Designing - Arms Pt. 2

It was at this time that I started to wonder if there was some way I could make a computer model that would allow me to play with the arms, to move them and see them fold and unfold. After looking at a bunch of different CAD softwares and not really seeing what I wanted, I arrived at Fusion 360 from Autodesk. While Fusion seems to be oriented around team development and pushes the cloud-based nature of the program quite hard, it also seemed to be exactly what I needed.

This is the part that caught my eye, nevermind that it was an extremely capable CAD software. I would be able to create an arm assembly and then make it move, this was really exciting at the time. To be honest it still is rather exciting to watch the arm assembly move in Fusion just by moving the drive arm.

Oh, and it's free. (for hobbyists and students)

On to the actual design, since I was extremely excited to try the moving parts feature, I immediately created an approximate model and set about making the joints.

This is the result, a very rough model. However, despite being rough and not to scale, it does function properly and after this, I have designed everything in Fusion rather than TinkerCAD.

This is the actual model of the arm assembly. Just about everything here is how the actual build turned out. Notice that the arms don't fold flat, if I would make the arms fold completely flat then they would not be able to extend properly.

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Designing - The Cells

A distinction I should make before going any further is the difference between solar cells and solar panels. When I am talking about the solar cells I am talking about the individual square parts inside of the panel. The panel being the housing for the cells, some sort of stiff material for the back and a sheet of glass over the front. The cells produce power and the panel houses and protects the fragile cells. The first step of designing the solar panels was to get the actual solar cells I'd be using since literally, everything was dependent on their size. I was able to find some panels for fairly cheap on eBay, so I officially began the project with the purchase of 10 A Grade 4.8W 19.6% 156mm Mono Silicon Cells. Here's what that means: A Grade - Panels are completely intact. B, C, or D Grade will have increasingly large chips missing from the cells. Read more here. 4.8W - This is the power output. 19.6% - This is the claimed efficiency of the cells. ...

Update - Drive System

Right, so my suspicions about the bond between the drive arm and drive arm were correct. When I tried to extend the panels using a pair of pliers the epoxy joints cracked and the axle broke loose. The panels did not extend at all. I've drilled a hole through the drive arm and axle, I epoxied a nail into the hole and it seems to be holding. I can now extend the panel with pliers. It takes quite a bit of force to do it. I kinda doubt a servo will be able to handle it.

Building - Arms Pt. 1

Building the arms was by far the most time-consuming task. If only I had a cnc.... The rim of wood around the bearing was needed but I didn't like the really thick arm, I drew this up in Fusion, printed out the drawing, and stuck it down with a glue stick. The slot in the middle was an idea to make the arms lighter and look cooler. I tried it with one arm and then ditched the idea, it really didn't work and was a lot of work. All cut-out, at this point I didn't have access to a scroll saw so this was all done with a regular handsaw and files. It's pretty rough but I cleaned it up as best I could. Already looking much better. The next step was mass production, I needed 20 arms total. For this, I bought a used Craftsman Scroll saw. It was very, very useful. All cut and drilled out. Removing the paper was annoying, I used the top edge of a file to scrape it off. Since I put it on with a glue stick it wasn't very difficult to scrap...

Martens Solar

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