I thought it would be cool to see what kind of Mechanical Actuators we could make using the 28BYJ-48 stepper motor and mostly 3D printed parts. The 28BYJ-48 is the motor that comes with all the arduino kits. It's a 5v dc motor with a max rpm of 15 and is capable of around 4 oz force/in of torque. You can get these motors with the driver for around $2 each.
##Direct Drive Dovetail Stepper Slide
Dovetails slides are not really good at long travels or fast speeds but they are very accurate with the addition of a gib to the dovetail way allows for adjustment of the clearances between the ways and the carriage reducing backlash. This is a direct drive slide as the drive screw is clamped directly to the shaft of the stepper motor. The downside to this is that there is a lot of slop in the motors shaft as it’s not designed to carry an axial load. The v3 slide I plan on making will address axial loads as it use an integral bearing flange.
The max RPM of the motor is 15, the pitch of the drive screw is .5" so the max speed will be 7.5" per minute. The motor can move roughly 7 lbs of weight on the carriage. The load capacity and life cycle can be greatly increased by using grease on both the drive screw and the way. The video shows the repeatability of the slide, after running for a few hours it was only .01" off location.
The mounting holes on the base, carriage, and the endplate all match up so multiple slide assemblies can be bolted together to make a two or three axis cartesian system.
- M3 Nut (14x)
- M3 SHCS x 6mm lg. (2x)
- M3 SHCS x 10mm lg. (2x)
- M3 FHCS x 10mm lg. (2x)
- M3 SHSS x 16mm lg. (4x)
- 28BYJ-48 Stepper Motor
Here is my amazon affiliate link to a set of five of these stepper motors and drivers. They are a little more expensive from amazon but you will get them a lot quicker.