My first hybrid gun

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
Vadim
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Tue Apr 30, 2019 4:37 pm

After two monthes i finaly made my first hybrid gun. It took so long because of the lack of money and knowledge. It's not fully finished yet but it already shoots.
Specs:
Chamber – 44cm of 2" steel pipe with welded in threaded fitting for a sparkplug. Walls are 3mm thick.
Barrels – 100cm 50mm barrel and 100cm 42mm barrel.
Ignition – originally it's been a chinese high voltage module but build in multiplier(not sure that i call it right) broke, so i had to cut it off and ask my dad to replace it with a bulky multiplier from an old TV and make a power supply for it(will switch to accumulators soon). Spark jumps 20-25mm in the open air.
The setup is bulky but when i finish the gun it will be more compact and build into the stock.
Sparkplug – car sparkplug. To adapt it to 1/2" fitting i took a 1/2" brass plug, drilled a hole in it, threaded a sparkplug into it. Then smeared a brass plug with acid from the inside and poured a molten tin into it. Basicly it is a homemade bushing, the sparkplug can be threaded out if i need. Originally it leaked, but i took it out, wrapped teflon tape arround it and threaded back in.
Valve – burst disk held by massive 2" union that i bought on the local market for 9$. Union has no threads, so it is welded to the chamber.
Metering – volumetric. I am using a 9 bar freon gauge. Metering pipe is attached to the setup.
Mixes – tested up to 5x, want to go to 7x but i am not sure that it is safe. Do you think it can handle it?
Ammo – wax slugs, wood slugs, saboted nails, vegetables.
Energy and velocity – HGDT predicts 2226 joules at 193 m/s with 120 gram projectile and 100cm long 42mm barrel at 5x mix. I will try to chrony it soon.
All the welding is done by my dad.

As i said it is not fully completed. I will make a stock for it soon, so i can shoot it as a handheld. Also i will clean up all the rust from the chamber and the barrels to make it look nicer. Maybe i will buy some pvc pipe and make a barrel out of it, because these steel barrels are too heavy.

Special thanks to keks2033, he have been helping me all the time. Also thanks to JSR for answering to my first topic with qiestions.
Hope you like it!
Questions, suggestions and reasonable criticism are appreciated!
Attachments
Wax slug filled with stones against 40mm wooden door at 4x mix. Entry hole
Wax slug filled with stones against 40mm wooden door at 4x mix. Entry hole
Exit hole
Exit hole
Gun with 50mm barrel
Gun with 50mm barrel
Last edited by Vadim on Tue Apr 30, 2019 5:37 pm, edited 1 time in total.
Vadim
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Tue Apr 30, 2019 5:03 pm

Here is a better picture of the gun and pictures of the ignition setup. Now the union has a piece of thread welded on for the barrel attachment, but this picture was made before.
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IMG_20190501_015458.jpg
IMG_20190501_020122_229.jpg
IMG_20190501_020156.jpg
hectmarr
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Tue Apr 30, 2019 8:55 pm

You will have a very good weapon. :) In general, everything looks solid, but I do not know if it is advisable to use a PVC firing barrel. I would continue with a steel barrel because it handles quite high pressures in this element. Consider an occasional traffic jam, for any unforeseen event, and the barrel must withstand these conditions well. For the subject of the ignition, with a simple piezo igniter, of those used in stoves or water heaters, it is enough to ignite a hybrid of up to 9x in my experience. Jack has made it work up to 16x as I remember. :roll:
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encendido-estufa-piezoelectrico-chispero-emege-euro-cmaza-D_NQ_NP_866121-MLA20704701198_052016-F.jpg
encendido-estufa-piezoelectrico-chispero-emege-euro-cmaza-D_NQ_NP_866121-MLA20704701198_052016-F.jpg (12.17 KiB) Viewed 8011 times
Vadim
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Wed May 01, 2019 5:09 am

Thank you!
Well, i will probably stick with my powerful ignitor, at least in this gun. Maybe it isn't necesery, but it gives me more confidence. Also i've never seen such piezo like on your picture. If i decide to use it, i probably need to order it from China. Shipping will take a lot of time and i hate waiting. But maybe i will try a simple piezo from a long nosed lighter just for experiment.
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jackssmirkingrevenge
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Wed May 01, 2019 5:18 am

Great work!
All the welding is done by my dad.
My favorite part to read, nothing like a good projectile-launching based father-son project :D
tested up to 5x, want to go to 7x but i am not sure that it is safe. Do you think it can handle it?
How much do you trust your dad's welding :)

If it didn't blow up at 5x, it can probably take 7x comfortably too.

What are you using as a burst disk?
Maybe i will buy some pvc pipe and make a barrel out of it, because these steel barrels are too heavy.
I'll second what Hector suggested and advise against this, a stuck or overly heavy projectile could turn a PVC barrel into a fragmentation grenade...
For the subject of the ignition, with a simple piezo igniter, of those used in stoves or water heaters, it is enough to ignite a hybrid of up to 9x in my experience. Jack has made it work up to 16x as I remember.
Indeed, the critical parameter is a very small spark gap, less than 0.5mm.
Also i've never seen such piezo like on your picture.
You can find one in a piezo-based зажигалка ;)

Less powerful that the one Hector linked to but still enough for ignition up to 16x with a small enough spark gap.

They look something like this:

Image
hectmarr wrote:You have to make many weapons, because this field is long and short life
Vadim
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Wed May 01, 2019 1:02 pm

Thank you!
I am cutting burst disks out of aluminum beer cans and milk cartons. I use 3 layers at 5x mix. Also tested with 3 layers at 6x today. Damage is imressive. 90 gram wax slug with 16mm marbles busted 50mm wooden board at 6x. Also got a chrony result with saboted 30mm steel ball – 190m/s. Ball together with a sabot had a weight of 131 gram. Part of the sabot(piece of cardboard tube) stopped right at the end of the barrel, so lets say that the chronied part had 121 grams of weight. Not bad i think. 109 gram wax slug with stones chronied at 181m/s at 6x. I think something confused the chrony, because 6x can not be slower than 5x. At 6x the recoil moves gun 50-60cm back. Anyway, i am quite impressed with power of the hybrid gun. Now, when i've played with it a little, i am going to finish it.
Attachments
50mm board shot with marble wax slug at 6x. Piece of the similar board on the right for reference
50mm board shot with marble wax slug at 6x. Piece of the similar board on the right for reference
Wax slug with stones against 40mm door at 6x
Wax slug with stones against 40mm door at 6x
50mm board behind the door
50mm board behind the door
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Wed May 01, 2019 3:59 pm

Vadim wrote:After two monthes i finaly made my first hybrid gun. It took so long because of the lack of money and knowledge. It's not fully finished yet but it already shoots.
Specs:
Chamber – 44cm of 2" steel pipe with welded in threaded fitting for a sparkplug. Walls are 3mm thick.
Barrels – 100cm 50mm barrel and 100cm 42mm barrel.
Ignition – originally it's been a chinese high voltage module but build in multiplier(not sure that i call it right) broke, so i had to cut it off and ask my dad to replace it with a bulky multiplier from an old TV and make a power supply for it(will switch to accumulators soon). Spark jumps 20-25mm in the open air.
The setup is bulky but when i finish the gun it will be more compact and build into the stock.
Sparkplug – car sparkplug. To adapt it to 1/2" fitting i took a 1/2" brass plug, drilled a hole in it, threaded a sparkplug into it. Then smeared a brass plug with acid from the inside and poured a molten tin into it. Basicly it is a homemade bushing, the sparkplug can be threaded out if i need. Originally it leaked, but i took it out, wrapped teflon tape arround it and threaded back in.
Valve – burst disk held by massive 2" union that i bought on the local market for 9$. Union has no threads, so it is welded to the chamber.
Metering – volumetric. I am using a 9 bar freon gauge. Metering pipe is attached to the setup.
Mixes – tested up to 5x, want to go to 7x but i am not sure that it is safe. Do you think it can handle it?
Ammo – wax slugs, wood slugs, saboted nails, vegetables.
Energy and velocity – HGDT predicts 2226 joules at 193 m/s with 120 gram projectile and 100cm long 42mm barrel at 5x mix. I will try to chrony it soon.
All the welding is done by my dad.

As i said it is not fully completed. I will make a stock for it soon, so i can shoot it as a handheld. Also i will clean up all the rust from the chamber and the barrels to make it look nicer. Maybe i will buy some pvc pipe and make a barrel out of it, because these steel barrels are too heavy.

Special thanks to keks2033, he have been helping me all the time. Also thanks to JSR for answering to my first topic with qiestions.
Hope you like it!
Questions, suggestions and reasonable criticism are appreciated!
Well done! Looks like a good, strong hybrid cannon. I see your spark plug sits outside the main chamber area and it still works good. That's good to see. I was wondering if it had to be way inside the chamber area but I guess its fine sitting outside. That's a relief for me regarding my own future use of spark plugs. Good to know. Cannon looks powerful!
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jackssmirkingrevenge
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Wed May 01, 2019 5:11 pm

Vadim wrote:I think something confused the chrony, because 6x can not be slower than 5x.
Could it be that the slug is disintegrating in the barrel?
Now, when i've played with it a little, i am going to finish it.
Some videos would be nice ;)
I see your spark plug sits outside the main chamber area and it still works good. That's good to see. I was wondering if it had to be way inside the chamber area but I guess its fine sitting outside.
For our purposes I don't think ignition placement is going to have a big effect on performance in a hybrid.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Vadim
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Thu May 02, 2019 12:13 pm

Moonbogg wrote:Well done! Looks like a good, strong hybrid cannon. I see your spark plug sits outside the main chamber area and it still works good. That's good to see. I was wondering if it had to be way inside the chamber area but I guess its fine sitting outside. That's a relief for me regarding my own future use of spark plugs. Good to know. Cannon looks powerful!
Thank you!
jackssmirkingrevenge wrote:Could it be that the slug is disintegrating in the barrel?
Yes, it could happen.
jackssmirkingrevenge wrote:Some videos would be nice ;)
I will make a video when i finish the gun. Maybe even this week, if everything goes nice.
Vadim
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Tue May 07, 2019 8:43 am

It is finished now!
Video will be soon.
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IMG_20190507_174139_873.jpg
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Tue May 07, 2019 10:14 pm

looks great! Can't wait to see the video
This weapon serves to silence the noisy speakers of the stupid of the other street! (joke) -Hectmarr
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Wed May 08, 2019 9:02 am

Lovely! Just need to stain that wooden stock and you have yourself some perfect post-apocalyptic chic :D
Cthulhu wrote:looks great! Can't wait to see the video
Same!
hectmarr wrote:You have to make many weapons, because this field is long and short life
Vadim
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Tue May 14, 2019 9:17 am

Finally, here it is:
[youtube][/youtube]
Sorry, not as much as i wanted to do. I prepared different targets and wanted to do at least 5 shots, but neighbour complained and promised to call police if i won't stop shooting. Maybe i will make a part 2 later on. For this purpose i have to go to grandfather's dacha that is located in the field – perfect shooting place.
But for now this it, i hope you still like it, at least this is better than nothing.
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Tue May 14, 2019 1:42 pm

Nice work! Here is a safety tip for you, shoot into a dirt hill or pile. That brick wall is going to bounce something right back at you.
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jackssmirkingrevenge
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Tue May 14, 2019 7:30 pm

Excellent! and as a small aside, your spoken English is impressive too.

I suppose you cannot blame the neighbor for complaining, a hybrid of this caliber is pretty loud... in fact, you and your cameraman should have been wearing hearing protection. Looking forward to more, keep it up!
hectmarr wrote:You have to make many weapons, because this field is long and short life
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