5 shot hybrid repeater

POLAND_SPUD · Tue Jan 27, 2009 6:38 pm

hmmm.... I don't see any point in making solenoids... sure it's cool to make something like this but if you want a good performance just buy one... there are lots of them on ebay

spudamine · Thu Apr 02, 2009 3:46 pm

I've now got it firing with a 2x mix, guess it's now officially a hybrid

fresh damage vid:
http://www.youtube.com/watch?v=Qwae9hKX9zA
From the vid you can see there is no recoil from the 1st shot (1X) but significant recoil from 2nd and 3rd shots(2X), despite the poor burst disks.
The 2nd shot uses a burst disk which is too strong, you can hear gas escaping around it for about a second before it blows, not too good really, good job I over-engineered the chamber.
The 3rd shot uses a much weaker, more brittle disk which blows straight away but probably at too low a pressure for maximum power.
That's the problem with using plastic burst disks, they deform before they blow so testing by slowly increasing the pressure gives a lower burst pressure than the instsantaneous burst pressure. clear plastics seem to be the most brittle and the best performers, the 3rd shot used the front of a cd case (1mm polystyrene), I think 1mm acrylic should be about twice as strong and nearly perfect.

ALIHISGREAT · Thu Apr 02, 2009 3:59 pm

nice to see its up and running again

but this question has been bugging me; what did you fibre-wrap the bottles with?

spudamine · Thu Apr 02, 2009 4:55 pm

It's fibre glass tape, got it from toolstation but I just checked and they don't seem to do it any more, better start rationing

It's damn strong, duct tape is easy to tear, but your hands will bleed before you manage to tear this stuff

SEAKING9006 · Fri Apr 03, 2009 9:26 am

This only makes me feel even worse about Texas legislature. Damn restrictions....

If I could do combustion you guys would have seen a PaK-40 replica by now. (Or maybe a KwK-36...)

spudamine · Fri Apr 03, 2009 2:32 pm

This only makes me feel even worse about Texas legislature. Damn restrictions....

It still mystifies me how you guys can regualate spudguns when you can go and buy pretty much any hardware you would want. I'm curious are they worried about people injuring themselves, or scared somebody's going to use them for crime?
Life's a lot more simple, if irritating, the other side of the pond - you're not aloud to do anything, thats why all test shots have been conducted indoors. To be honest I'm beginning to lose the enthusiasm for developing something I might never be able to fire outside.

Biopyro · Fri Apr 03, 2009 4:01 pm

I didn't realise that you were on the UKSGC until I saw this post on here.
I have fired all my guns - noisy or otherwise in my garden. It's a reasonable size, but neighbours are still 50-100m away. One side don;t like it in excess, and the other side don't mind, and surrounding neighbours have either said wow that's cool or nothing. I think they expect these sorts of things enough (and we are all on pretty good terms) to ask me directly before involving the police, but I think the key is to have a contingency plan if the police have been called (low pressure shots, something else it could have been etc, or just find a friend with some farmland and fire it there.

covey12 · Fri Apr 03, 2009 5:00 pm

i saw a video on youtube of you testing this cannons breech i think, it looks really cool

super spuder · Fri Apr 03, 2009 5:31 pm

whats up with using wood to hold the bottles? did you run out of aluminum building everything else out of it

I really cant wait to see this thing when its done.

spudamine · Fri Apr 03, 2009 6:04 pm

I didn't realise that you were on the UKSGC until I saw this post on here.

Ah two names, always gets them

My immediate neighbours are cool, but I'm in a very built up area, there are potentially lots of people around who could cause trouble. Somebody's dog always starts barking when I fire

i saw a video on youtube of you testing this cannons breech i think, it looks really cool

yep that's me

whats up with using wood to hold the bottles? did you run out of aluminum building everything else out of it

You're right I do have a bit of an aluminium fetish (a bit like JSR and his epoxy

) but there are limits to what even I'll do to dress up a few cider bottles, there's really no need for anything better here.

mark.f · Tue Jun 30, 2009 3:59 am

I'm bumping this topic because:

1.) The cannon is freaking awesome.
2.) It's in the wrong section, which is probably why I didn't see it (didn't have an internet connection when it was posted).
3.) I think it deserves more comments.

Good job. The manometric metering idea is especially unique, and is the first setup I've seen that allows lower mixes.

spudamine · Tue Jun 30, 2009 2:58 pm

Thanks Mark, I'm betting you saw the damage picture I posted in another topic, though what the hell did that and had a bit of a search

When I first posted this it wasn't finished so I put it here, it's still not finished but it's as finished as it's going to be any time soom so it could do with going in the showcase, If there are any mods out there could it be moved please.
As for the metering, I've seen it discussed elsewhere but I dont think anybody else has been mad enough to implememt it

5 shot hybrid repeater

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