Optimization of the SCALE-UP, a wire boom system for a space probe

Abstract: BepiColombo is a project with two satellites in collaboration between Japan and Europe with the aim to map Mercury's and to study its magnetosfär. An electric field instrument in one of the satellites has been manufactured and passed the qualification physicals on Space- and Plasmafysik, KTH. The instrument needs to be modified and improved by new requirements. The aim with the thesis is to produce a holder for the electric field instrument, identify critical tolerances in the construction and to generate the solutions. The selected holder maintains the probe sphere and preamplifier box at both ends and is balanced. One silicon O-ring and one axle plug will be used for stabilizing vibrational forces. Intersection pictures of the electric field instrument were in use with the aim to analyze how the parts relate to each other while moving axially, radically and during rotation. The most critical tolerance chain in radial link is clearance between feeder wheel and internal cylinder. The solution to the problem is to use reamer F7 in order to ream the sliding bearing after assembly in the backplate. The axle will have tolerance f8 and the hole of the wheel D9. After the choice of tolerances that are recommended the clearance between wheel and internal cylinder will be larger than or equal to 0,158 mm. The space for the wire in the metering ring is considered the most critical link axially. The solution principle to the problem is to choose right thickness for the teflon washer, screw and safe the nut in correct situation. Adding a small metal washer if necessary.