Saturday, August 16, 2014

Motion Control Rig Part 2

As we continue, the next thing I tackled was the camera cage. This was made from two 6" steel L brackets attached to two half-inch thick expanded PVC halves. Using a Dremel, I routed out channels in each of the PVC halves for accessory rails to slide through. I attached a quick release camera mount and bolted all the pieces together.

Using a small stepper motor from one of the printers, I was able to make a focus/zoom controller. I designed parts in Adobe Illustrator based on the size of the motor and the distance between the accessory rails. I was then able to use the CNC router at work to cut the parts out of acrylic.

I wrestled with a couple of ideas on how to get the tilt function working. After figuring out that my first option was going to be more complicated than it needed to be I ended up going with option two, which you can see below. I attached a Nema 17 stepper motor on to the upper L bracket and screwed a gear into the lower L bracket. I then ran a bolt through both brackets and the gear for a turning point. When the motor turns, the whole lower bracket tilts. The holding power of the motor keeps the position of the bracket when stopped.

For my Z axis, I was given a linear slide powered by a Nema 23 motor (thanks, Ivan!). I used the CNC router again to cut a mount out of half-inch thick acrylic.

I attached the mount to a pan mechanism that I had already built. The pan system was built around a bracket I had pulled from an expired vacuum fan out of a large flatbed printer. A small "Lazy Susan" connects the bracket to a round MDF piece with a hole cut out of the center.

Using silicone, I glued a timing belt around the outside of the MDF circle. I then mounted a Nema 17 motor to the bracket so that the motor's gear grips the timing belt and turns the MDF piece when powered.

That's it for now.  Still more to come...

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