Actually this is wrong. Jim is getting 300 oz/in of torque at 2" from center.
In servo specs that translates to a lot more. Servo torque is measured in oz/in or ounces of torque, 1 inch from center.
I don’t know exactly what the formula for it would be but I would guess 300 oz/in at 2" from center would be close to 500+oz at 1" from center.
So already his setup is out torquing the HS-805 and HSR-59XX series servos. At 2" from center, I doubt my HS-805’s would give me 70% of their rated torque at 1".
I’m not exactly sure what the proper conversion for every inch from center you move out but his 300oz/in at 2" would be more torque than an HSR-5995 at 1" on 7.2V. And Jim’s mosfets probably won’t jump off the board the motor won’t melt away if it is used continuously at that voltage.
no, he has 11 lbs 1 oz at 2 inches. that makes 22 lbs 1 oz (or 355 oz.) at 1 inch. so it gives 355 oz./in. But still that is great for a first try, imagine when he will try it with an even more poerfull mortor!!! And it will be great, it has almost the same torque as the 5995/5955 and it will be less expensive, so he will be hable to put it on his Lynx arms, so they will have tons of torque for a fraction of the cost. The Lynx arms where (and still are) better than any other arm on the market and that will only make them… just 10X better!
well me personally i like it and expect with the right gear ratio and the right motor combo this will do what “cant be done” better hurry before japan does it
Hey EddieB, yes you are correct. The extrapolated torque, that is the motors torque multiplied by the gear reduction, is usually more than the gear train can handle on very large (over 200:1) reductions. It’s also important to understant the torque values we are working with are STALL TORQUE values. While my MOTOR can handle the stall condition many servos can not! Many people know what happens to a 645 or 5645 if under too large a load for too long… Either the motor driver burns out, or the plastic melts to the gears. The GEARTRAIN on my gearhead motor is not rated for 350oz.in., but it is rated for enough to get some serious work done. If anyone builds a robot based on the stall torque value, they are dead in the water anyway. I am setting up a torture test for the gearbox at 175oz.in. to see how it performs over time. My guess is it will do much more work for much longer that a comparibly priced hobby servo.
Just clarifying some things for everyone. The 4.8 watts is at max efficiency for this motor. Max power is at 5.18 watts and 12.73 kg/cm. However that is not Max torque. Max torque(eg stall) is twice what it is at Max power, so 25.46 kg/cm. Which comes up to 353.5 oz/in so Jims scale is pretty accurate.
the original idea ihad for this too use a electric window motor (still is hehe) so i had,nt thought about the gear problem ur having with the gearheads ,how about attaching a fixed gear to a “C” bracket and attach the gearhead to the base so,as,to offload the strain,
Had to wait for the long Chinese holliday to finish before I could order motors (Taiwan). I am ordering today! I also received specs on another motor that looks to be very promissing for the stronger gear head servo.
How does 68kg-cm (944oz-in) stall torque sound? All wrapped up in a nifty SES compatible package. I’m ordering samples of this motor as well.
