The 156 MPH ARX 4S Race Frame

This is the launch frame that has been under development for quite a while and will continue to be developed. There were many goals and challenges to get to this point and is a culmination of things learned over many frame projects. It’s not exactly conventional, but performance is far beyond what I expected. The arms are an evolution of the XLR-1 DNA: a patent pending design that has been refined and enables the arms of the frame to be as thin as possible while maintaining a very rigid structure along all directions.

Features:

• Based off the 202mph XLR-1 frame project - Guinness record filed, methods approved, but has up to another 12 weeks of review time (long review for non-expedited applications)
• With 2600kv and APC 5150 props, and 4s lipo, capable of:
  Average speeds of 147.6mph (237.5kmh) and maximum speeds up to 156.6mph (252kmh)
• With 2600kv and APC 5150 props, and 5s lipo, capable of:
  Average speeds of 163.4mph (263kmh) and maximum speeds up to 170.9mph (275kmh)
  
• Taking lightweight seriously: 45g including all hardware and o-ring battery straps
• SCT - Shape-Changer Technology Frame: Just one configuration gets boring? The ARX frame is fully customizable:
  -Convert from true-x to stretched configuration in under 1 minute
  -Convert btw. 5” and 6″ frame size with optional interchangeable 6″ arms (available soon)
  -Assemble the frame in an inverted layout (build example is in the works)
• Plenty of room between the center arm plates for a 20×20 FC or 20×20 4in1 ESC
• The stack has virtually unlimited room since it attaches to the bottom which also makes working on the stack easy
• If electronics are mounted between the arm plates, windows are provided for USB/wiring access
• Accomodates 4S LiPos (and some 5S, e.g. Tattu 1300 75C 5S)
• Designed for 20mm wide FPV mini cameras, spacers can be used to accommodate more sizes
• A Runcam Split will fit on the ARX using the long camera cable.
• A Runcam Mini Split can be fitted by using a Runcam extension for the mini (not included and thanks to Jace for this info!).
• 16 x 16 motor mount pattern – 19mm pattern with special motor plates on request/available soon
• 2 large o-rings used as straps to hold in the battery and to hold the FPV camera mount securely in place and provide flexibility / dampening in case of crashing
• Protective braided mesh tubing to protect FPV camera wires included
• All blue anodized aluminum hardware included

Assembly/Repair

It is actually simple to assemble and doesn’t take any longer than any other frame. It is also very easy to repair and to work on. A nice side feature (unlikely to be used) is if all electronics are contained on the stack (no electronics placed between the arm plates), a build can be stripped of its electronics in about 5 minutes without unplugging/unsoldering. The “guts” can then be put on a different frame in about 5 minutes.
Surprisingly, I have not crashed this frame very much: I had 2 crashes where I slammed into a pine tree going 60mph and 90mph. After regaining orientation, it was still flying in both instances. If an arm does break, they don't take any longer to repair than any other frame - no tear down, unwiring, or teardown required. The 4 stack screw are loosened (to be able to "drop" the stack for arm clearance) and the motor screw coressponding to the broken arm piece is removed. The broken arm is pulled out, and the new arm "hooked" in.

LOS Test

Professional LOS test by ZombieSS77. His impression:

"The short description is, this frame performs on 4S the way most perform on 6S, it's a monster."

Thank God for Kabab

Professional FPV flying/input from KababFPV who flew a prototype frame – It is a bit different from the ARX, but the same arm style, same balance, and same material thickness so it was a good test of its handling capabilities:

Top Fuel Drag Quad

At first, this frame was fast, but nothing all that great. Then I put on some APC 5045 bullnose and 5150 props (both had nearly identical results):

• 4S: 147.6mph (237.5kmh) average and maximum of 156.6mph (252kmh)
• 5S: 163.4mph (263kmh) average and maximum of 170.9mph (275kmh)
  Yes, I forgot to remove the XLR-1 name off of the flight controller OSD...
  

  The Flying Bottle

  How About Your Own Speed Project? A printed 3D shell or fairing over the body would probably make this thing ballistic and things are in the works to maybe sell a shell for this frame. But in the meantime, this thing is a rocket as is or it is a perfect underlying structure for your own specialized project. Heck, I have one buyer that is putting a coke bottle over it, simple as that.

The (Very Near) Future

More frames and upgrades are in the works:

• 6" arms
• Inverted ultralight 30g 5" frame (pending tests)
• Inverted 6S race frame
• Freestyle frame