Idea for Homemade

[jwasko]

Okay, guys, in my introduction I told you that I had ideas for two homemades. Here's the first idea: the Falling Block Breech Loading rifle (FBBLR).



The main purpose of this gun is to have a breech loading Nerf gun that doesn't involve removin the barrel. At the same time, it's a bit less complicated than Bolt Sniper's magazine-fed rifles like the FAR and SCAR-N. It also includes a prototype mechanism for creating a good seal form plunger chamber to barrel.



Note: In order to see the pictures clearly, including what's written on them, you might need to save them to your computer and view them in some photo editing program or something.

Edit: Nevermind, it seems like you probably won't. 

Here's the explanation to go with the second picture:

1. The beginning of the trigger pull operates the mechanism. Pulling it back all the way fires the rifle in a way similar to BoltSniper's SCAR-N

2. The trigger's motion is transferred to a rotating thing, which then pushes on a short piece of music wire.

3. The "extender" act as a bridge between the "connector" and the plunger chamber. It is kept bin the PVC sleeve by the spring in (A) until it is pushed forward by the (2). When the trigger is pulled, it moves forward and partially out of it's PVC sleeve. The "extender" has a rubber O Ring in the back to (hopefully) create a good seal between the PVC and the "extender." This is necessay because the plunger shaft will be connected to the PVC and not the brass.

4. As you can see, 3 sizes of brass are used in this homemade. This idea came from Forsaken_Angel's Longshot mod, which uses interlocking, layered sections of brass to create a good seal. At this point, a piece of 9/16" brass becomes sanwiched between a piece of 17/32" and a piece of 19/32" brass. Once the 9/16" is pushed forward far enough, it hits a  piece of 9/16" brass in the "connector."

5. The "connector" is contained within the falling block of the rifle. When the block is down, a dart can be loaded into the connector. It is waht makes the rife  breech-loading. The connector, in addition to acting as a chamber, is also a bridge between the barrel and the extender. The spring in (B) keeps it in its PVC sleeve until the extender pushes it forward.

6. As the "connector" is pushed forward, its 17/32" and 19/32" brass sandwich around the 9/16" brass of the barrel, Thus completing the seal and effectively making the whole system into a single, long barrel.

7. The bulk of the barrel will be made of 19/32" brass. Thus, the dart will travel from 17/32" brass (in the "connector"), to 9/16" brass (for the first few inches of the barrel itself), and finally  a  relatively long segment of 19/32" brass (for the rest of the barrel). This is consistent with the usual method of making a nested brass barrel. Read an article on nerf barrels by CXWQ here:
<http://nerfhaven.com/forums/index.php?showtopic=1610>

A. and B. The connector and extrender need to be kept within their PVC sleeves in order for the falling block to be able to move easily. In order to do so, a piece of music wire will be attache to the brass. This music wire goes through a slot in the PVC. The slot will be of a length such that the connector and extender can only move forward of their starting positions (and only move an inch or so forward..I'm not sure yet what will be required). As mentioned before, a spring will keep keep the brass back.

C. I'm still not to sure how the plunger assembly will be put together. The main problem of this gun is that the it will be a long way from the tip of the plunger to the muzzle of the barrel. So, I will need a large (in volume) plunger chamber and a correspondingly large plunger. I'm also not sure how to connect the large-diameter plunger chamber to the (relatively) small diameter PVC in front of it. I think that they make fittings for that sort of thing, but I'm not sure.

Other Concerns: I'm a little worried about how the brass will interlock. The space between the 17/32" and 19/32" brass may not be thick enough to allow the 9/16' brass to fit between them easily.

[Lance]

Thats great!, I hope you get to make something like this.. you mite be the next boltsniper!

[Megamannt92]

It would be sweet if you could get something like this to work! You certainly have everything planned out.

If you do ever accomplish this please post pics here.

[jwasko]

It would be sweet if you could get something like this to work! You certainly have everything planned out.

If you do ever accomplish this please post pics here.

Unfortunately, I actually do still  have more planning. For example, I'm still not sure how the plunger and plunger chamber will be made.

But I most certainly will post pics when I make it.

... you mite be the next boltsniper!

Thanks for the compliment, but I don't think so. For one thing, this gun was made to be simpler than Bolt Sniper's guns.

[Lance]

If all works out well, maybie you could sell some and make a quick buck.

[jwasko]

If all works out well, maybe you could sell some and make a quick buck.

The key word in that sentence is if. But that's not a bad idea; however, I don't think I'd try to make too muck money. Only, say, $1000 profit each.

Just kidding! 

Anyway, a quick update: I think I figured out the plunger and cocking system, and I should be posting diagrams later this week.

If I can get all of the materials, I may be able to start construction over spring break (beginning of March, for me).

[Megamannt92]

If all works out well, maybie you could sell some and make a quick buck.

I don't know if it would be a "quick" buck since it prolly takes some time to make one of these. Not to mention cost of supplies and such. Unless you could have Flannel build you a gun making machine.

But anyway it looks like your gun is comming along nicely make sure not to give up on it.

[jwasko]

Unless you could have Flannel build you a gun making machine.

But anyway it looks like your gun is comming along nicely make sure not to give up on it.

I saw that topic about a gun making machine (somewhere). He wasn't actually able to make one, was he?

Hopefully I won't give up hope. I know that, no matter how much planning I do, I'll almost certainly encounter things that need to be redesigned once I actually start building.

Also, I'm not sure if I'll be able to find some of the parts that I need. I definitely need to go to several hardware stores this weekend and see what I can buy and what special parts I'll be needing to fabricate.

But I shall persevere! (hopefully  )

[Megamannt92]

I saw that topic about a gun making machine (somewhere). He wasn't actually able to make one, was he?

The gun making machine was a joke.
Flannel was making a dart making machine....Its still in progress(I think) he has not given up on it yet. The thread is on NerfHQ, and its simply hillarious to read that old thread.

[Duck_slayer]

Yeah it is funny.

[jwasko]

Okay, I finally finished the diagram for the cocking mechanism of the FBBLR.  I wanted to have multiple pictures depicting the whole cycle, but this took long enough by itself. Hmm...looking at the picture once I finished it, it seems to be way out of proportion. Anyway, here it is:




I have no good idea of what materials I'm going to use (other than a ton of PVC and/or CPVC, some springs, and maybe even some wood), so I didn't make a color key or anything like last time. I'm going hardware store-hopping this weekend, and hopefully I'll be able to figure it out. Once I do, I'll update.

Here's the explanation:

1. As I mentioned last time, this lever allows the falling block to lower when it is lowered. Once the block is in this position, a dart can be loaded into it. If you don't know, a similar mechanism is used in real rifles. The Sharps rifle was one of the early breech-loading rifles, while the Ruger No. 1 is a modern example. The real bullet is actually inserted into the barrel in front of the falling block, and the block itself was merely used to seal the breech.

2. As the lever is lowered, an internal armature (which is attached at an angle to the lever) rotates backwards (toward the butt stock and the plunger assembly within).

3. The armature forces this "cocking bar" back.

4. The bar is attached to the plunger. It pushes the plunger a portion of the way back.

5. This piece of music wire is set up like Bolt Sniper's SCAR-N. It will lock in front of the rearmost of the two catch faces (A) and thus keep the plunger back until the trigger is pulled.

6. At this point, the block will have been lowered and the dart can be loaded into it. Closing the lever will raise the block and pulls the bar back to the pictured position. Remember that, at this point, the plunger will be back of where it is pictured. For this reason, a slot (C) will be cut in the cocking bar. It will allow the plunger to remain motionless while the cocking bar moves back and forth. Also, it allows for the plunger to move forward when the gun is fired.

In fact, at this point the gun can be fired. However, this should only be done at short range. This is because the rotational motion of the armature cannot provide enough horizontal motion to push the plunger all the way back. There will not be enough air.

7. So, if you're in a hurry and only need a short range shot, using the lever action alone will provide a good rate of fire (although sacrificing range). But if you need a longer range shot, then you'll need an extra step before firing.

Pulling the slide back will cock the rifle fully by using the mechanism at B. This is is a piece of music wire that will engage with one of the catch faces. When pulled back all the way, the forward catch face will engage with the catch at 5. Once you let go a spring will bring the slide forward, and the beveled edge of the wire will allow it to return to it's resting place.

8. Now, the rifle is ready to fire at long range. Simply pull the trigger...

9. And the beveled trigger plate will push down on the catch, releasing the plunger.

D. This here will be some sort of piping that keeps the spring from buckling. I'll call it a "support tube." It will be fixed to the back of the butt stock, but able to slide within the plunger. It will be substantially smaller than the inner diameter of the plunger. Something else (such as a piece of piping that has a size between the plunger and the support tube) will push against the spring.

Overall Concerns:

My biggest concern is the lever-action cocking mechanism. It may not provide enough air to even provide a short-range shot. In fact, the dart may not even leave the barrel. In this case, the lever-action cocking will be pretty much useless. Also, even if it does work, I may have some trouble connecting the armature to the cocking bar. I can't think of how to explain the possible problem, so I'll just say that it's a problem with the fact that the armature is rotating. If it gets to be too much trouble, I'll probably just skip it entirely and use the slide alone for cocking the rifle.

Also, I'm a little worried about the size of the plunger chamber. I don't want it to be too long, because then the butt stock will have to be too long and I won't be able to reach the trigger. At the same time, it can't be too short or else the range will be complete crap. I definitely want at least 70 feet, but it's possible that I won't even get 20 feet.

That's all that I can think of for now, but like I said before I'll probably find a lot more problems once I start building the thing.

[Megamannt92]

What kind of spring will this thing have? And when you say "long range" how far do you think this thing will go?

[jwasko]

What kind of spring? Hmm...a fairly long, strong one. That's pretty much all I know.

Like I mentioned, I would like to be able to shoot 70 feet accurately (although I'd actually be happy with 50 feet).

When I said "long range" I simply meant a longer range. If you just pull down on the lever, you're only cocking the plunger a couple of inches and the range will probably be pretty short (maybe 20 feet). But, if you pull the slide, you'll cock the plunger back another few inches (say, 6 or 7 inches total) and the gun will shoot further.

I hope that answers your questions. If not, let me know.

Edit:

While taking my shower just now, I decided to drop the lever-action half-cock. It will provide little to no benefit while causing me lots of trouble. I've decided to "K.I.S.S." (Keep It Simple, Stupid), which has always worked well for me in the past.

On the other hand, I've I got an idea of how to make a clip for this that will require little to no modification of the gun itself. In fact, you could probably swap it out for another clip or the standard block in about two seconds.

[Lance]

This thing looks awesome, I can't wait to see it in action.. promise me you will make a vid!

[jwasko]

Hmm...how about I promise to do all that I can to try and get a video of it, if/when it is finished.

Then again: "Do...or do not. There is no try." (Yeah I'm a Star Wars geek)

I just found out today I have an English paper due right after break, so I don't know how much work I'll be able to get done on the FBBLR.  It's actually a research paper...too bad it has to be about people. I'd ace a Nerf research paper for sure. 

Then again, "dot com sites aren't legitimate sources" so all of my research would be meaningless in the eye of a professor.