Yes that is the goal, bigger, stronger etc. With the 32mm motor in the shoulder and the 22mm motor in the elbow I’m shooting for 16 ounces, but we’ll see what we can do.
sweet ,my life size johnny 5 is looking closer.
Jim u gonna put a warnig label on em
“USE OF THIS PRODUCT MAY CAUSE LOSS OF LIMB OR DECAPITATION” 
Here is a video of the prototype working with a Hitec 5755 amp! It doesn’t work perfectly, the deadband is too large. But it does show the mechanics are sound. Note the current arangement is not an accurate representation of the final product. Just a prototype. 
So anyway check it out.
lynxmotion.com/images/temp/ossmove1.mpg
thats is BRILLANT!!! thats looks so nice and smooth 8)
id like to see what it can do strength wise
THATS SMOOTH! And precision of the positioning looks nice too. I cant wait for that! Its deffinately a MONSTER servo!!!
21.653543307086614173228346456693 lbs.in stall
346.45669291338582677165354330709 oz.in stall
64.935064935064935064935064935065 rv.s shaft speed ,soooo lets gear it down too 1 rv.s
21.65lbs.in * 64.93=1405.7345 lbs.in 
???
where did i go wrong,this cant be right
It’s correct, the only drawback is the slow speed. The 60 rpm is about the speed of a servo, so it should work well. The cool thing is the motor can be swaped out for more reduction. this one is 231:1 and is 60rpm, the 455:1 is around 30rpm, and the 1014:1 is about 13 rpm. We’ll have to test the torque and performance of the two other ratios.
I did some torque tests tonight. I was able to get from 300 to 355 oz.in. at 7.2vdc. The scale is reading foot, ounce / at 2" from the axis. So you double that to get the ft .in. torque value. Multiply by 16 to get the oz.in. value.
Overall I’m very pleased with the performance. The motor warmed up nicely as I put it through a beating. The servo is capable of drawing 2.3Amps continuously when at stall, but the all metal geartrain was no worse for the wear.
300-355 oz./in @ 7.2V? Not to be a downer, but both the 805 and the 5955 should be able to do that.
I really hope the other geartrains have a dramatic effect on the torque. But in theory they should not. The equation, I believe is P=Tw where:
P = Power (kW)
T = Torque (Nm)
w = Speed (rad/sec)
(non-SI units have constants, but the linear relationship holds)
So gear train should linearly effect torque giving 700 oz./in and 1450 oz./in respectively.
Can the motor run at higher voltages? Evolution showed the 805 can go slightly higher and draw similar current for more torque. If this motor is close to the 805 at 10V we should be able to expect around 2000 oz. /in of torque at 13 rpm.
While this may seem impressive, I just want to remind everyone what industrial servos can do: active-robots.com/products/motorsandwheels/industrial-servomotors.shtml
That’s ~10,000 oz./in (120 kg/cm x 89.6) at 12V. That’s roughly 30 pounds at 2 feet worth of torque. Granted that’s almost a $500 servo, and twice the size of a Mega scale servo, but still.
The Biloid servos goto ~20V and get a lot more power (1400 oz./in range), all in the same size as a 5955 causing me to seriously consider OpenServo modding my 5955s so they could take higher voltages. However I doubt the stock 5955 motor could go to 20V, but going to 10V safely and getting a boost to 500 oz./in would be good (or 12V 600 oz./in bursts). The heatsinks might also help push the limit here further.
Just to note, I’m not trying to knock your hard work in any way. My disappointment only comes because I had set my hopes so high. Even if things only work out to my conservative estimates, there still is a place for a budget 2000 oz./in slower servo. Here’s hoping that there is some other problem causing it not to get as much torque as it should so that the finished product does even better. 
I understand what you want to say tillin9, but I think this open servo was made let’s say for the shoulder of an arm. so you could get the power of a 100$ servo for much less.
How can you modifie the 5955 (or any servo) so it can be overvolted? you have to change the motor?
Sam
and the electronic boards inside.
what is the gear box torque rating as specified by the manufacturer? It is very common to find motors capable of much higher output torque attached to gearboxes rated for less. you may not have noticed any wear after an hour of experiments but if you are exceding the design limits of the gear box then you may suddenly see it as a broken gear rather than some gradual wear pattern immediatly noticible by the human eye.
I am not trying to discourage anything either, rather just passing on observations of some customers products problems observed over the years. The cool thing is that when you identify the weakest link in a system and bring it up to the point the system meets the design requirements, then frequently you can then downgrade other components that are significantly over powered and realize a cost and size savings.
Not to be a realist, but this is exactly what I was expecting. Actually a little higher than I was expecting. The 5955 is $114.00 and would still require brackets to be able to build something. The 805 is analog (pretty much useless in high torque applications that require precise positioning), still requires even more expensive brackets, that don’t yet exist, to be able to build something with it. This servo will only cost a bit more than the 805 and does not require any additional brackets to integrate into the Servo Erector Set series of parts. Plus it will have the OpenServo I2C control capability with all of the other features associated with it. The thing to remember is this is the first of several gearhead based servos. I’m looking at a 32mm motor version that will be stronger. I’m also looking at a dual motor version of this servo that will have 700 oz.in. of torque.
Yes, this is a 12vdc motor. I can’t test it at 12vdc until I get an OpenServo board.
This has no bearing whatsoever on this project, and what it’s meant to do.
Im sure if Jim has decided to this its has already been backed up with information and research. Im sure its something all of us will need when its done. Heck, Ive been thinking of trying to build an entire arm out of this beast! Im sure the capabilities are way out of our expectations (as most of Jim’s inventions are )
Im sure I will buy 10 of these things when it comes out, SO NO MORE NAGGING THE GUY! LET HIM GET BACK TO HIS WORK!!
Joe I’m not certain if this is supposed to be a joke or not, but I thought the entire point of Jim putting his work out in the public eye was to invite comment and discussion from the group. The alternative is to design in a vaccum and hope more then the 5-10 people you discussed it with can find a use for it. 
lol, I can find many uses for it. Im not sure if EVERYONE ELSE can, but Im certain that more people will be able to put it to good work. Im not saying that your advice, input or conversations about this is not important or necessary, Im just excited and cant wait for Jim to finish this and put it out on the market. As I understand, this setup will replace servos for the shoulder and elbow of an arm and give more lifting capacity to it. I also understand that servos right now cant do this very good unless your willing to spend alot of money for high end servos. This will be cheaper which is why jim is building it right?
anyways, I didnt know this was “publicity kinda thing” to get people involved with it… 
Boy do I need an disclaimer 
I don’t know that I meant to imply generating publicity so much as gathering input from a cross section of lynxmotions user base, which this forum at least partially represents. consider that even the regular posters here range from high schoolers to college students to straight hobbyists to professionsals who also fringe upon (or more) this as a hobby. all of them are presumably lynxmotion customers and we all know for any group of active people posting on a forum there are 10x or more lurkers who just read. so you are probably correct it that this works as a sales tool as well, but I was thinking of it as more of a research tool for both marketing and technical perspectives.
A $50 gearhead motor below in the 64,000 oz./in range for the really big robot. Might have to remove the spool release knob in order to mount a pot on the end.
I see now. I think deffinately that people should ask and answer more questions rather than lurk around the forums…So if we look at it that way, its working isnt it?
I’m just like any other forum poster. I like to show off what projects I’m working on, and I invite constructive feedback. Hey, we’re all in this together.