Semi Auto Cartridge Hybrid Build Log (Lotsa pics)

[pneumaticcannons]

Look at what just arrived
took nearly 2 weeks to get here though
For those of yous who don't know what an ATtiny is, they are essentially micro arduinos capable of executing simple programs. Now I can finally get on with this hunk of plastic and epoxy.

[Spudrookie]

Apologies for the long delay in-between updates, I got distracted:



I recently got the ignition system working 100%
I had also gotten the new and improved ejection mech working but of course, minutes before making the video, one little metal part broke deeming the entire mechanism useless. Oh well
[youtube][/youtube]
All shots were done at 5x mixes

Pneumaticcannons, you're into RC planes too. I love building, not that much of a buyer. I also use Realflight alot.

[pneumaticcannons]

^ Yeah, i don't like buying much either, hence the ghetto plane. lol

Concerning this project, I've run into a problem. The solenoid which operates the piston runs from a minimum of 24v. I plan to run the ATtiny and other stuff from a 7.4v LiPo battery. Does anyone who knows a bit about electronics have a voltage step up or even a voltage doubler (I could use a 12v batt also) that they prefer? I have been looking at the MAX618 but am wondering if there is a simpler (8 pin or less) step up I could use. Thanks again.

[evilvet]

voltage step up or even a voltage doubler

Any basic non-inverting 741 op-amp circuit would do, this would be a starting point for the datasheet:
http://www.stanford.edu/class/ee122/Par ... _AN-31.pdf

And a random google link that explains it a bit more:
http://prometheusfusionperfection.com/2 ... p-circuit/

Cheers

[Squidjuiceonastick]

sorry this may seem like a derp question but i don't think its worth making another thread about it
How whats your ignition source? in terms of your ignition circuit?
i can't get a taser and i've tried making an induction coil and i need a lot of camera's if im going to use there capacitors for a decent spark
how did you do yours?

[pneumaticcannons]

The young yet dedicated pneumaticcannons procedes through a 2 hour google endeavor yet still possess merely a vague understanding of op-amps

So forgive me if I have missed something but can't op-amps only deliver as much voltage as their supply can provide? I'm looking to convert the 7.4 or 12v to 24 without a bulky 24v battery.
During my search, I found this extremely helpful tutorial on the the MC34063. I think I found my solution.

Squidjuiceonastick-
1. Nice username, lol.
2. Not a derp Q at all.
3. I'm using an old igniter for an old oxy/acetylene torch that the I.D. teacher let me have. I couldn't even find an image - sorry. However I do know that the circuit is essentially exactly the same as the circuit in grill ignitors. Also, you only really need one camera's cap to provide fat sparks. Your problem may be that you tried to make you're own coil, leading to inneficiencies.

[sagthegreat]

you could convert 7.4 into 12, but you would loose current

so in other words gaining voltage reduces current, and vise versa

[dewey-1]

Concerning this project, I've run into a problem. The solenoid which operates the piston runs from a minimum of 24v.

Do you have a part number/brand of the solenoid?
The current required for actuation is needed for any design considerations.

[pneumaticcannons]

Dewey- Here is the data sheet (courtesy of PS): http://content.smcetech.com/pdf/VZ1000_1002.pdf
The current consumption is about 90 mA.

you could convert 7.4 into 12, but you would loose current
so in other words gaining voltage reduces current, and vise versa

Yeah thats true but not a problem when you have batteries capable of providing 20+ amps with a conversion ratio of 3.3/1. The solenoid only pulls 90mA so I should have 6 or so amps to spare.

[pneumaticcannons]

Electronic aspect of the build is finished... only 3 months after I said it would be
TBH, I can't believe I actually got both circuit boards working. The voltage step up took me 2 tries and their were countless other things that had to be sorted out.
Although they can be tricky to get working, I highly recomend that anyone looking to build any type of gun requiring some sort of electronic control system, buys a few of these ATtinys. They have as many inputs as you need , are cheap(most importantly), and are easy to program.
Anyway, here's a video showing everything functioning properly.
[youtube][/youtube]

[POLAND_SPUD]

Very impressive
I like

[pneumaticcannons]

Thanks Poland
Now it's just a matter of finishing before the world ends
sorry I had too

[jackssmirkingrevenge]

Very nice work and thank goodness puberty is making you sound less like a little girl

[pneumaticcannons]

less like

So I still sound like a little girl then?

[jackssmirkingrevenge]

Give it a couple of years