Bonding Composite Core Segments into Fixture

Bonding the BB and seat tube transition segments into the seat tube, main pivot tube, and bottom bracket.
Preparing to bond the down tube core segment to the BB and main pivot

Bonding the down tube core segment to the BB and main pivot

Holding the 2 down tube segments together with popsicle sticks and rubber bands. This looks kindergarten, but it worked high school.
Dry fitting the down tube core segments showing large gaps

Large gaps between the segments were due to the imprecise sanding of the core clam shell segments. This is where molding into female molds would have really helped the construction.
Dry fitting the down tube core segments showing large gaps

Dry fitting the down tube core segments showing large gaps

Dry fitting the down tube core segments

Dry fitting the down tube core segments

Viewing into the seat tube to top tube transition segment with the epoxy visible on the link pivot.
Looking into the core segment after bonding to the seat tube

Looking up into the head tube segment.
Looking into the core segment after bonding to the head tube

This really looks bad, but remember the only purpose for these initial core segments is to form the beginning shape of the bike frame and hold the parts in proper position for the composite layups on top. This is not a structural assembly, and really I should have used fiberglass instead of carbon.
Down tube segment joint bonded and gap filled with epoxy

Joints bonded.
Down tube segment joint bonded and gap filled with epoxy

Down tube segment joint bonded and gap filled with epoxy

Segment joint near the head tube bonded and gap filled with epoxy

Segment joint near the head tube bonded and gap filled with epoxy

The epoxy at the joints will of course need to be sanded flat before reinforcing with fiber.

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