Stave Tooling & Plans for Future Stave-building (Tim)

Stave Assembly Tool Update Development of 2 nd generation Stavelet assembly tool – CF / Nomex sandwich construction – Brass inserts for dowels & threaded holes – Steel plates for magnetic chuck – Vacuum channel formed in FR4 – Ground CF top plate

Trial Assembly Studies Stave Components – Facesheets K13D2U/RS3 panels 1.3m x 0.31m (0/90/0) Cut out on pattern cutter – Honeycomb Nomex grade N636 (Korex replacement) – mm cell / 28kg.m -3 (1.75 lbs/cuft) Laser cut (1 st go as a trial) – ‘C’-channels Original manufacturing tool – slight lip on open edges (need to re-make tool to improve) – End Close-outs Peek (from QMUL)

Laser-cut N636 Honeycomb Honeycomb is not as ‘uniform’ as Ultracor CF Stress-free cutting results in good edge definition & perpendicularity Slight charring of edges

C-channel Jig 2 C-channels loaded into Jig Jig located on assembly tool using locator blocks Holes match !!!

Next Steps Manufacture of dummy stave – No cooling tube, no Allcomp foam – Steps (start tomorrow) End close-outs Honeycomb Grind Attach 2 nd side Manufacture of 1 st full stave – Cooling tube (from RAL) – Poco foam (have some left) – Steps Full assembly sequence

Low-density Adhesives / Stencils Single (few) use laser machined stencil from thin plastic (eg Perspex) 3/8” CF honeycomb has good cell uniformity so maybe glue can be applied to facesheet using a stencil – Trial stencil manufactured from 0.5mm thick Perspex – Area coverage 23% – Glue volume = 10cc / stavelet Low viscosity of neat Hysol 9396 means glue easily flows between stencil & CF face sheet – Looking into glass micro-balloons to increase viscosity & reduce glue mass (ρ≈0.67gcm -3 )

First Trials

Possible Extension Multi-use pattern – Thermal foam – ‘C’-channels & honeycomb Alternative Patterns – Corrugated core

Summary Aim to manufacture 1 or 2 dummy staves (<4 weeks) – General ‘training’ (assembly techniques & machining) – Flatness measurements – 3 point bending Move to Full Stave (4-6 weeks) – Use remaining Pocofoam – Need cooling tube – Maybe new ‘C’-channel jig ? Further investigations of stenciling – Thinner material (eg. 0.35mm Mylar) – Probably only applicable to large cell & very uniform honeycomb