Waist Turning Actuation With Servos , Lazy Susan?

 
#1

Hey.Bret brought out the lazy Susan furniture bearing idea. It's two flat plates with a bearing in the center. Any other ideas?? Another question is how to connect the servos to waist to move it.

Idea: two tires that fit directly onto servos are included in the kit and two continous rotation servos. I see all the time at carnivals the way they mount the electric motor there is a wheel and tire on the end literally pressed agianst what its turning. No gears to strip out.
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Why not do somthing like this? Take in mind my upper section weights 15 pounds because of batteries.

I have a regular omnibot drivetrain if anyone thinks that's usable. (regular Omnibot drivetrain is almost as strong but only 2/3 size.

#2

Using a wheel on a servo or motor is how I would do it. If you have electrical connections between the top and bottom sections though, you will want something to stop it from Turning completely around Say that you don't twist or break the wires

#3

Yea at the most the waist would have 180 degrees of.motion , 90 degrees right/left. there will be many wires passing from torso to base but with a few inches slack that shouldnt be a problem. That being said my challenge here is

1 picking where and how to cut torso

2 when I.make a torso base for the swivle plate (lazy Susan) to connect to. The front and Bach half must still be able to seperate so I can mount arms , neck and head.

#4

mcmaster does have small and large lazy susans ,small low cost about $8

#5

@jstarne1 - Since the lazy susan bearing takes all the weight and is very smooth action, it will take very little effort to rotate a lot of weight. One of the High Torque servos like I used in the shoulders of my omnibot should do fine. Mount the servo via a large servo horn to a cross piece in the bottom of your upper torso, and have a flat solid cover over the lower section with a hole cut in the center that just fits the outside dimensions of the servo. The servo is free floating in the lower section, however the lazy susan bearing holds the two sections together. I would separate the two sections right where the torso becomes the base. Forgive my quick and crappy drawing but I hope this helps to get my point across.
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#6

@jstarne1 at servo city they have a new gearbox for making turntable using worg gear and motor ,with 101 rpm motor plus gearbox you get 3 rpm at 37 lb of torque at 30-1 ratio

#7

How big is the Lazy Suzan that you have?
if 18" dia
You may want to either replace the bearing balls with acetal bearing ball(cMaster Carr part number : 9614K57 6.51 per bag of 100 http://www.mcmaster.com/#9614k57/=ggq132
and add some tefol spray to loosen the rocker bearing up. Its a bit stiff when you first purchase one.

use a pittman motor and a 3" diameter urethane wheel with a 3/4" diameter center for the axle
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anchoring the motor/wheel against the inside of the lazy suzan and connect the wires to a motor controller and then to EZ-B and you can have the lazy suzan rotating full circle or back and forth.

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hope that helps