Here is a wheelbarrow concrete mixer I made as my spring of 2012 project. All except for the drive belt and minimal hardware, the materials were “recyclables.” The tumbler is made from an old poly pickle barrel.
Below is the construction sequence, I took a lot of photos but some details may be lacking.
It all started with the pickle barrel. I had some concrete projects in mind, and I thought if I can just rotate this barrel with proper torque, I’ll have me a cement mixer. I began designing the mixer on March 19 by taking pictures and measurements on this barrel:
Also, I had just repaired a noisy wheel bearing on my 1991 Chevy Lumina APV minivan, but surprisingly the old bearing felt very tight and smooth in my hands, so I could not bring myself to throw it in the scrap bin. I saved it, not knowing for sure at the time what I would ever do with it. I realized it was an important ingredient of the mixer.
I took many measurements and spent a good deal of time on my trusty cad program, DeltaCAD, and began building the side frames:
Those 1″ binder clips are fantastic for clamping wood working projects! I used leftover plywood scraps from building a Peace Canoe, and as any boat builder knows from making plywood boats that you end up with a fair amount of oddly shaped plywood scraps. This was the perfect way to use up those scraps instead of just tossing them in the stove.
Some weeks later, the mixer was really starting to take shape:
The side frames are complete, and the rear bearing and gearbox assembly is done. I used Matthias Wandel’s excellent Gear Generator 3 program to make the planetary gear set which has a 58:7 ratio. The gear set has a 7-tooth pinion, 22-tooth planet gear, and a 51-tooth ring gear. (The bicycle wheels on the left of the photo aren’t part of the cement mixer.)
More shots of the ring gear / motor mount assembly:
Wood is so versatile. 😉
Now, time for the belt drive pulley:
After roughing the shape, I needed to route a groove in the big wooden pulley to guide the belt.
With no such thing as a wood lathe big enough to lathe a pulley of this size, the best thing to do is just temporarily rig a router. It made it perfectly round and true running.
And now here’s a video:
This is a small batch I can run much bigger batches, I think up to 2 or 3 bags, but after that it becomes too heavy to wheel around.