simpson muller (intensive mixer) from 1946

Discussion in 'Sand Mullers' started by thomas o'brien, Oct 8, 2020.

  1. I just bought a super old simpson muller from 1946, its a Model 1 with two crusher wheels, very large 3 phase 1.5 HP 1700 rpm motor. I converted it to 220 single phase with a vfd and it runs and works great.

    The whole unit is so heavy i can't budge it if i try to lift a corner (moved it with a forklift) the mixing bin is about 18". I spent a day cleaning off caked-on petrobond and layers of sodium silicate sand from decades of use.

    after a bit of use, the wheels get pushed up and don't touch the sand anymore.

    I am not sure what kind of gear oil i should put in this or if the spinning action has some kind of hydraulic effect on the wheels or if there is anything missing. The muller works great in general and gets my petrobond back to better than new condition it seems. I have some heavily used petrobond that held together really well ( like it was new) but it had no strength and i was struggling with the sand flopping out of my flasks if i wasn't careful.. no matter how i mixed it or oiled it it never gained its strength back. after it spent 5 min in the muller it was holding together like it was clay. its amazing what a muller does to sand.

    One of the mulling wheels gets pushed up and stays up (i can stop the muller and push it back down with great effort and it works for a while after that until it gets pushed up again). I have greased everything and cleaned everything but i have not taken anything apart. the mixing bucket was completely smashed and needed to be welded back together. The whole thing is made of cast iron.

    I called the company and they dont have any info on any machines before 1950. if anyone has any info or tips on using this, what oil to put in the gearbox, (is that a drain hole and a level checking hole? the fill pipe for the gearbox is on the other side from the two square bolts)

    when i lift the wheels up manually and let go they lower back down like they are held or driven with hydraulics. I am not sure if i need to fill the gear box with gear oil or hydraulic oil

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    Last edited: Oct 8, 2020
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  2. here is a video of it in action. the wheels are offset slightly so they dont run over the same sand. its a really nice compact mulling machine.
    I have put about a half a 5 gallon bucket of petrobond in it at a time and that seems like its limit. and sand starts spilling out where that missing cracked part of the bucket is. The sand bin is about 18" across and there is a scraper for the outside and a plow on the inside.

    This was running about half speed with the vfd the first time I tested it.




    and running full speed with about half a load of sand.
     
    Last edited: Oct 8, 2020
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  3. Al Puddle

    Al Puddle Silver

    are you saying the central shaft moves up and raises the wheels? No, you said one wheel raises. Are there springs that may have gotten weak?
     
  4. the wheels ride up on the sand and then they eventually stay up there, when i shut the machine down it takes a good amount of effort to push them back down like there is some kind on hydrolic pressure. when the machine is off for a while (a few days the wheels can be manually pulled up and puched down with much less effort.

    there does not seem to be any springs or mounting locations for springs or anything that holds the wheels down, I have not been able to find a machine like this online at all and posted it here for anyone thinking of building one or if someone finds another one.
     
  5. crazybillybob

    crazybillybob Silver Banner Member

    can you post some better photos of the Wheels and the mech in-between the wheels? We may not have seen this machine before, but there are a number of mechanically inclined folks here. With good pics someone might be able to figure out how the wheels work and what's wrong.


    Are 100% sure the motor is rotating the correct direction? it's very easy to run a 3 phase motor in reverse.
     
  6. Petee716

    Petee716 Gold Banner Member

    I see zerk fittings on there. Probably just gravity. I'd probably take it apart just to satisfy my sense of adventure, but it's probably just gummed up. Mixing incompatible greases can really make things sticky.

    Pete
     
  7. HT1

    HT1 Gold Banner Member

    my first inclination is that there are no springs, if there are they are a small torsion spring
    I really suspect the wheels are held down by gravity , those wheeels if solid would be quite heavy

    I have to go with Pete, open it up and clean it up,
    if not grease, grease, grease, grease

    Best of luck

    V/r HT1
     
  8. thank for the help. been away from the foundry for a few weeks but i pumped a bunch of grease in all the fittings again (clean grease came out in gaps etc) and probably just needs a bit of use and more cleaning. seems to work ok with about 2 gallons of sand (half a bucket or so). it doesn't seem like there are any springs at all,

    I also just found this video on youtube and i am 99% sure it's the same exact muller.



    cant contact the person who uploaded the video, he shut off all comments on all his videos and no amount of googling his name and foundry, class, etc came up with anything yet.

    does anyone have any idea what that brass thing sticking up might be? he sort of moves his hand over it when he is talking about an automatic oiler for adding the oil to the sand.

    muller.JPG
     
  9. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    .....that's an oiler, very common on older machinery.......those and Gitz type oilers (search that term). I wouldn't call it automatic. You fill the reservoir and then tip that little lever up to release a few drops at a time.

    Best,
    Kelly
     
  10. My plow is wearing out really fast on this thing (was already worn out when i got it and i should have done a casting of it at the time to preserve it)

    Has anyone ever cast ductile iron at home?
    any idea what kind of crucibles i can use?
    can I coat the outside of crucibles with the wash i use for the furnace?

    I feel like i am about to completely melt down the furnace.

    I have hundreds of bronze and aluminum melts done so far but have never done anything as hot as iron. Kind of nervous about going for it.
     
  11. HT1

    HT1 Gold Banner Member

    i doubt the blade is a casting it is probably a forging, from a wear resistant steel like Hardox, in which case building it up[ with a hardfacing welding rod is the easy answer


    V/r Ht1
     
  12. pretty sure it is a casting. Its not shaped like a forging and has the texture of a cast iron part. it has a parting line and looks like it had previously cracked and was welded back together. (I know welding cast iron is not the best thing but looks like that is what happened here) I dont think hardened steel forging can crack but could be wrong.

    I am thinking Pushers and plows are a consumable that is designed to be the weak part of the muller so nothing else on the machine breaks or wears. Its sort of a fuse in the system. If it was hardened steel the main parts of the muller would wear (floor or side wall) ruining the machine. if the plow wears then you just replace the plow (its probably been 40+ years since they were available though)

    Hardox was invented 30+ years after the muller was built.
     
  13. Tobho Mott

    Tobho Mott Administrator Staff Member Banner Member

    That is an oiler to keep the machine lubricated as Al2O3 pointed out. But you can see a feature for automatically spreading oil into petrobond sand (or water into greensand) like I assume he was talking about here on Clarke's muller at 6:30, it's the funnel looking thing in the center:



    Jeff
     
  14. Rocketman

    Rocketman Silver Banner Member

    I have a 1980's Simpson mix-muller, the wheels have a spring that loads them down. It's not crazy strong but has some force to it.
    I would bet they are supposed to be sprung. I wonder if they used a torsion bar system, that was more popular than coilsprings back then. It kind of looks like it could be set up for that
    But it certainly could just be heavily weighted wheels in which case you'll need to pull the pivot pins and clean them thoroughly

    When I got my muller I pulled the head apart and cleaned out the decades of dried grease and sand from the joints, I would highly recommend that for your unit

    As mentioned above, regarding the blades - hardfacing will be your best bet. Doesn't have to be a casting - hard to see from the pics but looks like it could be easily fabricated or forged from mild steel then hardfaced
    Regarding them being a mechanical fuse - that is usually elsewhere in the system, if present at all. Yours was made long before safety features.
    I forget his name, maybe BobS? from AA forums, had a spring loaded slip clutch built into his muller's head
    Mine does not have any safeties as best I can tell, just the belt that drives the gearbox can slip, but it will stall before it slips

    Here's what mine looks like in operation:

     
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  15. The lab muller in the original post....my friend has one for sale in PA
     

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