I am kind of curious to see what others have to say on their experience or opinion on mixing metal types of their ball and socket joints. What I mean by this is that the metal types of the plates and the balls are not the same. Things like steel or aluminum plates with brass balls but all combinations are fair game. I know what my experience has been to some degree on this but I like to see what others have to say. The sort sort of discussion I would like to stir up is listed below but is by no means exhaustive.
1. This works in a pinch but runs into issues quick
2. Works great for this situation
3. Cost is good but the life is short
4. It has or doesn't have complications when used with these items (i.e. chemical reactions)
5. Good if you are starting out but poor in intensive shoots
6. The common issues with this setup could be helped if it was done differently (i.e. design tweaks)
trikfx got me on the bronze tip back in '99 :) thank you for that.
for ball joints:
i like to make everything from the waist up out of bronze because it moves really nice but i'll use 316 stainless on the hips, legs and feet so they can get super tight. if i don't feel like milling joints out of an giant ingot of bronze, i'll make everything out of 316.
i use 440 bearings for the 316 joints. with the bronze, 302/304 balls work great.
o1 tool steel certainly makes for nice joints with 302/304 balls but you have to keep a close eye on the rust.
i use drill rod for small connecting rods and stainless for large connecting rods.
Thanks for joining in and sharing Patrick. I would also like to say great work on the zombie judge head mechanics.
the zombie judge was the coolest puppet i've ever had the joy to work on.
funny story.... i was called about the job at laika because jeremy spake remembered talking to me on this forum 8 years ago about armatures.
It was actually a Jeremy Spake comment to a news post on LIO's site that I first found out you were the one to work on it. It is crazy the things we remember sometimes.
by "sticking" I think the noted behavior is actually galling. The definition is broad, but stainless steel, aluminium and titanium are particularly susceptible to galling.
Shea Street said:
Good to know about 2024 sticking since I was going to try that soon. Kind of makes sense now that I think about it. 2024 is more susceptible to corrosion do to its copper content as its surface is usually clad in one fashion to prevent this. Machining would indeed remove a good amount of this clad for the socket plates and in general copper reduces corrosion resistance more than anything else. So even in great conditions this is going to corrode/oxidize and eventually make the balls stick.
It's not galling because that would leave gouges in the metal. 6061 is really bad about sticking. When machining 6061 versus 2024, the 6061 is noticeably gummier. 2024 isn't as bad, but it's gummier than 1018.
I've thought that phosphorized bronze,ball sockets and hinge joints would work well nicely together.Joints that require high torque or will be under allot of strain would do well with a metal that has a high anti-wear characteristic such as phosphorous bronze.