George Vontorne's muller

Discussion in 'Sand Mullers' started by bmac2, Oct 6, 2024.

  1. bmac2

    bmac2 Copper

    Ok let’s get this out of the way. The Vontorne sand muller small but for me casting is purely a hobby. I only have about 150-175 lbs of green sand so I don’t need a large muller nor do I have space for one. Up until now I’ve been mulling my sand in a 5 gallon pail with a paint mixer and it works but.

    I’ve had the plans for the George Vontorne's muller for a couple of years and had the time and materials so I thought it was time to build one.

    I used what I had around I came up with some 1in tube to mount the blades, a length of 1/2in gas pipe for the center column and a piece of 1/2in rod for the drive shaft and added a bearing block as close to the drive pulley as I could to support the shaft.

    Got a great deal on a 200 rpm 110v, continuous duty sealed industrial motor $24.50 (used) so all I needed for the drive is a single belt. The legs are 3/4in electrical conduit long enough to fit a 5 gallon bucket underneath and I use 1/4x 20 bolts to pin them in place. The legs are removable and the muller came out around 40lbs (18kg). With the legs off I can easily store it on a shelf.


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    Last edited: Oct 7, 2024
  2. FishbonzWV

    FishbonzWV Silver Banner Member

    Nice simple design. Anything beats mulling by hand.
    Yes it is quiet, my first reaction to a muller vid is to quickly slide the sound bar down. To my surprise, I didn't need to. :)
     
    bmac2 likes this.
  3. Petee716

    Petee716 Gold Banner Member

    It's really quite effective for greensand. Nice job. I found a gearbox for reduction from a 1750 rpm motor, so I made a frame with wheels. That made it much heavier. The loose belt is the best idea of all, ask me how I know!

    Pete
     
  4. bmac2

    bmac2 Copper

    Pete having that motor was a God send for keeping it on budget (budget set as close to ZERO as possible) and getting away with a single pulley drive. Most every belt drive machine I own I run the belts a touch on the slack side and I can’t count the number of times it’s saved my butt.

    I haven’t found many videos on the Vontorne muller but of the ones I have seen a lot seem to stir the sand more than beat it up. I think this comes from if you go by the plans the blades are supported with four 3/16” (~5mm) round rods. I went with 1” (25mm) flat bar wended at a slight random angle.

    To be totally honest this was mostly because I had a decent length of the flat bar in the garage and I was too lazy to go to my down stairs workshop and get some rod. Setting the angle of the flat bar is also more that I suck at welding than a design element but it sure works. In the video when I did the second check on the sand (2:37) you can see that I’m almost right at the bottom of the tank.


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  5. Petee716

    Petee716 Gold Banner Member

    I busted my first Van Torne up pretty good with a tight belt and no shear pin. (Just the motor/gearbox framing). It was a pea sized piece of aluminum tramp metal in the sand. Lesson learned.

    I think the rod recommendation is more of a material cost thing. I believe the real "mulling" action is occurring in that 1/4" gap.

    Pete
     
  6. bmac2

    bmac2 Copper

    In the video I mention that it’s some of the sand I used to cast the base plate. The plate the tank and motor are sitting on is 15 1/4” long 8 1/2” wide and I didn’t have anything around to make it out of so I thought I’d give casting it a go.

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    To get the 3” long fingers that support the tank in the right position I temporarily glued them to the base with the tank sitting in position on top of them, then drilled through 2 holes in each position for small locating pins and broke them free before the glue set.

    This was definitely NOT a one and done casting. My original pattern was only 1/4” thick I just couldn’t get it to fill. I didn’t have enough sand to do more than 1 flask at a time and having to mull my sand with the 1/2” drill between tries was a pain. What I finally got to work was adding some 1/8” Masonite (hard board) bringing the pattern to 3/8in and using the longest knife gate I could fit on the long side of the pattern. Then tilted the flask front to back rather of end to end so the metal had a shorter distance to travel, and pouring much hotter than usual managed to get it done.

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    Tidied up with the belt sander where I cut off the gate and did a bit of cleanup where the bearing will sit. Cleaned up the cast holes and cut the slots where the motor mounts on my mini mill. Pretty happy with the way this turned out, I’ve never cast anything this size before.

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  7. nihnimal

    nihnimal Lead

    Well damn, looks like someones making quite good progress. I made my own Vontorne style muller too but honestly for a hobby setup like yours this is a great little work tool. Especially if you're used to mixing by hand with a paint mixer. Imo many ppl underestimate how much sand conditioning can be improved with a small muller, especially in the case of raw sand. One thing to keep in mind is that 1/2” components, such as rods and gas pipe center poles will wear out over time. In greensand, the abrasiveness can be a bit brutal on these small steel parts, especially if they are not hardened or treated. If you plan to run them regularly it's a good idea to have one or two spares on hand. Otherwise, it's pretty solid and compact, and would be perfect for your scale of operation.
    And, if you have limited space storage is always a pain in the butt. Smart idea to make the legs removable. I did the same, went with collapsible legs to save even more space :)
     
    Tops likes this.
  8. bmac2

    bmac2 Copper

    nihnimal I have to agree. That's another reason I didn’t want to go with conduit, I figured what I had was an improvement with the material being heavier and that I have it completely closed off at the top but with it being completely buried in the sand when it’s working it will last longer but not last forever.

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    One thing I thought of AFTER I welded the 1/2” gas pipe to the tank was that I “could of / should of” put it in the lathe and cut a groove for a 0’ring. I don’t have any Idea if it would make a real difference or how long it would last but it would help keep the sand out from between the tubes.

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