Steering line keeper ring standard spec?

[councilman24 36]

Okay, I should know this. I should have it in my archives. But can't find it.

And it shames me to post it here instead of on my PIA Rigger Forum but I'll get a faster answer here.

I'm changing a couple of rigs from 1" keeper rings and 1" wide toggles to modern small rings and folded type 4 toggles. Many of you aren't old enough to have seen this version of the system. The ring is supposed to be 4" from the end of the riser.

But measured HOW?

I found in the old Paraflite manuals the 4" spec that became standard and a drawing but it did not say OR show how to measure it. So I go to measure some risers and find significant differences. Most measure 4" from ring attachment webbing to end of riser, but at least one set measures 4" from closest side of ring to end of riser. And another is in betweeen (probably wrong).

I think it's from the webbing but want to check.

No I can't call the manufacturer. The rig is no longer made and the company has moved on. But this is an industry standard measurement. I thought it was in a PIA technical standard but haven't found it there.

Someone from a gear manufacturer, how is it supposed to be measured?

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[JerryBaumchen 1,072]

Hi Terry,

My 2 cents: from the top of the riser to the top edge of the ring.

Jerry

[councilman24 36]

Thanks,

Sparky found it in PIA TS 100. I knew it was there somewhere but I missed it.

It is 4" from top of ring to end of riser.

And most of the risers I've measured tonight are wrong! A couple of Vector reserve risers were 4" from the webbing.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[Jeffrey 0]

Quote

My 2 cents: from the top of the riser to the top edge of the ring.

That’s how I have been doing it for the last 30 years. Dam, I bet that’s a lot of rigs.

Jeff

[riggerrob 561]

At Rigging Innovations, the standard is 4 inches from the top of the riser to the top of the ring.

[JerryBaumchen 1,072]

Hi Terry,

I got to thinking about this some more later last night.

Why the top of the guide ring is used is because this allows any size ring to be used and the brake loop will be correct.

It is simple geometry; if you have two rings, one large and one small. If you put one on one riser and the other on the other riser, but both at 4" from the top; then, no matter what size of the guide ring(s), the brake loop will always go to the top of the inside of the guide ring(s) which it wants to do when it has tension on it. Therefore, the brake loop is in the correct location no matter what size of guide ring is used.

Simple concept, huh?

Jerry

[councilman24 36]

Sure it makes sense,

But some that I measured were 4" from the webbing to the end of the riser.

And, the original Paraflite spec gave the I.D. and O.D. of the ring and stated 4" from the end but didn't say what point to measure it from. So no differing rings but no guidance on measurement.

Anyway, I'll follow the spec and start measuring the ones that come through.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE