Mirror Cells for the ATM-er
We are excited to announce we are now selling our custom flotation mirror cells specifically made for the amateur telescope maker’s mirror box. Our structures are professionally welded steel frames that substantially increase the overall rigidity of the mirror box.
The flotation points are first plotted with PLOP, then transferred to the bench at which we machine all of the necessary parts. Our frame work is of an open design, allowing for ample air flow to circulate around the mirror. After the frame is professionally welded, it is powder coated flat black for a beautiful and durable finish. The flotation triangles and support bars are machined from 6061 aluminum, while the points that come into contact with the back of the primary mirror are nylon. They are actual continuous points rather than large felt pads. By using this combination of materials, the structure is not only rigid, but the bottom of the mirror has more room for air to circulate which helps when trying to cool the mirror.
Inspired by the aftermarket adjustable sling by Howie Glatter (if you currently own a good mirror cell we strongly recommend his adjustable sling accessory), NMT has integrated an adjustable steel sling edge support into the frame work of our mirror cells. We use a welded 90 degree angle iron integrated into the framework of the cell itself as the connection points for our sling. This is superior to 3/8” bolts as the angle iron isn’t going to bend many a 3/8” bolt is known to do over time causing serious collimation woes. Affixed to the angle irons are linear bearings that have custom machined turnbuckles connected to them. After the primary mirror is dropped into the cell, the sling is carefully wrapped around the edge of the mirror and placed at the edge of the mirror’s true center of gravity. The turnbuckles make adjusting the size of the sling a snap! When the mirror is collimated at the beginning of an observing session, the sling moves up and down on the linear bearings, effectively keeping the connection points in the same plane as the edge support. This is a must with large thin mirrors. Without this integrated adjustable sling, astigmatism from “potato chipping” can cause less than desirable views, specially when pointing below 45 degrees.
When you purchase a mirror cell from NMT you won’t find yourself looking for any aftermarket hardware. Three large collimation hand knobs are included and connect to the 3/8-16 bolts that are used during the collimation process. We also include 3 large 3/8-16 bolts with mirror retaining clips that will be placed above the mirror.
To place an order for a mirror cell, we simply need the inside dimensions of the mirror box, the diameter of the primary mirror, and its edge thickness. We do not currently offer for sale 6 or 9-point mirror cells, however, an 18-point flotation will work beautifully for most any sized primary mirror from 12”-24”.
Mirror cells between 12″-18″are also available in aluminum, rather than steel, resulting in a reduction of weight by over 60%.
12”-14” – $398
20”-22” – $598
24”-28” – $698 27-point cells are available at this size for an additional $200.00
Custom sizes available: Please contact us
Current lead time on an NMT mirror cell is 30-45 days.