Hi there. I am a total newbie so please be as basic as possible when replying. My goal/project is to build a simple dummy that has moving arms. What i am trying to achieve is a practice dummy for martial arts. The arms do not ned to articulate, only move in and out over a 3 foot maximum distance. I have no desire to use pnuematics or hydrolics so would prefer a simple motor driven system. Like i said it is only a simple design i am after as i am sure that even that would stretch my mind let alone my income. Can any body suggest a setup or perhaps direct me to the appropriate place to find plans. The dummy itself will not be hit, and the arms will not be put under much strain as it will be used to practice blocking tecniques. I already own a ‘wooden dummy’ that is static and this helps great with form but not reaction. As an extra thought, would it be possible to implement a random timing of arm movement with out needing to use software/pc etc. Many thanks in advance for your time and help.
You want to move the arms of the manikin? Wood is a bit heavy and would require a strong motor, something a standard servo would not be able to handle. A micro controller could provide random movements but this requires a PC to be able to program the MCU but once the MCU is programmed, a pc is not required.
I’m not sure what motor would be strong enough to move the manikin arms. For me, I would probably want to use pneumatics for this type of application to keep it simple, because if motors are used, you will likely need to deal with gears and clutches to protect the motor.
Thanks sn96. If i was to use pnuematics wouldn’t i need a compressor? Its not that i am against pnuematics but i am unsure as to safety due to the high pressures etc. The arms don’t need to be wood, preferably coiled metal spring or robust flexi-plastics.
A full size arm is going to have a lot of leverage at the joint. Even metal coils is going to be hard on the servos especially if it is whipping around like springs do.
The only thing I can think of is to use Styrofoam. You can shave it, cut it and glue it. This would be light enough perhaps to make the arms and the servo could be inserted directly in the foam if you carve a nice profile where it has a snug fit.
Ok. I think styro foam would probably break, i know its tuff stuff so i will have to get some and test it. Other than that do you have or can u direct me to plans for pnuematics and motor driven models? many thanks, Lee.
You’ve got several issues you will have to deal with. Are you actually going to be striking the dummy arms that will be moving? For pneumatic actuators, you will need an air compressor and air control valves such as those in paintball guns or pneumatic spud guns. For a pneumatic actuator, you might get by with using a modified hand tire pump. Do some google searches and post up what you find.