Are HS-5645MG servos not needed for the Johnny 5? Since I’ve got them, should I use them or use HS-645MG’s instead (except for the actual hands where I’ve pre-built them with HS-475HB’s)?
Also, are 2 servos for the bottom Waist servo not required? Is 1 servo enough to lift that mass?
Thanks much,
Kenny
I am pretty sure that two servos are required to lift the Biped part of the Johnny 5 (best to be safe anyway). Also, I think those servos are sufficient for the Johnny 5.
I kinda decided it would be best to use two servos. Does that mean I actually need to use 4 servos at the base? Guess I would have to mount a dual servo bracket on the bottom C bracket? Darn, I’ll have to get all the Powder Coating stuff out again cause I only coated 1 dual bracket 
Which servos? The 5645’s or the 645’s?
The head is going to weigh a little more than 1/2 a pound and I’m thinking making one of the arms a long Johnny 5 style arm.
I originally put a 645 in the rotating base and then replaced it with a 5645. I really don’t know which servos to use. I stocked up on the 5645’s just for this purpose (my Johnny 5) and now I don’t want to use them 
But, I also don’t want to have to take this thing apart and rebuild it several times because I cheaped out and turned it into a wimp.
Jim, what servos are you going to include with the Kit when it is released?
Kenny
Ok, so I have this expensive programmer and these programmable 5645 servos. Because servo horns never fit exactly alike and because I’m using the aluminum horns, it seems that there has to be a way to set both servos to the same mid point programatically rather than physically by drilling new holes in the horn. 
I did the end stop programming as instructed on the site and I guess that somewhere in that bit of programming, a new center point can be set? I’m not exactly sure how to go about this.
Kenny
Hello Kenny,
Yes the programmer can be used to set the center and end stops. The instructions with the programmer explains how to do it. I honestly never thought about calibrating the two shoulder servos. I’m sure it could be done.
The first version of Johnny 5 had the dual servo bracket on the base. I used 645 servos for everything except the hands. I used an aluminum horn on the inside servo, but just drilled a plastic one for the outside servo to align them. It had a pretty good range of motion on the waist servos. On the latest version of Johnny 5 I opted to use only a single servo on the base with the understanding that the range would be limited to expression, not necessarily allowing the ability to bend over to extreme levels. I will probably use 645 servos for everything except the wrist and gripper which will use 475’s. If you have 5645’s I would use them in the two waist servo positions, the upper and lower servo positions. Because the arms are mostly for expression I don’t think 5645’s are required throughout as there is no real problem if the servos don’t position precisly. However if your plans involve the need to accurately position the arms I would go 5645 all around. 8)
