I was thinking about my grandkids’ marshmallow shooter, and started wondering "If you accelerate a marshmallow to a high enough velocity, would it be able to penetrate plywood?"
yep.
Many thanks to Technician for his piston valve design concept & inspiration.
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Posted: Thu Jan 21, 2010 6:14 pm
by twizi
very nice
is that a pvc barrel
what psi u usin
Posted: Thu Jan 21, 2010 6:17 pm
by Ragnarok
Neat, but I'd point out that OSB is not actually plywood - it's rather less impact resistant than true plywood.
Still, impressive performance nonetheless. Any idea what kind of velocity you're getting?
Posted: Thu Jan 21, 2010 6:27 pm
by John Conklin
Twizi: That is indeed a pvc barrel, pressure rated at 465 PSI. These shots were made with 160 PSI air.
Ragnarok: Yes, I know that OSB is not technically plywood, but it was the only thing I had in the bone pile at the time. My goal is to punch through 3/4" true plywood. -More on that as events unfold.
According to GGDT, the muzzle velocity is around 850 FPS and the KE is approximately 175 ft-lbs.
Posted: Thu Jan 21, 2010 6:31 pm
by twizi
did u use that drill press to make that pistion
Posted: Thu Jan 21, 2010 6:33 pm
by John Conklin
I did for the first one, but I have a machinist friend who turned this one for me.
John Conklin wrote:I was thinking about my grandkids’ marshmallow shooter, and started wondering "If you accelerate a marshmallow to a high enough velocity, would it be able to penetrate plywood?"
Wish I had relatives like that as a child
Nice build, though is it really "tactical" before you slap on a few weaver rails and add a scope, laser and torch?
Posted: Fri Jan 22, 2010 12:29 am
by inonickname
Wish I had relatives like that as a child
We're all family here Jack, never to late to be a child
Extremely nice. I'd assume you've taken into account annealing weakening the material, but it all seems extremely well done. Looking forward to seeing more
Posted: Fri Jan 22, 2010 12:36 am
by John Conklin
My god man!! I think you've hit on something here
A laser sight would be perfect!
The problem I'm having is that I seem to be losing interest in this gun because I'm already fixating on the next (newer/bigger/faster/taller) gun.
Is this the normal sequence of events in the life of a spudgunner?
This, by the way, is my first gas gun endeavour. It would seem that I'm going to be spending an inordinate amount of time finding new ways to propel food products at high rates of speed.
Inonickname: You are correct. The steel being used is 50 KSI P&O steel, TIG welded and stress relieved per AWS qualified procedures.
Safety is always first & foremost in my shop.
Posted: Fri Jan 22, 2010 12:40 am
by jackssmirkingrevenge
John Conklin wrote:The problem I'm having is that I seem to be losing interest in this gun because I'm already fixating on the next (newer/bigger/faster/taller) gun.
Is this the normal sequence of events in the life of a spudgunner?
Completely, welcome to the fold
Posted: Fri Jan 22, 2010 12:48 am
by John Conklin
Thank you.
I've been pouring over this forum for about a month now, and I'm pleased (impressed?) to see the very open exchange of ideas & feedback.
Posted: Fri Jan 22, 2010 12:49 am
by deathbyDWV
Very nice work on this.
Hmm... New ways to propel food products.
What is HYBRID?
CORRECT!!!
How about a hybrid?
Also the harder better faster stronger thing is all too normal.
And have you ever tried (just for fun) to make a marshmallow that you've already shot, shoot again? Even though they're squished, you could try...
Posted: Fri Jan 22, 2010 12:55 am
by John Conklin
I've been thinking about a hybrid, but first I'm going to try going supersonic with 200 PSI helium... just to see if it can be done.
I'll try the used marshmallow idea. Might be interesting!
Also, I'm going to paint some marshmallows fluorescent orange (to make them easier to track) and see how far I can lob one.
I really want a crono & high speed camera now
Oh... and a lathe
And time. Lots of free time.
And a butload of money.
