Kineticrazy wrote:
Dan,
I noticed the bearing in the video was still shielded. It was suggested in another thread to remove the shields, soak and clean the bearings with mineral spirits and then soak and lubricate them with silicone. Do you go through the same process?
I was wondering if anyone has tried thrust bearings. I happened upon them when poking around the internet...here's an example..
For kinetic sculptures, that are not experiencing high loads (I think?), would it be valuable to wash the bearings in mineral spirits, to remove the lubrication in order to reduce friction, without lubricating back?
I know the lubrication is there for a reason, but it also adds friction, and maybe for the weights involved in kinetic sculptures this isn?t an issue?
I have been testing various bearing configurations for pendulum supports. It is not exactly the same setup as a kinetic sculpture, but I believe some of the same principles apply. Less friction is better.
The load is around 8 ounces. I measure the time that it takes for the swing to degrade from +/-8 degrees to +/-1 degree.
Here are the swing times of various 623 (3x10x4mm) ball bearing configurations:
5m 50s sealed with factory grease intact
7m 40s shielded with factory grease intact
14m 00s shields removed and cleaned - low end of range
20m 50s shields removed and cleaned - high end of range
24m 30s shields removed and cleaned with Teflon dry lube added
The bearings were generic eBay versions costing around $5 for 10 bearings. 3 of the 10 were slightly tighter than the others. The remaining 7 would probably all last around 20 minutes or better.
My clock with ball bearings for the pendulum support has been running non-stop for two years with no signs of wear. Running then dry seems OK when the load is significantly lower than the rated max loads.
ArtF wrote:
>>24m 30s shields removed and cleaned with Teflon dry lube added
Good god, thats way better than I figured on top of head. Thats a long time to degrade ..
Art
It was much longer than I expected as well, especially since they were random no-name bearings.
A pendulum degrading in 24 minutes only needs 1/3 as much restoring force as an 8 minute pendulum. I hope to post a video soon showing the complete results.
FWIW, I tried a couple with mineral spirits: the problem is they seemed to gum up a week or so later...some kind of residue attracting cruft in my garage. (The stuff they sell here in SoCal doesn't look/smell like the stuff I remember from my youth.)
"Gunk" engine cleaner worked a lot better, except for the hassle of getting it out of the aerosol can so I could really soak the bearings.
Finally completed my laser-cut acrylic take on 'Zinnia' after letting the plans and parts sit for almost five years...
Did some re-engineering, mostly to get all the parts to fit the 12"x16" limits of my laser. Wheels are 20", which is about as big as I can segment one up without a ton of waste.
Short video of it in operation here: https://www.dropbox.com/s/fgyz2qq84whfc ... 9.mp4?dl=0