MAGPUL PTS masada ACR response-enhancing custom build completed.

Continuing from the previous post about the PTS Masada custom, we'll be doing more customization.

This completes the process.

AOE adjustments

We'll now do the final adjustments to the AOE before assembling the gearbox.

First, we'll temporarily assemble the modified parts and gearbox to check the Age of Engagement (AOE).

It's not bad, but since we're at it, let's make some adjustments.

My AOE (Angle of Engine) adjustments usually involve increasing the cylinder head size, as I use cylinders with a larger air volume. The main reason is that I prioritize responsiveness and don't want to significantly increase piston weight.

Based on this, I estimated that I needed about two 1mm thick sheets of Haneite. By the way, it's easy to do by cutting the Haneite to the appropriate size, attaching it to the piston head, and then cutting off the excess. For the hole in the middle, I made a small hole with a round file and then finished it off with a rubber grinding wheel attached to a rotary tool.

It also has the effect of extending the nozzle length, so I recommend it.

I recommend using 1mm thick Hanenite because it's easy to adjust.

• Haneite rubber, 1mm thick
I always use it for adjusting AOE (Area of ​​Effect). My aim is to reduce noise by absorbing shocks, and also to improve durability.

So I watched Age of Empires again.

I could probably add one more Haneite, but if the AOE were reversed, that would have its own negative effects, so I'll leave it as is.

Fortunately, the piston rack had sufficient clearance without any additional machining. Depending on the part, the rack gear may also need to be machined.

While I'm at it, I'll also check for play in the piston and gearbox, even though it's a bit late.

It worked perfectly without any modifications. The play is about 0.1-0.2mm.

That completes the preparation.

Assembling the gearbox

Finally, we'll start assembling the gearbox.

First, I'll adjust the shims, but in the meantime, I'll break in the motor.

First, I assembled the motor into the holder, but it was wobbly, so I wrapped a lot of masking tape around it.

Next is shim adjustment. Of course, it's based on the bevel gear.

Once the shims are in place, the rest is to carefully apply the usual grease. With this grease, it seems like it wouldn't be necessary to apply different greases to the plastic and metal parts, but I'll do so anyway. I'll use Bell Hammer for metal-to-metal and GAW for metal-to-plastic and plastic-to-plastic.

Bellhammer No. 2 Gold Grease
This is a classic, top-quality grease. No. 2 has the same ingredients as No. 0 but with a higher viscosity. I primarily use it for metal-to-metal connections.

GAW G-GREASE
This is a standard grease. It has a lower viscosity compared to the Bellhammer Gold series, so I use it inside the cylinders of both electric and airsoft guns. It's a bit pricey, but the quantity is large, so in the end, it doesn't feel overpriced.

Apply it to the gearbox.

Apply it to each part.

I actually quite enjoy applying grease.

Next, we'll assemble the parts.

done.

The PTS Masada uses a QD spring and microswitch system, making assembly quite easy.

Next is the electrical system.

Electrical system creation

First, we'll make the motor wiring using 1.25 sq Teflon wire. We'll use the length of the original wiring as a reference.

The initial hole I drilled for the wiring wasn't drilled enough, so I had to disassemble it again and drill a hole all the way through. It's the area marked with a red circle.

Next, we'll assemble the MOSFET.

Then, create the battery wiring using 1.25 sq silicon wire and attach the fuse and T-type connector.

The electrical system is now complete.

By the way, I've already broken two MOSFETs so far. The first one I connected the positive and negative terminals incorrectly, and the second one I soldered all six points at once, causing it to overheat and break. Be careful.

The gearbox now looks like the picture.

I used some yellow heat shrink tubing because I had some left over, but it's visible from the outside and looks pretty tacky.

Next, we'll install the gearbox into the lower receiver.

Lower receiver assembly

I tried to install the gearbox into the lower frame here, but the wiring was too thick and I couldn't. So, I modified the wiring retainer on the gearbox.

I used some leftover yellow heat shrink tubing, but it looks incredibly tacky, and I regret it now that it's finished.

It would have been too painful to take it apart after coming this far, so I wrapped it tightly in masking tape and started working on it aggressively.

Now we can finally start assembling it.

I forgot to take a picture, but aligning the selector switch on the main unit with the selector switch on the gearbox is a bit of a hassle.

Next, fasten the fixing bolts. There are two bolts inside the magazine housing and the cover at the bottom of the grip is closed.

Now that the gearbox is secured, let's check the relative positions of the nozzle and the magazine's feeding port.

Perfect. This is an important point to check, as it may not appear perfectly in this position depending on the individual specimen.

It sounds like a quick job when you write it down, but in reality, it involved repeatedly filing down the gearbox, reassembling it, and making adjustments until the nozzle was finally positioned perfectly.

The wiring is simply too thick to fit into the wiring groove, so I've had to file down both the gearbox and receiver to adjust the position.

It was quite difficult.

Hop chamber customization

We will temporarily assemble the hop chamber.

The wires are too thick to assemble.

The wiring is too thick, preventing the chamber from being installed, so I'll have to file down the area circled in blue again. I'll be careful not to cut all the way through, as the female thread and pin hole are close together.

I managed to assemble it after many attempts and adjustments.

Next, we adjust the chamber where the hop-up bucking fits. This model has some play because the barrel is easily removable.

You can see in the photo that it's tilted.

Therefore, we will modify it so that there is no looseness when the screws are tightened. The method is to insert a plastic sheet into the gap and shave it down little by little.

Next, we'll temporarily assemble all the chambers to check their relative positions.

The center position looks good, so I'll end it here for now.

Next, we'll customize the hop packing.

First, attach the hop-up rubber. This is a unique structure specific to Masada, so it requires careful handling.

First, measure the dimensions of the original hop-up rubber.

Next, I temporarily assembled Laylax's hop-up rubbers and measured them in the same way. I believe the one on the left is hard and the one on the right is soft. There was no explanation anywhere about which was which, so I judged by how it felt when slightly compressed.

As a result, it became 0.6mm shorter.

If it's longer than the original, the hop-up packing and bucking will interfere with each other when attaching the barrel, making assembly impossible. Conversely, if it's too short, the hop-up won't work. Therefore, adjustment may be necessary depending on the situation.

This time, I'm sticking with this setup because the 0.6mm original part is prone to deformation, while the long-acting hop-up rubber doesn't deform, so I think the difference can be compensated for.

At this point, we'll assemble the bucking into the chamber and check how it works.

The hop-up rubber comes down properly, so it's OK.

Next, we are working on modifying the inner barrel.

I installed Miyagawa-san's long-range middle nitrile packing with a hardness of 60. The left is hop 0 and the right is hop MAX.

It didn't work. The hop-up setting is 0, and the protrusion is too pronounced. With this setting, even a 0.25g BB might send it straight up into the air.

This is when I decided to make my own hop packing.

That's what I call the Original G-HOP Kai.

Finally, I can assemble the inner barrel and hop-up packing into the outer barrel and finish up. The handle is attached at this point.

Apparently, some units have play in the nut area of ​​this outer barrel, so it seems to be a point that needs adjustment. Fortunately, mine had almost no play, so I'll assemble it as is.

At this point, we assemble the barrel, chamber, and upper receiver and check how the hop-up descends.

With just a little hop-up applied, this protrusion looks good. It's nice and flat. I think it's probably just right for 0.25g BBs.

Finally, I install the Airsoft97 M100 unequal pitch spring into the gearbox, applying Tokyo Marui high-viscosity grease.

Now, just assemble the remaining parts and it's finished.

Live-fire performance verification

Finally, it's time to test the actual firing performance.

The measurements will be taken under the same conditions as always, using an ET-1 7.4V REDLINE 1200mAh battery with a storage voltage of 7.65V, and Tokyo Marui Bio 0.2g BBs. Hop-up is set to 0.

It's looking good. The variation is generally within ±0.5 m/s. However, about once every 10 shots, it reaches around 95 m/s, resulting in flyers. I think this is probably because my homemade hop-up unit has deformed slightly and hasn't returned to its original shape.

Next is the cycle.

I thought this was slow. It fired 16.4 rounds per second. However, after fully charging the battery to 8.4V, it fired 22 rounds per second.

It seems the Ronex A3 motor is quite voltage-dependent. I'm glad I cut the sectors. With a 2000mAh high-C rate battery, it should reach 25 rounds per second.

Next is a video of dry firing. The battery is fully charged at 8.4V.

Semi-automatic (video, sound warning)

PTS Masada Custom Semi-automatic

Fully automatic (This is a video; please be aware of the sound)

PTS Masada Custom Full

I'm quite proud of the good response I've achieved using a 7.4V battery and a regular switch (not an electronic trigger) (the only electrical component is a MOSFET).

The fully automatic mode is neither too fast nor too slow; it's just right.

Next, I'll check and adjust the trajectory of my homemade hop-up. If the adjustment goes well, I'll be able to customize even niche manufacturers' airsoft guns, which I'm looking forward to. (Like Tanaka airsoft guns, KTW airsoft guns, etc.)

G&G Bio-Bullets 0.2g
It's inexpensive and accurate, so I use it for a wide range of purposes, from performance testing to airsoft games. It's been my favorite since it first came to Japan (around 2008). It lasts a long time for a biodegradable product.

G&G Bio-Bullets 0.25g
It's 0.25g. I generally use 0.25g BBs when playing airsoft.

The finished product

Then I added some accessories I had at home, and this is how it looks. The actual color is a bit darker than this.

I think an EOTech holographic sight would suit it better (anime-wise), but there aren't any decent replicas available, and the real thing is too expensive for me to buy, so I'll have to settle for this.

Final specifications and summary

Here's the usual introduction of the final specifications.

I had a lot of trouble with the wiring this time.

This should give it a similar specification. The cost was about 13000 yen because the motor was half price during the Rakuten Super Sale, plus my labor was priceless.

While researching prices for Ronex motors, I found some rip-off listings offering the short type for over 20,000 yen. Conversely, the medium type is cheaper, probably due to low demand. It's infuriating that there seem to be rip-off sellers for all A1, A2, A3, and A4 types. Absolutely do not buy from those sellers; if you need the short type, disassemble a medium type, cut the shaft, and use that instead. If you can't do it yourself, a shop should be able to do it for you.

There was a lot of machining and fitting involved, which was quite tiring.

The materials are good, but it took a considerable amount of effort to customize and improve them.

There were more failures than what was written; for example, some gaskets failed to provide an airtight seal, and even a slight shift in the chamber caused air leaks.

Anyway, this model requires fine-tuning.The nozzle, feeding port, hop-up bucking, hop-up packing, and inner barrel are perfectly aligned.Let's process it so that it becomes like this.

I think the motor coil of the nail art rotary tool I borrowed from my wife has burned out and its performance has deteriorated because there's too much processing space and volume.

Thank you for your time.

I put it to practical use in early May 2021, after this article was posted.

The results of that ballistic analysis are listed here, so please take a look if you're interested.