Roto Casting

Got a question about techniques, materials or other aspects of physically building a model? This is the place to ask.

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Chacal
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Post by Chacal »

TonyG wrote:
some marvellous ingenuity on display!
Although my patent hot white metal concept on a Black and Decker should carry a government health warning :D
Have you tried to patent it as a weapon? Looks like a winner :D
Sheer elegance in its simplicity.

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TonyG
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Post by TonyG »

Have you tried to patent it as a weapon? Looks like a winner
Considered it as a boody trap - liquid metal version of a claymore mine :D - but couldn't figure out how to keep the metal molten long enough!
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Sparky
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Post by Sparky »

Schadenfreudian wrote:
tonyG2 wrote:...I just love Schadenfreudian's technique of swinging the mold in a bag about your head :D , if you are going for what is essentialy a single axis rotation, how can you acheive even coverage.

I would think that the "swing the cat" method will conentrate the resin at one end of the mold and a single axis "spindle" approach would leave the ends of the mold (at the axis of the spindle) with insufficient coverage.
None of this motorised malarkey for me, I'm a cheap git... :wink:

You're absolutely right that my method would give very uneven coverage - I'd actually misunderstood the first post on this thread, and confused 'rotocasting' with 'spincasting' (like, duh...)! What my cheap-as-chips technique does is to spincast (using the term as excellently defined above by Chacal) solid castings. I think if I had a go using my method for rotocasting it'd be a disaster!

BTW, although nothing I'm currently working on lends itself to rotocasting, this has been a very interesting thread, with great tips, and some marvelous ingenuity on display! :D
Spin casting can be done for cheep too, you have to get your speeds right, cobywan revealed some interesting test result with resin, flying white metal is bad. Atomized resin sounds bad too, the motor spun to fast (old disk sander) and the resin shot out of the mold and sprayed the inside of the barrel the mold was sitting in. But it also atomized the resin into a fog.

The motor for my rig was maybe 24 dollars surplus. The bucket was around 10 dollars, including the cost of the lid. The wood was the junk we pulled from the closet shelves (free accept it takes up space in the garage). The battery was salvaged from a backup power supply that died, new it’s about 15 dollars. But a 1000 mAh wallwart will work, salvaged from anything that needed DC.

I'm pretty cheep too. When it comes to mechanics if I'm not sure it will work forget it, because I can't do much finagling to get it to work.

This motor was left over from the big project, I got it because the first one was DOA, and I didn't want to wait for the return to go out and the replacement to come back. We were in need of setting up the drive and base mounting point. That's what I get for waiting to test it.

I think I can get the wiper motor to work after I rig a basic gear reduction like we did for the space station (flea market bicycle parts!).

BTW I've got some more updated pics some are up some are not. Soon though.
<a href="http://www.kc6sye.com/2_wheresaneatpart.jpg" target="_Sparky">Is this plastic thingy on the counter a neat part?</a> <a href="http://www.kc6sye.com/1_casting_inprogress.jpg" target="_Sparky">Let's cast it.</a>
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Post by Sparky »

Ok If you didn't see these are wonderfest here are pics of other roto cast thingys:
http://www.kc6sye.com/techmages_5_23_06.html

Also I updated the <A HREF="http://www.kc6sye.com/techmages_3_27_06.html" target="_blank">roto caster page</A> so you can see the wiper motor in pics and in action.

Can you say electric bull :?: :twisted:
<a href="http://www.kc6sye.com/2_wheresaneatpart.jpg" target="_Sparky">Is this plastic thingy on the counter a neat part?</a> <a href="http://www.kc6sye.com/1_casting_inprogress.jpg" target="_Sparky">Let's cast it.</a>
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Bar
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Post by Bar »

Ahh yes: The Roto-casting internal bulkhead machine...
If only you could patent it, Joe...
:D
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Sparky
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Post by Sparky »

If only I could make it reproduceable :!:
<a href="http://www.kc6sye.com/2_wheresaneatpart.jpg" target="_Sparky">Is this plastic thingy on the counter a neat part?</a> <a href="http://www.kc6sye.com/1_casting_inprogress.jpg" target="_Sparky">Let's cast it.</a>
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Bar
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Post by Bar »

Sparky wrote:If only I could make it reproduceable :!:
Did you make sure to re-route the secondary gyrodine relays? Or bypass the automatic phase de-coupler?
That usually works for me...
8)
I must retire to my couch of perpetual indulgence...
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