Aluminum Casting

[bmetcalf]

This was posted on another forum. The guy is casting his own subframe halves. He says he uses sand from Home Depot (a big DIY store chain) and adds bentonite. I know it has been done for a long time, but I am still shocked how the sand doesn't just collapse out of the top frame. It gives me a flavor of the time required to cast more complicated shapes, such as Vin crankcases.

[video=youtube;0ffn8l7XypU]http://www.youtube.com/watch?feature=player_embedded&v=0ffn8l7XypU[/video]

 

[ClassicBiker]

Bruce,
Pretty cool video. I've also read that linseed oil make a good binding agent when mixed 50:1 by either mass or volume. I hope he sifted the sand for foreign matter as the "clean" play sand, for my son's sandbox, I've bought from the Home Despot (no that isn't a typo) and (S)Lowes (neither is that) has been full of junk that would ruin a casting. What I'm curious about is where folks who do home casting like this get the aluminum they use. I can't see them using old soda and beer cans.
Thanks for posting it.
Steven

 

[roy the mechanic]

Brilliant video, for "flat " parts I would go to the local laser cutters and put the bevels on afterwards. These guys have saved me weeks of work on my current project.

 

[vibrac]

I had some parts made recently by water jet cutting I was suprised by the polishing needed on the edges to get a smooth polished edge(it was for modern levers and footrest plates very much on show) but the accuracy was superb and the cost was very reasonable

 

[Bazlerker]

Casting has some advantages over cnc milling as the skin of the casting has certain structural properties..

 

[Kansas Bad Man]

The best place for the little guy making a part or two is your local auto salvage. Most cylinder heads are made of aluminum these days and after the striping of the seats , guides and things like helli coils ,it makes for a nice size ingot. Very cheap in cost and the aluminum SPEC would be a useable aluminum for most motorcycle parts.

MAX

 

[Kansas Bad Man]

The cast aluminum parts are mostly die castings these days for production reasons. For stronger aluminum parts such as pistons, a sand casting is the thing of the past, to achieve the superior strength needed for any internal combustion engine with a volumetric efficiency of
1 1/2 HP per CI , the forged HT billet piston , machined on a cnc is the only way to go.

MAX

 

[davidd]

[FONT=&amp]The man clearly knows what he is doing, but there is quite a lot to the pattern making. This has been helped recent with 3-D printers that can make patterns. I like the "lost wax" method now that my pattern maker has died. There are lots of steps, but they are low tech and pretty easy to do at home. Start with a box and bury the part half way in clay. Add clay to parts that will shrink or that will need machining to size after casting. Smooth the clay with your finger and add some acorn nuts for registers. Attach one side of the part to the box with clay. You will pour the wax in this hole. Pour in some urethane rubber and let cure.



Flip the box over and pull all the clay out that used to be the bottom, but now is the top. Seal the corners with clay and touch up any clay on the part that was disturbed. Pour in the urethane and let cure.

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[davidd]

[FONT=&quot]You now have the two halves that make the mold. Pour in wax (done in layers)and you have your pattern.[/FONT]

 

[davidd]

[FONT=&amp]Make as many as you wish and send them to the foundry. They will glue on (with wax) sprues and vents. The trim the parts and send them back.








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