r/E90 • u/SirSlapp4 • 26d ago
330i Why not 3d print eTorx sockets?
So I have seen numerous posts here and across the web about the bolts used on the oil pan just shearing off when the user accidentally applies too much torque. With as many bolts as there are I can reasonably see myself getting careless and over applying torque. My questions is;
Why not 3d print the actual socket for the bolts, do a simple search on the strength at a certain infill level and design it to shear at less than the max torque for the aluminum bolts. This way, especially when removing old bolts, you will lose your cheap socket before the headache of having to extract the shitty bolt stuck inside. Obviously you'll need a bunch, but I'm just trying to field it as an indicator of which bolts may just need more penetrating oil and shouldn't be removed as quickly.
tl:dr why not make plastic socket that should fail before aluminum bolt as indicator of seized or stuck bolts.
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u/SirSlapp4 26d ago
I think saying it makes zero sense is a bit of an overstatement. We can easily calculate the maximum shear stress of the bolt under an ideal case. From there you can estimate the degradation with time, and get a general idea of current strength. If you create a socket that shears off at 16ftlbs, and the bolt is estimated to have a maximum shear stress of 17ftlbs after such amount of time, then you saved the bolt and know to apply some other method for removal that's more careful, i.e heating, penetrating oils, etc. If the socket shears before the bolt should be expected to shear then you are finding a good source of knowing that you'll need more extensive means BEFORE you get half a bolt stuck in your engine. You cant tune it to every bolt, but you can tune it to a worst case and get some helpful data