I read an instructable teacher mike, https://www.instructables.com/id/Metal-Barn-Star/
and I thought it would be a cool project for my student to make, But being in Australia I thought we might put an Aussie twist on it and do a seven-pointed start.
You can make this out of sheet metal or card, and change the shape so its " fat or skinny" and have as many points as you like.
I'll show you how to design a template for sheet metal and also design for the laser cutter if you want to make your star out of card
- You will need a CAD program
- Sheet metal
- Spot welder
- Glue stick
- Sheet metal folder or break
- Laser cutter if you want to make it out of card.
Step 1: Designing in CAD
I use an old CAD program called PTC prodesktop, have a look at my other instructables if you want to learn more about it.
If you have never made a Barn star before I would recommend that you start with a 5 point star and make one from card before you attempt the 7 point star in sheet metal
Just click on the photos above for all the screenshots and instructions on what to do in the little text boxes.
Step 2: Finding the True Shape of a Surface
To Make the start out of a sheet we first must find the true shape of one of the surfaces so we can make a template.
Make sure you save your work and follow along in the pictures above .
Step 3: Modifying the Drawing for the Laser Cutter
If you look at this drawing you will see the laser it will cut it to pieces, not what we want in a cardboard project, so we have to modify the drawing a little to give us some fold lines.
click on the screenshot and follow along.
Step 4: Assembling the Card Prototype
The reason to do a prototype in card is it's much easier to get familiar with the folds and correct any mistakes.
You will notice in the photos that one end of the tab is a little too big, and I had to trim it with scissors, Now I can go back to my drawing and correct it before printing my template out and cutting the sheet metal.
The prototype also gives me a good Idea of the angles that the metal has to be folded which can be difficult to get correct the first time in sheet metal
Step 5: Fixing Mistakes
So now I need to go back to my drawing and fix the tab, no big deal but it will make the next step much easier.
just click on the screenshots
Step 6: Cutting the Sheet Metal
It is useful to cut your template to about the right size and then find a piece of sheet metal and glue the template to it. Glue to the template edge of the sheet, then cut it with the guillotine and fold it with the magna bend folder. There is an angle gauge on the folder, so use it to fold it the same angle as your drawing, mine was 55 degrees
The last fold it difficult to do on the bender so you can put it in the vice, and try to get all the folds the same angle.
Step 7: Welding the Star
This is the most difficult step, Lay out the pieces and get them to fit together without welding them, you may have to bend the tabs to get them to fit. Either straighten them a little or bend them some more.
The most important thing is to get them all spot welded straight and with the bottom and top edge aligned, and there is no real easy way to get it to fit perfectly, you will have to spend a bit off time before welding to get it right.
Once you have it welded you can hang it on your wall.