Here's my guide to making your own Nerf Rapidfly Compact.....AKA Nerf Rapidstrike Mod
1. Lighter flywheel weight
2. Shorter barrel
Step 1: First Things First
SOME THINGS YOU'LL NEED:
****COMPACT BARREL MOD****
1. A DREMEL with a cutting wheel 409, 420, or 426 and a #11 bit or similar
2. An X-ACTO knife
3. MASKING TAPE
4. SHARPIE OR MARKING PEN
5. Brass tube is optional 11/16 K&S
****LIGHT WEIGHT FLYWHEELS****
1. A Drill with some bits.....3/32, 1/8, 1/4, 5/16
2. Small flat head screwdriver
****FIREFLY TECH MOD****
1. One 5mm UV LED 3,000-5,000mcd & One 3mm UV LED 3,000-5,000mcd
2. Two 10ohm resistors 1/2 watt
3. Wires AWG-26 plus heat shrink tubes and electrical tape
4. A soldering iron plus rosin FLUX
5. Super Glue
6. One Li-ion battery around 650mah or One "AAA" size Trustfire 3.7volt battery
1. Four Trustfire "14500" or equivalent
2. Box Battery Tray
1. The Meter itself
2. AWG-26 wires
3. JST plugs or similar
Step 2: Battery Tray Clips
If you have a hard time removing the inner barrel holder from the main shell your going to need to use a DREMEL with a #11 tool to buzz the tabs flat.
This will make dissasembly much easier the next time you feel like taking it apart.
Step 3: Lighter Flwheels
Making the flywheels lighter is critical for effficiency and speed. You will always gain potential by dropping the weight of the flywheels in a Nerf gun. It gives the flywheels a quicker response time to speed up when needed and takes less energy for the motors to turn.....
Now before you go and google Newtons Law and tell me that I'm wrong, - let me tell you that it does not apply here because the theory is based on momentum. This is not the case with nerf flywheel blasters because the motors slow down quickly from thier design......try spinning the flywheels by hand and you'll see that it does not keep rolling like a bicycle wheel which has tiny ball bearings. This means that we need to be able to speed up as quickly as possible in any given time. The awnser is to drill holes in the flywheel to get rid of some weight.
A perfect example can be found in those cheap tiny RC helicopters!!!!! Take a close look at the gears that move the main propellers.....They are not solid and contain holes cut out to reduce it's rotating mass for quicker response time of speeding up.
Race cars also benefit from reducing the weight of their "FLYWHEEL" becuase it's able to spin faster in a shorter amount of time.
NOTE: Reducing too much weight can weaken structural integrity so make sure you don't go to far with it. My guide will show you appropriate ways to reduce weight that work well -and still keep the flywheels strong.
Step 4: Stage 1 Weight Reduction
Pry the flywheels out with a small flat head screwdriver and turn them over. You'll notice that there are circles imprinted on the backside.....Take a sharpie and mark the centers. There are 4 circles on the back of each flywheel.
Take an X-ACTO knife and spin it like a drill by hand in each of the centers you have marked to get the holes started. This will keep the first drilling from skipping around. Use a 3/32 drill bit followed by 1/8 drill bit.....If you want the cleanest cuts just keep getting larger bits until you come to 5/16 of inch. Clean it out with the X-ACTO knife as needed.
I personally used the following bits:
3/32, 1/8, 3/16, 1/4, 17/64, 5/16
Step 5: Stage 2 Weight and Traction Holes
"On the side of the flywheel it is possible to get rid of more rotating mass and gain more traction by drilling holes."
By drilling holes on the side, you'll notice that when you push your finger down on it some of your finger falls through.....
Now imagine a dart squishing between the two flywheels. Some of the dart will press through giving added traction to the wheels. This is especially important when using higher voltages or more powerfull motors!!!
The picture holes on the side are 1/8 of an inch
I did do an extreme 5/16 on my raven flywheels and it works even better. The drawback of going that large is your kill the life of your darts faster. I would say 5/16----lasts about 100 or so cycles before they start ripping on 16.8Volts
-So the safe bet is to keep it between 1/8 and 3/16 of an inch wide.....
Step 6: Other Samples 001
Try experimenting!!! You'll notice that the Rayven responds differently from the Stryfe and the Rapidfire flywheels!
Q. Do I have a favorite?
A. Yes the Rayven, because you can reduce more weight and because of the design it retains it's strenght!!!
without warping :)
The other pic is just a sample of how to do the Vortex Nitron....They are not compatible.
Step 7: Compact Short Barrel Mod
"..... Of course shortening the barrel lenght reduces drag so cutting down a couple of inches will always help."
While it is possble to get shorter, I found this as my compromise. The final barrel lenght is 4 and 2/16 of an inch.
It looks good and keeps just enough room for a battery upgrade tray.
Step 8: First Cuts
Where going to focus on cutting the lower front of the main body first. Grab some masking tape and mark up exactly 2" inches and cut that bottom piece out.
Step 9: Taped Up -ready to Cut
"Always wear protective gear when cutting with a DREMEL tool or similar...."
I always cut just before the taped line because the plastic tends to melt a bit under high speed cuts.....Then just sand or shave down to the desired point.
Step 10: Cutting the Top Front-
Follow the cutt lines as shown marked by the sharpie.
Step 11: Cleaning It Up
Follow the dotted lines as shown. The cut comes upward flat against the wall 90 degrees.
Step 12: Finished Chop
So it should look something like this.....Then just do the other side and sand accordingly.
---350 grit, 600, 800, 1000, if desired.
Step 13: Chopping the Barrel Holder
Mark up some masking tape from the line where the arrow is pointed.....
Step 14: Taped Up
getting ready to cut.....
Step 15: Rough Cuts
Step 16: Clean Cut
You don't have to cut it perfectly just get it good enough.....It just lays on the inside.
Step 17: Bottom Rail Cutout
Follow the dotted lines and cut the piece out so that it will fit together with the main shell. Don't pay attention to the guide mat on the bottom--- it's just a mat.
Step 18: Hole Cut Off Center
I miss calculated my cut because I was just winging it at the time but the red cross hair shows where you should actually drill the hole.
Size should be 5/16
NOTE: Even tho I missed my mark it still closes perfectly so all you have to do is come close.....
Step 19: Bottom Cuts Final
Last your going to need to make some cuts for the screw areas check out the pic :)
Step 20: Inner Barrel Cuts
Using a pipe cutter I cut the barrel a 4 and 2/16th of an inch long.
I also put a 11/16th brass barrel on the inside to keep the inside of the barrel smooth. This gets rid of the drag caused by the spiral rifling on the inside of the stock barrel.
It's going to be a very tight fit so you might have to twist it in or sand the inside of the barrel with 350 grit sand paper slightly before inserting the brass barrel.
Step 21: Last Cuts
Put together the pieces and see if it all fits together. If it does it should look like this.
Step 22: Finishing Up
Step 23: Compact Barrel Mod Done!
Close it up and if it lines up correctly it should look like this!!
Step 24: Sample Pic
Step 25: Sample Pic
3. Intergrated Firefly Technology
4. Voltage increase to 16.8volts
5. Volt meter