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Yet another coil gun prototype

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LAN_403

V2006

Sat Dec 01 2018, 06:23PM

Registered Member #61550 Joined: Thu Apr 06 2017, 03:23PM
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Posts: 86

DerAlbi : it will take another hundred years and you will not do anything

Zuckerstange47

Sat Dec 01 2018, 07:13PM

Registered Member #61926 Joined: Wed Nov 22 2017, 04:08PM
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Posts: 34

V2006 wrote ...

DerAlbi : it will take another hundred years and you will not do anything

Your links do not work, again.

I modified them here:

Anyhoo, I do not understand why this link-posting is happening right here, and also in the comments of many youtube videos, that are distantly related to the topic.

V2006

Sat Dec 01 2018, 07:23PM

Registered Member #61550 Joined: Thu Apr 06 2017, 03:23PM
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Posts: 86

Zuckerstange47 Thank you

DerAlbi

Sat Dec 01 2018, 07:24PM

Registered Member #2906 Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727

And what do those videos show in particular? Some coilgun shooting.. so what?
What efficiency? What device weight? What shot rate? What projectile energy? There is none of the really important information in those videos.
2kJ @ 100V with 400mF... is exactly zero information except how much money you put in. Everyone can do that and accelerate some projectile with this energy.
I am not sure what i have not done and what exactly will take 100 years. My coilgun is finished and as far as i know with 27W/kg my linear accelerator has the best power density in the world (regarding the devices powered from capacitors), but i love to hear other results..

V2006

Sat Dec 01 2018, 11:22PM

Registered Member #61550 Joined: Thu Apr 06 2017, 03:23PM
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Posts: 86

DerAlbi
you have no such video
money spent many times less than you spent
for the money that you spend, I would do even better

coefficient of performance not less than 30%

projectile energy not less than 600 joules

*2kJ @ 100V Ñ 400mF

device weight:

DerAlbi

Sun Dec 02 2018, 01:45AM

Registered Member #2906 Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727

Sry, i dont find a weight nor shot rate

I found however that your projectile weight is given as "370 to 480g" which is an uncertainty of 20% for the weight alone. How is that even possible?
Your build uses a very big projectile. With such a design it is not complicated go get into the 3 digit energy range. You can think about it as if you have built a bigger and heavier motor: more iron and copper, more power, but also more weight. The tricky thing is to get more power out of the same build volume and materials. Also it is not difficult to put a lot of energy in the projectile as long as the projectile is fat and slow. Small projectiles at high speed is there the engineering begins.
I dont think you can compare my goals with yours. I have a magazine, automatic reloading, quite some complicated software and a complete case for my gun - it also adheres to local laws and is battery powered for as much as 200 shot per battery charge. I dont think that you have any idea what it took to get to this state, so sorry if i ignore your comment on my resource spending.

May i ask what you think you have done differently to anyone else to get the performance you see? (except building a really big gun)
You criticize that everyone builds the same stuff and there is too little development in the community..
Hands down, what is your invention here? (beside the size)
Can your technology be scaled down to achieve a 100J version with an 8mm diameter 30mm long projectile? If you build a small, light and compact demonstrator, i would be impressed!

For a start: is it an SCR-design, or resonant, or halfbridge?

V2006

Sun Dec 02 2018, 08:51AM

Registered Member #61550 Joined: Thu Apr 06 2017, 03:23PM
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Posts: 86

DerAlbi
370 Ð´Ð¾ 480 Ð³ - optimization experiments
370 Ð³. - for 10300 J (450 V) optimally
for 2000 J (100 V) optimally 550 g
I can do everything
but I have almost nothing
if i lived in dresden and had that kind of money like yours i would do everything
my material base is outdated
with modern material base everything is possible
8mm diameter 30mm long projectile - also possible
but this is unnecessary complexity
diameter of 12 - 14 mm will be more optimal

V2006

Sun Dec 02 2018, 08:57AM

Registered Member #61550 Joined: Thu Apr 06 2017, 03:23PM
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Posts: 86

here you can understand that the velocity of the projectile is great

370 gramm, diametr 22 Ð¼Ð¼, long 145 mm

DerAlbi

Sun Dec 02 2018, 11:59AM

Registered Member #2906 Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727

Ok, you totally misunderstand why i spend resources. You think that it spend all this time to get a 20J gun and find that pathetic - i get that; if you phrase it like this, you are right. But you totally miss the point of my build.
As far as i can tell from everything you say you have scaled up your coilgun and got a very big and powerful device - maybe the strongest hobbyist coilgun in the world currently.
Scaling up is a matter of resources - i totally agree and understand why you think you could have done better in different circumstances. You spent your resources to get to 600J; but scaling up is the most trivial thing to do in a coilgun. Nothing changes, everything just becomes bigger and with this, naturally things become stronger and up to some point also more efficient.
But you have not built anything new or innovative - its just big. You seem to use the optimization routine every hobbyist uses and you also seem to use the same concept as everyone else uses.
If your goal was to create the ultimate big gun, you succeeded, but this was far away from my goal, so dont compare us.
My gun is the smallest possible with high shot rate and decent output energy with scalable concepts behind it. I broke several usual design rules of coilguns and reinvented a lot of components to get the most energy transfer out of the least volume and weight.
I am sorry to say, but having had those ideas was more a matter of sleeping, walking and shitting than the fact that i spend all my money on the gun. Money made the quality possible, but the performance is not a budget issue. This is about engineering skill and creativity and understanding the device in depth, not scaling up the known concepts.

So i really do not understand your criticism that the community is not moving forward: scaling up has nothing to do with evolving the technology. The last time this forum has seen something truly innovative was the member "Yandersen" with his resonant foil capacitor design.
If you could spend more money, i am quite certain you would get in the kJ-range quite easily. But it would still be the basic SCR design. How would that move the community forward? Kinetic kJ-range coilguns had been done, so whats the point of scaling? New concepts (that are in reach for hobbyist) is what we would need. My design unfortunately isnt suitable for hobbyists.

V2006

Sun Dec 02 2018, 02:03PM

Registered Member #61550 Joined: Thu Apr 06 2017, 03:23PM
Location:
Posts: 86

Ok DerAlbi send money - i will make a small model
there are plans to make a small model
but there are no more capacitors
there are no wires either
in general, there is nothing
in the presence of investments I will do everything

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