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Aluminum Mirror Cells.  Copy this from to your computer, fil out the important numbers, and email to

Joe and his equipment in the High Calif Desert
Draper, Grinder, Manual Grinder, Overhead Crane, Mill, Lath and Bandsaws

Please down load this text to your word or notepad and fill in answers.
Type in your answer by adding a colored line between questions. Units can be Inches or mm, but be sure show the units.
1. Mirror cell can be made from Aluminum 5052, 6061 
                                            Plastic material ?
                                            Thin Steel material ?
                                              NO SST!! too hard to cut.
2. BOLTS and NUTS shall be in           English Inches,
                                          or            Metric mm.
3. Measure the Outer Diameter of mirror to 1/16 inch =       
                                               Check for out-of-round.

4. Measure mirror outside EDGE thickness =             units?                  .
5. Does your mirror have a flat bottom ?  yes      or       no.
6. Mirror has a center mount bolt?
      If your mirror mounts from the center let me know, i can modify.
      if your mirror back has a convex or concave bottom i need
                      the radius of curvature =                     units?
7. What is the FOCAL LENGTH of the mirror =                    units?
          or the Focal Number F# =
8. Does the mirror have a central hole in the middle?
                   What is the diameter of the center hole =          units?

9. Weight the mirror =                   lbs  or                  Kgm

10. Is the mirror outer edge a flat edged        or          tappered.
If tappered what is the OD diameter of the bottom edge of the mirror      units?
                                                                  and Top edge                  units?

11. There are two parts to the mirror cell.
The back plate that mounts in the tube or box ID ?
    I can make you just a new back plate ?
    I can make you just a new mirror cell plate ?
    and you mount your old parts around the new plate.
12. THE BACK PLATE must fit inside the ID of the tube or box?
               what is this ID of the tube,    units?
              the box ID width            and            length units ?

13. I need the tube wall thickness?     or    OD diameter  if a round tube ? =
14. I need the square box wall thickness if you want a square back plate?
15. You can choose a different material for the backplate ?  Al or Plastic or Steel?
16. The back plate can have a hole in the middle for a cassigrain focuser.
     what diameter hole do you need so your focuser will fit =           units?
17.  The back plate can have a center hole for a 9volt DC fan if not using it
cassigrain?   Hole size is about 2" diameter.
18.  The back plate can be a "Y" shape of 3 arms 120 degrees apart?
      The back plate can be SOLID to help block dust and dirt?  which?
19.  The back plate will bolt to the TUBE ID or the BOX ID using
brackets shaped in the form of an "L".   What SIZE bolts will you want
to use to bolt the back plate "L" to the ID of the TUBE or BOX ?
inches        1/4"             3/8"             1/2"    bigger? smaller?
metric          2 m            4m               6m      other?
20.  Back plate bolts are of two types.
The standard mirror cell will have 3 bolts using springs to separate the
back plate from the mirror cell itself.  These bolts are about 1/2" diameter threaded bolts. The bolts ends in a wing-nut which you use to adjust the tip and tilt of the upper mirror cell.  I provide 3 more smaller bolts, usually 1/4", that
you tighten against the mirror cell plate to hold it rigidly in position.
A system of bolt inside of bolt is another method to attach the back plate
and the mirror cell.  This is made from a 1/2" bolt which is drilled out to allow
a 1/4" bolt to pass up through the middle.  The 1/4" bolt screws into the upper
mirror cell back.  The 1/2" bolt is then used to adjust the tip and tilt. I usually
add a spring to help off load the weight of the mirror and cell but the bolt in a
bolt does all the adjustment. You then just tighten the inner 1/4" bolt to secure
the position.
Choose the upper mirror cell material and thickness?
Materials =   Plastic about 1/2",   Aluminum from 1/4" up to 1/2", Steel 1/8"
      mirror cells up to 12.5" are cast aluminum shells.
      mirror cells over 13" are hand made from plate aluminum.
       If your mirror is thin, 1" then 1/4" aluminum should work for the cells.
       if your mirror is heavy, 2" or more in thickness then 3/8" aluminum is used.
22.  The mirror cell will be a 3 armed "Y" shaped plate. Each arm will
hold one rocker arm for the rocker pads?
      The mirror cell can have 6 arms "Y" shapped to add more strengh ?
23.  The mirror cell plate can have a cassigrain hole?   yes       or    no?
24.   what size will the hole be for your cassigrain? =                units
25. If not cassigrain i can mount a 2" fan in the center hole ?  yes or no ?
optional is to mount 3 fans on the "Y" arms. I can mount 3 each 1" fans
on the arms to help cooling.
26.  The mirror cell holder takes many forms. Please see the
autocad drawings on the telescope page to choose a type.
      The mirror cell can have a protective ring around the OD at the height of the mirror?  this is used to hold all bolts and edge clips.
      No protection for the edge of the mirror?
27. Now choose the cell float system. 3, 6, 9, 18, or 36 ..etc points.
      If the mirror is less than 8" OD, 3 or 6 points will do.
      If the mirror is 10" to 12" then 9 or 18 points is a must.
      My default is 18 points for larger mirrors > 12" up to about 20".
      Mirrors larger then 20" should use 36 point support.
28.  If you are removing a mirror cell of wood with a back plate
       of wood then you must weight the old wood cell ?          lbs or  Kgm?
       The mirror cell I make can be as close to this total weight so your tube will balance in the same place.
29. Shipping will depend on the weight in lbs.  15lbs USPS = 25$  IN USA approximately.
 Run fedx, ups and dhl from your computer using my town and zip to get
real shipping.   Lancaster, CAlifornia, 93534  for mailing to you.
Shipping to France costs about 200$ to 500$. Add that to your cell cost.
good luck on shipping costs.

30.  The cell will be painted flat black from the top. It will
          not be painted on the back sides. This helps cooling.
31.  Will you want the metal back plate polished on the
       out facing side?
32. The back plate or the cell plate will have letters stamped
or machined into it to identify the cell maker.  Send a list
of letters you would like stamped in the metal. if you want your name on it?
33. What type of edge clips will you want to keep the mirror
from falling forward out of the cell.  The standard "L" type,
or some other design.  The mirror cell edge clips will be adjustable.
34.  What type of rubber or cork or teflon baby bumpers do you want
on the rocker pad points that support the back of the mirror?
   leather,          cork,            rubber,            teflon,           plastic?
you want a material that will not compress over time and defocus.
35. time to manufacture this unit.
the precast aluminum cell parts take a couple of full weekend to machine
and add the rockers and clips.
cells that are hand made may take up to 3 months. There is no rush
for quality.

Simple "Y" "Y" mirror cell. For light mirrors.
Open type 3 "Y" arm mirror cell.

Typical 18 point Cell layout
Note this is a 6 "Y" spider cell.

The Royce Center Mounted Mirror Cell.
This is the *" center mount mirror cell.

Mirror with Ring Edge Protection ring
Larger mirror need edge support by a ring and teflon tipped bolts

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