Ballnuts in thin horizontal seams

that guy named sebwrote:

I think aiding on them has made me feel a lot more confident in them. I think the idea of hand placing pitons is generally not even considered by most people though, I was only exposed to it through aiding in the valley. 

Have you fallen on them?

Thank you everyone for the thoughts. I ended up firing this headpoint today and did in fact nest two blue ballnuts in the horizontal seam with a sliding-X, shown below. 

Interestingly, the left placement (new) went into a part of a horizontal seam that flares in the back, making this ballnut a bit of a passive placement. Not what it's rated for, but, surprisingly, this placement took body weight, so we rigged it on a sliding-X. This was a sort of headpoint where it's still best not to fall. 

Fabulous! Congratulations!

The one with the passive setup looks bomber - I would say a ballnut functioning well is pretty nearly passive so good find! And good send

I contemplated the "passive" ballnut placement and figured I would share my thoughts, for those interested. 

Below you will see some examples of the forces on the system in an active (parallel crack) and passive (flaring crack, as is the case here) placement. Actively placed, the central trigger wire on the ball plays no role in the holding power of the slider nut. The slider nut will hold depending on the coefficients of friction and angle of the slider's incline, shown below with some simplifying assumptions. 

Interestingly, in a passive placement, the ball will slide up the ramp to it's maximum expansion (not shown) until it's stopped by it's own trigger wire, whose tension is now proportional to the force on the piece. It's a curious question, how much force the central trigger wire can handle. Our placement took body weight, albeit it could've been a hybrid of these two extremes. Part of my Devils Lake headpointing strategy is placing "exit plan" gear; placements that, at a minimum, hold body weight, and allow you to bail mid crux by down climbing to them. 

Michael Wolfewrote:

Regarding placement: I was worried in the opposite orientation (ball facing down, slider facing up), the thin cable connected to the ball would badly pinch on the sharp edge in the event of fall. The small clear shrink wrap around this cable seems pointless in that scenario. 

Regarding pitons: there is a strong no-hammering ethic at Devils Lake. There is grey area around hand-placed iron (knife blades, sky hooks, etc) to protect hard leads. This particular route has been lead in such a style. I'm on the fence about the ethic there. 

I appreciate the perspective from the Gunk's community. Can anyone speak to taking a whipper on a blue ballnut in a similar horizontal?

I think if you fall on it you’re retiring the piece because of cable damage, and I agree that two would be better than one, and worth the investment if it’s a route you really appreciate. The small retracting cable breaking doesn’t seem like a safety concern though, because as long as the ball stays wedged under the nut, the placement will hold, regardless.  It also looks like placing it ball down might increase friction as the nut would press down and inward on the ball as it’s weighted and I am guessing that would increase friction. 

First off, congrats on the send.  

This is an interesting dive into sketch pro esoterica.  
One thing to toss out for consideration in tying together a nest of dubious pieces is to preferentially connect them with a girth hitch vs a sliding x.   To a large degree it’s splitting hairs, but for pieces on the margin, minimizing overall peak loads if one fails, is what we’re striving for and the girth hitch fits well here.  

This seems relevant: Ballnuts used in horizontals in R ascent

Vid: Color Blind 5.13R