BLH-06 Zephyr - HPA Dart Blaster

BLH-06 Zephyr

This blaster was designed after much frustration in the search for a better HPA blaster. I built an HPA semi auto longshot years ago and while it worked, it had a lot of problems. Extremely inconsistent shot-per-shot performance, frequent jams, and worst of all extremely poor air efficiency, resulting in running out of air in the middle of games. Originally, I wanted to acquire a supercore to run something more efficient, but at the time they were not being manufactured at all. I was stuck at a dead end.

I kept waiting and waiting and eventually I acquired a cosmic nomad by roboman automations. Eventually. I had to wait over a month for the item to ship, and when I checked to see if a second one could be acquired for other builds, they were out of stock and replaced by a pre-order for the next eventually batch. While I eventually converted the nomad I bought into a cool HPA blaster this one requires a battery for operation and was far from the original vision I had when I built my longshot years ago. I wanted something battery-less, literally "plug and play", that would last multiple games without needing to refill my tank, and would get 250 fps and consistent shots.

Now, BLH-06 "Zephyr" exists. It fulfills all of my requirements and so much more. It runs great and delivers incredible performance, and most importantly of all you can source every single piece of hardware from online sources that almost always have the parts in stock.

Theory of Operation

All pneumatic components are connected to each other with pneumatic rated tubing and fittings, except past the QEV exhaust port, where air is no longer contained in a pressurized sealed environment.

Airflow travel path:

1. Tank

2. Regulator

3. Quick Disconnect

4. Release Valve (trigger)

5. QEV

6. Air Cylinder/Piston, which acts as the Tank

   1. Release valve not actuated: normally open air flow path to air cylinder

   2. Release valve actuated: Air in line between release valve and QEV drops in pressure, QEV activates, air flow path goes from air cylinder to exhaust of QEV, which is connected to the pusher and barrel.

The barrel and pusher do not store pressurized air, and thus are not pressure vessels.

DISCLAIMER AND WARNING

THIS BLASTER IS NOT MEANT FOR NOVICE USERS

Multiple parts inside of the blaster are pressurized with air. While there are no 3d printed parts or in fact any parts not rated for pneumatic pressures that contain pressurized air in this blaster, this is still much more complicated and dangerous than a springer or a brushed flywheeler. Please approach this build with caution.

Do not attempt to service this blaster while there is a source of pressurized air connected to the internals. Do not stick your finger inside of the magwell, or near the pusher with the top cover removed, while a source of air is connected. Failure to do so can result in broken fingers. You have been warned.

With that out of the way:

BOM:

https://docs.google.com/spreadsheets/d/1jpqziYdDEyQXDnSZzJXsZDmh9qoF_qcQz2RRGpVRRO8/edit?usp=sharing

If you do not want to modify the step files I recommend you follow the BOM as closely as possible and order the exact models for the QEV/Exhaust Valve, 3 way Normally Open control valve, and Air Cylinder.

Build Guide:

https://docs.google.com/presentation/d/1wECtLvepbSRSZ6SPcem0RRZjV-3-HJ79EOBeipKIHc4/edit?usp=sharing

If you have any questions feel free to ask in the comments. I will try to answer them as best as I can.

Recorded FPS Numbers

1-1/16" Bore Cylinder - 1.2g Bamboo Darts

60cm length 13mm ID Kuryaka Barrel

• @60 PSI - 190-210 FPS

• @80 PSI - 242-257 FPS

60cm length .495" ID Barrel

• @80 psi - 220 FPS (average)

• @100 psi - 260 FPS (average)

50cm length .495" ID Barrel

• @80 psi - 265-283 FPS

• @100 psi - 284-305 FPS

35cm length 12.75mm ID OoD Tightbore Barrel

• @80 psi - 217-221 FPS

3/4" Bore Cylinder - 1.2g Bamboo Darts

60cm length 13mm ID Kuryaka Barrel

• @100 psi - 225 fps (average)

50cm length .495" ID Barrel

• @100 PSI - 230 fps (average)

50cm length 12.75mm ID OoD Tightbore Barrel

• @80 psi - 220 FPS (average)

• @100 psi - 235 FPS (average)

40cm length 12.75mm ID OoD Tightbore Barrel

• @80 psi - 210 fps (average)

• @100 psi - 225 fps (average)

3/4" Bore Cylinder - 1.0g Worker Darts

40cm length 12.75mm ID OoD Tightbore Barrel

• @100 psi - 248-262 FPS

• @80 psi - 240 FPS (average)

FAQ

• Is this High Pressure Air powered blaster safe for use?

All components that hold air are rated for pneumatic use. The maximum pressure that can be run in this system I can safely say is 150 psi.

• What are those alternate files?

"1-1-16 Bore Cylinder" are alternate files designed for namely a cylinder with 1-1/16" bore. This cylinder is much too big, and is incredibly inefficient. (approx. 58cc of air internal volume, vs 3/4" bore approx. 28cc of air internal volume) The performance gained for the air spent is not worth it but it will let you hit over 300 FPS at 100 psi.

"10-32 Body Rods" replaces the rods used to hold the body, normally 6-32 threaded rod, with 10-32 threaded rod. Much stronger but I did not find this necessary. However, 10-32 rods are much more common in the nerf scene.

"PVC Stock" are the files used for the stock that you see in the photos of the example blaster. This stock requires glue and there are plenty of picatinny rail stocks to choose from nowadays, so I have made it optional instead.

• This list of parts is long and expensive, is there a DIY kit that has everything to make it simpler and cheaper?

If enough people ask for kits, I will try and organize a group buy. I do not expect enough people to be interested to warrant such a process though. Due to the cost of the larger pneumatic components though the price per kit would still be nearly the same as a self source price.

• Why are there so many heat sets?

I like heat sets. And the ability to tear down a blaster without worrying about stripping plastic.

• My printer doesn't fit the parts, can you cut them up and make them smaller?

My print bed is 256x256 and this size is required to print all pieces. A significant redesign of parts would be required to make the larger pieces fit on a smaller print bed, for the moment I do not see enough traction and popularity of this blaster to do so.

• Why are my FPS numbers worse than your recorded numbers?

Check all seals and ensure that you do not have a leak in any part. If you redesigned the internal parts to fit your own pneumatic pieces make sure you are not blocking any intake or exhaust ports. Check that your pusher is sealing inside of the barrel, that your barrel is seated all the way down inside of the blaster, and that your pusher is sealing inside of the "core" print with plenty of grease for smooth operation.

Credits

Red Cowl - Picatinny rails and collet design

Change Log

v1.01 - updated "Body Middle" for 6-32 and 10-32 threaded rod filesets as well as the master fileset.