So I actually managed to pull of an entire project. Despite I'm ironing out the bugs and flaws, the project is more or less complete.
So, why a trommel. Us gardeners are always cursed with finding a nice soil, rich and free of stones and clay, which in Slovenia means soil deeper than 5cm. Clay and stone prevent roots to freely grow and makes tilling a nightmare.
You can do the old fashioned way, manure will enrich the clay to make it more soil like and stones can be picked out when tilling and in 2 generations you'll observe a nice garden from the other side.
Or you can sift the soil and mix it with compost. We have those screens at home, flat on a wooden frame and you have to sweat a couple of years of your life to sift one wheelbarrow worth of soil.
That's where a trommel comes in. It's rotation equals an endless screen and constant movement where the only work you do is shovel material in.
So before I begin, let me explain my design. Like I said, Slovene soil is clay heavy and very compact.
, Where I throw material in and the waste drops out on the other side would prove inefficient.
Here's why
These small clumps of soil will hapilly bounce to the end of the trommel and be thrown out as waste. But they can be easily crushed.
So I designed the trommel with one side closed off and 3 river stones inside to crush these lumps.
So first, as every invention begins, a truckload of coffee, paper and pen
As soon as I had some good ideas stewing in my head, I needed to gather material. A friend donated a whole bicycle to pick apart, the net I had to buy (€20) and the 6 small wheels (€2 piece). Wood was in ample supply at home.
The 2 bike rims were measured and one of them had spokes cut away. Same with wheels and the plans were drawn in a CAD program
The devil was hidden in the project.
So I only needed to start woodworking. Small wooden plates to reinforce the joints and screws only, no glue. I want the thing to be able to disassemble and put away when not needed.
Measure twice, cut once and one side was completed.
The rim turned nicely with little resistance. That was a sign I was on the right path.
Before completing the frame I wanted to make the drum. I was unsure how the rims would connect with the net and I wanted to make the frame around the drum.
So, a bike rim and a net.
I closed the spoked side with a barrel cover. The bike gear was there if I decided to make it with a bike chain. The plans were still stewing in my head.
Finishing the frame was an afternoon work at this point
The trommel was operational at this point and was even tested by tunring it by hand.
But I'm much to lazy for that
Let's make it spin with electricity