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Member Since 16 Feb 2008
Offline Last Active Mar 24 2015 08:18 PM

Topics I've Started

Supreme Crossbow Internals

15 June 2011 - 02:36 PM

These are my latest crossbow internal replacements. They use a full 1.5" wide plunger tube and a shortened (higher spring constant) [k26] spring. They have 5.5" stroke (which is limited by the actual crossbow shell, not so much the internals) and shoot 130' with a hopper. Because of the new and improved method of making these, they are much sturdier, sound dampening and do not rotate in the shell. They overcome all of the issues of previous models. The primary detriment to these is the time required to make them - light work spread out over about 3 days, with steps needing to be done at particular intervals.

Materials:
Plunger tube
Nylon plunger rod
Polycarb scraps for handle and plunger head
Skirt Plunger head
Bushing
[k26] spring
2 Standoffs
Great Stuff expanding foam

Misc:
Goop, e-tape, 1/2" screws (6-32), 4 washers, between 1.5 and 2" screw (6-32)

Copy/paste-able parts list for mcmaster
8585K431 1
8732K13 1
9562K46 1
91780A337 2
9637K26 1

Total Cost (each):
~$25, depending on how much you pay for polycarb scraps

Your first step is to cut your plunger tube to 9" in length. I recommend making a batch of these at a time because of the time requirements and the materials used (covered soon).
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Next is the new method. Following the can's directions, shake the can of great stuff vigorously for 2 minutes or so. Put the dispensing nozzle on the tip. This stuff is one-time-use per can, and will last only as long as you're using it within 2 hour intervals. You'll want to be doing everything at once here.

Spray a layer of the foam on top of your plunger tubes. Try not to leave any gaps, but don't worry if you do. Set a timer for 40 minutes.
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After your timer goes off, put another layer of foam on top of that one. Set your timer for 1 hour this time.
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Once this timer is done, peel back any of the foam that dripped too far down. If you let it cure for too long, it won't come off cleanly. Now flip your plunger tubes over and foam up the first layer. Timer for 1 hour. Typically you'll want 3 layers total on this side, with an hour between layers.

Let these 5 layers cure overnight. Do not let them fully cure (24 hours). While they're in this in-between stage, the foam is soft on the inside. You should be cutting out the body now.
Take your foamed tubes to your band saw. Cut off the overflow on the ends, then the tops, making sure to make those cuts parallel. Finally, cut down the sides. You need these cuts to be at the sides of the plunger tubes. Your blade should be grazing the sides of the polycarbonate. Here's the cut progression:
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After this, we can set up our cuts for the supports.
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Draw a line to represent the top of the plunger tube. Draw a parallel line 1/2" above that. This will be your top - make it on thinner side.
Draw a line to represent the bottom of the plunger tube. Draw a parallel line 3/4" below that. Draw a vertical line 5.5" from the front of the plunger tube, and another vertical line 8" from the front of the plunger tube.

Cut along the bottom most line for the first 5.5", then cut 1/4" below the bottom of the plunger tube up to the 8" line. From there, cut out the corner.

While these are still soft, mark vertical lines on both sides at these points (distance from front of plunger tube): 4.25", 5", 6.75", 7.5"
Take a dremel with a boring bit (correct me if this name is inaccurate, this bit it used to cut channels normally) and cut out in between these sections over the distance where there is plunger tube. This is where the crossbow's internal supports go.

Once you have those done, fit your internals into your shell and mark where the decorative holes in the shell are onto the internals. Poke a screwdriver through these marks and insert your standoffs:
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At this point, you can add your bushing with e-tape, goop and a screw. You can now leave these assembly to fully cure. The foam will harden around your standoffs, making them very sturdy.
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While this is curing, cut your plunger rod to 12", with a notch 2-7/8" from one end (location is the back of the notch, where the catch meshes). Drill and tap both ends.
Cut your spring to 7" in length, cut a polycarbonate circle 1-1/8" in diameter with a 5/32" hole in center, 1/8" thick. Cut your priming handle of choice.

Finally, sandwich your skirt seal between the polycarb circle (front) and a 1-1/4" metal washer (back) onto the end of your plunger rod. Next put on your spring, then your catch, then your priming handle.

Once your plunger tube is cured, put lube (I recommend o-ring lube) in the plunger tube and insert your plunger assembly. All together:
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When putting this into your shell, the front will have a gap. You may need longer screws in the screw ports - use 3/4" #6 wood screws. Use 6-32 screws with matching washers into the standoffs through the holes to distribute the load of firing and keep the shell together at the top.

All together:
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This is the first crossbow to be able to use a hopper to break 100' ranges.

If you'd like, you can add extra layers of foam to create more features, such as this example grip for a missing-grip crossbow:
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Special thanks goes to Muttonchops for letting me use his pristine crossbow to make these kits.

The 6 kits pictured here will be available for sale later today.

Cpvc ĎSplat (Ps-800)

15 June 2011 - 12:58 PM

Mods for Beginners: Cheap and easy, Just Like Your Mother
Cpvc PistolSplat (Ps-800)

This is sort of a blast from the past. I first posted this to the LGLF blog in 2008 as a help to beginning nerfers so they could spend less time agonizing over mods and more time nerfing. Long story short, it's not on that blog any more, so I'm putting it up here. There will be a couple of other threads like this coming too.


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Required Materials

Pistol Splat (can be found at Spencers or online):
Cpvc coupler
Cpvc

Total- about $15

Required Tools:

Screwdriver
Dremel
Hot glue gun

First, cut through the top and bottom of the red cap at the front with your Dremel. You will also have to cut through (or otherwise remove) the cap at the end of the feedport. Remove all screws in the side and open the blaster.

You will need to remove the gray piece in the middle that pivots, as well as the sliding piece at the front:

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Pull out the plunger tube:

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A spring may fall out when you do this. You can throw this away; it is only there to weaken the gun.

Put a layer of hot glue around one end rim of the cpvc coupler, and slap it onto the black end of your plunger tube. Making sure itís centered and straight, add another thin layer of hot glue around the joint. Once that layer dries, put another. Layering like this adds tensile strength, making your mod last significantly longer.

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Replace the plunger tube where you got from. If your cpvc coupler doesnít fit nicely inside, you may have to sand down where it goes using the Dremel. The sizes of the couplers vary, but mine fit in well without needing any further modification.

Put the two halves of the blaster together, and replace all of the screws.

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Cut a 4-5Ē piece of cpvc (if using stefans or converted dart tag darts; optimum length will vary. Experiment! Cpvc is cheap!) and push it into the coupler via the front.

Youíre done! You should have a superb, primary worthy pistol at this point. Itís not the fastest or furthest shooting thing out there, but it beats out most, and itís simple and reliable.

Some tips on use:

To load, pull out the cpvc, put a dart in the back, and place the barrel back into the coupler. To prime, pull the lever arm up and push it all the way down. And to fire of course, pull the trigger!

The gray piece from the center that we took out was the trigger lock. Do not dry fire the gun (fire the gun without a dart in the barrel). If you do prime the gun and need to unprime it, pull the lever all the way back, and pull the trigger. Then slowly lower the lever.

Do not store the gun loaded or primed. This will deform your dart and weaken your spring, respectively.

Again!

18 February 2011 - 08:43 PM

Happy birthday Ice Nine, you snuggly bastard.

Slambow Video

03 August 2010 - 03:04 PM

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Rtp, Pump Action Homemade.

04 June 2010 - 10:05 PM

The goal of this homemade was just to make a working pump action homemade where you didn't have to move your hands to prime the gun. I went though many many designs for that goal, but most relied on a separate handle that would have to be carefully constructed to handle the torque from pulling back the plunger rod. I eventually settled on this relatively minimalist design. There are only 7 parts to cut for the base model, not including whatever handle you decide to use.

::Disclaimer, I'm really tired right now, so some parts of this may be a bit unclear. If anything is confusing, just let me know and I'll do my best to remedy the situation.::

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::See bottom for firing video::


First, you need to download and print your Templates
Make sure you have everything from the Parts List.

1) Cut them out, paste them onto your plastic. The two plain circles with yellow coded centers are from 1/8" thick polycarb.
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2) Drill out the holes and cut out the appropriate parts, as per the legend and templates. Except for the 1/8" thick parts, tap all holes coded yellow with a 10-32 tap. When you cut your circles, the tapped one and the circle center/untapped one need to be able to move through the plunger tube easily. The last circle should fit firmly in, but not too tightly.
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Ignore the odd holes I drilled in some of the templates. I was testing out different sizes of plunger rods.


3) You'll need a scroll saw for this part. Feed the blade through the holes marked as squares and cut out along the line.
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4) Before removing the paper from all of your parts, you'll need to mark the direction your parts need to face. With the template side facing up, turn all of the circles so that the dot is at the top. Now, mark all of the sides with an L (or other asymmetrical symbol). You can now remove the paper if you'd like.
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5) Line up the tapped circle and the square center circle in the way they need to assemble and vice them. To the sides, drill and tap straight through them with a 5/32" bit and 6-32 tap.
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6) Start feeding 1" 6-32 screws through the tapped circle until 1/2" is sticking out. Push the other circle onto the end and finish threading the screws through. Once you're done, it should look like this and measure 1" long total.
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7) Take four threaded rods and screw four locknuts on until they are 5/8" from the end (5/8" gap, not including the body of the nut itself). Now thread rods through your circle-center, untapped hole, then through the square center and then into the threaded circle. Thread one up until the end is flush with the circle, and thread the rest so that a little more than 1/4" is sticking out.
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8) Push your catch onto the end of the rods, followed by the washers. Line up the rod sticking out the most with its respective hole on the back plate. Rotate the back plate until it's tight against the other three rods. Rotate each of the other rods so that they thread into their respective holes. Make sure your catch moves smoothly and your loose plate slide along the rods nicely.
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9) Now you'll make your plunger tube. It needs to be 10 5/16" long from 1.5" OD polycarbonate tube if you're using a 1 1/4" long bushing. If your bushing is shorter, make the tube shorter by the same amount, and vice versa. Goop/e-tape/o-ring or whatever you want to do, but seal the bushing to the end of the tube, and secure it in nicely. I used goop, e-tape and a 2" bolt through the entire thing, a la +bow.
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10) This is a good time to mount your gun body onto a handle or larger shell. For this, I just used a maverick handle and corresponding trigger. You'll also need to tighten those locknuts down onto the catch as much as you can, while still letting the catch move freely.
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11) From here, you need to attach the tube to the body. Move the sliding piece all the way to the catch and push the plunger tube all the way down onto it. Drill through the end of the plunger tube and into the sliding part with a 5/32" bit and tap the hole. Screw in a 1/4" length screw. Mark the plunger tube with the L. Don't worry about it breaking here, this part isn't load bearing. If you did it right, there should be a nice 5" gap.
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12) Slide your tube assembly down the rods a little bit so that the spacer is in a comfortable angle for sliding. Drill, tap and insert three more holes and screws through the tube and into the spacer. It should now move very smoothly.
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Caution: I'm pretty sure this video is nsfw. Pull out my dick have sex with your mom and everything.


13) Here you'll just want to make your plunger rod. The length for this should be 8 5/8" plus the distance from the back of the plunger tube to the back of the catch when the gun is collapsed. This should be about 1/2", making your length about 9 1/8". Cut your notch starting 3/8" from the end, and drill and tap the opposite end. Screw your plunger head between two 1/8" thick circles into there.
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14) Cut your spring to any length between 7 1/8 and about 8" (the longer it is, the harder it is to prime, but the more powerful). Lube up your plunger tube, insert your plunger rod, notch up, then your spring. Push the body of the gun onto the back, and screw the spacer into the back of the plunger tube. It should be done now, bearing the tons of fine tuning you'll need to do.
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If you didn't catch it, at the end of the video I mention how you can use this as a hamp-type mechanism for mercy kills. This system is pretty powerful, and I hope to see it adapted to many uses. It's certainly not the typical pump action method, but it sure works nice.

That should be everything. Enjoy.