Aeron Hip Pivot Bolt

Aeron Hip Pivot Bolt is the only real issue I have with Herman Miller Aeron chair. In past 14 years about 8 of them broke on me. Actually the "bolt" itself is ok but the casing for the bolt that is made out of some unknown material (looks like bakelite to me). The chair comes with 12 year warantee so they replace the bolts but it takes time, after 12 years when they brake you can get new ones for 25-50$ but again, it takes time to ship them, especially if you are not in the USA.

So what can you do but print a replacement. IMHO this is only TEMPORARY replacement, I'm right now testing the PLA printed one and, well, it works for few hours so far :D maybe it will work long enough till the new replacement part arrives, if not, I can print one every day till the replacement part arrives it's a 10g part easy and quick to print.

I made two objects

• Hip Pivot Bolt.stl : this part is very hard to use, it is most similar to original but in order to push metal part of the bolt (that you have from the broken original) in to the plastic you have to heat up the part with external heat source. Maybe if you print it with nylon it will be elastic enough so you can push the bolt in to it with some force (I tried pushing just mechanically in to PLA and was not successful but when you heat it up it goes in)
• Hip Pivot Bolt - EasyPush.stl : this part is ideal, made out of PLA the bolt will snap in place. The front "enclosure" of the bolt is not important for the functioning of the part so this is easy to print and easy to install

There are no "clips" to hold the part in place but these clips are just for ease of installation and are one of the main reasons these parts fail (they always break exactly on clips)

I printed in PLA, 0.2mm layer, 10C hotter than normal (to increase strength), 10% higher infill rate (110%), with max perimeters (so the whole part is printed with perimeters)

PA would maybe be a better choice, PA filled with CF might be ideal, dunno

UPDATE: I'm 140kg in Aeron C, approx 12-14h/day after 10 days the PLA part broke, 3min replacement (I printed 4 so I can quickly replace it when it fails) and I'm back in the seat. PLA obviously can't work as permanent solution but as temporary solution, you print few so you can change them every few days till the original replacement part arrives, it makes sense

How I Designed This

source: https://cad.onshape.com/documents/027f392dfacfe9e210025146/w/364cf3e2d14c0d2f47699876/e/ce2831077983000f6ddf3d91

Category: Office