Mancraft PDiK HPA Engine Review

Here’s my review of the Mancraft PDiK HPA Engine (made in Poland). Checkout their website

UPDATE: Mancraft has updated the PDiK and has eliminated the dual air lines, which also fixed the problem with the air line pig tail pulling out of the grip.


Happy Airsofting!

– Rudy

Hopup, Buckings and Barrel Testing and Troubleshooting

I’ve posted a video that demonstrates some of the tests you should do with your hopup, bucking and barrel to troubleshoot BB feeding problems. The video shows the BB drop test, BB push through test, and how to test for air seal on the PolarStar Fusion Engine.

Happy Airsofting!

– Rudy

Here’s a follow-up video showing how to sand down bucking lips.

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

High Powered Airsoft BBs, official ammo of Bingo Airsoftworks

I’m happy to announce that High Powered Airsoft (HPA) is the official BB of Bingo Airsoftworks. HPA BBs are certified biodegradable and are top notch high precision ammo. These are premium maximum performance biodegradable BBs. HPA BBs are available in .2g, .23g, .25g, .28g, .3g (white) and .4g (tan) weights, sold in 1 kilo bags.

I will have the BBs available for sale on my website soon, or check for a dealer near you.

HPA Banner Bingo Airsoft

Viva Arms M1919 PolarStar Fusion Engine Conversion

IMG_2306The Browning M1919 is classic machine gun widely used throughout the early to mid 20th century, but it’s not so common as an airsoft gun. Although there are several airsoft models available, you don’t typically see these on the field, generally due to their size and weight. The Viva Arms M1919 is designed as an airsoft gun utilizing a V7 gearbox. McCenzie Mento sent his Viva Arms M1919 out to be converted to use a PolarStar Fusion Engine as the V7 gearbox had broken apart. Machine guns are particularly well suited for HPA conversions like the Fusion Engine since they can handle a tremendous amount of rounds with little maintenance and no worries about the gearbox or piston breaking down.

IMG_2287To fit the Fusion Engine into the M1919, a special bracket was 3D printed so it can use the same mount points as the V7 gearbox. Also the bracket was enhanced to lock the hopup in a vertical position, increasing the consistency and reliability of the gun. The hopup in the gun is proprietary to the gun. It allows the BBs to feed from the top and it uses a set screw to adjust the hopup. A custom length 42mm (overall length) Fusion Engine nozzle was needed, and the bucking was swapped out for a Maple Leaf 75 degree bucking to improve the feed and accuracy of the gun.

The existing trigger switch mechanism was used and simply wired up to the mini circuit board attached to the Fusion Engine. The FCU was mounted inside of the main body of the gun, along with the box mag motor control unit. There is also plenty of room in the gun for the battery.

IMG_2316The original box mag mechanism couldn’t provide a lot of BB feed pressure causing the BBs to be chopped in the hopup. So it was swapped out and replaced with the same MAG box mag mechanism I use in my Nerf gun conversion, and the same one used on the M2 conversion. I 3D printed a feed bed to fit the M1919 box mag and also significantly increased the capacity of the magazine.

Adding the Fusion Engine into this M1919 has brought it back to life and now it’s truly a formidable defense and support weapon. Time for McCenzie to invest in a lot of BBs!

Happy Airsofting!

– Rudy

PolarStar Fusion Engine Tips and Tricks, Nozzle Alignment, Safety Lever and Barrel Extensions

When adjusting nozzle alignment issues with a V2 PolarStar Fusion Engine, the most difficult alignment issue to solve is having the nozzle sit too high in the hopup. This isn’t a common problem, it often occurs when an upper receiver and lower receiver aren’t matched (from different manufacturers). One way to bring the nozzle down so it’s centered in the hopup is to add a small set screw to the back of the Fusion Engine. You can then adjust this screw as needed to bring the nozzle down. The set screw, when pushed out from the back of the Fusion Engine, presses up against the back of the lower receiver, forcing the nose of the Fusion Engine down. Without the set screw, in this case, the buffer tube screw will pull the Fusion Engine back, raising the nose of the Engine. The set screw prevents that from happening. Note that using a rear set screw as shown may cause misalignment in the pin hole above the trigger. In this cause simply leave the trigger body pin out. The Fusion Engine will be held in place by the grip screws and the rear buffer tube screw and the pin isn’t needed. You can see in the last picture the downward rake of the Fusion Engine and the missing trigger body pin. This was needed to get the nozzle centered since the upper receiver did not match the lower properly.

For the V2 PolarStar Fusion Engine, if you need to adjust the nozzle up in the hopup, you can help center the nozzle by adding a shim under the front cylinder, or, if possible, you can tighten the rear buffer tube screw (assuming the screw goes into the back of the Engine). Note that tightening the rear buffer tube screws puts pressure on the trigger body pin and the rear body pin, so have the pins installed before tightening the buffer tube screw, and loosen the buffer tube screw before removing them. For shimming, I use simple washers from the hardware store, but sometimes thinner shims are needed. Just about any material can be used a shim, even cut up business cards. If you would like different thickness washers, official P* shims are available from P* retailers.


Sometimes the placement of the V2 PolarStar Fusion Engine within a receiver causes the semi auto trigger pull to have a “bump” feel to it. This is due to the safety lever being partially engaged and when you pull the trigger; it hits the safety lever then pushes it out of the way. One way to fix this problem is to grind down the selector plate by about 1mm. This allows the selector plate to site a little further forward without engaging the safety lever. See the picture below to show the small cut in the selector plate. An alternative is to cut down the “D” part of the “P” safety lever to allow the selector plate to move forward more.

IMG_2237 P1060983_annotated

A small tip when having problems with shot accuracy and consistency. Always remove your barrel extension or flash hider when trying to solve shot consistency problems. You want to eliminate anything past the inner barrel as the potential cause for the problems. Check the extension or flash hider for any white marks, which would indicate the BBs are hitting it on the way out. The pictures below show where the BBs were hitting the end cap on this extension. There wasn’t any play with the inner barrel, so the end cap was drilled out to make the hole bigger so the BBs wouldn’t hit it.


PolarStar Fusion Engine Parts Identified

Here are some pictures that identify the various parts of the PolarStar gen3 V2 Fusion Engine. I hope this is helpful in creating a common “vocabulary” when discussing various parts of the Fusion Engine.

Happy Airsofting!

– Rudy

M2 Machine Gun PolarStar Fusion Engine Conversion

IMG_2201The The M2 Machine Gun or Browning .50 Caliber Machine Gun is very large machine gun, and it’s extremely rare to see one as an airsoft gun. Tom DiQuattro wanted to have his M2 replica converted to a PolarStar Fusion Engine gun so he sent it out to see what could be done.

The M2 replica is massive. It’s almost 6′ long, and it weighs in at 36 lbs without the box mag. It was decided that real .50 cal ammo can would be used as the box mag for the gun, and with the box mag fully loaded, the weight of the gun tops 50 lbs!

IMG_2202The replica was made with a solid aluminum barrel. It was not bored out. I attempted several tries to bore the barrel using extra long drill bits, but I just managed to mangle up the barrel (lesson learned!), so I had to ship the barrel back to Tom where he had a friend with the right equipment properly bore out the barrel. The barrel is connected to the main body of the gun by large threads. This required that the hopup be able to fit through the front of the gun, so it can be inserted with the outer barrel, since a long 650mm inner barrel would be used with the gun.

IMG_2177A G&G/CA M14 hopup was used since it had a narrow profile and could fit through the front of the gun. To hold the hopup in place, and to provide a way for a BB feed tube to attach to the hopup. a 3D printed hopup block was created. The hopup block sandwiches the hopup and locks it in place, and also supports the front of the Fusion Engine. The rear of the Fusion Engine was held in place by another 3D printed bracket, which also supported the mini circuit board and MCU box mag circuit (which links the box mag to the trigger on the FCU).

The bottom of the gun was uncovered, so another 3D printed piece was created to close up the bottom of the receiver.

IMG_2168The trigger lever on the replica was simply a metal piece held in place with a pin, pushing against a spring. To have it work with the Fusion Engine, a hard stop was added to prevent the switch from hitting the buffer tube, and a micro switch was added so it would be activated when the trigger lever was pressed.

The .50 cal ammo can was modified to hold a MAG brand box mag. A large 3D printed feed bed was used to hold the box mag mechanism in place as well as feed the BBs down into the box mag. It has a giant capacity of about 19,000 bbs!

IMG_2173The M2 Fusion Engine conversion was a bit of a challenge (especially that solid barrel), but with the extensive use of 3D printed parts (the Makerbox Replicator 2X 3D printer has been a fantastic investment), it was able to be assembled in a very user friendly and maintainable way.

When hooked up to a large air source, high BB capacity, the M2 Fusion Engine gun will provide game changing firepower to any airsoft skirmish!

Happy Airsofting!

– Rudy

Here’s are some videos of the M2 assembly and disassembly procedure:

Here’s a sustained fire test video:

(more videos coming soon)

How To Update The PolarStar Fusion Engine Firmware

I offer a service to upgrade the PolarStar Fusion Engine Firmware, but for those that would like to upgrade the FCU firmware themselves, here are the instructions on how to do it. Please note that PolarStar Airsoft nor Bingo Airsoftworks can be held liable if you damage or destroy your FCU by attempting to update the firmware. Please proceed at your own risk.

To update the FCU firmware, you’ll need the following:

  1. IMG_2215Purchase/acquire the AVRISP mkII programmer and download and install the Atmel Studio 6 software
  2. Plug the programmer into a USB port on your computer. The light on the programmer should be red.
  3. IMG_2213Carefully remove the heat shrink covering from the FCU. It’s easiest to cut on the edge of the circuit board with a razor blade.
  4. Insert the 6 pin connection header into the connector on the programmer.
  5. IMG_2216Attach the programmer to the FCU and hold in place using a clip or rubber bands. Make sure the red line on the data cable lines up with pin 1 on the FCU circuit board programming jumper pad (pin 1 has square solder trace)
  6. IMG_2217Attach a fresh battery to the FCU. The light on the programmer should turn green.
  7. fcu_firmware1Launch the Atmel Studio 6 software and access the Tools | Device Programming menu.
  8. Make sure the Tool drop down reads “AVRISP mkII”. Make sure the Device drop down reads “ATmega169A”. The Interface field should be “ISP”. Then click Apply.
  9. Click on Device Signature Read button, and a device signature and Target Voltage should be displayed.
  10. fcu_firmware2Click on Memories option in the left column.
  11. Backup the existing firmware by clicking on the “Read…” button. Enter a file name and accept. The programmer will read the current firmware and save as the file specified.
  12. In the Flash (16KB) field, enter or navigate to the path of the new firmware .hex file from PolarStar Airsoft.
  13. Make sure “Erase device before programming” and “Verify Flash after programming” are checked.
  14. Click on the Program button to program the FCU. The light on the AVRISP mkII programmer should turn orange while programming.
  15. Disconnect the battery from the FCU, disconnect the FCU from the programmer.
  16. Important: Reset the FCU (hold the settings button down while plugging in the battery) and then verify that the firmware revision is correct (most current is re22)
  17. IMG_2211Reapply heat shrink to FCU. Punch a hole in the heat shrink for the select switch before heating and shrinking.

Happy Airsofting!

– Rudy

Wolverine Airsoft SMP HPA Engine pre-order available

Wolverine Airsoft SMPI am now accepting pre-orders for the Wolverine Airsoft SMP HPA engine. The SMP is a high performance HPA system that uses one moving part, one solenoid valve, and can be dropped into virtually any airsoft gun platform on the market. Checkout for more details.
The Wolverine Airsoft SMP sells for $390 (free shipping US). You can pre-order a V2 or V3 SMP for a deposit of $100 (only a limited number of pre-order units are available). It is anticipated that the SMP will be available in early July.
Contact Me if you would like to pre-order a Wolverine Airsoft SMP engine.

PolarStar Fusion Engine FCU Firmware Upgrade Service

FCU with re22 FirmwareI’m now offering a service to upgrade your rev2 FCU firmware to the latest revision (re22). The new FCU firmware adds anti-stiction mode with automatic varying poppet dwell. This feature will automatically add a few extra ms to the poppet dwell if the gun has been idle for a period of time to help eliminate “dead-shots”, where the poppet fails to open on the initial trigger pull due to o-ring static cohesion.

I charge $18 to upgrade your FCU firmware to the latest version re22 (covers return shipping for US locations, international is +$8). The upgrade includes removing the existing heat shrink, uploading new firmware, and reapplying new heat shrink covering. Note that updating the firmware will also reset the FCU shot counter to zero. Only available for rev2 FCUs (gen2 and gen3 V2; V3; M249 and M240B Fusion Engines).

You would send out your FCU, and it will be sent back within 2 business days. I guarantee that your FCU will will be sent back in good working order, and you will not have to worry about your FCU being damaged or “bricked” due to the firmware upgrade.

G&G GK5C PolarStar Fusion Engine Conversion

IMG_2126The G&G GK5C airsoft gun is very unique and rarely seen on the field. It is the airsoft version of the Swedish AK5C, which is an evolved version of the FN FNC.

The GK5C uses a V2 gearbox, but it has a few external modifications to support the unique dual selector plate implementation for the ambidextrous fire select levers. It also uses a rear gearbox pin that has been moved to a custom location, so an additional pin through hole is added to the GK5C gearbox.

IMG_2119Converting the GK5C to use the PolarStar Fusion Engine required a few extra modifications to support the ambi fire select levers. Part of the top selector plate guide rail on the left side of the Fusion Engine had to be milled away to make clearance for the selector plate.IMG_2121 On the right side, custom mount holes were added and the right selector plate was modified to use the new mount points.

IMG_2124The rear body pin is in a custom location, and unfortunately, this location is right where the Fusion Engine solenoids are located. So the rear body pin was omitted. Instead the holes were covered with self adhesive foam pieces. The lower receiver is molded in such a way that it holds the Fusion Engine very securely using the grip screws and the rear stock bolt, so the rear pin wasn’t really needed anyway.

The GK5C uses a split hopup like the KWA and JG guns (unfortunately) and it requires a custom length nozzle. Quite a bit of chamfering was needed on the hopup BB feed tube and upper section to make sure there was a clear pathway for the BBs to feed.

IMG_2112The gun has an interesting design that allows the front hand guard to be opened by pushing a lever on the right side. The FCU and battery can be located in this space, though it’s a relatively tight fit with the outer barrel and dummy gas tube.

Overall, though, the Fusion Engine works well in the GK5C, and with a bit of customization, the ambidextrous selector functionality can be maintained. With the PolarStar Fusion Engine, the GK5C gun can turn into a top performer on the field and set itself apart even further in a world crowded with a ARs and AKs.

Happy Airsofting!

– Rudy

New custom conversion scheduling system

I’ve changed the way I’m handling custom conversion work. I’ll now be using a reservation system. I have a list of available conversion dates available on my website (See available dates here). If you’d like to have custom work done, contact me here or through email to sales -at- bingoairsoftworks -dot- com. We’ll discuss what needs to be done and I’ll quote the cost and generate a paypal invoice for the work. Then a deposit of 50% or $100 (whichever is less) is required to reserve an available conversion date. You would then send out your gun so it would arrive on or before the reserved date. I’ll do the conversion, test and tuning, and send the gun back, generally within a week.

This will allow me to better control my workload and also offer much more predictability on when you will get your gun back.


– Rudy

Guitar PolarStar Fusion Engine Conversion

photo 1 Here’s my latest PolarStar Fusion Engine conversion. A truly unique airsoft gun. For those that are Guitar Hero fans, now you can show your strumming skills on the Airsoft Field.

photo 3The guitar has been specially modified so it uses the strum bar as the trigger, so you can do extremely fast semi-auto fire by strumming up and down. The whammy bar is used to enable full auto mode. It has an integrated box mag with a capacity of 5000 rounds (there’s a lot of space in the guitar body!)

Future upgrades will allow multiple fire modes by using the keys on the guitar neck, including multiple burst modes.

photo 2It comes with a built in sling as a bonus. So next time you are on the field and someone is rocking out, they just might be the most dominant head-banger on the field with a PolarStar Fusion Engine powered guitar!

Happy April Airsofting!

– Rudy

(I hope you have enjoyed this April Fools post…but watch this space…flights of fancy may yet turn into reality!)

Echo1 AR-57 PolarStar Fusion Engine Conversion

IMG_1827The Echo1 AR-57 is a unique gun that uses P90 magazines on a AR platform. To accomplish this, a proprietary hopup is used with the gun that requires an extremely long nozzle. The nozzle is one of the longest I’ve seen on a gun, beat only by the nozzle on the Sig556. To have the Fusion Engine work within this gun a custom hybrid nozzle had to be made extending a SCAR H nozzle with an AEG nozzle.

The mag well on the Echo1 AR-57 is not used, but it works well as a location for the FCU and the battery when stored in a dummy magazine.

IMG_1825The basic install is the same as any standard AR gun, except for the nozzle and changing the wiring to go forward so it can go into the mag well.

IMG_1826Look for this unique Fusion Engine gun at an airsoft field near you! (Ok, maybe if you know Brian in Vermont) 🙂

Happy Airsofting!

– Rudy

Keyword: ar57

Maintaining the MP7 Fusion Engine Conversion

Additional updates have been made to the MP7 Fusion Engine conversion. The enhanced design allows the Fusion Engine to be extracted from the MP7 without requiring the gun to be taken apart.

The upper solenoid cradle has been redesigned to allow the fire select switch to be mounted on the cradle, and the trigger switch implementation has been changed so it now uses the standard trigger/battery contacts on the top of the switch assembly. Additionally the solenoid air supply fittings have been changed so the stock Fusion Engine fittings can be used, which allows more air to flow to the solenoids, especially the poppet solenoid, so the poppet triggering can be more reliable.

My friends at Amped Airsoft were nice enough to make a video showing how to extract the Fusion Engine from the MP7. Check it out below.

Happy Airsofting!

– Rudy

Updated video on maintaining the Fusion Engine MP7