Casting request exploratory...

Discussion in 'Request casting service' started by Matus, Nov 27, 2022.

  1. Matus

    Matus Copper

    I've been doing lost foam casting for a while to avoid paying the massive expense of getting a custom part fabricated by CNC machining large billet blocks. I typically cast parts slightly larger than my final part will need, and then of course machine it and drill any necessary holes.

    I'm not a casting expert though and am currently troubleshooting failed castings, so I thought I'd see what it would cost to cast the next part I'm working on by someone who does this all the time and knows how to do it well.

    I'm looking at this part, it would basically be two 6" OD discs about 3/4" thick connected by a tube 3.5" OD tube, with a hollow center of 2-3/8" going through all of them. I'll machine it down to final dimensions and drill all holes necessary. The final part would look like this:


    upload_2022-11-27_15-5-6.png


    Here's the drawing with all the final dimensions:

    upload_2022-11-27_15-8-6.png

    Of course the pattern would just be the two discs and the center tube and be larger to compensate for the shrinking after casting and the machining, I was adding at least .125" all around. My current pattern looks like:
    upload_2022-11-27_15-10-54.png

    I haven't tried casting it yet because simpler smaller castings for me failed.

    I'd like to save the sprue so I can stress test it later to get a general approximation of the strength of the casting. It's well over-engineered for it's purpose but I still like to collect the data.

    Let me know if you'd be able to make a part like this, and approximately what it would run, or if there are any questions. I'd have another one later that is basically half of this thing (half height tube and 1 disc). I'm happy to coordinate final dimensions of the pattern that may make for a more convenient foam pattern making experience. I'm located in Washington state, so probably north america based is ideal for shipping.

    Thanks!

    Matus
     
  2. Jammer

    Jammer Silver Banner Member

    What type of metal? Does the dimensions include shrink allowance?
     
  3. Matus

    Matus Copper

    Oh jeez after all that I forgot to say the metal. Aluminum.

    The dimensions in the drawing are the final dimensions after casting & machining, so the pattern would need to be larger, hopefully not too much larger so I don't have to spend hours and hours machining (I don't have a CNC) I can do a new drawing with approximate pattern dimensions.
     
  4. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    For what and how will the part be used Matus? You will likely have a difficult time casting it as presently gated due to poor packing under the horizontal annular surfaces. Try something more like this:

    Matus.jpg

    Best,
    Kelly
     
  5. Matus

    Matus Copper

    This particular part connects the sprocket to the wheel hub.

    Thanks for the drawing! I'll definitely move the sprue and cast it that way if I do end up casting it. I'll start up a different thread on my casting troubles and suggestions after reading more through the forum.
     

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