Aero-Tuff Seatbelts

[22LD]

Thanks, Jim. I'll definitely look into that. I didn't plan on inertia reels for the back, so that should work just fine.

[Rollie]

I had a couple ideas about that, one was to use 5/16 steel cable with vinyl tubing on it, to protect the tubing, and wrap it around the tubing and attach the shoulder harness to that. That would have been easy, but I didn't think I would like how it looked so instead I took a couple pieces of 1/8 thick 4130 and heated them and bent them around a piece of tubing and drilled them for the harness. I out a long notch in the middle of each so they would sit one on each side of the small tube that goes up to the stringer and could swivel. If that makes any sense. I had planned to do something like that when I did the fabric interior so I had put a fabric tape in the right place with a slot cut out so its a fairly neat install. as opposed to just cutting a hole in the fabric. I'll see if I can remember to take a couple pics today, thats probably better than trying to describe it.

[Rollie]

This is how I mounted my rear seat shoulder harness. It isn't painted yet, nor is the rear bulkhead so its not all that pretty, but I think it will be functional. Its pretty well hidden so it wasn't easy to get very good pics.

[Bcone1381]

The Details of proper seatbelt installation interests me.

Today for some reason I sought out design aspects of a properly engineered system. Simple design aspects that we don't realize until they are needed are abundant and amazing. I learned about the importance that the lap belt hit the pelvic bone, and how to accomplish that. Only then we can properly position the anchor points of the lap belt. When I was studying this, I thought about this thread.Specifically Rollie shoulder Harness attach point. Rollie hit the bullseye without pulling out the torch.

If you have not given your restraint system much thought, then please refer to this free online book called Construction of Tubular Steel Fuselages.

http://www.raptorairworks.com/documents/134-construction-of-tubular-steel-fuselages-v2.pdf

You have to dig down to chapter 10 on page 127. There are Great diagrams of forces are applied to a body during accidents, Lap Belt Geometry, Hardware design and selection, Attach point design and selection, They should include Rollies restraint design for the shoulder harness. I copied his photos and pasted them into the "Seat Belt" section of my build manual that I am developing for myself.

Brooks Cone
Patrol #303

[alaskabearhawk]

If you haven't already, check out AC21-34. A majority of information in the book came from there. You can also check out my kitlog on the subject. This is number three out of five: http://www.mykitlog.com/users/displa...g=205221&row=4

[rodsmith]

I am using y style shoulder harnesses front and back. I was going to mount my rear shoulder harnesses to the 5/8th x .035 tubing at station F like Rollie did. It occured to me that I could just wrap the strap around the tubing and save the weight of an attach point. I question the strength of that size tubing. Would like thoughts as to whether it needs some reinforcement, I could split a short piece of thicker tube and weld it around the 5/8th and or add a short diagonal from the attach point back to the longeron.

[S Lathrop]

Here is what I did for the shoulder harness mount. I am using a Hooker system with an inertia real.

[rodsmith]

I did something very similar for the front shoulder harness mounts, it is the mounts for the rear harnesses I am concerned with now.