13 replies to this topic

[Megothitinheadbydart]

I built this after getting sidetracked from building my FAR(stupid 30 year old dremel).

The body is 1" 200 psi pvc and the the barrel is 2'' of 1/2" cpvc. The plunger is cpvc and has a 1/2" pvc encap with an O-ring as the seal. It is powered by two 4" 28lbs compression springs that I found at Home Depot and the plunger stroke is about 4.5". I haven't tested the range yet since it's literally a blizzard outside but it sends micro Stefans at least 20ft with almost no drop from a straight shot.
Questions? Comments? Annoying responses that don't help anyone?

[Ronster]

Looking great!

I would have done the handle differently, though. Like Bolt did his, with the extra halves.

[NerfMonkey]

Depending on the strength of the spring I'd use between and 4 and 5" barrel, as the plunger stroke is about that of an NF, maybe a bit more.

[davidbowie]

you should definitely add a longer barrel and some half-sections to thicken the grip. Otherwise, excellent work.

[Carbon]

Very nice! What makes up your trigger/catchpin mechanism? Yours looks very solid.

Edited by Carbon, 12 February 2006 - 07:49 PM.

[Megothitinheadbydart]

I just added a 5" barrel and it seems to increase the dart's velocity quite a bit, but I can't be sure since there is about a foot of snow outside where I live. I think I'll leave the grip as it is, I have small hands and it fits me perfectly without the half sections. The catch mechanism is just two pieces of angle iron, a ground down nail and a couple of rubber bands. Plus a zip tie.


The pictures are pretty self explanatory, the nail taped to the second piece of angle iron(flattened in a vise, the holes make it bend away from the middle on either side, giving it that gull wing shape) goes through the coupler inside the pvc that seats the spring and catches a brass tubing lined hole in the cpvc plunger.
Carbon is right, the whole mechanism is very solid with no play whatsoever, but the trigger pull is very stiff and I have bruises on both my index fingers, one from the plunger key ring(The plunger is very hard to pull back) and one from the trigger, which is wrapped in elecrical tape but none the less hurts like hell when you fire more then once in a while.

[Carbon]

Wow, your'e harnessing a lot of force, there. I use much the same system in my guns, and I've wondered at what point would the nail just shear off... Judging from your experience, not anytime soon.

Considering how much raw power you've got there, you should be able to shoot a lot farther than 20 feet. Is your o-ring giving you a good seal?

[Megothitinheadbydart]

It does shoot a lot farther than 20ft, I just don't have a place to shoot it indoors that is longer than that, and there is a a foot and a half of snow outside my door right now, so when I finally test it I'll post the ranges but untill then all I know is that it shoots 20ft with almost no drop. The seal could probably be better, I'll redo it on my next version since I cut the groove a little to deep on the lathe this time.
I think on my next version I'll make it like your SNAP-2 Carbon, but with a spring loaded clip on the side and a slightly different action.
As for the spring, you're right, the two springs have a ton of power, but I think I'm using a much thicker nail than you, mine is almost 1/4" thick and I'm pretty sure that it would be immpossible to pull the trigger much sooner than the force would shear the nail. In fact, if I had a spring much stronger the angle iron I'm using as a lever between the nail and the trigger it would bend out of shape(I already bent it in a vice to get it flat with a V popping ou of the middle) , therefore effectively stopping me from firing the gun, and leaving me with a ticking time bomb.
You used a clothes pin with a piece of angle iron glued to one of the long arms in you're guns, right Carbon? My system is very different, I use two sperate pieces of metal. One acts as a lever(the flattened piece behind the trigger, it has a V bend in the middle that is the fulcrum), and the other has one side as the trigger and the other side goes back fromthe trigger and pushes up on the end of the other one that does not have the nail attached to it, the nail is far behind the trigger, not in front of it like in your guns.

[Carbon]

Oh, it hits the wall at 20 feet…sorry, I missed that. Very nice!

I get your trigger system, nice approach to a linkage, and a good way to reach behind the handle. If your trigger pull is too tough, you could adjust the fulcrum on your “seagull” to give yourself a better mechanical advantage. Make the side which is under the pin a fourth (or so) of the length of the other arm, so you can get the lever action working for you. You could also make your trigger arm longer than the other side of the lever…you shouldn’t have to pull a linkage that hard. If you’ve already done that…then man, that’s one powerful gun!

You’re right, the nail I’m using is tiny compared to yours…I’m just using a wide-headed finishing nail. Your brassed catchpin hole is very nice, and would solve the problem I’ve been having, with the catchpin eventually eating the edge of my pvc catchface. I’ve been meaning to grind down a washer to cover the catchface surface, but haven’t been looking forward to that…your way is much easier.

[Lukeinator]

Your trigger pics are messed.

[euphemism]

That obviously means you aren't a sneaky bastard like myself. I'll be nice, this link should work.

[Lukeinator]

Wow, that's a really nice set up you have there. It looks pretty reliable. Thanks euphemism you sneaky bastard.

[southpaw]

Very nice. I did something nearly identical awhile back but the glue for the handle ran into the trigger-hole and ruined it. Yeah, the nail-trigger really kills. I wrapped some E-tape around it to increase the surface area. I am interested as to how you got your catch mech to work because apparently your pics aren't working.

Edited by southpaw, 16 February 2006 - 07:11 PM.

[yourmomsanerfer]

what did you put on the bent angle iron to hold the spring back, hence cocking it? is it literally a nail?