Super great timing on this cake contest! It's my sons birthday again. Obviously his cake had to be something out of the ordinary. See past cakes -
volcano
helicopter

we were just on vacation at Disney so I didn't want to get too elaborate due to time constraints. My son asked for a tank cake. I'm sure he would have been happy with a cake with a picture of a tank on it or a model tank. But I would not have been happy. First I decided that the turret would rotate. That is pretty easy. I toyed with the idea of having it shoot something (what says happy birthday more than getting shot in the face with whipped cream) That idea got shelved as soon as I imagined the look on my wifes face. To up the difficulty level I decided to make the gun go up and down as the turret rotated.

-Imagine wife smiling-

It is a little difficult to see the gun raising and lowering due to a bad camera angle. Look at the camo icing and the gun shield and you can see what is happening.

Please check out my other instructables and I also have a diy podcast called mechanicalmashup.tv

Step 1: The Mechanism

I started with some scrap parts I had laying around, mostly stainless steel. The stainless sheet metal was the same piece of scrap I used for the volcano cake last year. Since it was not going to shoot anything, I started with a solid stainless barrel, welded a bracket and a pivot onto it, and fixed it to the turret pan.

By the way, nothing puts a smile on my face more than describing how I make cakes with a welder:)

To make the gun travel up and down, I decided to make a rod and cam type system. I welded a guide tube to the turret pan and made a "cam" of sorts out of a metal disk that I heated with a torch and bent randomly. I then fixed this to a tube that would act as a bushing for the turret pan rotation.

I had a slow turning motor sitting around the house and mounted it to a piece of wood as a base. I welded legs to the cam and drilled them into the wooden base. I set it all on a bit of an angle so the tank would be tilted slightly when done. You can see that the turret pan warped a bit during welding but I was not too concerned and I did not bother to correct it. The push rod was installed to slide along the cam and raise the barrel.

The last thing I did was put on the barrel guard. I used perforated steel for two reasons, one was it would be really easy to bend a slight curve into it and two was so the icing would have something to adhere to.

Step 2: The Cake

The turret pan was hot glued to another piece of wood that was to act as the base. Anything that was to touch cake that was not stainless was covered with tin foil.

I made 4 cakes for this. One cake was baked in a pot the same diameter as the turret pan. A little bit of carving and I had my turret shape and clearance for the barrel and mechanism.

The other cakes were baked in a 9 x 11 inch pan. Once cooled the rounded tops were sliced off. These tops were used for the ground. The main parts of the cake were carved to fit around the mechanism and stacked to create the rough tank shape. All pieces were "glued" together with icing.

A bit of carving with a sharp knife and it was starting to look like a tank.

Step 3: The Icing

I planned to use fondant icing right from the start. This was my second attempt at using the stuff. I wish I could take a course on the application of fondant because it really can't be as hard to work with as I find. What a pain in the butt this icing is!

To get the fondant to stick to the cake, you need to ice it with regular icing. It is way easier to ice if you freeze the cake first.

It is way easier to freeze the cake if you check the dimensions of your freezer prior to building the base!
I had to shuffle a lot of food around but I eventually got it to fit. Oh well, this was a seat of the pants project to begin with.

I mixed colours into the icing as I just bought one big white tub of fondant. The fondant needs to be rolled onto wax paper because it is quite sticky. It even sticks pretty well to the wax paper. I found this to be to my advantage in some cases as I rolled out the tracks. After I used a piece of wood to put the tread in, I stuck a piece of wax paper on top, flipped the whole thing over, peeled off the new top side of the wax paper and used the othe strip of wax paper still stuck to it to move it to the cake, placed it on the cake and then peeled the wax paper away.

One bit of foresight I had was to make the turret easily removable. This helped in decorating more than I can express. I perched the turret on a pitcher so it would not tip over on the push rod or the axle and decorated it there. The stainless barrel was wrapped with fondant and a little bit of detail was put on like a hatch with periscope.

Wheels were added on the side, these were just icing rolled flat and cut out with various sized cups and caps. The camouflage was added by smooshing random shapes. all detail is stuck in place by simply wetting the area you want to fix it too.

The last step was to crumble up some cookies to make the dirt the tank was driving on.

That's all folks! hope you enjoyed this and see you again next year for Brody's 7th birthday.

I'll post a vid of him blowing out the candles in a few days.

Step 4: Blowing Out the Candles

Note the screen on the laptop.

Brody the birthday boy had seen the cake several times prior to this, so that is why he is not too surprised.

Thanks to all the people who have come out to vote for us :)