Articulating arms, bearing sources, FREE gauges! A three-fer!

[Toolmaker51]

Or a Thread Hack?
From latest Tool Of The Week;

I have regularly used my articulating arm and noticed no degradation of clamping force over time. The mating surfaces between the ball bearings and the side brackets do wear with use but due to pressure rather than by rubbing together.
In use the clamp is kept loose until the correct position is found when it's then tightened very firmly. Adjustment whilst tightened isn't necessary so wear isn't an issue.
Wear with use would increase the surface area of the mating parts and allow greater friction between them anyway.
I used 10mm thick steel for the brackets and therefore didn't need to bend up the sides for added rigidity.
Use the largest ball bearings you can find, (mine are 25mm) and rusty (but wire brushed clean) is best.
A good source of free used large bearings is your local Caterpillar or heavy machinery dealer. Mine came from the main bearings allowing rotation between the body and tracks of a large excavator. The bearing was 400mm in diameter before I destroyed it to remove the balls themselves.
Also the plastic knob to tighten the assembly needs to be heavy duty, large in diameter and with a sturdy steel or brass insert for the thread. I used a 75mm diameter knob with an M12 thread. You need to screw it down tightly so movement is almost impossible.
The end result is extremely robust indeed.

Bearing disassembly tip.
Destruction is a common route, most use thin high speed parting wheel to section outer race, extract balls.

Late last year, helped out in a shop that services water pumps. Not automotive, these feed cooling towers, giant laundry machines, fire suppression, flood ice rinks, fountains, flood basins [run off, after all its only California], more than I can name.
Approved by different vendors to perform warranty work, tearing down several every week. Part entails diagnosing bearing failure, like reading spark plugs.

Oh yeah, promised a tip.......harvest your balls while you have them.

Lay bearing down flat, pull out rubber or metallic seals. Remove enough grease to work inside.
Identify which side of retainer/ separator rivets are headed [usually flat]. Secure bearing in milling vise, that side up. C-clamp inner to outer race.
Spot drill or mill the rivets so they'll punch through.
Remove clamping, drop out the retainer/ separators. Wash out more grease if needed, unnecessary to be spotless.
Stand bearing up on the outer race, push the balls to lower side, crowding them together. Lift inner race up and out; some have a pair of notches making this easier yet.

Why? How well are bearings made? Cutting them up often throws away perfectly good ring and plug gauges.

Bearing Diagnosis Charts should sell bearings. Have no insight why they are hidden away, or ask insane prices; though many are likely to buy one before advertising a designer label T shirt for the same price... They google readily enough.

https://mmsallaboutmetallurgy.com/20...poster-timken/