Universal Mirror Cells - in stock.

Top view of Universal Mirror Cell

This cell takes either standard or conical mirrors from 8" to 13.1". The front plate fits the back of up to a 12.5" conical mirror.

Comes with three adjustable tube supports. Three extra tube supports are optional - for six total. Optional mirror clip sets are completely adjustable.

Perfect replacement for the Orion XT series Dobsonian - solves the problem of collimation bolts backing all the way out, requiring difficult reassembly.

 Universal Mirror Cell for 8" to 13" primaries.
 Mirror Clip Set (3)
 Extra Tube Supports (3)

Universal Mirror Cell materials and specifications.

The Universal Mirror Cell fits a minimum 8-3/8" interior dimension tube. Two 1/2" Baltic Birch plywood plates contain 2-1/4" hex head bolts held securely in the top plate. Washers under the top plate cap heavy duty flat ended springs that ride on the bolts between the top and bottom plates. Bottom of springs are captured in wells in the top of the bottom plates. Bolts pass through bottom plate, washers and contained by the collimating knobs. The tube supports are 1/8" aluminum, which can also be used as mirror clip assemblies. Wooden parts painted flat black.

Weight: 0.85 lb.
Height: 2.75" from back of collimation knobs - can be made 0.375" (see mounting below).
Mounting: Uses 1/4-20 screws - three available positions - see this image.
1.  0.375" forward of the rear plate.
2.  0.375" back of the rear plate.
3.  0.875" back of the rear plate.
Optional Mirror Clip Set adds 0.1 lb.

Optimized Standard 8", 10" and 12.5" Mirror Cells

Top view of standard mirror cell.

Bottom view of standard mirror cell.
Optimized 6" Mirror Cells - in stock
Top view of 6" mirror cell.
Bottom view of 6" mirror cell.
Min. Tube ID

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0.8 lbs.

 After your order is placed
you'll be taken to a form to enter:
(1) mirror diameter, (2) mirror thickness,
(3) focal length or ratio, (4) secondary size.
 8.0"  $130
1.0 lbs.
 10.0"  $140
1.2 lbs.
12.5" $150
1.4 lbs.
We can design and manufacture the rear cell plate to a specfic tube diameter for precise fitting. Check the appropriate box on the form after ordering. Adds $50 to price.

6", 8", 10" and 12.5" Mirror Cells: What does "optimized" mean? Each cell we ship has your mirror's support placement calculated using the program PLOP to obtain the best results for your primary mirror. We collect the necessary information (mirror diameter, thickness, focal length, secondary size) to do this calculation on a form after your order is placed.

Materials and construction specifics:

Top and bottom cell plates: are very rigid 3/4" Baltic Birch plywood. 3/8" x 2-1/2" hex bolts are captured in the top plate. Bolts pass through top plate, then through washers located under the top plate. Heavy duty flat ended springs go over the bolts against the washers. The springs are captured in machined wells in the top of the bottom plate. Bottom of the cell plate has three washers over the ends of the bolts, all captured by three collimating knobs. The spoke ends of the bottom plate are drilled transversally to take 1/4" bolts for mounting to your tube. Cutouts in the spoke ends are for lock nuts to secure the mounting bolts.

Mirror supports: 6" cells have three indexing marks on the top plate that we use for positioning adhesive backed felt pads at the calculated optimal positions to support your mirror. 8", 10" and 12.5" cells have three pivoting arms attached through the sides of the top plate with 1/4-20 bolts. The top of the three arms the height of the top plate. Each arm has two raised rounded areas at their ends which are extend 1/8" above the top of the plate. An adhesive backed felt pad is then placed at the calculated optimal position for your mirror.

Mirror clips: are individually cut to be 1/8" above the surface of your mirror and extend 1/4" to have 1/8" over the mirror surface with an adhesive felt dot underneath. 1/8" of the clip's vertical shaft extends over the top plate locking it so there is no sideways tipping. The clip is secured though its bottom outside surface to the top plate with removable countersunk #12 screws into the ends of the plate's spokes. Removing one mirror clip allows access to the mirror. Mirror clips allow 1/4" overall space around the mirror. Use thin adhesive backed felt dots for less room around the mirror.

Baltic Birch plywood is very rigid. Cutouts in the 8", 10" and 12.5" cells are designed to minimize weight and allow maximum ventilation. All cells are drilled to attach a fan. Cells measure 2-1/2" from the front of the mirror plate to rear of the back plate. Collimation knobs extend 15/16" beyond the back place. Mounting bolt holes are 0.354" forward of the rear of the back plate. 12.5" cells can be custom designed to fit inside rectangular mirror boxes. Larger mirror cells upon request.

We are always working on improving our products; above information is subject to change without notice.