38 replies to this topic

[dapperrogue]

Edit: I'm going to collect as much information as possible in this first post, like a thread index.

Overview - The blaster is now named the L-Shot (Lambda-Shot). It is a bolt-action rifle that accepts N-Strike mags. It is best described as a blend of the +Bow and Longshot.

It all started with this, the L-Shot Prototype:

Here's a youtube video where I explain how it works. The basic operation is the same between the prototype and rev 1, so most of the information is in this video.


I then designed and built a better version, L-Shot Revision 1 (on the left):

Here's the youtube video about the changes:
http://www.youtube.com/watch?v=9wovA97NgBY


Model and Templates:
Meaker VI generously made the following 3d model and printable templates:


12" x 12" pdf: http://dl.dropbox.co...4889/LAMBDA.pdf
8 1/2" x 11" (will have to line them up): http://dl.dropbox.co...LAMBDA_8511.pdf
Google Sketchup: http://dl.dropbox.co...64889/HMLS3.skp


Parts List:

Stuff I got from McMaster:
8574K26 2 Each Impact-resistant Polycarbonate Sheet, 1/8" Thick, 12" X 12", Clear
8574K28 1 Each Impact-resistant Polycarbonate Sheet, 1/4" Thick, 12" X 12", Clear
8585K431 1 Ft. Impact-resistant Polycarbonate Round Tube, 1-1/2" Od, 1-3/8" Id, 1' Length, Clear
8585K631 1 Ft. Impact-resistant Polycarbonate Round Tube, 1-1/4" Od, 1-1/8" Id, Clear, 1' Length
91780A337 10 Each Aluminum Female Threaded Hex Standoff, 1/4" Hex, 1-1/2" Length, 6-32 Screw Size
90272A146 1 Pack Zinc-pltd Stl Pan Head Phillips Machine Screw, 6-32 Thread, 3/8" Length
90272A148 1 Pack Zinc-pltd Stl Pan Head Phillips Machine Screw, 6-32 Thread, 1/2" Length
6435K54 2 Each One-piece Clamp-on Shaft Collar, Black-oxide Steel, 9/16" Bore, 1-5/16" Od, 7/16"w
90131A104 1 Pack Abrasion-resistant Reinforced Rubber Washer, 1/2" Screw Size, 1-3/8" Od, 1/8" Thick
9637K26 5 Pack Continuous-Length Compression Spring Spring-Tempered Steel, 11" L, .844" OD, .08" Wire
8538K18 5 Ft. Nylon 6/6 Rod 1/2" Diameter
9562K46 1 Each Stretch-fit Rotary-shaft Ring Seal, 1" Shaft Diameter, 0.95" To 1.07" Shaft Diameter

Stuff you can get from your hardware store in smaller quantities:
90272A151 1 Pack Zinc-pltd Stl Pan Head Phillips Machine Screw, 6-32 Thread, 3/4" Length (I used 5 of these).
91090A109 100 Pack Zinc-Plated Steel Large-Diameter Flat Washer 1/4" Screw Size, 1-1/4" OD, .04"-.06" Thick(I used 2, for my plunger head)
90126A509 100 Pack Zinc-Plated Steel Type A SAE Flat Washer NO. 6 Screw Size, 3/8" OD, .03"-.07" Thick (I used 1 or 2, for my plunger rod)
90295A080 100 Pack Nylon 6/6 General Purpose Flat Washer Off-White, NO. 6 Screw Sz, .32" OD, .02"-.04" Thk (I used 2, for the catch)

Stuff I got from my local hardware store (didn't find 17/32 brass on McMaster, only 9/16" and 1/2" -- probably there somewhere though):
9/16" Brass tube, 1 foot - Dart pusher, plus misc. brass
17/32" Brass tube, 1 foot - Barrel
1/2" Brass tube, 1 foot - Breech

Stuff I don't know where you would find, but probably have in your house already:
2 small springs, one for the trigger, and one for the catch. These fall out of nerf blasters if you take them apart. Pretty sure mine were from various Longshot locks.
Coarse Threaded screw, 1 1/4" (wood screw?) - I had these lying around my house. Used for plunger rod ends, because 6/32 thread ripped out of the holes.

Writeup Part 1 (ignore the catch assembly -- it has since changed):
http://nerfhaven.com...ndpost&p=311529

Writeup Part 2 (the final handle assembly -- see below):
http://nerfhaven.com...ndpost&p=311678

These two changes came after the two writeup parts were posted. The updated parts are in the printable templates:
Revised Catch:
http://nerfhaven.com...ndpost&p=311746

Revised Priming Handle:
http://nerfhaven.com...ndpost&p=312223


I will continue to keep important information indexed in this post.


-----Original Post lives on below-----

Video here:

FNG reporting. This is my homemade rifle. My goals were to produce something that accepted Nerf mags, shot streamlines, had 100'+ range, was easily serviceable, and didn't look like a plumbing project gone awry.

Some notes:
Construction is out of polycarbonate. The sides are 1/8", with 1/4" pieces for internal bits and the grip. It used a bit more polycarbonate as a plusbow would have: three pieces of 12"x12" 1/8, and two pieces of 12"x12" 1/4. (I'm working on a second version that will use two sheets of 1/8 and one sheet of 1/4).

As you'll see in the video, the plunger tube and outer brass breech are connected together as a unit, operated by the priming handle. To reduce the 1 1/2" polycarbonate air chamber down to 9/16, I made 3 polycarbonate rings with a hole saw (just under 1 3/8 outer diameter, 9/16 hole), and used two 1 3/8" rubber washers to make it air tight (ring, washer, ring, washer, ring). The rubber washers stretch over the brass nicely. Screws hold it all together -- the middle ring has set screws to hold the brass in place, the outer rings are held in place with screws through the air chamber. I used a polycarbonate rib inside the 9/16 to push the dart *just* into the 17/32 barrel.

The breech itself is about as simple as I could make it. Just a 3 1/4" long section chopped out of the 9/16 brass, half the diameter. I left 1" of intact brass at the end that always stays around the 17/32 barrel. Since the whole thing travels about 6 inches when you prime the gun, it has to travel really far forward over the barrel. The barrel attachment is very near the nose of the gun. The barrel is held in place with shaft collars. McMaster part number would be 6435K54.

It uses the original plusbow plunger head. I will be changing it to Split's plunger head in the second version.

It met all of my goals except one: firing stock streamlines. The [k26] has way too much power for them. Ideally, they'd fly far, but the reality was they'd tumble through the air with a kicking spiral. To fix this, I hot-glued the tips of my darts. No idea who came up with the idea, but it isn't mine. Hot glued streamlines fly really far and don't tumble. However, they do not fly all that straight.

Things I like:
Fires at least 60 paces.
I think it looks cool.
At point blank range, a dart will go through both sides of an empty cereal box, so that's awesome.
My friends are terrified of it.

Things I don't like about it:
It's heavy.
It's hard to prime.
Not accurate beyond medium range.
It was my first time using a scroll saw, so up close it is pretty ugly.
Should have built it to fire Stefans.


Let me know if you want a writeup or some pictures.

Edited by dapperrogue, 07 March 2012 - 05:03 PM.

[andtheherois]

This is definitely awesome, However I think all that polycarb would be overly expensive for those of us who can't find places that sell scrap sheets. A write up would be nice, but I would suggest looking at ways to reduce cost as much as possible.

[ACE11]

Wow. This is amazing, writeup please! Hope to see more stuff from you in the future.

[KoRnEd]

From the video, it looks so sick! Anyways though, pictures would be nice for those who don't want to watch the video. Also, a writeup of this might be very nce, rather than a vague description. Good work!

Edit: Also, in your video, you dryfire your blaster. Not a good idea, even with polycarbonate.

Edited by KoRnEd, 10 February 2012 - 05:51 PM.

[ArcAngelXVI]

As a fellow FNG, I must say that this is impressive. What you've basically made is the +Bow analogue to the Longshot, and with the dwindling supply of them (at least in the US) that's great. Like others have said, I certainly wouldn't mind a writeup and even some templates to make this myself.

My only gripe is that you might want to blunt up the front of the blaster - pointed polycarb edges and exposed brass aren't exactly safe. And while you might not run into somebody, you could conceivably fall and injure yourself all the same.

[Lanceraxe]

If the Longshot and the Plusbow had offspring this would be it. That thing is menacing, nice work!

[pinhead52]

Very nice work. I would like to also throw in my two cents on the write-up/template begging, though the design actually seems pretty simple (in it's basic form), especially after seeing the monstrosity Hasbro had to build to get the same effect.

I also have to ask, why no pump handle? You said in your first post that it's hard to prime. Is it just too hard to build a pump handle that allows you to get the force you need?

[dapperrogue]

Thanks for the awesome feedback. Ok, photo time.

Here are a few shots of the whole thing, next to a Maverick:






This shows the magazine slot, plus a closeup of the foregrip (1 1/2" hex standoffs, machine screws give more grip than smooth polycarb), and a good view of the breech hole (closed).



Same shot, breech open.



Closeup of the catch end in the plunger rod. This was dremeled out. It took a decent amount of time. Don't recommend it (I have plans to use a different catch next time). This shot also shows what holds the back of the spring. This is a 1 1/4" diameter polycarbonate tube that slides into the back of the air chamber. A disc of 1/4" polycarbonate (with a 1/2" hole for the plunger rod) sits atop it. Ignore the holes in the air chamber tube, those were previous attempts to attach the priming handle.




This ugly business is the firing mechanism. From bottom right, that's the end of the trigger. It sticks out of the bottom of the gun (not happy with that). The triangle it connects to is essentially a bell crank, translating the horizontal pull of the trigger to a vertical push that raises the catch plate, releasing the plunger rod. The "stock" was added as an afterthought, to keep myself from getting stabbed in the shoulder by the plunger rod. More hex standoffs are used here (primarily stylistically).



Here's the 'sandwich' I referred to earlier: Polycarbonate ring, rubber washer, ring, washer, ring. You can see the set-screw in the middle. The lower, off-set screw head you see holds the center ring (and the breech tube) from rotating.



Another shot of the assembly, and also a good demonstration of how the priming handle attaches. This box is ugly, and I really hate it, but it is secure. I have a better design for next time. I don't suggest doing it this way.



Required Nerfhaven Business End Shot. Yes, it is dangerous. More importantly, brass is soft and it isn't protected. Will have to figure out a way to protect it. Also shown here is the 9th hex standoff. It pushes the front of the barrel down so that the back end rides along the inside top of the 9/16 brass tube. This keeps it from catching on the back of the breech hole, but does add some friction when priming.




Now that you can see it close up, you can see the "quality" of my handiwork. Scrollsaws don't like to cut straight at all, so I need some more practice (note wavy edges pretty much everywhere). Also, I don't suggest anyone drill several bazillion holes with a cordless drill if they want square results. From far away in the dark (and in shaky you-tube videos), it looks pretty good though, right?


Answers to your questions:
I'll do a detailed template/writeup of the next one, since it will be improved. I want to get a drill press first, since (as you can see with the closeups), next to none of the holes are straight. Plus, I've got a few improvements to be made. However, it will still operate the same and have the same basic parts.

For now, though, it is completely transparent and pretty self-explanatory, so if you've built a plusbow, you can probably replicate this. I didn't take any construction shots, unfortunately, so perhaps the best way to address construction/mechanical concerns would be to answer them in this thread.

There's no pump handle because I wanted it to operate bolt style, like a longshot. You can see in the video that my longshot already is pump action. Changing it to a pump action gun wouldn't be too hard, I suppose, but due to the length of the gun the ideal pump location is right where the magazine goes. Flip the magazine loading to the top? Put it out the side like a raider? Dunno.

Yes, it was relatively expensive, and yes, most of that was polycarbonate. The next revision of this will use less, but by its nature it will use more than a plusbow, due to the extra polycarbonate needed to support the barrel and house the movement of the air chamber.

Re: Dry firing. Thanks for the heads-up.


I will happily answer any other concerns you guys have.

Edited by dapperrogue, 10 February 2012 - 07:54 PM.

[Daniel Beaver]

Neat. The mechanism looks pretty simple, which is good; there are so many ways that these clip-fed guns can fail. Nice work on that catch, in particular. Any plans to make it pump-action?

Edited by Daniel Beaver, 10 February 2012 - 07:36 PM.

[Curly]

That's wicked. I love that it still has the LS silhouette. If your darts fit that barrel there's no reason it can't use stefans if you mod the clips. With streamlines you can simply cut the tip in half and drop a weight in, then fill with hot glue. Besides the foam wearing down, those kinds of darts are incredibly durable because the tip isn't held on by just glue. You could also yank the streamline core out and make a slug dart on it, but domes shoot farther.

[roboman]

Your work is quite nice. To improve the straightness on those long cuts, I'd suggest clamping a piece of aluminum angle stock or even a 2x4 to the table of your scrollsaw, as a makeshift fence.

[soloz1]

I want one.... Got an estimated total cost of the parts?

Edited by soloz1, 11 February 2012 - 01:45 AM.

[Guitarzan]

Dude I love this thing!!! I especially love that it resembles a gun, accepts clips and has a brass breech system. One of the coolest homemades I've seen in my months of lurking here. Can't wait to see further development of this thing man

[Swiftone1990]

Very nice man. How heavy is this thing?

[ThatBritishGuy]

You could also think about nesting a 1/2" brass pusher inside the 9/16 for MK.2 to avoid the polycarbonate ring, that's what most people use in angel breeches and the like and it really helps. It also reduces deadspace by a tad but it doesn't seem like you need to do that if your hitting 110!

Great idea by the way, i've always wondered if someone could make a replica of a longshot.

[HasreadCoC]

For every 200 FNG's, we get the next Captain Slug, or Ryan & Kane, or Boltsniper, and you seem to be one of those 1-in-200 FNG's sir. You know what? I think it's all worth it, all the other new guys with their thread necros and other trouble, when we get people like you.

All I can say is, keep up the good work, redesign, perfect, up the power, all that, and then open commissions. After that, design some other awesome thing and keep going.

Maybe you could do a Crossbow silhouetted blaster next?

[Ozymandias]

Maybe you could do a Crossbow silhouetted blaster next?

From the original +bow thread:

Main Project Aim: Develop a homemade version of the Crossbow that has performance comparable to one modified to level 4.

On a similar note, if you haven't picked a name for this yet, might I suggest +shot?

[HasreadCoC]

From the original +bow thread:

Meh, it should look more like a crossbow though. Theres I difference between having similar performance, and actually looking like it. I'm imagining Tracing the crossbow shell and doing it all polycarb. No nylon for the stock, polycarb side-plates. A full, exact, trace, but with maybe a well-done handle for comfort, possibly with a part-wood foregrip, and part-wood stock-plate.

What I love about his design is that it really *looks* like a longshot. I think we just need a specialized +bow to do the same for the Crossbow.

[KoRnEd]

On a similar note, if you haven't picked a name for this yet, might I suggest +shot?

He should call it an L-Shot

Keep Doing good work!

[dapperrogue]

+Shot seems like I'm stepping on a few toes. Also, I always assumed the "+" represented the "cross" in "crossbow."

I was trying to come up with something that meant a million to one chance... e.g. a "long shot." The best I could come up with was "Hail Mary," but it sounded kinda religious.

I like the feel of L-Shot, but the "L" should stand for something. Lambda (the Greek letter) is often used for wavelength, which I like. Also failure rates in mechanical engineering, which is appropriate.

Lambda-Shot, L-Shot for short, it is.

It also gives a good nod to Captain Slug's +Bow, which is what inspired this project.

[Meaker VI]

...Yes, it was relatively expensive, and yes, most of that was polycarbonate. The next revision of this will use less, but by its nature it will use more than a plusbow, due to the extra polycarbonate needed to support the barrel and house the movement of the air chamber.

Have you considered pricing out 1/4"-1/8" plywood, MDF, or hardboard/Masonite (the stuff they make pegboards out of)? I've gotten 4'x8' sheets of Masonite for ~$8, and for large surfaces like you've got, it'd be much cheaper than polycarb. Shoot, 1/2" furniture-grade plywood sheets might even be cheaper than polycarb; I think I got a 3/4" thick 4'x8' quarter-sawn Oak sheet for $60 (~$2 per sq. ft., for those who can't multiply and divide).

[dapperrogue]

Ok, got a bit of work done on the new version. Haven't had much time, but figured you'd want to see progress.

So, consider what I've already shown you the "L-Shot Prototype", and this "L-Shot Version 1." I'm making it in four parts, so it will be easier to explain/assemble: The stock (shown here), the reciever (middle bit that holds magazines), the barrel housing, and the action (part that moves back and forth).

Parts!


As before, but after a whole lot of cutting. I *would* have managed to get this whole thing out of two sheets of 1/8" polycarb, and one sheet of 1/4", but I screwed up one cut and will have to go get some more plastic. Ugh. The problem with no room for error, right? Side note: Don't use a fence to try and make straight cuts on a scroll saw. The blade will wander -- by as much as 1/8 of an inch in my case when I tested it on a piece of scrap. Straight cut, but not parallel.


Ok, business time. Here's a closeup of the new catch parts. This time, the catch will stick into the 1/4" catch tube, rather than catch once it protrudes. This will allow me to simply screw a wide washer into the catch end of the plunger rod, rather than dremelling the end of the rod as I did before.


Here's the catch assembled. Most of the machine screws are on the other side, but one of the screws holding the spring went in on this side.


Here it is actuated. By pushing back on the "L" shaped bit, the catch gets pulled down.


The catch is screwed to a back plate, along with the catch tube. In order to hold the catch tube in place, I used a disc of 1/4" polycarbonate that matched the inner diameter of the tube. A hole was added to allow the ramp of the catch to protrude into the tube.

Edit: The catch tube is 1 1/4" OD, 1/16" wall, and is 7 1/2" inches long.


Here's the trigger and handle assembly. I made it a bit fancier this time, but still hollow in the middle. I happen to like the totally clear look, and once sanded they feel pretty good. Speaking of which, I still need to sand it down so the edges aren't sharp.


And here I've added the sides to test fitment. Also added here are the air-chamber guides. They are two pieces of 1/4" x 6" x 1.5" polycarbonate to form a box around the air chamber. This helps it slide back perfectly straight. The trigger is screwed into the lower one, so the air chamber will actually slide on the screw heads. Note that the trigger isn't connected to the catch yet. I will add a linkage using 1/8" polycarbonate pieces. However, other than that, this piece is done.



That's all I got done this weekend. Next I'm going to work on the action next (air chamber/breech/handle assembly, along with the plunger rod). Expect the next installment Wednesday or so.



Before I go: I want to make templates for you guys. What should I use to do so? Don't say paint.

Edited by dapperrogue, 24 February 2012 - 12:58 AM.

[Meaker VI]

Before I go: I want to make templates for you guys. What should I use to do so? Don't say paint.

Sketchup. It's free, easy, draws straight lines that are easily controlled, its got built-in file distribution (3d warehouse), and it can provide a nice 3d model too. If you don't think you're skilled enough in it, I could probably draft the thing up off of several sketches in an hour or so.

I'm pretty interested in this project because I'm currently working on something similar; though I'm trying to use wood and PVC instead of polycarb and brass. I'm struggling with getting everything anchored to a frame so I can get a trigger and slide motion going, so I'm going to try to build a cardboard model and then use 1/4" or 1/2" plywood and 1/8" hardboard. If yours works with 1/4" / 1/8" polycarb, I can probably just swap those parts out directly.

As for your blade-wander, try using a wider blade and just follow the lines you've drawn. Fences don't work well on bandsaws either, and I suspect the mechanics behind that are similar for scroll/jig saws.

Will it be pump-action in the final version?

[shardbearer]

This looks pretty cool. I would suggest using PVC for structural instead of Polycarb to reduce cost and machining time. Also dont try to replicate the LS design, but instead make the best possible blaster.

I would suggest OpenSCAD or SketchUp for 3D modeling.

OpenSCAD takes a programmer's approach, which I find much easier and totally unambiguous, which was my gripe with SketchUp, but if you are not a programmer it would have a fairly steep learning curve. Everything is typed out, and the graphical interface is only for viewing your creation. For example, here's what I type to make a 1 1/4" plunger tube that is 12" long:

difference(){
	cylinder(h=12, r=.83);
	cylinder(h=12, r=.69);
	}

Wonderfully easy and concise, much easier than mucking around with an inaccurate mouse. I typed that out in 30 seconds, and before I found OpenSCAD, I tried for an hour to get that in SketchUp.

And I like both LibreOffice-Draw and Inkscape for 2D Templates. Though Inkscape on Mac is very ugly.