Reducing chatter in the RA gearbox

Reducing chatter in the RA gear box

Today was a slow day focused on just two objectives: getting the RA gearbox to chatter less, and learning to use the CCD camera software.

We have known that the RA gearbox “chatters” quite a bit, the sound of the meshing of the teeth of the stepper motor axle gear to one of the two former planetary gear boxes (the planetary function reduced to a simple rotation). When I loosened the mounting bolts and manually hold the drive gear, it was perfectly quiet.

What’s more, the RA axle gear has two sets of teeth, a larger, outer set and an inner, smaller set–the design of that particular axle fitting as provided by Alan of AWR Technlogy, England.

While Dan and I had believed the inner, smaller gear of this one-piece configuration was not touching the outer of the two planetary gears, a close inspection demonstrated otherwise. So, we set to filing the inner teeth down to a smooth surface to make certain there was no undesired, secondary contact (it sounds more complicated than it really is).

Elineema, Eliatosha, and I borrowed a file from the kitchen staff (who use it to sharpen knives) and in roughly 30 minutes had the inner axle smooth. Upon reassembly, the chatter was notably reduced, but remained. Further testing found the position of the stepper axle 0.5mm too high such that the teeth of the axle gear do not fully set into the brass teeth of the first RA gear. I am going to consult Dan on whether it is ok to leave this as-is, or find a way to reduce the gap.

At the same time, Zacharia worked on the control software for the Orion CCD camera. It is a finicky, clearly incomplete piece of software that works irregularly, at best. We attempted to set the white balance and contrast, as instructed, but for the most part, are unclear if it is working.

Tomorrow a contractor comes to clean, wet sand, and apply a coat of epoxy to the floor. Finally, we will have the floor we intended with a beautiful shine that is easy to clean. Shoes off policy from here on out!

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