62 replies to this topic

[Boot]

Wow!

I started out looking at the springer component, and was impressed just by the build quality... But then I realized that it also functioned as a semi-automatic system!

The way you integrated semi automatic capability while still keeping the "human power" aspect is very interesting. I always thought hand pumps were the way to do that while maintaining semi automatic capability, but this way you get all the benefits of HPA setups without the danger of running out of 'fuel'.

Although I may be missing something, when the plunger is pressurized, where does that pressure escape? A interesting project would be to retain that pressure until firing, thus turning the system into a sort of pressurized springer, actuating the breech while having all the benefits of a air pressure blaster.

As everyone else has said, this is awesome beyond words, especially the projectile calculations! It is interesting to see that the asymptote is only at 300, I would have expected higher. I find it surprising that the nerfing community has gotten as close to that maximum mark as they have, I guess it just serves as a tribute to the awesomeness of this community

I am thoroughly inspired, not just to work on projects, but to look further into the projectile calculations (with what little knowledge I possess on the subject). I REALLY look forwards to your friends (and hopefully your) future work!

[shardbearer]

Boot, on Mar 9 2011, 05:39 AM, said:

As everyone else has said, this is awesome beyond words, especially the projectile calculations! It is interesting to see that the asymptote is only at 300, I would have expected higher. I find it surprising that the nerfing community has gotten as close to that maximum mark as they have, I guess it just serves as a tribute to the awesomeness of this community

This is with a stock streamline, not the screw weighted monstrosities used to hit 250'.

This gun is potentially the record for a stock dart, no?

Edited by shardbearer, 09 March 2011 - 05:53 AM.

[Abyss Mods]

Woah. Just woah. That is one of the most beautiful homemades I've ever seen.

[shardbearer]

What psi does this take (from the compressor)?

[utahnerf]

Is the FPS constant? How much does it vary from shot to shot?

[thedom21]

That is crazy! Simply crazy.

[ahtanie]

Wow that is some awesome shit.
You have massive talent there.
Great job!

[Eh Watt]

I really don't know if there's much else to say, but:

- This is like my dream cannon and I want one
- I'm really glad you're still alive
- Merry Christmas

My favorite part is the semi auto. I just love semi auto Nerf guns. YOu've managed to combine extreme functionality, durability, and great looks all in one crazy awesome package. Boltie, you've done it again. Fan'-friggin'-tastic work, man. I mean that.

[FatNerfer]

That's a pretty spiffy blaster you got there.

[Dayko]

That is spectacular!!! The craftsmanship is amazing. I am in awe of this blaster. Very good work, Bolt.

[LotusNerf]

Oh my fucking god...that is like the most spectacular thing I've ever seen. I'm so happy that you're still here! You and Slug are like my role models of all homemade blasters!

[Possemhunter]

That's what happens when people with machine shops also nerf. No one compares to what you do.

What I find interesting is that I have literally come up with plans for a nerf gun that functions completely identically.
I'd have posted pictures of my designs but everyone hates idea threads around here, (which is one reason why I haven't been around here much lately.) I've just never been able to build them for lack of a metal lathe. I have access to a metal lathe now in school, so just maybe I'll take a shot at building something.

[thedom21]

Would you have/will you have design plans for people who do have the machining capabilities to make this?

[boltsniper]

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Is the FPS constant? How much does it vary from shot to shot?

It's dependent on the dart diameter. Good new fat darts get in the 190's pretty consistently. In general it varies from 175 to 195.

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What psi does this take (from the compressor)?

It runs great at anything above 90#. The higher it is the faster it cycles. Under 90 it starts cycling slowly and if it gets too low it will not retract far enough to trip the valve off so it will just sit there and vent.

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If you had to give an educated guess, what is the cost of materials for your final version?

Hard to say an exact figure. I keep a lot of raw materials on hand so I didnt procure much for this

Estimates
Aluminum: ~$120
PVC: ~$5 (negligible amount)
Polycarbonate: ~$40 (I did buy a square foot of 1/2" polycarbonate for use on this, which isn't cheap)
Teflon: $30 (had to buy a square foot of this too)
Valve: $40 (yeah, expensive ass valve)
Screws: $15
Steel: ~10 (negligible amount)
Other Random parts: ~50

So that's $310. But considering the cost of the teflon and polycarbonate is non recurring and that I could feasibly build more without making those expenses again, The actual cost per rifle in materials is probably around $200

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Is there any chance of getting detailed plans on this or the CAD files perhaps?

Yeah I can upload and IGS or STP file of the model probably. The model is 95% accurate to the real thing. I didnt bother running tubing lines or springs or a few other details.

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Would you have/will you have design plans for people who do have the machining capabilities to make this?

I doubt I will ever do detailed drawings for the machined parts, but I can make the model available

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Although I may be missing something, when the plunger is pressurized, where does that pressure escape? A interesting project would be to retain that pressure until firing, thus turning the system into a sort of pressurized springer, actuating the breech while having all the benefits of a air pressure blaster.

That's what the 3-way valve is for. A standard open-close 2-way would trap the air behind the bolt preventing it from being returned to battery. The 3-way vents the trapped air to atmosphere when it is not activated. SO valve activated the bolt cavity is connected to the air line. Valve deactivated the bolt cavity is vented to atmosphere It makes an audible *PSSH* sound when it vents. You can probably hear it in the videos. I kicked around a few passive venting ideas but all would have reduced effective plunger volume so I dismissed them.

Edited by boltsniper, 09 March 2011 - 06:36 PM.

[PVC Arsenal 17]

Very inspiring work. Every aspect of this project is an achievement in its own right. I thoroughly envy your machines and what you've produced with them. And of course, nice AR's.

[bogboogalars]

I would be very very interested in that CAD file. If you could find some spare time and upload it I would greatly appreciate it, either file type is good with me.

[Exo]

It seems like the dearth of modifications translated into a glut of homemade guns. That's three beastly semi-autos posted up in a month! Sorry, I had a vocab moment. Nice work, looks great.

[Solscud007]

I love the Magpul cross bones. Nice AR you got there. oh yeah badass looking ATR.

I am interested to know more about the aerodynamic ballistics of the nerf dart. Of course those figures are computed but practical? Im soley basing this on poor first hand experience of having darts spiral out of my long shot. There are so many variables but is it simply a matter of barrel length?

I always thought the mass of the dart was never enough to carry the dart enough through the air. Sort of like a poorly crafted paperplane. Adding a little more weight forward of the CG helps stability through the air.

Edited by Solscud007, 10 March 2011 - 01:44 PM.

[boltsniper]

The code does assume a ballistic trajectory...one without swerving and spiraling, etc. You just have to choose your darts carefully. Straight stiff uniform darts will give a pretty good ballistic trajectory.

I agree about the mass. What I like doing is take a 6-32 1/4" setscrew and shoving it through the hole in the tip of a streamline into the cavity in the dark orange rubber tip. You can fit 2 in there but 1 does a world of good and doesn't add a huge amount of weight .

The gun delivers the same amount of energy to the dart regardless. So if the dart weighs more... than the muzzle velocity drops. What's interesting is seeing this when you punch the dart weights and velocities into the codes and the muzzle energy never changes. Impact energy changes though as the momentum does increase with dart mass.

[shardbearer]

FatNerfer, on Mar 9 2011, 01:57 PM, said:

That's a pretty spiffy blaster you got there.

Oh thank god. I read that as shitty.

Anyways, are the ranges given using a setscrew in the dart boltsniper?

And your website hasnt been updated in a while.

[soloz1]

Great job, Bolt! Your bringing sexy back to Haven!

[Solscud007]

boltsniper, on Mar 10 2011, 11:13 PM, said:

The code does assume a ballistic trajectory...one without swerving and spiraling, etc. You just have to choose your darts carefully. Straight stiff uniform darts will give a pretty good ballistic trajectory.

I agree about the mass. What I like doing is take a 6-32 1/4" setscrew and shoving it through the hole in the tip of a streamline into the cavity in the dark orange rubber tip. You can fit 2 in there but 1 does a world of good and doesn't add a huge amount of weight .

The gun delivers the same amount of energy to the dart regardless. So if the dart weighs more... than the muzzle velocity drops. What's interesting is seeing this when you punch the dart weights and velocities into the codes and the muzzle energy never changes. Impact energy changes though as the momentum does increase with dart mass.

Ok that makes a lot more sense. I thought you were getting some really great results on stock nerf darts. Inconceivable haha.

The observations you have are often found in Airsoft. bb weights are controlled with tight tolerances. Which is why it pays to buy the good stuff. .20g bbs dont cut thru the air as well as .25 or .28g bbs in moderately modified guns. although FPS is slower with a heavier bb, they fly farther, stabilize better in cross wind, and have similar energy upon impact. Yes they sting as much and reach farther.

So it makes sense to add weight to stabilize the darts.

Thanks Bolt.

[AcepilotZero]

I can honestly say I have never seen anything more beautiful, in design or application, in my entire life.

[boltsniper]

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Anyways, are the ranges given using a setscrew in the dart boltsniper?

No, range is with a stock dart. Range with a weighted dart is not that much different though.

[Ro-Sham-Bo]

I've never seen such craftsmanship. Once again, you've outdone yourself. Seeing the FAR got me in and seeing this is pulling me back in after a long absence. Absolutely amazing work.