For the turrets rotation and elevation control we looked into several options and finally settled on the Saber tooth dual 5A motor driver for R/C by Dimension Engineering. Normally used in combat robotics for motion control, this controller really delivers performance for this project. We will post a cheaper motor control concept in the future, but for 60.00 it was a no brainer for this paintball turret.
Honestly I haven’t met a Susan that deserved to have a lazy device named after her… in fact this highly useful device provides both the drive method for rotation on our turret as well as a strong durable union between control base and turret. The plans are designed with both 6” and 8” Lazy Susan compatibility.
The drive shaft and Barings:
This is the important key to smooth movement on the elevation control for the paintball guns. We are using ¾ OD ¼ ID ( that’s .750 OD and .250) skate bearings because of how easy they are to find. We also are using a 11-14” precision .250 (1/4”) shaft to connect the drive sprocket to the upper turret elevator assembly. The shafts are inexpensively available from robot market place… however use them at your own risk, I have personally had some bad experiences with their fulfillment methodologies…
The motors we will be using are GHM-02 or a ML-50 50:1 Geared Motor for the elevation drive motor and a COPAL 30:1 Gear motor for the turret rotation. These will run about 25.00 each typically, however you are welcome to use any motor you want, and the designs are fairly flexible with regards to motor choice.
Matt Trossen of www.trossenrobotics.com is an excellent provider of motors and other robotic equipment and I highly recommend him as a vendor both from personal experience but also as a favor to a long time supporter of inventgeek. If you’re a fan of inventgeek, support Matt for helping us grow and do projects during tough times.
We picked up these battery packs up from Digikey for about 2.00 each to provide power to our motor controller to drive the motors in the project. One of the nice features about the Saber tooth is an onboard BEC (battery elimination circuit) that reduces the battery requirements by one pack in this system.
Noise reducing capacitors:
To reduce the electrical noise from the solenoids and motors in this system (thusly improving its controllable range and predictability) we will be using Monolothic ceramic X7R series capacitors from Panasonic. 0.1uF at 100 volts.
One note on power tools: use them at your own risk. Be sure to read and understand any and all documentation on the tools you use. No amount of documentation can make up for experience, but there are many people with serious eye injuries from the school of hard knocks. If you don't know what you are doing, don't do it, and find someone that can help.