Postscript for the failed bronze cannon pour
by John
This is what the casting looked like after I had removed most of the investment, and turned a flat surface on the top of the casting.
I was surprised that the levering pins, and the big thread came out much better than the simpler flat surfaces. That might be because I had concentrated on those areas with the painted on investment slurry. And also because that end was at the bottom of the pour. That end got the first, most liquid melt, and the pressure of the melt above.


Having decided that my casting equipment is inadequate for this this size and weight object, I do not intend to have another attempt at making a 1:10 bronze Ottoman bombard. Plus, even this sad 3/4 complete component is VERY heavy. I would not enjoy carrying the full size 1:10 model.
The only question remains, what will I do with the above failure? It could join my gallery of failed parts (like the crankshaft of the triple expansion engine, which had a single incorrect dimension). It is useful to occasionally survey this gallery. It does motivate me to measure twice, cut once. Or it could become a very heavy and expensive door stop. Or I could drill out the bore and use it as a specimen flower vase. Or I could cut it up, and use the bronze in future projects. Maybe I will just sit on the decision for a while, unless any readers have any persuasive suggestions.
I am reminded of one of my late father’s aphorisms. “He (or she) who never made a mistake, has never made anything”.
Hi John
Well worth displaying I think together with your story should continue to make a good talking point for a long time.
On a side note my first triple crankshaft didn’t make the failed gallery after it bent at 90 degrees it finished up as bar stock. ~Ian
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Sorry to hear the pour didn’t turn out. I’ve got a box of failed cannon projects from earlier on and I know there’s one rusting away out in the forest behind my shop about as far as I can throw.
I’ve been impressed with the possibilities a 3d printer can provide, so you inspired me to buy one! I printed a test cube last night which came out fine and now I’m looking forward to experimenting further. I’d really like to cast a bronze astrolabe someday.
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Well, the inspiration works in both directions Jeff. I followed in your footsteps with rifling, and I have it in mind to make a breech loader like your 110pr. Is it not wonderful how the Internet make this intercontinental fertilisation possible?
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