First of all, there is a lot of talk about motor swaps. The 130 motors that come with the RS aren't too shabby. They play well with battery voltages near 7.2 or 8.4V and deliver quite practical performance. Plus, compared to swaps, they are free.
Finally, this is a guide for how to deal with the basic electrical work, resulting in the most "vanilla" possible RS build. It's your "Stage 1 kit". One you know how to upgrade the electrical system, it's a bit clearer how to add the use of different motor and battery options, further switch and control system upgrades, bells and whistles like pusher speed control strategies and electronics such as ammo counters and selective fire systems, integral lighting and electrical accessories, mechanical mods, integrations...
What You Need
- Dremel or other handheld grinder
- Diagonal cutters (dikes)
- Needlenose pliers
- Flush cutters
- Heat source for shrinking heat shrink tubing
- Phillips screwdriver of any size that will not slip on external RS screws and fits into all counterbores on exterior of gun
- Soldering iron (30W minimum recommended heater power; no conical tips)
- 3/16" polyolefin heat shrink tubing
- Battery connector of choice (shown: W.S. Deans)
- Reliability warning: Do not use Tamiya connectors, industrial/automotive quick disconnects ("spade connectors") or anything not designed for high current applications and repeated connection cycles
- Be mindful of available space. If you use a larger pack in the stock battery box, use a smaller connector such as Deans.
- Lead free electrical solder (Shown: Alpha Metals Flo-Temp)
- Lead free solder is recommended for higher heat resistance and mechanical strength for reliability. This is not electronics work. If you use leaded anywhere, do not use it on the motor or switch terminals.
- PTFE (Teflon) insulated hookup wire (recommended): 16 or 18 AWG
- PVC insulated hookup wire or silicone insulated hobby wire: 18 AWG
- Cyanoacrylate glue, liquid
- Soldering flux (optional)
- Full-size microswitch with roller-lever or simulated roller actuator, 10A rated or higher, to fit FCG and grip internals (optional, but recommended)
- Battery pack
- Voltage: NiMH/NiCd: 7.2V (6-cell); LiPo/Li-ion: 7.4V (2S); other chemistries (LiFePO4, etc.): similar voltages
- Minimum recommended capacity: 1000mAh
- Minimum recommended continuous current rating: 15A
- Physical dimensions to fit intended mounting location, etc. (Note: 6 cell NiCd/NiMH Sub-C packs, which are common, high-capacity and current-capable, will fit the stock underbarrel battery box)
- Example links
- Battery charger to suit battery
What the NIC knows as "trustfires" or "ultrafires" (Li-ion, LiCo chemistry, 14500 or 18650 size cells) are absolutely unsuitable for most nerf applications they are often seen on (really, any nerf applications except low-load lights and electronics) as they cannot supply the necessary current. This type of cell is simply the wrong choice for a motor pack of any sort (and that is without going into the quality issues of the actual "____Fire" brands) since they are not designed for high discharge current and have much too high an internal resistance. Same goes for other types of batteries with inadequate current capability, such as alkalines, and some types of low-discharge-rate NiCd/NiMH and Li-ion/LiPo packs out of electronics, lights, etc. which are distinct from RC-type high current varieties.
Bottom line: Those junk toy/flashlight-style battery solutions (you know the ones) have no business being in your nerf mod. Use an appropriate RC-type battery pack. This is not a personal opinion of mine, it is not a fancy upgrade, it is what basic design practice says this gun requires. Quit griping and making excuses and do it right.
Remove the stock battery tray. We are going to discard that, since cell holders have way too much resistance to be used here and have no use on a mod.
Remove these two screws on top of the endcap...
And separate the tray. Put it in the junk pile and set the endcap aside.
Remove all receiver and barrel shroud screws and split the gun. Do not remove any screws from the stock as its disassembly is unnecessary.
Cut this wire and put the left shell aside.
Remove these lift-out parts from the right clamshell and put aside: front sight post, 3 rail accessory latches and springs, jam door, front and rear carry handle sight tubes, 2 sling loops, buttstock assembly (do not lose the pin); mag release group (3 parts); magwell liner, barrel, twist-lock fitting, battery box cover nut mount.
You should be left with this:
Both the barrel shroud halves have these spring terminals.
This is the jam door switch. Do not remove it from the receiver. Leave it there to act as a detent and stop the door from rattling. If you don't have one of these switches or a substitute device, you will have a loose jam door.
Again, this wire is incredibly undersized garbage. You don't want any of it in your mod.
Remove motor hold-downs. Also, cut off that round orange plastic (heat-staked) in the center of the PCB to allow removal.
Remove this screw on the left side of the flywheel cage, remove the rubber sheet and discard. This device is intended to prevent locked-up flywheels from mag malfunctions that allow darts to fall forward. There are rumors about accuracy effects of this device, but in the end, it is the root cause of the Vigilante malfunction in which foam compression due excessive push force stops a dart from reaching the flywheels and causes a subsequent jam. Removing it is mandatory particularly for HvZ players and is key to seeing the RS's potential for remarkable reliability in actual use.
Do not be concerned to damage the PCB edges, lift the pad, etc. Do not cut or damage the 6 switch terminals - everything else is fair game to be leveled.
Of course, if you have the soldering iron ready, you can also clean up the PCB nicely.
Remove completely, grind down, or melt off any sharp edges or points on remaining solder away from the switch terminals to avoid punctured insulation on nearby wiring.
I don't normally do that, but I was pressed for time and didn't feel like fighting with clips. Om nom.
Switch button: Flatten the rear end and cut the tab on the top.
The stock cycle control and trigger switches are perfectly fine as they are. True, a microswitch upgrade would be more durable, have a better trigger feel and be more precise and more tunable. The stock switches in these 2 locations are 2-pole models of this class of switch, though - the same low-cost switch used in the Stampede which rarely causes any trouble despite high currents. We will bridge those poles together just as in the Stampede, Vulcan, Swarmfire type applications, and we are only powering a single 130 (or 180, perhaps) pusher motor which has a very low load and average current draw. So it's safe, more or less.
Next. These 4 bosses in the left half of the RS receiver need to be removed; the bottom two ground smooth and flush. The top two were formerly used to clamp down the FCG, but we will install screws in those existing holes/bosses and get rid of the stock janky methodology here. Less risk of a wire getting pinched and less annoyance during assembly.
Note that we lost one receiver screw as a result of the microswitch install. No problem though.
In this guide, we are building a "front-wired" RS. In "front wiring", the battery leads exit the rest of the harness at the flywheel cage area. The only difference is how the flywheel cage's negative connection is handled and where the battery leads go.
To avoid excessive and unnecessary wire, we will bring the negative battery lead in from the battery box, strip 2 spots of insulation, and connect to the negative terminals of the flywheel motors to provide them a ground. No need for a separate flywheel negative lead that goes back and splices into that ground wire somewhere else.
If you do not want to put your pack in the stock battery box and would like battery leads to exit toward the rear of the gun, omit the negative lead's continuation past the flywheel cage, re-route the positive battery lead to where you want your connector to go, add a negative battery lead alongside that, and splice said negative battery lead into the negative/ground wire back by the FCG. You will see what I mean.
Since this is a simple electrical system with basic RS functionality and nothing odd added on, it will perfectly reflect the oft mentioned schematic of the simplest-case control strategy for the RS (courtesy Rexar5/HvZ Forums):
One wire at a time.
Lay out one end of a spool of wire with a few inches sticking out the end of the battery box (so you can plug the pack in easily when this is a battery lead) and the rest going back to the flywheel cage area. Use appropriate color for a negative battery lead/ground; here, brown.
Hint, regarding wire: Do not use a commercial wire stripper on Teflon insulated wire unless it is designed for this insulation or is high-precision and very sharp. Use a knife with a whittling motion to strip Teflon wire and cleanup with flushcuts or scissors. Do not roll a blade on the wire to score insulation; this can nick the conductor and increase the risk of breakage, and should only be done (lightly) for silicone insulated wire which has much thicker and softer insulation.
Flux and tin (flow solder onto) the motor terminals. Tin the wire joint areas.
Hint: Do not add additional flux beyond what is already in flux-core solder when tinning Teflon insulated (almost always silver plated) wire. This can cause wicking of solder resulting in hardening the wire and increased risk of breakage. The silver plated copper solders very easily and excessive flux is not required or beneficial.
Solder the negative lead in place on both motors.
Add a similar positive lead. This one will not continue on past the cage. Choose appropriate insulation color for switched flywheel power; here, white/red.
Fish a positive battery lead into the bundle (here white). This connects to nothing in the cage area. Set it at the same length as the negative battery lead end.
Add pusher motor leads. Keep them flat to the case as shown! Z-bend the ends if necessary.
Here's where you're at now: FCG in place, pusher box in place, and 5 loose wire ends.
Route flywheel power wire through FCG clips and solder to NO terminal of the flywheel switch, which is the nice new micro you just installed.
Trim the rib off the bottom edge of the left FCG shell so wires can pass over this area without being squashed by the grip frame.
Route remaining pusher lead alongside and down to center terminal of trigger switch.
06-05-14 Edit: I am seeing some RS rewires on the internet where people soldered wiring to the more convenient outer traces on the switch PCBs that are electrically connected to where I solder the wires. Don't do that. I have you soldering directly on top of thw switch pins for a reason - the PCB trace is a total joke for handling high currents and shouldn't be in the circuit.
Add a lead to the top terminal of trigger switch.
Rough numbers: 80-100fps 400-460RPM