Wax piston sprue extruder?

Discussion in 'Lost wax casting' started by Zapins, May 21, 2018.

  1. Peedee

    Peedee Silver

    The thrust bearing plate on the augers I worked on were a square steel plate with a round collar welded on to receive the bearing. The auger tube had a matching square flange welded on and four bolt holes to secure. With clearance holes it was possible to line up the shaft and centre the bearing plate before mudering up retaining bolts. The only 'close machining' was the bore that took the bearing outer shell, the rest was alignment.

    Don't know that is much help with that end of things?
  2. Zapins

    Zapins Silver

    Found a local guy to machine the extrusion screw to dimensions, bore and key the shaft. More pics to follow.

    The outside of the screw is at dimension, next will be the shaft/key. Then I'll be able to set it up and start testing. Maybe in the next week or two it will be finished.

    I don't think it matters that the low lying areas are left rough, though maybe I'll give them a polish with a flap disc if I feel like the wax isn't extruding properly.
  3. Jason

    Jason Silver Banner Member

    There ya go man! Onward and upward!
  4. Zapins

    Zapins Silver

    Yee-haww. I'll be happy to get this baby up and running. Couple hundred bucks invested in this thing so far for motors, gear boxes, pids, metal etc. I hope it works as well as I think it's going to lol...
  5. Jason

    Jason Silver Banner Member

    I bet that was fun to center on that lathe. :eek: Look on the bright side, if this thing sucks, you can melt that thing down into a squid.:p
    Zapins likes this.
  6. Zapins

    Zapins Silver

    He machined this little defect out. Still waiting on the clean pic. He's going to cut the slot and key soon hopefully and update with pics. But here's a new pic for you all. I'm hoping I did a decent job welding the defects inside this little piece so when he keys it it's all solid.

    I've got to get a small 5x4x3/4" thick plate to him so he can machine a groove for the thrust bearing and I can weld in the plate at the base of the screw so the backward thrust of the screw is transferred to the bearing then to the plate to frame rather than directly to the drive shaft and motor.

    Tobho Mott and joe yard like this.
  7. Zapins

    Zapins Silver

    Machining done. The fit is good between the shaft and cylinder. Next step is I need to seat a thrust bearing into a thick steel plate so the screw can push back on it. Then I can weld up the frame.

    I wonder if wax will squirt out the back? If it does I can cut a slot for a rubber seal.

    20190829_173419.jpg 20190829_173137.jpg 5887940181.jpg 5887940851.jpg
    Mark's castings, Tobho Mott and Jason like this.
  8. Jason

    Jason Silver Banner Member

    Your welding in the location of that key looks good zap. I bet that was easy as pie to broach. Besides being a little gummy, the stuff is nice to work with.
  9. Zapins

    Zapins Silver

    I bet. Glad its sorted. Just need to assemble it all and get that last part machined to accept the thrust bearing. How many thousandths undersized do I make the slot for the bearing?
  10. Jason

    Jason Silver Banner Member

    That's a question for your machinest. Is he going to press it on?
  11. Zapins

    Zapins Silver

    I think I'll give it a shot on my lathe. He was saying its going to take about 2 hrs to bore through and make the slot on the lathe and was quoting about 75 bucks. I think I'll drill out the inside diameter with a hole saw then bring it up to final dimensions. Might be a good first project for me on the lathe. It's just a hole, hopefully it's not too difficult for a complete novice like me to do haha.
  12. oldironfarmer

    oldironfarmer Silver Banner Member

    If you are wanting a press fit about 1/2 a thousandth (0.0005"). If you want a slip fit, ten (0.010").
  13. Zapins

    Zapins Silver

    Maybe I should just have him make the slot for the bearing? Its 75 for 2 hrs work but that's about the same cost as me driving back to CT and paying tolls and gas. And doing it myself will delay the project many weeks if I can even set my lathe up to do it.
  14. Jason

    Jason Silver Banner Member

    pay the man.
  15. crazybillybob

    crazybillybob Silver Banner Member

    what Jason said

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