Physics Projectile Motion Video

        For a recent physics assignment about projectile motion, we were given 2 choices: we could build some kind of projectile launcher, or we could film an example of projectile motion, such as a soccer ball being kicked. In either case, we had to do a report. Originally, I felt like building something, but then I got the idea of filming a snowmobile jump. Not only was it fun for me to do, but it also gave me the chance to play around with movie editing, which I thoroughly enjoyed.

Here's the product of my work:
(You may want to skip the calculations, that part is somewhat dreary) 

Coilguns 101

        Over the past few months, I've been doing quite a bit of research into coilguns and how the work, so I thought I'd do a write-up on them.

      When a conductive wire, such as copper wire, is rolled up into a coil, and an electric charge is applied to it, it creates an electromagnetic field. The higher voltage applied to it, the larger the field. This means that a metal object will be pulled towards the coil with more force if more voltage is put through the coil.

       

        A coilgun operates with this basic principle. The copper coil is wrapped around a plastic barrel(it doesn't have to be plastic, just a material that doesn't conduct electricity). Then, a very large charge is released into the barrel over a very short period of time, creating a quick but extremely powerful magnetic field. When a bullet is placed in the barrel, a short length behind the coil, the magnetic field pulls it towards the coil with great force, causing the bullet to fly down the barrel with great speed. 

        The large burst of energy required for the coil is generated with the use of a capacitor. a capacitor is much like a battery, in that it stores energy. However, a capacitor can release it's energy much faster than a battery. So if a high voltage capacitor fully charged, then connected to a coil, it will release all the energy into the coil very quickly. 

        When talking about coilguns, you may hear the term 3 stage, or sometimes 3 phase. This simply means that multiple coils are used to keep the bullet at constant acceleration down the barrel.       

Welding cast iron brackets

     Today, 2 brackets that hold up a side shelf on our wood stove broke off, so i took them into welding class to see if I could fix them. I was worried they wouldn't weld well, as they are made of cast iron, and neither me, nor my welding teacher knew if it would work. To my surprise, I easily joined them with a MIG welder, and grinded the weld so it was flush with the rest of the piece, then polished it off. Here's a picture I took after I did the first one. It was much easier then I thought it would be, and I am quite pleased with the final product.

Loader Bucket Completed!

      I finally completed the loader bucket today, the welding took a while because I was welding outside, and the weather has been rather dodgy lately. I used a Lincoln arc welder running at about 130 volts, with 7014 AC rods I believe. As you may be able to tell, I completely welded the patch to the bucket, covering every edge, gap, nook, and cranny. Generally it would have been easier(and maybe a bit structurally stronger) to just use a bunch of short welds spaced along the seams, however, it is a bucket that is used to haul manure and other liquids, so I needed to make sure that it wouldn't leak. Overall, I'm fairly proud of the job, especially since I've only been welding for a few months.

Before

After

The Loader Bucket

 This is a loader bucket we use around the farm for odd jobs. As you can see, it's rusted out around the bottom. I'd thought I'd put my newly acquired welding skills to use at school, and build an inner plate to patch the rusted spots. (it's currently incomplete, pics will be posted of the final product).