To start i’m sorry if this has been asked before, i did a search and didn’t find much.
I want to know what the best servo to use with the scout system is, that is also the cheapest. I’m thinking $15-20 per. I know that is a pretty tight budget, but i need some advice. Lynxmotion recommends using the HS-5645 servos, but that would be near $600 just for servos. It also says the system can be used with the HS-5475’s. I would like to know, how much weight is minimal configuration. Would i be able to add a custom torso and sensors…? Is there an even better/cheaper servo, or a modification for them?
Can i use a combination of those two servos?
Times are tough and i cant spend that much money to get started. Maybe sub $500 at maximum.
Thanks
-Quinn
Lynxmotion recommends using the HS-5645 servos and rates these servos to be the minimum ones to use, because simply 'other servos just wont cut it. you can certainly mix different servos. you might like to change some of them for HS-645MG servos, but your fully rigged scout will have problems walking. i tested different leg designs to save on weight and cost.
I’m working on a scout right now and I went with 5645’s. I got them for a fair bit less than retail because I went into my hobby shop and told them I wanted twelve.
As for their strength, I have found through testing that you can safely run them at 7 volts or so and get a bit more torque. We do it in rc rock crawling all the time. I power mine through a 10 amp switching voltage regulator that is programmable from 5-9v in 0.1 volt increments. I don’t have a whole lot of weight on it right now but I can push down on it pretty hard without it moving.
Whatever you do, try to use digital servos. It seems they are better at holding a position for a long time than analog servos are… maybe check out some of the bluebird servos on hobbyking.com
I would not recommend anyone use 5645s at 7 volts. I would encourage them to use the 5685 which is the LiPo friendly version of the 5645. The 5685 is designed from the ground up for Lipo battery use.
Think of it this way Jim, a ‘6 volt’ nickel battery is around 7.5 at a full charge, and the servos are fine, right? so running a 5645 at 7v is actually about half a volt less than it sees when connected to a standard 6 volt nickel battery. The lipo friendly servos can handle up to 8.4 v, which is what a 2s lipo is at a full charge… which IS a bit too high for a 5645… but I feel that 7 volts is just fine.
I would say more like 7.25 vdc fully charged. It’s in our battery specs. The NiMH will not hold that voltage for very long though. Within minutes it is in a comfortable range. You’re using a regulator for 7 vdc which does help immensely. I wasn’t really thinking about that when I posted. We’re good.
Ah, yes. I would definitely not use a battery that had a 7v nominal voltage. The closest thing to that would be a 6 cell nickel battery at 7.2v nominal, and 8.5 or higher at peak. O.O
We tried the 10 amp CC BEC on a Phoenix, but it could not handle the surge at startup. The Phoenix draws around 8 amps when walking and only about 1 amp standing still. So it should have worked. A biped should not have this problem though.
Also what are your guy’s thoughts on different powering options, it was getting pretty specific up there, i’m talking about is there a way to use my boards I/O ports and its 5.5v output, or a separate 9V battery… are 9V’s okay to use?
What if you threw some 5980’s in the mix? Say 8x5685 and 4x5980? Which servos in a standard scout are under the most load? Or is the next step up to just go with 12x 5980?
