Abstract: 

Why go slow? We need to take pictures at very slow speeds and at a continuous rate using a hyperspectral camera! With the old electronics board, this was not possible, but the new one works amazing!

Objective: 

Rotate the stepper motor at very slow and steady rates to allow the camera to take pictures. 

Materials and Methods: 

Using the Sparkfun’s EasyDriver Stepper Motor Driver, we are going to drive the stepper motors for this project. We were previously using Adafruit’s TB6612 Stepper Motor Driver but it was not giving us the performance that wee need.  Here is the wired up motor driver:

Results:

Using Sparkfun’s board we are able to achieve the results that we wanted. We are going use the new board instead. It works great at very low speeds and is very steady.

Dependencies: 

https://www.sparkfun.com/products/12779

Most of the design for the rotating system is complete, but there are still some minor things to straighten out. One of the next things to design is the actual attachment to the pole that will be holding the whole system. This attachment has to be really strong because it will be holding the whole weight of the camera and rotating system. Here is the initial design of the base:

My initial idea is to have the attachment slide over the top of the pole and use some bolts as set screws to make sure that it will not move or fall off. The attachment has to also be connect to the motor housing. As of right now, I have four bolts coming from the motor housing into the base attach. I am trying to think about a way to get the nuts into the piece itselft, this way they are secure and will not fall out. I might just end up making a bigger holes on the bottom and use a socket to tighten them. Here is the the pole that we are using for this project.

This week I will finish the design and print it. I will then proceed to mount the rotating system on it, and start testing the whole thing. 

Here is a video for this week’s update. We now have the Arduino driving the motor. There are some things to work out with the 3D printed parts, but we are seeing the project come together.

I have 3D printed the pieces from the initial design. Here are pictures of the pieces: 

This is one of the most important pieces of the whole assembly. This made from two pieces that screw together. The top piece holds the 360 swivel in place and the bottom piece is the shaft coupler. The next iteration needs some improvements, but this design works great. 

This base is the rest for the shaft coupler; the base plate of the shaft coupler rests on the bearings. The shaft base connects to the motor housing making a solid base for the camera. 

Here is the assembled piece. The motor electronics have been tested and soon will be integrated. Some more things have to be edited in the desing before printing a working version. 

The post before this one outlines the CAD for these pieces, for a more detailed description of the design look below. 

This project is intended to be a mount for a hyperspectral camera. The interesting thing about this project is that the mount has to be able rotate and tilt up and down. The spinning and tilting will be determined by the user of the camera. Here I will post pictures of the CAD renderings and explain how they all go together. 

This first image is the model of the first design. This mount is composed of four printed pieces: motor mount, shaft rest, and the shaft( motor coupler). the shaft is made out of two printed pieces that are then screwed together.

This 3D model is the shaft base/rest. The base has four ball bearings on which the shaft will be resting on. Theses ball bearings will allow for a smooth rotation of the camera. If these were not to be there, the shaft would be resting on plastic and the would potentially have a rough rotation. The hexagons that extrude from the sides are the locations of the ball bearings. This base will be the connecting piece between the shaft and motor mount. 

This 3D model is the motor housing. It is a pretty straightforward design. This model will house the motor and connect to the base that will be connected to the pole. It has slots that will allow airflow through the piece and keep the motor from overheating. 

These two models are the shaft/ motor coupler. The top model is the piece that attaches to the 360 swivel and the bottom model screws on. This is the piece that rests on the four ball bearings and will be spinning.

I will now be printing the pieces and verifying that they all fit how they should be. Most of this design will be used for the other project. This other project will also be for the hyperspectral camera, but this design will have rails instead of a pole.