Vacuum Former

Step 2 The Oven

First we will build the oven. The oven consists of a wood frame with an inner layer of hardibacker cement board and an aluminum inner lining. To build the wood frame you will need some 1x3 lumber, which you can get from Home Depot or Lowe's. For the parts of the oven I will refer to the part numbers form the .pdf file of all the parts of the oven. Parts VF-01 and VF-02 and some #8 x 1-1/4in. wood screws will be used to construct the frame. I used a miter box saw to cut my 1x3 to length but a circular saw or jig saw could do the same thing, just make your cut square. Place the wood pieces in a rectangular shape with the shorter ones(VF-02) on the outside. Drill pilot holes through the VF-02 parts and into the ends of the longer pieces(VF-01), the wood will split if you don't do this, plus it will make it easier to run the screws in. A 1/16in. dill bit is a good size to use. Screw the rest of the wood frame together in this fashion, making sure you keep everything square.

Now we need to cut the hadibacker board. Hardibacker board is basically drywall for around showers, it used because it doesn't absorb moisture. Its made with cement so its also a good heat insulator which is why its used in the oven. You can cut the hardibacker by scoring it with a utility knife and then snapping it but that can be hard to do when you need long thin pieces. I would recommend using a jig saw to cut this board. I found out the hard way that you can't use a normal jig saw blade to cut cement board, so you will need to get a masonry blade for your jig saw. When you go to the hardware store to get it, look for one that says it will cut tile, thats what you want. The blade doesn't have teeth, the cutting edge looks like a glue/sand mixture just globed on to the blade. I started with cutting the long thin pieces first, parts VF-03 and VF-04. First I cut them to the 2-1/2in. width and left them a little long. Then I went and fitted the pieces to the frame, so that every piece fit nice and snug. You want to keep the oven as tight as possible so you don't have to worry about holes or gaps for the hot air to escape.

Now you need to make the aluminum inner lining side parts, VF-07 and VF-08. This is aluminum flashing which you can get from any Lowe's or Home Depot. I got a roll that was 14in. wide because the flashing will be used on the bottom panel of the oven which is 11in. wide. Aluminum flashing is very easy to work with and can be cut with normal scissors, I'd recommend a nice sharp pair just to make it easy. Again here cut the pieces to the 2-1/2in. width and a little long, then fit the pieces to the frame. Now screw this all together through the flashing, Hardibacker, and into the wood.

I know the animation is not the best but I think it gives you a really good idea how the oven goes together. This is my first real attempt at using SolidWorks. You might be asking how does the large sheet of Hardibacker, VF-05, attach to the plywood, VF-06. That will be explained in the next two steps.

Comments

[GM2009]

I want to build something similar but will use Quartz heaters from small oven. Backerboard is nice but the problem is that is to big in my opinion to buy. You use only one portion of it and have big leftover. It is bulky to transport to and not so easy to cut. Another solution is to make your own concrete boards with concrete mixed with sand and fiber (search 'concrete board' here). That way you can make any size you want. You can also make one piece shell (in steps). This method has its own benefits. When mixture is poured, wooden pegs can be added for screw holes. I think that Vacuum Former Design 2 is better than this one. Most industrial formers are done with heater above (plastic sagging and melting problem). I've made few of my own forming machines and none was as good as I wanted. Forming is simple, but I have to repeat few key points for success: -Good uniform heater. Working with kitchen oven is fine for tests but for good results good custom made oven is needed. -Good plastic holder frame. Has to be robust and accurate, otherwise vacuum will not be achieved. I always add strips of 150 Al sand paper around to hold plastic better. -Good and accurate frame sliders. It is important that frame with heated plastic be transferred to vacuum plate quickly and accurately. -Good vacuum plate. Having good seal is even more important than vacuum source. Vacuum cleaner can produce enough of vacuum for forming but only if there is a good seal. High end vacuum pumps will help if finest detail is needed (but only if all above is achieved).

[fleazy421]

a circular saw with fine blade is the best for thin strips just make sure to setup a fan to blow the dust away

[vernonstien]

I'm with you so far......