Technex

Hi guys,

Looking for a new steering servo.

How does the Hitec HS-5645 compare to the Cirus 704MG (which struggles like heck to turn the wheels in grass).


I recently got a HS-645MG on the throttle and brakes, works awesome, very precise, centers great etc. Would it have enough torque for the steering if I was to get another one?

The 5645MG seems to have slightly more torque and speed, but uses more of the battery, is it worth the extra cash?

Also I've heard the 5645 is more water/dust proof, is this true?

Running a 6V pack, and just bashing/having fun but I need a tighter steering circle etc.

Thanks!

NitroVette

Get the 5645MG, I use one in my Savage and it's a good servo. It's digital and has more torque and better holding power.

Technex

Thanks NitroVette, I'll wait for a few more replies then I'll go ahead and buy one.

46u

My Feedback: (3)

HS 645 is SLOW!!!!!!!!! If you run a digital servo you need a radio with EPA or you will fry it. The 5645MG is all so SLOW!!!!!!! Anything over .13 is SLOW!!!!!!!!!! If you ever run a couple fast good servos you will NEVER go back.

Technex

Don't forget I'm looking for torque over speed, this truggy has a poor steering circle anyway, is pretty heavy and wide tires.


I am using a DX7 so radio latency/EPA etc isn't a problem, I always do this no matter what the servo is anyway....

SAVAGEJIM

I say go for the 5645, sped the additional money, you will not regret higher torque and the digital functions.

As a basher, servo arc speed is nothing to me, I personally prefer insane amounts of torque. If a 500in-oz torque servo were available, I would buy it, even if it had a horible arc speed time of .15 seconds.

Technex

Agreed, I like the tight steering when the car has stopped and over ramps and bumps when I get a chance to go on them.


Okay sounds like the 5645 wins, what are the disadvantages though, just more battery usage? And my current Cirrus servo is meant to have even more torque (specs). Although I guess because it is a poor make and non-digital that's why it struggles to turn the wheels?

dacaur

hehe its funny you should say that .15 is "horrible", because the hitec 645 is .20/.24 at 6v/4.8v.... thats why people call them slow. They are tough and strong, but not good for steering duty because they are more than slow, they are horribly slow

the 5645 isn't much better at .18/.20.....

I would go for a hs 5625mg. just about the same torque as the 645, with faster speed than the 5645, but in the price range you are looking at with the 645 and 5645....

Hs 5625
[email protected] sec at 4.8v, or [email protected] sec at 6v.

steering circle isn't affect by the speed of the servo. Torque can affect it if your servo is too weak, but the design of the truck is the #1 determiner there... what the speed of the servo DOES do is make the truck react faster to your steering inputs. with a slower servo, you will tend to turn the wheel further in quick turns, because it doesn't react fast enough, then it takes longer to get back to center.... You might not think that the .07sec difference in time is enough to worry about, but trust me, it is HUGE and you CAN tell the difference driving it... there are servos that can make their full 60 degree arc in that much time....

Technex

Thanks dacaur, I wouldn't go for the 645MG now for steering, I agree I think it perhaps would be to slow and unresponsive.

The HS-5625MG vs HS-5645MG. Now I personally would say the HS-5645MG would be more suited as it has more torque and less speed.

Price and weight are the same .

HS-5625 MG

Torque 4.8/6.0v : 110 / 131 oz. 7.9 / 9.4 kg.
Speed 4.8/6.0v : 0.17 / 0.14 oz.



HS-5645MG

Torque:10.3kg.cm(4.8V) , 12.1kg.cm(6.0V)
Speed:0.23sec/60°(4.8V) , 0.18sec/60°(6.0V)

It's a very heavy pretty much full CNC Lighting Stadium PRO-R with wide GRP tires/wheels.

bikeracer

Stick an ACE 1015 in there and have done with it.

Dunno where you got the 645 from that's precise and centres great,all the ones I had before they failed early or caught fire never centred in the same place twice in a row.The Hitec rep said it was basically my own fault for buying their cheap sport servos!!!

.

Technex

ACE = Thunder tiger right? No thanks...

The 645 I have centres fine... Anyhow, I already said I'm not going to get the standard 645 thanks.

Druss

Tech you have it backwards, Ace makes them, Thunder Tiger private labels them. I have 3 of them and they work as well as my futaba 9452s.

Argess

Quite a while back I bought the 645MG for a steering servo in my Savage 25. At that time, it was a recommended unit for that applicaiton. I think at this time, there are a lot more choices. Regardless, I have never had an issue with the 645mg. Works great.

dacaur

I have 2 645's and have never had a problem other than they are sooooooo slllllooooowwww.....

46u

My Feedback: (3)

Just curious have you all ever tried fast higher torque servos? I had a 645 in my Savage once and after getting good servos that are MUCH faster with 200 oz of torque I will never go back. Hard to compare unless you have tried both.

Argess

No, 46U, I havn't. I'm sure there are better units out there. When mine finally packs it in, I'll upgrade to a faster better unit. However, as I'm a poor driver, who does off-road bashing, would I benifit from a faster servo to a noticeable extent?

Crave

I have 625MG and it almost never centers properly, it's a real pain.

dacaur

Yes. When you have a slow servo, the wheels dont turn as fast as you can turn the steering wheel.. and when making small corrections, you will tend to overcorrect becase the truck is slow to respond.. you get used to it eventualy so you can drive it ok and dont even notice it, but you will be amazed when you upgrade to a faster servo... the truck may feel twitchy at first till you get used to it, but you will be a better driver for it...