I posted at Christmas about an anniversary cake I did for my in-laws that leaned and collapsed.  It was a 12 inch, 10 inch, and then double height eight inch.  I used the wrong type of supports and thought I had my problem solved.

 

I tackled another cake today that was a 3 inch high 10 inch bottom tier, an seven inch high 8 inch middle tier, and then a carved top tier.  Everything was going perfectly, I had cake boards between each layer, as well as a cake board in the middle of the seven inch tier, cut my wood dowels perfectly evenly, and when it was done and I moved the cake to take a picture, one of the dowels in the bottom layer shifted and the cake collapsed.  This was literally ten minutes before she was coming to pick up the cake.  I put the middle and top tiers on a new board with a border at the bottom, wrapped up the bottom tier for her to serve from the kitchen and refused to take any money for it.  She was still thrilled with it, and very gracious that it was a two tier cake instead of a three tier but I was NOT happy!  What am I doing wrong?  I am going to see if I can get my hands on SPS, but I'm in Canada and I've never been able to find it.  The only thing I can think of was that the bottom tier was moister than usual for some reason and the dowels didn't sit quite as securely as I would have liked.  How do I avoid this in the future?

 

I only have a before picture, not an after.

 

so sorry this happened--stellar cake--beautiful work--

 

how many dowel are you using for each tier--and how close to the the outside perimeter are you setting them?

 

what size are the dowel 1/4 inch?

Yes, that stinks...it's a very cool cake.

 

Can you refrigerate?  Are you putting a little buttercream between your tiers to help them stick?

 

And are you doing a center dowel?  To do this, you will want to beef up you bottom base board - I do 3-4 rounds hot glued together - and use a sharpened dowel that is hammered thru each tier, separator boards, and all the baseboards.  Carefully so you don't miss the dowel and hammer the cake!  

 

For the above cake, you could have hammered it down thru the "button" at the top of the helmet and covered the hole with the button.

 

Just some thoughts since I am not sure what you have done in the past to try to remedy the problem.

Thanks for the compliments on the cake - it was pretty cool before the bottom tier squashed on me!

 

What I did was started with very cold (partially frozen cakes).  Leveled each cake round (two for the bottom, six for the middle) so they were about 1-1.5 inches in height, sandwiched the layers with buttercream, and then crumb coated the tiers and let them sit and settle for about two hours.  Then I measured and cut the dowels and stacked the tiers.  I had a cake board on the bottom of the middle tier, stacked three rounds on top of it, dowelled that, and then but a board and the next three rounds.

 

I used six 1/4 inch birch dowels in the bottom tier.  Usually I put them about 3/4 of an inch in from the perimeter of the tier above it, but this time they were a bit more closer to the centre, but not terribly so.  I did not center dowel, which may have contributed.  The only times I've center dowelled was where I built it from the bottom up stacking it through the dowel - frankly, hammering the dowel through the cakes scares the crap out of me!  I sharpened a dowel with a pencil sharpener and tried to push it through one of my cake boards today and there was no way it was going to go through.  I couldn't bring myself to do it with the finished cake!  Thank you for the tip on gluing boards together, though.  That is helpful.  I need to figure out the centre dowel thing - how do I ensure the dowel goes through all the separator boards easily without warping and bending the separator boards and making the cake go wonky?  What kind of boards do you use?  Mine are cardboard and then covered with a thin foil on top - they're pretty durable.

 

Hubs and I discovered one other potential problem - I thought my oven was a bit finicky when I baked the cakes, the 10 inch rounds took forever to bake.  Then tonight it took an hour and a half to bake some simple chicken breasts (should have taken 35 minutes).  The 10 inch round seemed way moister than normal - they were baked, but the consistency was off.  I think my oven is on it's way out and that might have contributed.  But I don't think that is completely to blame.

AOh, and yes, I put some buttercream between each tier.

 Wooden dowels are skinny sticks that, even when cut level, can shift in a moist, slippery environment.........like cake.  All it takes is to have one move laterally, from " l " to " / " and the problems begin.

 

The hollow cylinder--a straw--is much less prone to lean because it doesn't displace cake.  It actually uses the cake "plug" that forms in it for extra stability.  I suggest giving straws a try--bubble tea/wide bore straws if you can find them.

 

As for the central dowel, sharpened and hammered, they'll go thru anything. Pushed in, I suppose they could buckle a thin cardboard, but hammered, it's quick & painless.

In order to avoid lateral shift on tall tiers, I use 2 full length dowels about 2 inches apart--nothing can spin on 2.

Thanks Maybenot for saving me the trouble to type exactly what I wanted to say!

I used to use wood dowels but since discovering the bubble tea straws, I converted. Another plus is that they are so super easy to cut!

How much weight will a bubble straw hold up before it buckles?

And a center dowel does nothing to keep tiers from collapsing.

I have made a 4 tier wedding cake with only bubble straws holding it up. And that's a heavy cake!

I pretty much go by AZCouture's  example list but I add 1 or 2 more than hers for 9" tiers and over. It may be unnecessary but it's for my peace of mind!

AI use something called poly dowels. They are similar to straws in shape, but they don't bend like them. I would definitely recommend using bubble straws, or the SPS system

A

I might too, I was just estimating off the top of my head. When I'm actually stacking, I determine right then what I'm going to use. But always those amounts for six inchers and smaller.

The only thing that I can add is that your bottom board doesn't look very thick.  It may have been that when you picked the cake up, it flexed and that was enough to shift a dowel.  I'd recommend you try a sturdier base board.

and--are you scooting the cake around to center it after you stack it on there? you have to get it right just about the first time--especially if you have the dowel that far out--all you need is for one to go wonky for it to fail--if you're pushing the cake around you can dislodge it easy--

 

and when you place the next tier on are you letting it rest too long on the dowel on the opposite side of where you're holding on (in the process of placing it) --this can make the dowel slip and become unstable--

 

what i do is pull all my dowel back up several inches, then center and lightly place the tier on those and let the weight of the cake sink the dowel back down--and you can get a good placement this way--if it's a real light tiny top tier you have to coax it down with a skewer though (push from the top down and recover the hole)

 

and do your dowel come to within an eighth inch of the top of the icing either way sticking out or just under the icing--and you are cutting the dowel equal in length to each other after inserting one to get the correct measure--at the deepest part of the cake --

 

just some other thoughts for you

ADon't have much to add, but if you are in Canada, you can find bubble tea straws at Sobey's. Sometimes bulk barn will carry them in the summertime (they are usually labelled milkshake straws)

AA hollow cylinder is stronger than a solid shaft---it's proven physics. Take a straw and try to crush it lengthwise between your palms. You can't.

You need fewer straws than wooden dowels for supports--to support a 12", 6 straws; 8", 4 straws.

I agree with LizzieAylett, I think the board that the cake is sitting on might be too thin, and moving it would shift the dowels.I always use the 1/2'' or a cake drum for wedding cakes or tiered cakes.

You mentioned that your cake boards had paper on the top...did you cover the bottom of the board also?  buttercream will soak into the board and the board will not be able to support the weight of the cake if it is soaked with the grease from the buttercream.  I cover the bottom with foil and then cover it with cake foil so it is completely covered.

 

I had a 7 tier cake start to collapse because of grease soaked cardboard...lesson learned!

Thanks, everyone.  Some helpful tips and information, I'm going to try again with a practice cake with straws, using K8Mephis's way of setting the cake on the tiers, and gluing the cake boards together.  I've only ever been able to find thin cake boards, I don't know why I never thought to glue a bunch together!  So simple, but so genius!

AI only use wood dowels and don't have trouble, but not all dowels are built the same, either. The wilton ones they're selling now are horrible and bendy. The thin board is probably what did the damage if you were moving that heavy cake around, though. A base board needs to be totally non-flexing.