Friday, October 21, 2011

Nerf Dart Tag Speedswarm - Mod Guide!

This Mod Guide will cover some performance mods for the Nerf Speedswarm.

Mods covered:
- Air Restrictor (AR) Removal
- Plunger Air Release Seal
- Plunger Padding & O-Ring Replacement
- Voltage Increase
- Aftermarket Spring Replacement (Optional)
- Rotating Barrel Dart Post Removal (Optional)

Note: Most of the modding steps are similar to the Nerf Swarmfire Mod.

Disclaimer: Modify at your own risk. Modifications may wear out or damage your blaster. Please be careful when using hobby tools!

:: AR Removal ::

Step 1: Disassemble your Speedswarm. Make sure to remove all the screws before detaching the casing layers.

Step 2: Open the motorized spring plunger casing. Move aside the cover, rotating barrel and battery sled.

Step 3: Separate all the spring plunger parts and gear components.

Step 4: Take the plunger tube and use a rotating pipe cutter to cut the front section. Make sure the cut line is positioned over the blue area under the white plunger tube casing.

Rotate the pipe cutter 2-3 times, and try to pull apart the plunger tube. If it doesn't move, rotate the pipe cutter again, do not over-tighten the pipe cutter! Keep testing. It will eventually separate into two parts and the AR will just drop out.

Discard the AR components and glue the plunger cap back on with 2-part epoxy glue.

Alternatively, the AR can also be drilled out with a motorized drill or dremel. Just make sure the plunger and seals are not damaged in the process.

Note that the white colored "target" shaped plastic grill inside the plunger tube has to be intact, that part is required as an impact barrier for the plunger rod.

The AR removal mod is done!

:: Plunger Air Release Seal ::

Close up the air relief hole on the side of the plunger tube. This is essential to create an air-tight plunger seal.

In my example, i use 2-part epoxy glue to fill in the air relief hole.

:: Plunger Padding & O-Ring Replacement ::

Without the AR, there is no air buffering system to cushion the plunger on tube impact.

This results in very high wear and tear on the plunger and tube casing, by both normal firing and dry firing. Due to repeated direct impacts on the tube (hence the loud cracking sound during firing) over time, the plunger and tube may become damaged.

Therefore, padding should be applied to the plunger to help cushion the impact.

In the following photo, i attached a cut-out piece of soft foam bumper padding to the tip of the plunger.

To test the plunger air seal, block the tube exit and try to push the plunger rod into the plunger casing, if the air seal is optimized, there should be some resistance in the plunger. It should also still be able to move smoothly when the tube exit is not blocked.

If the plunger seal is loose, simply replace the stock o-ring with a more air-tight aftermarket o-ring.

:: Voltage Increase ::

The voltage feed to the Speedswarm's motor determines its speed.

To increase the Speedswarm's Rate of Fire (RoF), simply increase the amount of voltage to its motor.

There are many different types of batteries available to create higher voltage power sources, its up to the users to determine which setups suit their usage best.

In my examples, i choose to use 14500 size Li-Ion Rechargeable Batteries (Brand: TrustFire / Unprotected versions).

Such batteries can be installed in the original Speedswarm battery sled without additional modification. I just use dummy AA battery spacers to fill the empty slots.

14500 size 3.7V TrustFire unprotected Li-Ion rechargeable batteries can be charged up to 4.2V each, so i use 4 of them (with an additional 2 dummy spacers) to get around 16.8V of power.

:: Aftermarket Spring Replacement (Optional) ::

One way to increase the speed of air delivery through the plunger tube is to replace the stock spring with a stronger aftermarket spring.

Photo Top: Stock Spring / Photo Bottom: 10kg load Spring

Note that due to the thicker spring wire of stronger aftermarket springs, the plunger rod's 4 plastic strut "fins" at the front will need to be trimmed abit narrower so that the spring can fit over the rod properly (or else the spring will end up sitting too far back).

Note that i use TrustFire 14500 unprotected Li-Ion rechargeable batteries. These unprotected Li-Ion batteries have high discharge rates which are necessary to provide the required torque to the motor to handle heavier spring loads.

Be advised that regular Alkaline batteries may not have high enough discharge rates (separate factor from voltage) to enable the motor to pull such heavier spring loads.

Due to the smaller size of the Speedswarm's motor, it generates less torque and speed compared to the larger motors found in the Swarmfire or Stampede, hence even with the voltage increase, a heavier spring tends to slow down its rate-of-fire (RoF) alot... therefore after much testing, i reverted my units back to stock spring setups as i preferred to maintain a higher RoF configuration.

:: Rotating Barrel Dart Post Removal (Optional) ::

This mod is also optional, it is mainly for users who want to be able to use solid core DIY foam darts (ie. stefans) or as a modding step before re-barrel mods.

Detach the rotating barrel from the casing.

Use a wire cutter to remove the dart posts.

Note that the dart post removal mod does not affect power or range significantly, it just allows more flexibility in the usage of various DIY foam dart designs.

:: Modified Nerf Speedswarm - Range Test Video ::

:: Sample Test Fire Data ::

PTG: Parallel-To-Ground (Shoulder height, no elevation)
ATG: Angled-To-Ground (Aimed higher, 30 degrees elevation)

Distance is measured at where the shot lands (Average of 10 shots).

Stock Speedswarm
PTG = 20 ft
ATG = 30 ft

Modded Speedswarm (AR Removal & Voltage Increase)
PTG = 50 ft
ATG = 60 ft

Note that the tests were done under controlled conditions with customized foam darts. The results are sample estimates for reference (your results may differ depending on materials and mod techniques used).

:: Summary & Game Usage ::

After using the Speedswarm in Nerf games, i've found that it is most effective when equipped as a close quarter sidearm. Thanks to its compact form factor, it can be easily holstered in a belt pouch or even in a large side pocket (can't holster a Swarmfire as easily).

For players who use long range blasters which require additional time to prime or pump up between shots, a holstered Speedswarm can be quickly drawn to counter opponents who advance too near... thats a potential lifesaver (and game changer) for many players! :)


  1. hello i was wondering how you made your stefans in the speedswarm range test video and what materials you used thanks ^_^

  2. imodify,

    The stefans that i use are made using customized silicone tips and red foam, the tips and foam are all custom made.

    You can check with hanzo at the NerfSG forum or inform3r at the OzNerf forum to get them.

  3. you measured the distance of the modded swampfire (AR removal & voltage increase) around 50 - 60 feet. Was that with aftermarket spring replacement mod too??

  4. DzPhoenix,

    That range test measurement i did was only AR removal, plunger air release seal and voltage increase, but still using the stock spring.

    With the aftermarket 10kg load spring (same ones as i use in my Swarmfire mod), the range improves further by 10-15ft, but the rate-of-fire (RoF) drops significantly to even slower than stock RoF (due to the lower torque in the smaller motor)... so i kept it at its most optimal configuration by using just the stock spring.

    I tend to prefer doing mods that improve the best aspects of a blaster (for the Speedswarm, its as a high RoF sidearm), while still retaining its overall effectiveness. :)

    Stronger springs can still be used though, just have to consider the trade-off in slower RoF.

  5. Brass it! You should punch through 70!

  6. soloz,

    Well, from my testing, the original barrel slots are already around 3" deep and fit the foam darts perfectly.

    I use 1.5" length stefans in my modded units, so the original barrel slots act as short barrels (and since the barrels and stefans don't protrude out, the Speedswarm can be holstered smoothly).

    I have sanded the slots wider and tested installing longer 6" length brass and PETG barrels on one of my units, but found that the performance didn't increase noticeably (even with stronger springs), which i guess is probably due to the smaller plunger volume to barrel length ratio.

    Adding longer barrels does make them stick out a few inches though so its more difficult to holster them properly as the extended barrels tend to snag easily.

    So overall, it seems that just using the original barrel slots is a more optimal configuration.

  7. Lanh, Duc, Joey & Sydney Nguyen-Khoa,

    At this moment, i've not spotted them in stores yet, so i've no idea of its retail price. I'll update my review once it pops up at local stores.

  8. hey sgnerf,

    Is there any NERF gun that has the systems of Fully Automatic and Manual Priming.(if possible im looking for a small gun like this speedswarm,but,the problem with it is, its just to loud when being fired).

  9. itachi1201,

    So far, the only blaster that fires in full-auto and has a manual priming handle is the Nerf Vulcan, the rest of the other full-auto blasters don't have that manual priming feature.

  10. can you replace the padding from the foam bumper that you used in the speedswarm mod,to soft rubber padding that you used in the reverse plungers mods?

  11. somebody,

    The padding i use is actually the same type of material in both blasters, they are both padding made of dense soft foam (even though it's labelled as "rubber" on the Volkmar-Fix pack, it's actually foam). :)

  12. hey sg i was wondering if the rechargeable batteries that you use can be charged with any kind of charger thanks

  13. imodify,

    The Li-Ion rechargeable batteries i use can only be recharged with specific Li-Ion chargers (have to check the battery and charger specs beforehand), you cannot use normal Ni-Mh chargers as that may result in damage or injury.

  14. What are the chances of replacing the motor with something that has a little more torque? Does it look like it might be an easy job or something that would require a lot of structural work?

    1. Anonymous,

      Replacing the motor is relatively simple, just de-solder and remove the stock motor, then re-solder and install in the new one... though that is if you can find a suitable motor of the same size, otherwise you'll need to customize further to fit it.

    2. Do you think a swarmfire motor might be able to fit in there? Or will it be too big?

    3. Kap,

      The Swarmfire motor would be too large to fit into the Speedswarm, it uses a smaller motor due to the space limitations in its more compact shell.

  15. What charger do you use for your trustfires? I'm just starting out with voltage modding for the first time and ordered some but I don't have a charger yet.

    1. Erik Hall,

      I use the TrustFire TR-001 Multifunction Li-Ion Charger (ordered from, it has dual independent charging channels and has the safety feature which monitors and automatically stops charging once the batteries are fully charged.

  16. would a maverick spring addition work at the stock voltage?

    1. plopper4568,

      Not sure if the Maverick spring can fit (it might be abit too wide for the plunger tube), but you can try and see if it works.

      Using alkaline batteries at stock voltage would probably not be able to supply enough amp current allow the motor more torque to pull heavier spring loads (its already relatively slow even with stock spring setup)... i guess you'll have to do additional voltage mods for such configurations too.

    2. Ok, I'll keep that in mind

  17. Can 14500 protected Li-ions fit in the battery compartment, or do I have to use unprotected?

    1. Anonymous,

      Its possible, though the fit might be abit tight 'cos the protected batteries are slightly longer.

  18. In your opinion do you think 21 volts too much for the motor? I'm not too impressed with the 16.8v RoF but at the same time don't want to burn out the motor too much more quickly.

    1. Karl,

      The cause of the slower RoF in the Speedswarm is because it is using a smaller motor (presumably to fit into the smaller casing form factor), which has lower torque and speed output, compared to the larger motor in a Swarmfire.

      I guess you can try higher voltages, though the motor will just have a higher chance of overheating and burning out sooner (so do be prepared for that if you do higher voltage mods).

  19. would a recon o ring work for the speedswarm ?

    1. af,

      I don't think so... they have different dimensions.

  20. is there another spring we can use? or do you know where we could buy one? this is adrianfoo from nerfsg forum :)

    1. af,

      You can use the 10kg aftermarket spring for the Swarmfire in the Speedswarm (their plunger dimensions are similar).

      But as mentioned in my mod guide, the Speedswarm's motor is smaller in size and generates less torque, so the RoF really slows down alot with aftermarket springs. :)

  21. i got the speedswarm working, its much better. I prefer distance over ROF so I think I will just use the 10kg swarmfire spring. Would the O ring and silicone plunger protector working as well?

    1. af,

      Yes, the o-ring and plunger padding can work on it too... but due to manufacturing variations, do test the original o-ring seal first. If the stock o-ring seal is already good, then there is no need to change it.

  22. Hello, SGNerf.

    I know this guide is very old, but would this also be applicable to the Powerbelle, seeing as it is a re-shell of the Speedswarm?

    1. Philip,

      I have not modded the Powerbelle, but i guess it should have a similar design as the Speedswarm.