Elements in Harmony IV

36"f/4.5

If it's up there, it's in here.

April, 2006 - May, 2007




It all started with an email. He had a mirror, I had a truck it fit into... Deal.

The 36" mirror front....



36inch mirror front.jpg

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The 36" mirror back....



36 inch mirror back.jpg

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Due to the honeycomb structure of the backside Vaughn sent me a pencil relief drawing of the backside before I picked up the mirror. This enabled me to start fabricating before the Memorial Day trip up to SLC....



Mirror Template.jpg

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3" square steel tube was used as the frame of the cell. Calculations show no part flexes more than 0.0002 of an inch....



Steel Cell.jpg

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Time for some welding!



Time for some welding.jpg

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Well on my way to having a scope..., yea right...it's just the beginning.



State of the Workshop.jpg

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Memorial Day Weekend Road Trip!!! 10 hours of driving we were at the Bryce Canyon Pines Campsite just 2 hours south of Salt Lake City. We got our campsite as a base of operations, made the two hour trip the next day to get the mirror and get back to camp. The third day we drove the 10 hours back to the Phoenix area.



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We got the tour of Vaughn's workshop and loaded the mirror crate into the back with a half inch on each side to spare....



It fits....jpg

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Safe and sound in the garage....



Home safe in the garage.jpg

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Stuff is getting attached to the cell....



Cell Front.jpg

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The remote colimation feature puts spring tension on the belt since they can strech over time....



Cell Back.jpg

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The larger sprocket is pinned to a 1/2-20 threaded rod which passes through a custom brass insert. The other end of the rod is attached to the cross member and secured so the cross member can only teeter-totter with the triangle supports at each end....



Motorized Collimation.jpg

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All the mounting holes are there with the exception of the light blocking pieces of 1/4" Masonite board....



Getting there.jpg

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Here all the wiring is done. in the clear bag near the center of the cell are the RH (relative humidity) sensor and the 5 thermocouples....



Solar.jpg

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30.1% RH in the garage....



30.1% RH in the garage.jpg

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The control box and TC meter along with the wiring harness. The white connector at the right is the remote collimation 9 pin cable that goes to a small hand paddle with three center-off ON_OFF_ON toggles and a master ON_OFF once colimation is done. Then it just unplugs from the control box and is stored.



Control Box.jpg

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1/4" stainless steel cable wraps around the perimeter and there are two support stanchions at 45 degree points with 2" travel linear bearings attached. Once the mirror is put in place the cable will be placed on the center of gravity, taking into consideration the 1/2" depth of the curve on the frontside and the 19 hexagons (no shortage of math problems). The linear bearings will give near-zero friction when the mirror is tilted by collimation and keep the mirror centered....



Linear Bearings.jpg

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