openCortex: Mold Making page




		May 16 5:48am PDT

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	PARENT CATEGORIES Shell

DISCUSSION TOPICS	Mold Making OCID nd00000125	SIBLING CATEGORIES Composite Shell Construction Composite Shell Materials Shell Design

	CHILD CATEGORIES Plugs


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	Related Content (13)

	The John Lee Top Plug Photo by David Johnson created 8/15/2002 submitted 11/11/2002 12:37:18 PM This photo shows the top plug for Yale's 2003 ASC entry, The John Lee. This photo was taken after machining and before surface finishing. The plug was sanded to a smooth bare-foam finish, then any defects were filled using a short-hair fiberglass autobody filler. It was then painted with an epoxy primer-sealer. Following this coats of primer-surfacer were used and then wet-sanded off to create an automobile quality finish on the plug. Then the plug was sprayed with a final primer-sealer coat before waxing to prepare it for the molding process.

	Mold Sanding Photo by eloy avila created 11/17/2002 submitted 11/17/2002 06:33:10 AM Here is an intermediate sanding step between coats of primer sealer. We used 150 grit at first and the last few steps were 400 grit and up. A final wet sanding was done to finish it off.

	The John Lee Top Mold Photo by David Johnson created 11/7/2002 submitted 11/11/2002 12:22:32 PM This photo shows the completed top mold of Yale's 2003 ASC entry, The John Lee. The mold was made by spraying chopper glass on top of a foam plug. The members in the picture are washing the PVA (a release agent used in the mold making) out of the mold to prepare it for layup. The mold is supported by a metal frame in order to provide support for the weak chopper glass mold. Metal was used rather than wood to allow for high temperature cures.

	Mold Structures5 Photo by eloy avila created 7/15/2002 submitted 7/14/2002 09:38:33 PM Here foam has been glued to make a new mold. The foam is held together while it glues. Expanding foam was used as glue. The gluing foam was sandable and had similar thermal and expanding and density properties as the large foam blocks.

	Mold Structures4 Photo by eloy avila created 7/15/2002 submitted 7/14/2002 09:32:04 PM Here foam is layed down on a torsion box after being cleaned of loose foam particles and before being glued for a new car mold.

	Mold Structures1 Photo by eloy avila created 7/15/2002 submitted 7/14/2002 09:22:52 PM Here you see foam soon to be transformed into new molds for a solar car.

	Team Lux Shipping Crate Photo by David Johnson created 7/10/2002 submitted 11/15/2002 07:22:33 PM This photo shows the structure of the shipping crate Team Lux used to send its stack of foam out to be CNCed into the top plug of The John Lee. The bottom of the crate was the torion box used to support the foam stack. The foam was glued directly to the bottom plywood skin. The top of the crate was covered with plywood to prevent damage during shipment. The crate (torion box and top) without foam weighed 1400lbs. Total shipping weight was 3600lbs.

	Detail View of The John Lee Foam Stack Photo by David Johnson created 7/12/2002 submitted 11/15/2002 07:37:36 PM This photo shows the foam stack for the top plug of The John Lee inside its crate shortly before shipping out for machining. The photo clearly shows the disadvantage of using epoxy for gluing foam blocks together. The low viscosity epoxy ran out from between the blocks and coated portions of the next layer of the foam stack. Ultimately this caused no problems in machining, but it wasted glue.

	Gluing Foam to Torsion Box Photo by David Johnson created 7/11/2002 submitted 11/15/2002 07:32:24 PM This photo shows the completed gluing of the first layer of foam for The John Lee top plug to our torsion box. The foam was donated to the team in 23.75" X 80.5" X 4" (+/- 0.25" in any dimension) blocks. The foam stack contained 7.5 blocks in the bottom layer (3 columns of 2.5 blocks each). Extreme care had to be taken to fit these blocks together so as not to leave gaps between the blocks that would cause voids in the machined plug. The photo shows the many heavy objects the team used to hold down the blocks during the epoxy cure. Epoxy resin was used to attach the blocks to the torsion box. It is not an ideal adhesive to attach foam to plywood due to its low viscosity and the absorption properties of the plywood. Thus significant amounts of adhesive were used on this first layer.

	Mold Structures6 Photo by eloy avila created 7/15/2002 submitted 7/14/2002 09:45:06 PM Here the old Stanford Afterburner/Third Degree Burner molds are loaded onto a truck.

	Mingi at Work Photo by Alex Selkirk created 4/7/2001 submitted 1/7/2002 01:23:17 PM This is a picture of mingi at work. They are working on the backburner for asc 2001.

	Mold Strcutures7 Photo by eloy avila created 7/15/2002 submitted 7/14/2002 09:48:28 PM Here Dorian West (father of the Stanford Afterburner series) stands and says goodbye to the old molds. They served us well.

	Mold Structrues3 Photo by eloy avila created 7/15/2002 submitted 7/14/2002 09:30:02 PM Here two torsion boxes are completed with heavy duty casters for easy moving. The old Stanford Afterburner top shell is seen on top of one torsion box.