Multimatic Takeaways + Documentation

Owned by Minqian Lu
Last updated: Nov 03, 2021 by Yanshen Zhou
2 min read

  • KITS! First layer bridging can be significantly reduced if we do the first layer in small pieces, we just need to “hide” the seams in a clever way. Multimatic usually does this by hiding seams on corners and bends, since the light already bends there so it's harder to see it.

    • I think it just helps with bridging in general? not just the first layer

    • Also need to keep in mind the overlap will add extra thickness and might not be great for all panels

    • If overlap is not desirable, seams need to be repeated in different spots each layer

  • The release film is crucial for keeping resin content

    • Comes in either perforated or non-perforated

  • when bagging, set your perimeter, plan your pleats, and then bag everything but the pleats

  • debulk the layup after core to ensure it sticks down.

    • Can even do layers (cant remember if he said first layer or every layer after core)

  • for “gaps” in the core (as present in the A-bulkhead), we can add strips of carbon to “round out” and fill those gaps

  • Use wax instead, 6 coats. If we keep using frekote, then seal the sanded surface first and then add the release, 1 layer of mold sealer to seal everything before mold release

  • Use the better inlets, buy vacometer???

  • Spraytac carbon fiber for infusion to conform it to the mold, make it easier to work with

    • if we use spraytac before we cut the carbon fiber the fraying edges typically hold better

  • Wider vacuum bags are available (so we dont need to envelope)

  • Vacuum tubes can be placed in pleats hanging off the mold, which helps when curing odd shapes

  • https://docs.google.com/document/d/1RlXZS-FH854rbqIMnmCPXVK76w19K6UTyGZGS73-gZw/edit?usp=sharing

 

11/3/2021 Meeting w/ Multimatic Notes:

  • previously used large pieces of carbon, maybe try considering designing parts to split into smaller parts (design layup to hide seamlines in transitions)

    • ex. make paper templates of aerobody panels and see how they fit together

  • Material choice: don’t think of panels as structural (multimatic has 3 layers of different thickness carbon fiber with 1.1-1.3 mm total thickness)

    • think of panels as cover panels that can survive regular wear and tear

    • current layup (3 layers - core - 2 layers) is fine; no critiques from multimatic, maybe do (4 - core - 1) instead since inside layer doesn’t really matter

  • Debulk first layer to prevent bridging in next layers

    • next layers go on first layer easily and will conform to all corners as long as first layer is done correctly

  • Multimatic surface bags large complex parts but for smaller parts they envelope bag

  • Production molds at Multimatic are all made of tooling carbon (alot more expensive than MDF)

 

Reaction to Current Team Status

  • still willing to help and potentially during the design process as well

  • they’re sad they won’t get a ride in the four-seater…