Thank you for such a complete reply... thought I had made my usual mistake of going on for too long, where more than half of my questions get ignored.
Firstly, I already preordered (almost didn't... I know I technically don't need another welder... and after shipping, and converting from USD on paypal.. I think it came to something like $225... and as per my usual overbuying tools, I even ordered everything I need to build 2 of these welders as well: http://www.instructables.com/id/DIY-Ard ... ot-Welder/
...so I might have one hell of a comparison review coming once I have all 3 in my hands to try). I will say, if you want to make a cheap welder that's a step up from just capacitors or a LIPO and some mosfets... that DIY Arduino spot welder is probably the cheapest one you could get that's controlled by a microprocessor and does 2 pulses, and appears to be solid/simple enough to get the job done many times without breaking. Of course I'll be able to back that statement more when I do the comparison.
TBH, I ordered yours for 2 reasons (neither being necessity)... reason 1, as far as I can tell, yours appears to be the best one in it's class. And reason 2, even if I build a custom one similar to the popular designs, tho ideally more powerful, I don't believe I'd be able to accomplish what you did here.
I also just saw your "power supply" build on the previous page... looks pretty cool... actually VERY close to what I was considering building. I think it's an awesome option/alternative to using LIPOs till they die and having to replace them... I'm sure many people will be interested. Tho I'm not sure if I would buy one, or build one myself.. I like building things myself, and been looking into essentially taking an AC to DC power supply, and hooking it up to a bank of capacitors (or even one super/ultra capacitor.... saw a 3,000F capacitor new on ebay for ~$40.... would need to check some more of it's specs... but at least from my basic math I would think something like that may be enough to use alone for a high power welder like this one. I'm still trying to figure out if there is any real benefit to using a bank of small capacitors vs just 1 large one.
I need to address the "I don't like cloud anything". First off, you are gonna be left behind if you refuse to utilize "the cloud".... it is the future of computing, in the very near future every home/work computer is simply going to be a Display, an input device, and an internet connection... All actually processing, running of applications, etc. will be done on the cloud. It will make it so computers cost next to nothing, but will easily have 10,000 times (really any number can be put here, 10k is just to make a point) the processing power whenever they need it, and your files will all be accessible from every device that you use, anywhere. I'ts simply the obvious progression of the internet and personal/business computers. One major problem today is all the misuse of the term "cloud"... what it really boils down to is near infinite processing power and storage for you, however much, and whenever you need it, but only when you need it. In stead of every person having to spend a ton of money on a computer that they don't even utilize 1 percent of it's total ability (ie running at 100% usage of all processors and storage at all times), and even having multiple computers per person... the clouds is, and will be, a pool off this, that gets temporarily allocated to a person as the need it, and taken back when they aren't using it. There are so many benefits to this, from computers being insanely cheap, but seemingly performing with next to infinite power, to things like drastically reducing electronic waste over.
Anyway, end rant cloud rant, begin Fusion360 rant.....
But to clarify, what I mean by Fusion 360 being cloud based (which to today's standards it halfway is) just means that you create an account (again, free for all students and hobbyist), and every file you work on is stored within the cloud storage automatically. You can still save things locally, but everything you work on, and everything you add to a project is uploaded (and actually converted when it's not the native file type, since it supports pretty close to everything it possibly could). So, if you go to use Fusion360 on any other computer (yours or anyone else) and log into you username, all of your projects will immediately be available to you, as if you were using your home/work computer. The fact that the application is free (unless you are making significant money from it's use) is just incredible in the first place... it's really like 10 different, amazing, complex (but intuitive) applications merged into one fluid application... and besides the applications being free, all the benefits of it's cloud storage are also free. IMO, it's incredible that they have done things this way.... for students and hobbyists to be able to use/learn such a powerful application for free, it's truly amazing... and for those who get really good at it, there will be plenty of job opportunities for them (as well as opportunities to make their own product/company). And aside from all this, as you become more familiar with using the program you realize how well thought out and intuitive it is (autodesk has been in the game for a LONG time, and always one of the best, tho usually one of the most expensive out of reach options for anyone who was not a professional). I've tried tons of 3d modeling applications in the past.... never got anywhere with them... it's incredible how quickly I was able to pick up enough to build/model close to anything I have thought up/needed. I promise, if you have any free time, especially if you own a 3d printer (or have access to one, or any other type of CNC machine) it is so worth trying Fusion360... especially if you ever wanted to build a custom product of your own.