1. Radial defining system for the Blanco primary mirror
V. M. Blanco 4-m Telescope
Andres Montane
11/26/2018

2. Parts involved Support Base Primary Mirror Definition Point
Mirror Cell
Counterweight
Support Base
Andres Montane
11/26/2018

3. Parts involved Support Base Support Base Primary Mirror Nut
Definition Pad
Definition Point
Definition Point
load cell
Belleville Spring Washers
Support Base
Support Base
Andres Montane
11/26/2018

4. It is necessary to absorb 1.2 mm for thermal contraction
movement
load cell
movement
It is necessary to absorb 1.2 mm for thermal contraction
Preload 250 Kg
Nut
Belleville Spring Washers
Andres Montane
11/26/2018

5. Belleville Spring Washers
Andres Montane
11/26/2018

6. Belleville Spring Washers
Andres Montane
11/26/2018

7. It is necessary to absorb 1.2 mm for thermal contraction
Belleville Spring Washers
adjustment screw
Andres Montane
11/26/2018

8. Parts involved
load cell
Andres Montane
11/26/2018

9. load cell
Resolution = 200g
Andres Montane
11/26/2018

10. Space and position of the definition point
Primary Mirror
Definition Point
Ring Girder
Andres Montane
11/26/2018

11. Space and position of the definition point
Mirror Cell
Support Base
Ring Girder
Andres Montane
11/26/2018

12. Sartorius Load Cell Electrical Specifications
Output impedance = 635ohms
Sensitivity = 2mv/V at Rated Load
Repeatability = <0.1% of Rated Load
Elastic Deformation =<0.1mm at Rated Load
Load Cell Diagram
Andres Montane
11/26/2018

13. 4m Load Cell Electronics Block Diagram
North
Load Cell
x100
ADAM
6017
8Ch
16bit
A/D
x100
East
Load Cell
Ethernet
South
Load Cell
x100
x100
West
Load Cell
+/-5V
Supplies
115VAC
Andres Montane
11/26/2018

14. 4m Load Cell Location on Telescope
South
Load Cell
4m Mirror Cell
East
Load Cell
West
Load Cell
19”Rack in Cage
Electronics
Ethernet
North
Load Cell
115VAC
Andres Montane
11/26/2018