Puddle Muller

Discussion in 'Sand Mullers' started by Al Puddle, May 6, 2018.

  1. Al Puddle

    Al Puddle Silver

    We won't know until the end of this thread whether this muller works. If it does work, this design should help other home casters get over the muller hump. Gotta have a muller.

    The concept sketches show a rotating drum pinched between the drive and muller wheels. The dump gate is a hole in the center of the rotating drum.
    IMG_1379.JPG IMG_1380.JPG

    This could also be a side muller if I change the orientation of the muller wheel. I'll think about that some more.

    This design, I hope, will alleviate the problems of fabricating a dump gate, a clutch, and drive system that others have wrestled with.
    I welcome any suggestions, concerns, or kudos. Thanks.
     
  2. Petee716

    Petee716 Gold Banner Member

    This is quite an interesting idea. I'll be very interested to see how the drive will work out. Very neat. The hole in the center has my attention at the moment though. I think that if its not covered or plugged somehow it will probably continually drop sand before you want it to. A cone shaped plug incorporated onto the bottom of the drum that can be raised or lowered an inch or two from underneath by means of a lever or cam (with the machine turned off momentarily) would resolve it. A shroud of somewhat larger diameter of a similar shape to what you show in the side view drawing, fixed to the framing not the drum but in close proximity to the drum, would direct the sand into the pail.

    Pete
     
  3. Al Puddle

    Al Puddle Silver

    Thanks, Pete. Yes I'm pretty fuzzy on the drive system. I'm hoping a simple lawn tractor tire will provide enough grip on the bottom of the drum.

    If the drum was 30" diameter with a 6" hole will I be able to get a bucket of sand in it?
     
  4. Al Puddle

    Al Puddle Silver

    The drive system is getting a little clearer.
    IMG_1381.JPG
    I'm gonna scavenge the motor from the cement mixer. It turns at about 30 rpm. The motor is a 0.37 kW and runs at 1680 rpm.
    Comes with a convenient bracket for mounting.
     
  5. Al Puddle

    Al Puddle Silver

    After considering some geometric calculations it turns out the rear wheel of the lawn mower could be direct coupled to the gearbox giving me a 30 rpm rotation. However, the wheel is 8" wide an will likely rub on the bucket underneath. Besides, it's 18" in diameter. To use a smaller wheel, like the fromt wheel, I'll need to add a chain and sprocket set to increase the speed of the drive wheel, trying to maintain the 30 rpm drum speed.
     
  6. Al Puddle

    Al Puddle Silver

    Ok, the frame will be 5ft high. Does 2" square tubing fit over 1-1/2"? In case I need to raise the height of the cross support. I'm leaning to having my local welder fab up the frame and drum and then leaving me to find rollers and figure out the drive system and well, of course, the mulling section.
    The drum walls will be 12". Hopefully, that will be adequate height to experiment with both horizontal and vertical muller wheels.
     
  7. That looks a lot like one I've used: it was built for green sand and later repurposed for resin sand. It was made from a ploughing disc for the base with a rim welded to the ploughing disc that also formed the drive pulley for a horizontal belt to a 1/2 Hp cement mixer motor. The roller is hollow steel machined into a barrel shape to match the curve or the plough disc.


    plough disc muller.jpg
     
    Last edited: May 8, 2018
  8. Al Puddle

    Al Puddle Silver

    That looks simple to build. I wonder if it has rollers. How well did it work?
     

  9. It's pretty old, 1970's at least and has outlived many motors. I'd have to take photo of the underside, there's a hole in the middle that's blocked by a cap that slides up and down on a shaft. Once everything is mixed you grip the knob in the middle and slide the shaft/cap up to reveal the central hole and use a curved steel guide to dump it out the hole into a waiting container. You have 2 minutes to use the sand once part A and B are mixed before the resin goes off. I have never seen it used for it's original use of mulling green sand so I'll have to ask the owner how well it worked. I have a video somewhere of it in operation if you're interested: there's a large measuring can for the raw silica sand and the resin batching system has a chart to batch out the right quantities.

    The roller can move up and down on a pivot and there's a steel handle you can push on to raise the roller, a lead ingot hangs by a loop of rope off the handle to counterbalance the roller and it can be slid along the handle to adjust the down force of the roller.
     
    Last edited: May 8, 2018
  10. Melterskelter

    Melterskelter Gold Banner Member

    Concerning the volume capacity of a 30” dia and 12” tall muller tub: yes it should easily accommodate a 5 gal bucket of mulled sand. My muller has a 24” dia and is 12” high tub and handles a bucket of sand weighinga little more than 50 pounds. Mine has a 7 amp motor which is just adequate.
     

Share This Page