Report on construction of LP2 spaceframe endplate 2011-10-20 LCTPC wp137 Peterson

inner endplate, outer plate, strut components Delivered: Endplate components: inner endplate, outer plate, strut components Screws to mount the strut mounts Jig plate and alignment brackets Granite table for assembly and measurements Measuring tools Current activity: Measuring precision hole locations Setting up for assembly, preliminary assembly Determining what other parts are needed 2011-10-20 LCTPC wp137 Peterson

in-row height brackets height is dialed in to ±25μm outer height brackets alignment brackets x,y, z rotation height is set to ±25μm Height of mullion at center can be 25μm above the jig plate. Hold-down is needed. There is significant (1mm) bowing without the in-row height brackets. Although the screws for the alignment brackets to the outer plate drop right in, there is some tension placed on the outer plate. jig plate is flat to ±25μm strut mount 2011-10-20 LCTPC wp137 Peterson

Require hold-downs for the mullions as stated on previous page. Comments: Require hold-downs for the mullions as stated on previous page. Screws to attach the strut mounts to the inner plate are too long by about 1 thread. Next shorter available is too short. It is risky to tap deeper. Shortening the aluminum screws is painful. Measurements of precision holes with calipers is repeatable with σ=18μm. In the last 2 months, there may have been motion of the holes at the level of σ=20μ, but it is difficult to tell. 2011-10-20 LCTPC wp137 Peterson