Video of Casting Small Complex Cannon Parts
by John
This video was taken and edited by my daughter Eleanor. I was doing an aluminium pour of some parts for the Armstrong RML cannon, explaining the process to her. I was hardly aware that she was videoing, so the interaction is conversational.
Although the pour was not a success because none of the parts were good enough to use, it does show the process as seen by someone who previously knew nothing about it.
There is also a 20 minute video of the whole process which I will add to this post when it is available.
Reader Rob has suggested that the positions of the defects suggests that air entrapment is the cause of the voids and that the fix is to position some vents at the positions at risk. I will try that with my next pour. Thanks Rob.
Here is the 22 minute video. Just as recorded. Not planned or edited.
johnsmachines 
Hi John,
Looks like you’ve been really cranking in your shop with a lot of drilling, riveting and now, casting with 3D printed parts. It’s all very impressive!
I’ve done casting on a larger scale, both lost wax investment and sand casting of aluminum and bronze. I think you need some little risers off the uppermost parts of the casting that will both let air escape and supply hot metal back into the casting as it cools. Third time will be a charm.
Aloha,
Richard
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Thanks Richard. I will try that in a day or two, and post result. John
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What an interesting video of the pour, well done to the camera person! Could be up for an Oscar!! I agree with the comment from Rob, I saw the funnel fill up before the aluminium had reached all the voids and no air bubbles coming out, extra vents I think are needed and/or a larger dia at the bottom of the funnel. A great learning curve though, I would love to give it a go someday.
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