HALO Assault Rifle Polarstar JACK Conversion

Here’s a HALO Assault Rifle converted to HPA with the Polarstar JACK engine, for Cameron Jones.

A few key points on the conversion:

  • It uses a standard M4 nozzle but the hopup is an AK style hopup.
  • A slide switch was added to provide semi-auto capability
  • The barrel is really short, to accommodate room the IR BB counter sensor
  • It is a bit of a challenge to access the internals (hopup, barrel, engine, etc). Plan to be very patient if you need to do any maintenance on this gun 🙂
  • The weight of this gun is surprising, it’s relatively heavy…but I guess I’m used to using only 5 lb airsoft guns 🙂
  • It looks really cool and is very rare! (I don’t believe you can purchase this airsoft gun in the US)

(I’ll update this post with more comments and information when I have time)

Happy Airsofting!
– Rudy

VFC MP5 Fusion Engine Conversion

IMG_0720Here are some pictures of a Polarstar Fusion Engine installed into a VFC MP5. This version of the MP5 has the extra 3 round burst mode, but since the FE doesn’t currently support the extra fire mode, the conversion locks out the extra fire select position.

The main issues that have to be addressed are the selector plate, the trigger and the routing of the wire harness to the front. The selector plate is slotted so the cog on the fire select switch can move the plate back and forth. The fire select cog is rotated 180 degrees so it is now at the top to reach the plate. There are two screws added to the body which prevent the fire select switch from over rotating in either direction.

The trigger needs to be moved from the stock gearbox to the Fusion Engine. Unfortunately the tail on the trigger doesn’t reach the hard stop in the FE lower assembly, so a screw was added to fill the gap. It is important that the trigger have a hard stop to prevent over travel from the trigger lever which can damage the Fusion Engine trigger microswitch.

The last issue is running the wire harness to the fore grip area (if you choose to put the FCU and battery in the front). There is very little room in the gun for the wiring, so the hopup block needs to be removed and milled/dremeled out to make clearance for the wire harness connector to pass through.

The Fusion Engine nozzle length (measured at 42.25mm) is basically the same as the M249 nozzle, but the M249 nozzle doesn’t have a chamfered nose, so a custom nozzle is needed, or the M249 nozzle can be modified to work. It’s may also work with an AK nozzle, which might be a tiny bit too long, so it may need to be cut down a little.

Happy Airsofting!

– Rudy

Nerf Rhino-Fire Dual Wolverine Airsoft SMP Conversion

49-IMG_3220Nerf just released a new tripod mounted fully automatic Nerf gun with dual reciprocating barrels called the Nerf N-Strike Elite Rhino-Fire Blaster. With the modifications that I made to the Nerf Vulcan Xtreme, the Rhino-Fire seemed to be an ideal candidate for conversion to an HPA airsoft gun. Since I’ve done a dual PolarStar Fusion Engine Nerf gun already, I decided to give the Rhino a try using Wolverine Airsoft SMP HPA engines.

12-IMG_2934The Rhino uses motorized flywheels to shoot the Nerf darts, so the firing mechanism was relatively simple which left a lot of extra room for Nerf to add a mechanism to reciprocate the barrels, which ended up taking the majority of the space withing the Nerf gun housing. The Wolverine SMP is a very small HPA engine designed to fit within a gearbox shell, so it turned out they were the perfect size to fit within the Rhino.

28-IMG_3188I utilized some of the same techniques from recent a M2 and FN 30 builds and created 3D printed blocks to support the engines and integrate a custom hopup. An adjustment screw was added to the back of the support blocks, between both of them, to allow the cross angle of the engines to be adjusted.

38-IMG_3203The stock trigger switch was removed and replaced with several leaf microswitches. Once switch turned on the box mags and reciprocating barrels, and one trigger switch for each SMP. The stock trigger was a multi stage sliding switch and it just didn’t work reliably as a trigger switch. I used my SMP mini circuit boards to link the trigger and full auto switches to the SMP wire harness. Two SP3T slide switches were added so allow each SMP engine to be in safe, semi, or full auto mode. To make this work I modified the mini circuit boards and added a diode to allow the slide switches to handle all three modes using 3 wires. smp_selector_circuit

The two drum mags were modified to use a MAG brand box mag BB feed mechanism. 3D printed parts were used to create a mount for the feed mechanism as well as make a cover plate and fill port. Each drum mag will hold about 4000 bbs and the MAG feed mechanism can easily reach 40 rps, especially if 11.1v lipos are used.

The Wolverine SMP powered Nerf Rhino-Fire is a very fun but frightening airsoft gun. The larger hollow out barrels of the Nerf gun amplify the sound of each shot making this HPA airsoft gun one of the loudest I’ve used. Combined with the relatively high rate of fire delivered by the SMP, the cacophony behind the two laser streams of BBs, anyone trying to oppose the Rhino dual SMP would certainly know trouble was heading their way!

Happy Airsofting!

– Rudy


Here are some images of the stock Nerf Rhino internals and externals, for reference.

MP40 PolarStar Fusion Engine Conversion

IMG_3141The MP40 is another iconic WWII gun, and I finally had an opportunity to convert it to use the PolarStar Fusion Engine thanks to Steve Nagy, who sent his out to get the full HPA upgrade.

The MP40 airsoft gun uses a very unique gearbox design. To have the Fusion Engine fit in the gun, the existing gearbox shell was cut and milled to house the V2 Fusion Engine upper cylinder. The stock trigger switch was removed and replaced with a microswitch so there would be room for the valve air lines. The fire select was also handled by adding a microswitch which is activated by the full auto selector plate lever.

The design of the MP40 allows for room behind the gearbox to house the battery, which provided plenty of room for the FCU and a small lipo. A mini circuit board was used to link all the switches to the wire harness, and a custom length nozzle was needed since the engine was installed set back from the front of the gearbox face.

The MP40 also has an interesting magazine and hopup setup, so a bit of work was done to get those parts to line up properly, but now that it’s powered by the PolarStar Fusion Engine, it brings the reliability of HPA powered gun to this WWII classic.

Happy Airsofting!
– Rudy

Matrix MG42 PolarStar Fusion Engine conversion

I’ve previously converted a Shoei MG42 to use a PolarStar Fusion Engine, but the Matrix MG42 uses a different gearbox shell with allowed most of the FE to be installed within the gearbox. The Matrix MG42 also has a microswitch installed above the trigger to allow the box mag to be activated when the trigger is pulled, so a separate MCU circuit isn’t required.

This conversion, for Justin DeLance, also included an update/repair of the drum mag. The internals of the drum mag were replaced with a MAG brand box mag mechanism. Custom 3D printed parts were used to mount both the solenoids and the box mag motor.

Happy Airsofting!

– Rudy

Magpul PTS Masada Wolverine Airsoft SMP Conversion

Here are few pictures of a Wolverine SMP installed into the Magpul PTS Masada. Since the SMP is a cylinder replacement HPA engine, it installs easier into the PTS Masada than the PolarStar Fusion Engine, as the PTS Masada uses a non-standard V2 gearbox.

The PTS Masada doesn’t use a standard trigger board or fire select mechanism, so the trigger board that comes with the SMP can’t be used. The trigger has to be hooked directly SMP wire harness, and a extra microswitch is needed for the fire select.

A PTS Masada specific nozzle is needed, which is available from Wolverine Airsoft.

This PTS Masada conversion was for Carey Frennier who provided his limited edition blue-colored SMP. A Redlineairsoft grip connect was also installed for this conversion. The gearbox shell was also cut to make it easier to access the SMP for maintenance.

Happy Airsofting!

– Rudy


HPA Engine Reviews

I’ve posted a video review of the 3 major airsoft HPA engines available on the market: PolarStar Fusion Engine, Wolverine SMP, and Valken V12. (I’ll update this post with all 3 parts when they are available).

Here’s part 1 – Intro and PolarStar Fusion Engine:

Here’s part 2 – Wolverine SMP:

Here’s part 3 – Valken V12

KWA mk1 1911 Gas Mag HPA conversion

Just a quick post on a KWA mk1 1911 gas mag HPA conversion. Max Hereen sent out his KWA 1911 to have it converted to use an HPA tank. Unfortunately the 1911 gas mags are very thin and the standard 1/8 NPT quick disconnect plug wouldn’t fit, but using a 1/16 NPT to 1/8 NPT adapter allowed it to be attached to the bottom of the mag.

Firing the pistol powered by HPA is a real blast. Consistent firing for all the rounds in the magazine and minimal impact due to the temperature really makes a case for having a dual regulator and air rig setup and have an HPA side arm along with your Fusion Engine powered primary!

Happy Airsofting,

– Rudy

HPA gas mags

Example of other gas mags converted to use HPA