The Barrel Sander is coming along again, after a small detour to build the (M003) Auto Loading jig. Here is the nine sides bolted inside the barrel. They do three things:
- Make the barrel stronger so the wheels that it turns on have more support than just thin metal.
- Provide a disrupted circle which will cause the materials to actually turn instead of sliding.
- Protect the inside of the barrel from the sanding action.
All of the parts are getting into final position. Getting ready to build it!
Most standard 60HZ AC motors come in approximately 3600 RPM or 1800 RPM. The barrel sander needs to spin at about 30 RPM. To achieve this, the following approximate pulley sizes will be used:
- 1800 RPM motor
- Shaft to 2″ Pulley
- Belt to 7.5″ pulley
- Shaft to 1.75″ pulley
- Belt to barrel (approx 23″)
- End Result is approx 30 RPM
(This was from memory so might be fractionally off).
Here is a render of the pulley assembly (draft):
The inside of the barrel tumbler needs a polygon (made from wood) in order to (a) give enough “traction” to turn the contents, and (b) protect the barrel from repeated impacts. I’m going to use Oak or Maple to do this. Based on the width and thickness of available material, I chose a 9-sided polygon.
Here is a picture of the CAM operation prepared using Fusion 360. I will make nine of these with just a fraction of an inch extra that I can remove on the jointer while getting a tight fit.
Machine M002 is in the works. It is a barrel tumbler for wooden parts. This project will allow us to knock sharp edges off of small wooden products by the hundreds at a time. More to come!