Hi guys, I am a young engineer from Germany and in the past 4 years I invested a lot of my time in developing a Coilgun. A Coilgun is basically an electric motor. It uses coils/inductors to create a magnetic field which attracts a ferromagnetic projectile to accelerate it. I kind of think it would fit in this forum. Sorry that I have to blast you with a wall of text but I think my final question needs some context. State of the Art: There are a lot of Coilguns out there – most of them displayed on Youtube by hobbyists. Before you search yourself, let me summarize: the most viewed coilguns are the pretty ones. Most showoffs are made by shooting glass, cellphones, whatever.. basically everything that would break if you let it drop from a table :-D OK - some are penetrating thin aluminum cans.. the projectile energies reach up to ~20J. Now some technical stuff: Being an electric motor a Coilgun converts electrical energy (stored in capacitors) into kinetic energy. This energy conversion has of course an efficiency because there is also heat as a byproduct. Here is the catch: The typical Coilgun design you find on youtube reaches around 1% - 3% efficiency. Pathetic, isnt it. This is why most titles say “xxx kJ-Coilgun” which is mostly a reference to the electrical energy stored in the gun. This of course is pure click bait, because 1% of 1kJ electrical energy is still just 10J in the projectile. Now keep in mind that 1J of electrical energy can be stored in 1g of component weight in current capacitor technology. So if you want higher projectile energies – lets say 100J – then you need to store an insane amount of energy which comes in capacitors which weigh so much, the whole device is basically unusable. Also there is the issue of “the more powerful the motor/coilgun has, the more copper is involved” and copper is heavy too. So here is what I did: After some of research, tests and experiments I came up with a Coilgun design that is far superior to the hobbyist designs. I can reach up to 40% efficiency which changes the whole game. With 40% efficiency you can build a 100J (kinetic!) Coilgun and would only need 250J = 250g worth of capacitors. Actually I can sacrifice the efficiency and make coils not from copper wire but aluminum wire which has 30% more losses, but just 1/3 of the weight! Still lets say 20% efficiency only requires a capacitor bank of ~600J. Manageable. So in conclusion what I can offer based on this: - 100J – 120J projectile energy (100m/s muzzle speed) - rifle form factor (80cm – 90cm long) - 5.5kg overall mass (still heavy but thats why its such a leap forward – I reached a manageable weight with all the improvements.) - 2 shots per second (if you want that… [I dont really care]) - should be classified as toy in Germany (using a special rail design as projectile guidance) The gun has no “barrel” in a legal sense. - it will cost 1700€ retail. (sry!) - its as silent as it gets. The projectile inevitable pushes some air out of the gun but thats about it. - it shoots (L)40mm x (dia)10mm iron dowel pins which are readily available and should mostly be reusable if not deformed. The flight characteristics are currently unknown but I suspect its not too bad. Also as electrical device there are a lot of security issues. I actually mean it in a good way. Its easy to incorporate a fingerprint sensor for turn on (family safety), accelerometers to disable the gun while free-falling or when impacting the gun (getting slapped by a supervisor?) and much more stuff. (No, I wont include Bluetooth for remote shooting – I actually will do everything to prevent this scenario, sorry) I really think there could be a marked for it even with the hefty price tag. Its not only a technical curiosity, it also has some elegance and ease of use. There is also the technical aspect for some interested people since I can give access to the coil timings in the firmware. I am currently developing a prototype which will show the technical achievements of the engineering I did. Its only a 20J gun, but in pistol form (26cm long) which will incorporate all proof of concepts of a bigger gun (its really just a thing of scaling stuff up in the end[whick makes a lot of stuff actually easier]). This prototype must then be evaluated by the German authorities to make it an official toy gun ;-) Then I need to actually scale it up. This small prototype should be finished around 1 year from now, I am around half way done. So here I talk money: its sooooo expensive! Expensive in two ways actually: first of all its actually expensive then I only work for 24h a week to have sufficient time for the project – thus cutting my salary quite a bit. In the last year alone I made 3k€ minus to get things done. The obvious solution is crowd funding – but I suck at marketing. See, my problem is: I am an engineer. I made an extremely cool electrical design which most people will never understand, appreciate or even care about. Its primarily visual coolness that sells! I currently only can sell a design scheme, nothing else. I am extremely hesitant to advertise the half finished idea because I do not want to be one of the crowd funding parasites who made a few renderings and promises curing world hunger and become a millionaire – even that would be easier :-D I am currently not ready to ask for support because I dont even know how the final gun will look like. How can I promise anything as long as its not done – I can promise electrical specs of course, but as said thats not what people care about. Yet, I need the support. Not only financial but I also need people that keep asking me for progress to keep up my motivation. I would even like to stream my engineering sessions to be honest. Doing everything by your own gets lonely at times. Man, I would even like to go so far and go full time on this gun. My current job at the university is a huge source of depression – seeing the education system fail student for student and being part of this system where no one can fail to become a PhD is just ridicules – I dont value that title anymore so why bother.. There is also a lack of crowd funding sites available for stuff like guns (terms of service restriction)… I searched a lot of platforms but I didnt find anything that gave even a bit of security to the funders. The best I found is gofundme.com but I dont expect much publicity there to be honest. My crowd funding goals would be either to finish the current small prototype or to develop the big 100J version. For 100 guns I would need around >150k€ and 2 – 3 years of time to get it absolutely right. I also need community input to make it attractive for the user So now lets formulate my actual question: - When to go public with the project? (When the prototype is done? Now? When the final look stands?) - How to be trustworthy for crowd funding? (Should I share concept work which is not related to the finished product to give people an impression of progress?) Can I somehow show off the things I learned and the abilities I have that qualify me for this project without having an annoying bragging factor attached? Also please ask any open question – technical or personal, I try to answer. I can also show what I have actually done so far – just for now its enough text. Apologies to everyone who actually read it.