I've been sand casting since 2000, and have mixed sand by hand since I started. I always wanted a muller, and spent a long time looking over designs and watching videos etc. I started this last winter and I'm back to trying to finish it.
Disclaimer: There isn't a straight cut, good weld, circular hole on this thing. There was no plan, I just started grabbing scrap around the shop and putting it together. My only constraint was that it come apart to allow for mods/replacement parts. No layout dye, just a sharpie marker, beer, mig welder and plasma cutter.
The motor I had at the time is a 3600rpm 1hp 3phase which I am running with a VFD. To get the muller down to a good speed (20-40rpm), I geared down 6:1 with the belt drive, then 6:1 again with a chain drive. I run the motor at about 1000 rpm, but I'll eventually replace it with an 1800rpm motor which I can run faster. I went chain because of the shaft assembly, which is the front hub/rotor/drive-shaft from a 2006 ford ranger (can anyone say spare parts at pick-n-pull!). I bought a sprocket at Princess Auto that I drilled to the bolt patter on the hub, and you have an instance drive train.
The tub is an old air compressor tank I got at an auction, cut with a plasma cutter with no steady rest while squatting.......
The tub legs are from a teleport I had kicking around, and there are a few brake rotors, stair risers etc. that make up the rest of the super structure.
Inside the tub is a wheel I got from castor land. The drive shaft only comes up through the tub by about 2 inches, and I splice it to another shaft with a coupler with a couple of bolts. This makes the insert re-designable as required, and inserts a point of failure in case of too much stress.
The orange handle raises/lowers the wheel, which I've gone to after trying 'floating wheels on springs etc. in a previous design. The reality is that you can only put so much sand in the muller before it will either a) stall, or b) bind the wheel. I found that by setting the height fixed, you can identify how much pressure/compression you want and set your wheel at that level.
The muller isn't finished, I'm working on the paddles to turn the sand after it is packed. That will be a modular design as well to allow for blade replacement/placement.
Well, on with the show -- here is a video of the muller to-date:
Disclaimer: There isn't a straight cut, good weld, circular hole on this thing. There was no plan, I just started grabbing scrap around the shop and putting it together. My only constraint was that it come apart to allow for mods/replacement parts. No layout dye, just a sharpie marker, beer, mig welder and plasma cutter.
The motor I had at the time is a 3600rpm 1hp 3phase which I am running with a VFD. To get the muller down to a good speed (20-40rpm), I geared down 6:1 with the belt drive, then 6:1 again with a chain drive. I run the motor at about 1000 rpm, but I'll eventually replace it with an 1800rpm motor which I can run faster. I went chain because of the shaft assembly, which is the front hub/rotor/drive-shaft from a 2006 ford ranger (can anyone say spare parts at pick-n-pull!). I bought a sprocket at Princess Auto that I drilled to the bolt patter on the hub, and you have an instance drive train.
The tub is an old air compressor tank I got at an auction, cut with a plasma cutter with no steady rest while squatting.......
The tub legs are from a teleport I had kicking around, and there are a few brake rotors, stair risers etc. that make up the rest of the super structure.
Inside the tub is a wheel I got from castor land. The drive shaft only comes up through the tub by about 2 inches, and I splice it to another shaft with a coupler with a couple of bolts. This makes the insert re-designable as required, and inserts a point of failure in case of too much stress.
The orange handle raises/lowers the wheel, which I've gone to after trying 'floating wheels on springs etc. in a previous design. The reality is that you can only put so much sand in the muller before it will either a) stall, or b) bind the wheel. I found that by setting the height fixed, you can identify how much pressure/compression you want and set your wheel at that level.
The muller isn't finished, I'm working on the paddles to turn the sand after it is packed. That will be a modular design as well to allow for blade replacement/placement.
Well, on with the show -- here is a video of the muller to-date:
