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Post questions and info about hybrid (compressed gas with fuel) powered cannons here. This includes discussion about fuels, ratios, ignition systems, build types, safety, and anything else relevant.
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Unread postAuthor: SpudFarm » Fri Mar 27, 2009 11:16 am

update:
i was at the shop today, the first thing that meat me at the table was a drawing of a VERY complex cloth hanger made of steel and a note: "*shop name* send the bill to me"
so i used the whole day at that, the last fifteen minutes was free for me though and i found the materials and the 2" tap so basically it's all ready if i get better time next friday.

oh and i also made an APFSDS round. 20cm of 1.25cm thick hardened steel with fins that is going to engage a rotating motion. i think i will test it on a tree or something else that falls into my mind.

have a nice day :)
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Unread postAuthor: SpudFarm » Sat Mar 28, 2009 5:02 pm

well i think the plan is pretty much done now, the first shot will be this penetrator at 7x mix. it will first hit the biggest piece of wood i can find, penetrate a thin plate after that and then into a row of fuel cans filled with sand.

i do consider shooting only the sand since that would be exciting when i can find the penetrator again. it will make a good video to :)


so, the sabot will probably be made of a 42mm copper pipe. it will be sealed at one end with molten lead (1cm thick) and the pipe will then be cut lengthwise so only the lead keeps it tougether. then i sticn the penetrator in there and fill it with wax (up to the end of the fins) to keep it somewhat stable while i stick the whole thing into a sheet of styrofoam.
this will be taped with one layer of ducktape for a good seal and coated with grease.
i will also add some classic cloth behind it incase the lead disk fails.

so what do you think? will it hold up?
the penetrator weights 210g

Thanks :)

oh and sorry for doubble post but i want to get an answer :P
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Unread postAuthor: psycix » Sun Mar 29, 2009 2:25 pm

Here's your answer.
I wouldnt use a lead backplate. Far too heavy as a sabot, and if the plate would be part of the projectile, it will have a larger impact diameter, thus no longer being a sabot round.
Why not a simple slice of wood instead of lead? Or if you want to cast it: epoxy.
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Unread postAuthor: SpudFarm » Sun Mar 29, 2009 3:37 pm

no the lead will be casted first, then the penetrator is inserted after it have set and then wax to keep it stable while i puch it into the styrofoam.

wood would 100% sure not hold and i have very high doubts on the lead aswell.

at the same time i can't use anything that makes it get a bigger diameter.
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Unread postAuthor: psycix » Sun Mar 29, 2009 4:48 pm

Lead is too soft.
I'd still vote for wood. If a 1cm thick wood plate can't hold it simply use a thicker one. Because its lightweight (compared to lead) it can be as long as its diameter without problems.
One of the most important things of a sabot is that it is light. And you are using LEAD?!
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Unread postAuthor: D_Hall » Sun Mar 29, 2009 4:54 pm

psycix wrote:if the plate would be part of the projectile, it will have a larger impact diameter, thus no longer being a sabot round.


Just a matter of semantics, but what you're saying is NOT necessarily true.

Everyone is familiar with the term "discarding sabot." That brings up a question: Is there such thing as a "NON-discarding sabot?"

As a matter of fact... Yes, there is.

They're primarily used in aircraft in anti-armor kinetic rounds. The problem with discarding sabots is that they tend to get sucked up by jet engines (that's bad, mmmkay?). Solution? You make a kinetic round with a sabot that stays with the projectile until impact. A non-discarding sabot.

At impact, the penetrator does it's thing while the sabot gets stripped away by the target's armor.

In any event, the point is that anything introduced into the bore to allow a sub-caliber projectile to be fire is by definition, a sabot. What happens to that sabot after the projectile clears the barrel is irrelevant to it's initial classification, but obviously determines whether the sabot is of the discarding or non-discarding type.

So... What you propose? That would indeed be a sabot... of the non-discarding type.
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Unread postAuthor: psycix » Mon Mar 30, 2009 6:06 am

Non-discarding sabot? Okay.

Yet still, lead is far too heavy.
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Unread postAuthor: SpudFarm » Tue Mar 31, 2009 9:03 am

i want to use lead because it will stick to the walls of the copper pipe without an extra pain in the arse.
wood would have to be secured and that's tricky when you already have bad space to even get the sabot in the breech.
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