stave tooling & plans for future stave-building
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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 - PowerPoint PPT PresentationTRANSCRIPT
Stave Tooling & Plans for Future Stave-building
(Tim)
Stave Assembly Tool Update• Development of 2nd
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)
– http://www.compositematerialsltd.com/pdfs/nomex_honeycomb/cormaster_n636.pdf• 4.8mm cell / 28kg.m-3 (1.75 lbs/cuft)• Laser cut (1st 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 2nd side
• Manufacture of 1st 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