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Lap belt attach points

PostPosted: Tue Aug 22, 2017 3:59 pm
by danerazz
I have been thinking about the fact that, in an accident, the only thing keeping you from exiting through the windshield is the aluminum tube the seat slides on because the lap belt is attached to the seat.

I have been considering attaching cables or brackets to the big cross tube behind the seats. I noticed at Oshkosh a couple guys had done just that, but in different ways.

I liked the ideas, but, like the short sighted idiot I commonly am, I did not photograph this. Does anybody have photos they would like to share on a solution to this? If you don't want to publicly, maybe PM it to me with a promise I will not share anything of yours myself.

Re: Lap belt attach points

PostPosted: Tue Aug 22, 2017 6:29 pm
by SuperFly
Dane,

I dont have access to my airplane at the moment, its at dads in the hangar. But I made loops of stainless steel cable slid through a piece of plastic tubing then crimped eyelets on each end, wrapped around fuselage frame tube, and bolted through lap belt tabs. Works good, but sorta in the way of the seats, so you have to watch when installing seats to ensure not on seat belts.

Ill try to get pics tomorrow.

Re: Lap belt attach points

PostPosted: Tue Aug 22, 2017 7:10 pm
by danerazz
Thanks! Pretty sure it was yours I saw at Oshkosh, really wish I would have taken pictures. Apparently my memory doesn't work quite as well as my camera.

Also, as I recall you had a really nice set of seat belts, where did you get them?

Re: Lap belt attach points

PostPosted: Tue Aug 22, 2017 9:55 pm
by FlyerChief
Hi Dane,
Here's a photo of the straps the factory was supplying shortly after we bought our kits. I picked up a set in 2014 from the factory, but they would be very simple to make. As SuperFly mentioned, they just fasten around the fuselage cross-braces behind the seats.
Dan
Straps.jpg

Re: Lap belt attach points

PostPosted: Wed Aug 23, 2017 7:03 am
by danerazz
I didn't know the factory was supplying them now. Really wish there was somewhere these updates were documented and organized.

Re: Lap belt attach points

PostPosted: Wed Aug 23, 2017 7:27 am
by BucF16
Hi Dane, Here is a photo pf Ben's "Belt Loop" :mrgreen:

It was good to chat with you there!

Re: Lap belt attach points

PostPosted: Wed Aug 23, 2017 7:28 am
by danerazz
Perfect, thanks!

Re: Lap belt attach points

PostPosted: Wed Aug 23, 2017 11:37 am
by Tralika
Is that 5/32" cable, same as the flight controls?

Re: Lap belt attach points

PostPosted: Wed Aug 23, 2017 8:42 pm
by SuperFly
Thanks Bruce, I didn't make it by to snap a picture today. Appreciate you posting. It is 3/16" cable. I had some 3/16 SS cable here so Iused that. Im no expert by any means, but I think the 5/32 would probably be fine as well.

Dane, The harnesses are from Crow. I really like them, but they are a bit heavier than the factory ones. But they are very comfortable with the padded shoulders.
Crow makes harnesses for about every sport imaginable (i think started in auto racing). You can specify how you want them, color, buckle style, etc. They'll build to suit.

Re: Lap belt attach points

PostPosted: Wed Aug 23, 2017 9:26 pm
by danerazz
Thanks, I thought it may have been crow.

As for the cable sizes, if you think about it, a 200# non-gender specific person at 9g is 1800lbs of force. Each half of the seatbelt carries half of that, or 900lbs. A cable loop has two ends, dividing the force at each end in half, 450lbs per eye, but the middle of the loop will bear closer to the 900lb because it is a single piece, not two separate cables at a given attach point. A 7x19 SS cable has 1760lb rating, galv is 2000lb. 3/32 7x7 is 920 lbs, so even it would be adequate. 1/8" cable is WELL suited and easy to work with. I am pretty sure the control cables are 3/32 as well, at least on my standard highlander.

Re: Lap belt attach points

PostPosted: Thu Aug 24, 2017 1:06 pm
by danerazz
danerazz wrote:A 7x19 SS cable has 1760lb rating, galv is 2000lb.


I meant a 1/8" 7x19 cable.

Re: Lap belt attach points

PostPosted: Fri Aug 25, 2017 11:11 am
by AV8R Paul
I wonder why the factory hasn't just added welded in tabs to mount the seat belt too. It would be a lot easier than making those cables.

BucF16 wrote:Hi Dane, Here is a photo pf Ben's "Belt Loop" :mrgreen:

It was good to chat with you there!

Re: Lap belt attach points

PostPosted: Fri Aug 25, 2017 11:22 am
by danerazz
That would be easier. They could do two tabs side-by-side at each point and the seatbelt would just fit between with a bolt in double shear, or just one big tab per point, either way.

Things I wish I thought of earlier. Oh well, when I build the next one...

Re: Lap belt attach points

PostPosted: Fri Aug 25, 2017 11:26 am
by Tralika
For those that have made this mod, do you experience any interference with the flap cable or pulley?

Re: Lap belt attach points

PostPosted: Fri Aug 25, 2017 9:33 pm
by SuperFly
Jon,

Yes, It can cause interference, but it seems only when folding the seats up, you have to be sure not to set seats on top of belts, especially the tails of the loose end of lap belts. It has not caused any kind of control interference, but i can see some spots on the tails that are dirty from the cables. No wear, and no drag, but has been touching. Its not a perfect answer, but I feel like it is a safer option than tying myself to the seat. I want to stay inside that welded steel cage until I decide to exit. ;)

Speaking of control interference, Has anyone else had trouble with the bolt on the flap handle that attaches the cables, and more precisely, the cotter key on said nut, catching and hanging up on the seat cushion? I have tried several different arrangements, but no avail. What I want is an acorn nut, but it has to locking some how. Any ideas anyone? (btw, this is on a SS)