I'm very new to this, I've had success so far with stacking two tiers. Now I'm wanting to try three. Does the cake need to be dense to stack? I've had more head aches trying to find the "perfect" recipe. I prefer a more dense cake anyway, but others may not. Anyway, I have so much to learn. Thanks for any advice/suggestions.
I have done a few three tier cakes, and my cake recipes are not particularly dense. Of course they are not angelfood. I would say just make sure the cake can handle the weight of the fondant if that is what you are using, and then use dowels cut to size to support. I would put one dowel every two or three inches under the tier above, for instance if you are putting an 8 inch cake on top of another cake, use about 7-9 dowels, depending on shape. 4-5 dowels would be enough for a 6 inch cake on top of that. HTH!
I just did a 5 tier stacked baby shower cake, using only dowels. It was just box mix cake with raspberry filling. It held up solid. Just make sure your dowels are cut the same length and are perfectly vertical.
Or just take the guesswork out and use SPS. I use it for every cake. I never have to worry about a dowel shifting and the cake leaning. I never worry about the cake being stacked centered. And whatever you can lift you can deliver preassembled.