Metrology of the Stave250 Assembly Jig (Tim)

What do we need to measure?

Procedure Measure PH2 and define as (0,0) – 4 point: DIA=0.043 / CIRC=0.001 Measure PH1 and define PH2-PH1 as primary axis – 4 point: DIA = / CIRC=0.001 – Distance PH1-PH2 = Measure front edge of 14 Vee-blocks at 4 points along length (See plot) and reconstruct line of best fit – Y= x10 -4 X Measure Tooling ball – ( , ): DIA=8.207 / CIRC=0.011

Vee Blocks

CAD Analysis

Comparison with SmartScope Procedure – Mount jig on Smartscope & reconstruct lines along the edges of the Vee blocks (sub-stage illumination). Construct datum axis – Measure tooling ball as a composite of 3 sub-circles Diameter = / CIRC = – Measure PH1 as a composite of 3 sub-circles Diameter = / CIRC = – Measure distance from Tooling ball to PH1 parallel to Vee-block datum axis – Diameter/2 = – Measure PH1 offset to Vee-block axis

Vee-blocks (CMM vs SmartScope)

CMM Survey with Back-lighting Pin-holes and tooling ball measured with back-lighting to try and improve measurement – Hi-tec torch (Wifi/3G enabled) Results – Pin-holes / mm with 4-point circularity of 0.001mm – Tooling ball 8.205mm with 20-point circularity of 0.025mm

Comparison of CMM Vee-block alignments

Survey with 4mm dowels (CMM#3) 4mm dowels held into Vee blocks with tool-makers clamps. Inner edge of dowels reconstructed using back illumination via reflection from aluminium.

Comparison of Vee-block surveys NB 4mm dowel data offset by mm

Summary ParameterCMMCMM #2CMM#3SmartScope Ref Offset Y Ref Offset Y Dim Y1 to Y Ref Offset X