Another 3D printable rigging tool

[parachutist 1]

Pin straightening block:

[inline pinblock.jpg]

This is a tool I needed recently. I added holes ranging from 2.3 to 4.0 mm, suiting a variety of pins. The STL file is inside the attached .zip. I hope some people find it useful

[format 0]

Material is that tough?
No danger of damaged plastic?
How much print costs?

Very interesting piece, inspiring

What goes around, comes later.

[parachutist 1]

format

Material is that tough?
No danger of damaged plastic?
How much print costs?

Very interesting piece, inspiring

Thanks! It cost me about $1.75 in materials for this print, using PLA plastic, and probably another $1 in electricity. The plastic is plenty strong, but if it ever did get damaged you could print another in a few hours.

[SkyGoblin 0]

If a pin is bent, and you straighten it, does that weaken the pin at the former bend?

[RiggerLee 61]

In theory, if you did it a lot or if it was a big bend. Remember the pin is like formed by a hammer extrusion process. It's pretty tough and ductile/malleable not sure the correct word in this context. We've been straightening minor bends in pins forever. So in a properly made pin, excluding the capewell fiasco, straightening a small bend is no big deal.

Lee

Lee
[email protected]
www.velocitysportswear.com

[rmarshall234 13]

RiggerLee

In theory, if you did it a lot or if it was a big bend. It's pretty tough and ductile/malleable not sure the correct word in this context. We've been straightening minor bends in pins forever. So in a properly made pin, excluding the capewell fiasco, straightening a small bend is no big deal.

Lee

Agreed.

And, I believe the concern with straightening the pin too many times is that it becomes "work hardened". In which case it becomes more brittle and therefore more likely to break. Not sure we could straighten it enough times for this to really become a problem though. ??

Having said that, if I become concerned enough about the integrity of a pin, it gets replaced.

[Deyan 36]

SkyGoblin

If a pin is bent, and you straighten it, does that weaken the pin at the former bend?

At the latest PIA symposium, Nancy from Parachute Labs (those are the people that manufacture a lot of pins) did a demo where she bended and straightened a pin to 90 degrees angle 27 times before it broke....So I guess straightening a slight bend will do nothing to the strength.

.....or was it 37 times? Nancy?!

"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

[rmarshall234 13]

Great info, Thanks!

[riggerrob 598]

The Capewell Service Bulleton CW01-03 shows a test block similar to this new plastic block. Capewelll specifies soft aluminum or soft stainless steel.

Part of Capewell's problem was that they used a different alloy of stainless steel than the original MIL SPEC.

John Sherman (Parachute Labs) will give you a lengthy description of the various alloys used to make ripcord pins and will conclude that PL uses the best alloy.

[parachutist 1]

SkyGoblin

If a pin is bent, and you straighten it, does that weaken the pin at the former bend?

Each case is different. If a pin has a definite bend at one specific point on the shaft, then I'm likely to recommend replacing the rip cord. This block was used to encourage an out-of-true pin with a slight curve to be straight again.