears. the specs are: 1.59x0.79x1.48 inches, 1.90 oz weight, 111.1 oz.-in. torque, 0.10 sec/60 degrees speed.

your car may feel twitchy with faster and stronger servos, but if you set it up right, you can enter and exit corners much better and your car will wander less at speed in the straights. i used to have a 3003 in my tc3 but i felt a huge improvement in handling with the 9402. i didnt even change my suspension setup, since my car understeers with the 3003. with the 9402, it felt much better.

[TB-EVO 1]

Marvi,

where did you buy your 3PJ??? How come it comes with a S9402 servo?????? It should came with a 9101 servo. Man you are so lucky. did they mess up the packaging or something??? Tell me where you get it. I will buy my next radio from them!

[KilRuf]

I use an Airtronics 94257/94357 servo. Pretty fast and has excellent torque. I used it in my touring car and now my truck. I don't think I could ever go back to a slower servo (it runs a .06sec/6v). I've always raced with the slower "stock" futaba servos when I first started out. Then I went to a semi fast servo. And now this. I tried to drive this one guys car once and couldn't drive it worth poop because he had a slow servo. I guess my brain was used to the speed of my servo. So when I went to the slower one, it wasn't use to the "lag". Anyways, faster the better for me. Along with my M8, you can adjust it's steering curve and whatnot to your driving style and/or car. Just my 2¢ and experience.

Mike

[ 08-26-2001: Message edited by: KilRuf ]

[Railman]

Kilruf, We have a couple of the 257's & out of curiosity how does it compare with the later 357? Can you tell any diff in them in actual use? Thanks, Joe

[jeepinator]

Railman, I have a 157, a 257 and a 357.
I have not done a side-by-side, double blind test ( :p ), but the differences seem only evolutionary. The 257 is actualy rated faster than the 357. The 357 seems to have more holding power, so it will probably seem faster in real use ... The 157 is just simply slower and weaker (could be due to age as well, I have had it quite some time !).

I am not sure anyone but the most skilled drivers could tell the difference (I doubt I could).

[RustlerBoy]

Just use what you have tell you feel you need to upgrade! Thats what I did! I used a S3003 until I broke it in my T3 and I decided to upgrade, and I got a Cirrus metal gear for $22 brand new at HobbyPeople.net!

[marvi]

tb evo: i got mine from our lhs in the philippines. i think they get rc stuff from HK. i got my 3pj pcm about 3 years ago and it came with a transmitter, receiver, and 2 S9402 servos. well, im not so lucky because a couple of months ago, i fried one 9402 and it cannot be repaired, even by the futaba service center. i made the mistake of plugging it in backwards in a receiver without bec so when i connected the fully charged battery pack, it smoked. :(

[rims']

cirrus servo's are good cheap servos. :D ;) :p :cool:

[KilRuf]

Can't tell difference I don't think... Can't go wrong with either. No need to "upgrade" hehe.

Mike

[Railman]

Thanks for the input Jeep, & Kilruf. ;)

[TB-EVO 1]

Marvi,

What??? it came with 2 S9402 servos??? that two servo along is like 200 dollars. How much did you pay for your radio (the whole set)? the 3PJSpcm only came with 1 s9101 servo. You are very lucky.

[ctaylor8211]

Does anyone know what servo the JR Racing XR3 comes with?

[marvi]

tb_evo: it was about US$300 (PhP 15,000.00) three years ago. Today, it goes for almost US$400 (PhP 20,000.00) I think its a lot cheaper in HongKong, maybe 20 to 30 percent cheaper. my 3pj came with 2 9402's (but im down to one now.) but i think you can buy just a 3pj pcm transmitter and receiver only for even less.

[qua77ro]

CTaylor, it comes with either 2 JR 250 servos(standard servos not really good for any serious playing) or 1 JR 550 which is a better servo than the 250's. I used the 550 that came with my XR3 as my steering servo in my nitro 1/10th rs4, until I picked up the KO servo.

[Mason Copeland]

Well all I can say is I smoked through 2 hitec hs303 standard servos in like 5 months I'll probably never experience a high end servo...not worth the mula...least now I have a friend with like 5 extra servos lyin' around...

[MtnKodiak]

OK, It's newbie-question time! I have a feeling that this will be an easy one, but I really don't know the answer...

If you strip your servo, and have to replace it, do you have to stick with the same brand? Same model?

A friend stripped the (cheezy) steering servo in his HPI Rush RTR, and we were wondering if he could just slap a Futaba in there or something. He doesn't even know if he has a servo-saver or not, poor chap. The brand is some unknown (to me) Asian-sounding name.

I have the stock S3003 servos in my GT, and I think they're just fine. But what do I know, I've never tried anything else, and I don't race my truck anyway so who cares.

thanks, --mK

[qua77ro]

my favorite manufacturers of Servos are..

KO
JR
Futaba
Hitech in that order. I stick to KO and JR personally.

[KilRuf]

Hey MtnKodiak, no you don't have to stick with the same brand and/or model. All you have to be aware of is the connector and the wires in the connector +/-. This is so that it works in your receiver and you don't fry it. Yada, yada, yada. Hope this helps! :D

Mike

[Jwelch]

I have never really cared much about high-end servos, until I toasted about 4 servos when I started playing hard. I'll still buy a servo with less torque, but it's gotta have steel gears.

[MtnKodiak]

Thanks for the reply, KilRuf. That's what I thought but I wasn't sure.

--mK

[tadium54]

i think that if you are just bashing, standard servos are ok, but thats just me.