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by Pennywise
Sat Sep 10, 2022 7:57 am
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Re: Vortex feeding issue

I inherited a 3d printer from a friend of mine, so naturally my first project (after a few dnd minis) was doing some experimenting with vortex block design. The design in question has a skirt surrounding it to aid in loading, and since making the model, i have attached a couple of shrouds to avoid j...
by Pennywise
Sat Sep 10, 2022 8:10 am
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Re: Vortex feeding issue

I inherited a 3d printer from a friend of mine, so naturally my first project (after a few dnd minis) was doing some experimenting with vortex block design. The design in question has a skirt surrounding it to aid in loading, and since making the model, i have attached a couple of shrouds to avoid ...
by Pennywise
Sat Sep 17, 2022 8:10 am
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Re: Vortex feeding issue

The air inlet is most visible in models 1 and 4. At the top of the rendering in number 1, and the bottom of 4. Something I should clarify, when the gun is fired with spring and plunger in place, I get the feeding issue; a few bbs shoot out, followed by only air. The spring is mounted to the back plu...
by Pennywise
Thu Oct 13, 2022 10:49 am
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Hammer->Qev->Piston rifle

This is my first cannon posting, though i've dabbled in 'spuddery' for many years now. I finally had some time to try a new build design, and I think it turned out pretty well (though i'm still tinkering/redesigning it). 1/2" copper barrel, 3/4" copper cylinder. delrin piston with o-rings, and an eq...
by Pennywise
Fri Oct 21, 2022 7:15 pm
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Re: Hammer->Qev->Piston rifle

Yes, JSR, the QEV was added due to difficulties in getting the hammer-valve to trigger my piston. I figured a QEV is probably more sensitive to a smaller drop in pressure than my piston was, and it worked out to be true. The current design using the Delrin piston (with orings) and largely reduced pi...
by Pennywise
Thu Mar 02, 2023 6:04 pm
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Hammer valve-->Piston

I have wanted a lathe since I understood their capabilities. Late last year I finally bought one. A Monarch 10ee, that happened to be born some 3 months before my grandfather (4, 1942). After some careful (read 'creative') planning, and stressful (read 'careful') execution, a friend and I managed to...
by Pennywise
Tue Mar 14, 2023 10:15 pm
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Re: Hammer valve-->Piston

Im highly considering paying for the history of my machine. Monarch will sell information about then original purchase (price, accessories, etc) as well as where it was shipped to. Yes, the hammer seat and piston seat are both brass-on-steel. Appreciate the compliments, guys. Right now I'm building ...
by Pennywise
Tue Jun 06, 2023 10:33 am
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Spherical interior vortex block

A while back I started tweaking the design of a standard vortex block. I'm not sure what the specific design style would be called, but I'll just keep this simple and call it a 'block'. The typical design allows the bbs to continue spinning around the center hole until they 'find' the outlet. With 3...
by Pennywise
Fri Oct 06, 2023 5:20 pm
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High pressure 50cal rifle

I posted some time ago showcasing a high pressure 'Toolie' style valve I built out of stainless steel. This is the progression of that project. I'm sorry for making a new post, but I figured it'd be easier than modifying my old one. Feel free to move this if needed. shown below is the valve assembly...
by Pennywise
Mon Oct 09, 2023 10:54 am
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Re: High pressure 50cal rifle

Here are photos of 2 test shots done today, in Feet Per Second

Done at 2000psi
20231009_104830.jpg
20231009_102741.jpg
20231009_105236.jpg
The mass of this last shot is 147grain. This gives an energy of ~230ftlb. Not too shabby for a bit under half pressure.
by Pennywise
Mon Oct 23, 2023 9:43 am
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Re: High pressure 50cal rifle

Thank you! This has been a fun project so far. I believe I'm going to (sorry for the pun) bite the bullet and purchase a .50 barrel/barrel liner to make one with. In an effort to maximize performance, I believe a professionally built (read "highly consistent bore") barrel will be my best bet. As for...
by Pennywise
Thu Nov 23, 2023 9:47 am
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Hybrid geometry

I have attempted to find some testing in regard to the geometry of a chamber-barrel transition, but it has been mostly fruitless so far. I am building a hybrid from a section of 1.5"ID stainless. The barrel will be .5"ID. The actual combustion portion of the chamber will be ~6" long. From what I hav...
by Pennywise
Tue Nov 28, 2023 4:32 pm
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Re: Hybrid disk burst pressure effect on performance

This is very interesting. Intuitively, the highest pressure accumulated before burst would result in the highest velocity. It would stand to reason, though, that you want the disc to burst late enough to raise the chamber pressure sufficiently, but early enough for there to be unburnt fuel mix being...
by Pennywise
Wed Nov 29, 2023 4:16 pm
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Re: Hybrid disk burst pressure effect on performance

Correct me if this theory is flawed, but could it be more than simply the effective chamber being larger? The unburnt portion of the fuel has mass to it, and so as it's being propelled by the expansion of the burning fuel behind it, it pushes the projectile faster and faster. As the flame front catc...
by Pennywise
Tue Feb 13, 2024 12:09 pm
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Re: Combustion cannons

Assuming you mean PETN/ETN. Discussion of the use of explosives is not allowed on these forums, to my knowledge. Also, given the level of knowledge you have shown in your multitude of questions on this forum, I'd STRONGLY recommend you do not attempt to utilize this material.