Another Kiwi

Discussion in 'New member introductions' started by Guster, Mar 13, 2019.

  1. Guster

    Guster Copper

    The big prize for the day is a china painters kiln I picked up this morning to help with lost-wax casting and a few other things.
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    Dial goes up to 800C even though the manual states 850C and rated at 2kW which makes it perfect for running on a 10A supply. I think it would work great with a replacement PID controller. Might even spring for a multi step programmable one.
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    Looks like nichrome element coils but for the $300 I bought it for I’m happy to spend the rest to upgrade it to kanthal.
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  2. Jason

    Jason Silver Banner Member

  3. Guster

    Guster Copper

    Inside measurements are 300mm (D) x 300mm (W) x 280mm (H) which gives you room for a decent flask over a drip tray. It is a bit more peasoup green but not a bad colour compared to some out there.

    I have a basic PID and might just fit that as is. It is nothing fancy as you take what you get in NZ unless you want to double the price with the added cost of shipping even though the exchange rate is quite favourable right now. Alternative is to check if there is a supplier for that in Australia.
     
  4. Jason

    Jason Silver Banner Member

    That sounds like the size of my current kiln. Great for jewelry and small glass work. But it would be way too small for my lost wax bronze work. Burning out large amounts of wax STINKS to high hell and will turn a kiln black in a heartbeat. Not to mention the HORRIBLE SMOKE! I'm using a junk pottery kiln and I stuck it on wheels. When it comes to burnout time, I wheel it over by the garage door, open it up and stick a fan blowing that wretched stuff outside.

    My little kiln is dogpoop brown. Same size as yours.
    20190318_002256_1552887216448.jpeg

    Here is my catpizz kiln. Works great... Cost $25bucks!:p It doesnt smell like catpizz anymore.

    kiln.jpg
     
    Guster likes this.
  5. Guster

    Guster Copper

    That little brown one is neat too. I am hoping I have nowhere near as much wax in mine to deal with as some of your patterns. Really just for those small high detail items. I am conscious of the smoke and what soot can do to the heat coils. My kiln will go on a stand at some point. Right now it is sitting under the house till I have room in the shed to deal with it. A few other projects to move along first.

    ...

    Talking about projects - another rainy day and another project finished. This is what I've quietly been working on making parts for after I found a sturdy piece of pipe for it. I had the little 1/4hp motor, bearing and steel already. I present to you what Andy calls a sand fluffer. Based around the one on the Oldfoundryman YouTube channel. Hardest part was making a flexible shaft coupler until I found a scrap of flexible urethane to make a 'spider' with. Couplers this size can be quite expensive. The couplers are just flanges with 2 steel pins mating in the urethane disk.
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    All assembled with a nice stainless chute. I ran out of steel flat bar to make a stirrup to hang it from the top end. For extra points I found some small rubber gaiter to put over the coupling to keep sand out of it.
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    As always, a picture of the bottom business end. Definitely don't want to stick your fingers anywhere near the bottom. Always good general wisdom.
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  6. oldironfarmer

    oldironfarmer Silver Banner Member

    Pretty cool! You do nice fabrication work.

    Do you have that bottom sealed bearing shielded against fines packing against it? I bet all these parts will wear a lot faster than you'd think. I've been wanting to build one of these but couldn't understand from Martin's video until I watched with sound. duh. You may want a funnel extension for a bigger target when you're in full commercial production.
     
  7. Guster

    Guster Copper

    Thanks Andy. Not the prettiest contraption I've ever built but without many working examples I didn't want to trow too much money and time at it. The only steel I bought was the large pipe offcut. Most of my friends thought I'm having a bad go at making a jet boat drive. o_O

    The spoke holder on the axle is the same size as the bearing cup as you can see in the last photo. It has a small lip that overlaps the edge of the bearing holder so the bearing is mostly concealed. Not enough but it makes a difference. Was planning to add an additional small surround over the outside but this was the first assembly to make sure it runs OK.

    Good thing there won't be too much 'production' happening. But wear was the main reason for leaving the mill scale on and forgo any painting.
     
    Last edited: May 18, 2019
  8. oldironfarmer

    oldironfarmer Silver Banner Member

    Your pump impeller on your jet boat drive needs some work. All it's going to do is stir water at this point.
     
  9. Guster

    Guster Copper

    Though seems like I solved the problem of getting bogged down in the sand. :D
     
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  10. Guster

    Guster Copper

    We had a long weekend with great weather so I thought I'd make some fire and melt some metal.
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    First lession: my first flask is much to large. About 45kg of sand in that but by the time I had it rammed up I just had to cast something. Didn't even bother with a riser. The runner froze to one of the cavities too.
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    But the center one came out allright.
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    So with little time to spare the next day I made some smaller flasks about 300mm wide. Still very large so I have a plan to make some smaller ones. The one to the right poured well though the left one leaked between the flaskes and only the right casting came out.
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    With daylight left I quickly rammed up another mould and cast again.
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    My sand is still a little wet and could use more mulling. These parts are not the simplest. But for first castings they came out good enough for me to machine some 3D printer carriage parts from them. As luck would have it the srinkage in the middle part is in an area that gets machined out.
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    Glad I hadn't built my pattern making bench yet as it was way too small in my plans. My sand fluffer also failed to work the first time with the sand getting packed up so I've removed the first set of fingers and some of the fingers in the final ring and works much better now. Will see how it goes.

    A lot more work and a lot more to think about.
     
  11. PatJ

    PatJ Silver Banner Member

    I love watching people pour molten metal.
    There is something mysterious about that, I guess the big thing is seeing if it turns out as expected.

    Are you making/posting videos of your casting sessions?
    .
     
  12. Guster

    Guster Copper

    Meh... kinda bored with aluminium now. Time to melt something yellow. Just kidding, it's always fun to skim the dross and see shiny liquid underneath. The only sad thing is when the pour runs short - or metal leaks out the blink'n flask. :oops:

    Hadn't thought about videoing. I'm definitely not well set up for it and very conscious of the family around the place when I melt. I had just lit the furnace when my wife wanted to wheel a barrow right through the middle of where I was working. Trying to nudge the LPG cylinder out of the way. :confused: Else I'm so in the zone I need to remember to take a photo now and then.

    I have to pour some lead soon to make a keel bulb for a friend's RC yacht. Making a plaster mold from an 3D printed pattern. No furnace needed either but still fun. Should get some use out of the kiln to dry out the plaster too.
     
  13. oldironfarmer

    oldironfarmer Silver Banner Member

    Glad you got your feet wet. I thought your finish looked fine.

    Does it look to you like the middle casting shrank because of the riser? I've had the best luck feeding through a big riser into a mold. Then the riser has the hottest metal and will continue to feed the mold. A riser in the middle of a mold may still cool first and suck up metal. I had that problem with my burner manifolds, trying to add to the boss on top to make a feeder resulted in the part shrinking but the "riser" pretty much held it's shape. A big riser entering the mold fixed the issue.
     
    Guster likes this.
  14. Guster

    Guster Copper

    It is a bit rough in parts. Partly due to getting tired from ramming with a piece of wood and not ramming enough or consistently. This left soft spots which would sink or mar just by looking at it. The sand could use more mulling to make it more consistent as well. It really shows up on the parting line where some edges would crumble really easily. The other was that the two outer patterns had draft in one orientation then I realised I wanted to change something which also changed the orientation. I also couldn't waste a whole day waiting for more paint and filler to dry so I used bare wood patterns, sanded very smooth and Still managed to pull them but it did make a mess here or there. A lot of simple things that can easily be improved on and these will machine up very clean. It was nice to get my feet wet and not in a bad way.

    Thanks for the advise on the shrinkage Andy. I'll add it to my list of things to try next time. All three parts have shrinkage and while these can accommodate it there will be future parts that wont. ;)
     
  15. Guster

    Guster Copper

    Not too shabby after a little fettling and turning all the rest into tinsel! :)
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  16. oldironfarmer

    oldironfarmer Silver Banner Member

    Looking good!

    Did you notice any cavities or porosity when machining?
     
  17. Guster

    Guster Copper

    A little... most of it machined away. You can see the worst of it in the bottom left corner of the top machined casting. The rest is pretty decent given it is varied scrap of questionable origin cast by a novice of similar questionable origin. :D
     
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