Hello, 
I need to make a cake with a 14" round bottom tier, a large egg shaped cake, then an 8" round on top of the egg and a 6" round on top of the 8.  In other words, 4 tiers but the next to bottom tier is a 3d egg shape that stands about 12" tall.

I plan to use an MDF base with a metal flange drilled in and either PVC or pipe put into the flange for the center support.  Will this work?  And I plan to use supports in the egg itself but I'm worried the bottom part of the egg will squish on itself.  Does that make sense?

Thank you for your help,
Cris

AI would have a cake card board at least every 4" height, so 2 extras with dowels within the 3d egg. Myself, I would also be tempted to do the very base of the egg (the curved part) from foam and then ganache it with the upper cake parts so it appears to be a seamless egg. I'd be too worried to have suspended cake. I don't think the weight above is an issue, so long as it's properly supported with a good internal structure. As someone has said before, you could support the upper tiers above a jelly layer or even air, so long as you have good internal structure.

so it's actually a 6 tier cake with the egg being three 4-inch tall tiers all rolled into one humpty dumpty that will not have a great fall  you could do the phlange thing or use something like this: 

http://www.efavormart.com/acrylic-cake-stand-tubes.aspx

http://www.efavormart.com/acrylic-cake-stand-plates.aspx

so you could anchor a 16" tube into a plate that's under the 14" tier -- the tube inserts in the plate nice & firm -- then thread the 14" tier and the egg shape down onto it then just place the next plate and add the 8x6-- and of course i'd anchor the bottom plate onto the baseboard like with gorilla tape or something  -- y'know  you would have holes cut out of the egg so it threads down the tube good -- and you would board & dowel the bottom two tiers of the egg like any other cake -- the 8x6 would be held up by the plate on top of the tube -- 

i used to have a giant chalice i did like this but it's on the other computer that doesn't work right now--

oh look what i found -- the base is idk 22" or 24" the cake was a 16" so this is quite large

Thank you.

That chalice cake is big!  I'm happy to see it held up.  I'm pretty nervous about the egg!

Thank you again, I appreciate your time.

Fingers crossed for me!!

Cris