long shot - need some help with foundry patterns.

[Seanz0rz]

so i have this school project (one of many this quarter) that requires our group to create a match plate to green sand cast our part/model, etc of choice.

trouble is, we have a complex parting line and we are having a hard time wrapping our heads around what the match plate should look like.

i think pictures would convey better than words:

here is what the finished part should look like:
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/school/AIRPLANE.jpg
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/school/AIRPLANE2.jpg

you can see the parting line along the fuselage

here is the basic match plate pattern. you can really get a feel for the parting line:
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/school/matchplate.jpg

the problem comes when i try to reconcile the bottom to the match plate. im not sure what to do here, any ideas?
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/school/matchplate2.jpg

[Seanz0rz]

steve be deleting my posts!
-its cool man, i see how it is!

repost:
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/school/matchplate3.jpg

that is my solution so far. it still needs some tweaking but hopefully that will work in some way.

any one with any experience with sand casting or knowledge of the process please chime in!!! even if you have no idea what im talking about but think you might have something useful to say, im all ears!

[Robinhood4x4]

steve be deleting my posts!
-its cool man, i see how it is!

repost:
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/school/matchplate3.jpg


Ok, quote button this time, not the modify button!

Anyway, I'm not much help, not much experience with sand casting. But what is the blocky thing sandwiched between the two halves?

[Seanz0rz]

that is the match plate. basically you take the top, positive half of the item to be molded, glue it to a flat plate, do the same with the bottom, matching them up perfect. when you make your sand molds around this, then each side of the mold will fit flush and tight, and have a cavity exactly like the first two pictures.

parting lines (where the plate separates top from bottom) must be at the largest cross sectional area. for our object, that parting line is over different planes because of our complex geometry. so we have to build a box that will allow some of the bottom to grow up into the top mold, and some of the top mold to come down into the bottom mold.

the last picture i posted is my potential solution. basically make the plate very thick to overcome the issues, although im not sure that is the proper solution to my problem.