6-Point Cells

The 6-point cells described here all use six support points arranged equidistant around a circle. Each pair of points is located on a pivoted bar. The bar pivot points are midway between the two mirror support points.

Diagram of six point cell

Diameter = Mirror Blank Diameter in Inches
Thickness = Mirror Blank Edge Thickness in Inches
f/ = Focal Length in Inches / Diameter
Obs Dia. = Central Obstruction Diameter in Inches (This is usually the diagonal mirror minor axis.)
r1 = Radius of circle on which the bar pivot points lie as a fraction of mirror blank radius.
d = Distance separating the two support points on the bar as a fraction of mirror blank radius.
r2 = Radius of circle on which support points lie as a fraction of mirror blank radius
P-V = Peak to Valley Mirror Deformation with this cell in Waves (1 wave = 500nm)
RMS = Root Mean Square Mirror Deformation with this cell in Waves (1 wave = 500nm)

Pyrex
DiameterThicknessf/Obs. Dia.r1dr2P-VRMSFocus Shift
1215.32.360.5010.5880.5881/581/303-0.041mm
12.51.254.982.140.5040.5820.5827.96nm1.41nm-0.028mm
12.51.51200.4900.5650.5651/651/464
12.51.581.830.4940.5710.5711/711/443
12.51.561.830.4960.5730.5731/711/437
12.51.552.140.4990.4990.5761/721/436
12.52.21200.4830.5580.5581/741/566
12.52.281.830.4870.5620.5621/801/580
12.52.261.830.4880.5630.5631/801/577
12.52.252.140.4900.5650.5651/801/580
13.11.04.43.10.5170.5970.59711.7nm
1/43
2.36nm
1/211
-0.042mm
13.11.562.140.4830.5580.5751/631/382
13.11.552.600.4870.5620.5791/641/381
13.11.54.52.600.4950.5630.5801/641/378
13.12.3562.140.4880.5640.5641/731/534
13.12.3552.600.0.4910.5670.5671/791/538
13.12.354.52.600.0.4910.5670.5671/791/537
14.51.562.140.5000.5780.5781/481/277
14.51.552.600.5020.5800.5801/481/272
14.51.54.52.600.5030.5810.5811/471/270
14.52.37562.140.4890.5650.5651/591/413
14.52.37552.600.4910.5680.5681/531/416
14.52.3754.52.600.4920.5680.5681/591/414
161.62562.600.5010.5790.5791/391/223
161.62552.600.5030.5810.5811/391/220
161.6254.53.100.5060.5840.5841/391/219
163.0062.600.4880.5630.5631/491/365
163.0052.600.4900.5650.5651/531/368
163.004.53.100.4900.5660.5661/531/367
181.7562.600.5020.5790.5791/291/166
181.7553.100.5130.5830.5831/301/165
181.754.53.100.5060.5850.5851/291/163
183.2562.600.4870.5630.5631/391/282
183.2553.100.4890.5650.5651/391/284
183.254.53.100.4900.5660.5661/391/283
204.0062.600.4860.5610.5611/321/237
204.0053.100.4870.5620.5621/321/239
204.004.53.500.4880.5640.5641/321/240

Plate Glass
DiameterThicknessf/Obs. Diar1dr2P-VRMSFocus Shift
60.37561.30.5160.5960.5961/1591/773
200mm15mm740mm0.5200.6000.6001/1201/622-0.036mm
80.37561.520.5260.6080.6081/511/234
80.561.520.5180.5980.5981/861/417
80.7561.520.5050.5820.5821/1241/692 -0.024mm
100.8751200.4960.5720.5721/701/409
100.87581.520.5020.5790.5791/741/411
100.87561.830.5060.5840.5841/741/405
101.31200.4880.5630.5631/891/619
101.381.520.4930.5690.5691/971/631
101.361.830.4960.5720.5721/1001/631
10.50.8756.681.830.506 0.5840.5841/641/345-0.056mm
12.50.8751200.5000.5770.5771/351/190
12.50.87581.830.5070.5860.5861/371/190
12.50.87561.830.5110.5900.5901/361/183
12.50.87552.140.5140.5930.5931/351/177
12.51.51200.4890.5650.5651/551/371
12.51.581.830.4940.5710.5711/601/376
12.51.561.830.4960.5730.5731/601/371
12.51.552.140.4990.5760.5761/611/370
12.52.1251200.1/1/
12.52.12581.830.1/1/
12.52.12561.830.1/1/
12.52.12552.140.1/1/
13.11.04.43.10.5170.5970.59713.8nm
1/36
2.77nm
1/180
-0.048mm
13.11.562.140.4980.5750.5751/541/324
13.11.552.600.5010.5790.5791/551/324
13.11.54.52.600.5020.5800.5801/541/321
160.87562.61/1/
160.87552.60.5010.6010.6011/141/68
160.8754.53.11/1/
161.62562.61/1/
161.62552.60.5030.5810.5811/331/187
161.6254.53.10.5060.5840.5841/331/187
161.87562.61/1/
161.87552.60.4990.5760.5761/361/220
161.8754.53.10.5010.5790.5791/371/220
162.12562.61/1/
162.12552.60.4960.5720.5721/391/247
162.1254.53.10.4980.5750.5751/401/248
1/1/

BVC
DiameterThicknessf/Obs. Diar1dr2P-VRMS
101.2561.830.4970.5740.5741/1161/718
121.561.830.4970.5740.5741/791/488
12.51.561.830.4980.5750.5751/711/432
141.552.60.5030.5800.5801/531/309
161.552.60.5060.5840.5841/361/198


© 2002 Mark D. Holm