building a lynxmotion robot with tower pro sg5010 servos?

[animaniac]

hi everyone, I plan to built my first robot on a budget, so buying 18 servos ain't cool... do you know if it's OK to use cheap chinese servos sg5010? their specs are the same as the basic ones except 5 times cheaper! if you know a better brand or where to get good deals, thanks in advance.

[Joker94]

well cheaper servos are ok but they come with a few payoffs. i have found that the gears are often made of more brittle and often more delicate plastic. it is ok if you don't plan to have heavy loads. they defiantly wont be as accurate as more expensive servos.

the reason they are 5 times cheaper is they are 'clones' of a 'real' servo. they have cheap electronics and cheap gears and all.

so in the end it all comes down to how much you are willing to sacrifice for price. you will be sacrificing quality and accuracy.

what sort of robot will it be and how much accuracy do you need.

[animaniac]

I plan to build a hexapod (18 DOF) then a biped walker (12 DOF). I heard the MG995 was horrible so I am concerned about performance. will it be precise enough for a walker? how does the servo react during slow movements? is it jittery?

[Joker94]

if you have a good connection and a clean PWM signal it should not be jittery.

the biggest factor that will cause jitter is weight on cheap servos. better quality metal gear servos i have found to be the best for none jiteringness.

i am not sure how it will go with the weight of a hex or biped. my guess is that all of the servos will be different. theoreticallly it will be fine as the weight will be low but dont hold me to that.

[paulstreats]

One thing that I have found with cheaper servo's is their physical weight. The cheaper ones perform similarly to the more expensive ones but they weigh more(due to having larger motors and lesser gearing).

 While not seeming like much of a disadvantage, it can lead to an overall detrimental effect to something like a robotic leg.

[KurtEck]

Another thing to consider is will the servos fit into the lynxmotion brackets.  There are some servos that are larger than the equivalent hitec servos and have problems.

Kurt

P.S. - On my first Hex I was short by 2 servos when it arrived, so I went down to a local hobby store and bought a couple of equivlent ones.  Both of these two have since fried themselves where I think I have only had one hitec 645 die (out of 16 when first built 18 now).