Never been done before balance scale experiment.....badaboom ;-)

[Rsadams]

Get yourself one of those round magnification swivel lights from harbor freight or even a good one... When working on the knife edges I do it under the magnification so you can really see what's happening , it helps alot....

 

[Webster]

update on my magnet mod, it dampened the scale too much and the repeat ability went to heck so I removed the extra magnet. It takes longer to settle but it ends up in the same place now which is the main point for me

I used a piece of 600 grit paper followed by a extra fine diamond hone meant for wood chisels to touch up my M5. I don't use any type of lube either dry or wet and clean the blades and the ways with isopropyl alcohol before each use.

quick edit on lubrication, in my opinion the scale operates more on balance than anything and any type of oils viscosity would act to inhibit the pivoting just my opinion but I tried dipping the blades in Imperial graphite neck lube. 5 minutes later I was scrubbing it off with alcohol. Did not work worth a darn for me

Oil viscosity has practically no effect on freedom to pivot. The magnetic dampener is a big form of friction. It's the dampener that slows the beam movement. If you had no friction in the bearing and no magnetic dampener the beam would swing for a very long time. It would only be slowed down by air resistance against the moving parts. In other words settling time is dependent entirely on friction.

 

[BoydAllen]

Oil attracts dust and that is bad. Every scale that I have tuned has been with dry knife edges and bearings. The amount of pencil lead that I have used has been so small as to not transfer or show up as powder in the bearings. It is not required. When I evaluate a scale returning to zero it is with a web cam to give magnification and eliminate parallax. Without those advantages small discrepancies get lost in the noise. The fixed observation point of a camera, phone, or pad as well as the magnification that they afford is pretty much a requirement for getting the most out of a tuned scale.

 

[JimSC]

Oil viscosity has practically no effect on freedom to pivot. The magnetic dampener is a big form of friction. It's the dampener that slows the beam movement. If you had no friction in the bearing and no magnetic dampener the beam would swing for a very long time. It would only be slowed down by air resistance against the moving parts. In other words settling time is dependent entirely on friction.

After finding out for myself that lubing was a bad idea I confirmed it by doing a bit of research. Seems all beam scale manufactures will have the statement "Never apply lubricants to knives or bearings, nor allow foreign matter to accumulate." in the owners manual somewhere. I look at graphite as "fine dirt" and keep my knives perfectly clean.

look under care and maintenance http://www.idelsur.com/wp-content/uploads/2014/06/ohs-manual-mecanicas-01.pdf

top of page 4 on this one

http://www.scalemanuals.com/myweighmanuals/TripleBeam-Manaul.pdf

 

[Macropod]

Magnets do not increase friction to provide damping. There is an induced current in the copper when the beam is moving and this creates an opposing magnetic field.

Look up Lenz's Law for a better understanding.

 

[alinwa]

Magnets do not increase friction to provide damping. There is an induced current in the copper when the beam is moving and this creates an opposing magnetic field.

Look up Lenz's Law for a better umderstanding.

Fuh'GEDDABOUT Lenz's Law, too boring....

Since it's already been brought up, try "eddy currents" cuz this stuff is just too freakin' kewl for skewl!!!

THIS is magnetic damping on copper..... friggin' AWE-summmmmm

https://www.kjmagnetics.com/blog.asp?p=eddy-currents

(of course macropod IS RIGHT........ but too boring LOL!!)

 

[Macropod]

Boring for most folks, but if you are in the electrical game, maybe not.

 

[Webster]

Magnets do not increase friction to provide damping. There is an induced current in the copper when the beam is moving and this creates an opposing magnetic field.

Look up Lenz's Law for a better understanding.

Never said it's mechanical friction. If it slows the beam movement it does the same thing as friction.

 

[BoydAllen]

Webster,
The force diminishes with the movement, so that when it stops there is none. What people are seeing is that the damping force, combined with friction leads to the beam stopping in different places. Remove the friction and it stops in the same place. Have you ever tuned up a scale, or use one that was?

 

[truck driver]

After reading this thread I had to go and check out my scale.
I have one of the older RCBS/Ohaus 10-10 ( NJ ) scales that I bought when I first started reloading back in the 1970s.
Any way I decided to give it a good cleaning since it sits on my bench uncovered most of the time and it gets a good dose of dust when ever I do any wood working. I brush it off occasionally before I weigh any thing but for the most part I guess I have abused it by not keeping it covered.
I checked the weighs and contact points and the knives are still sharp enough to shave my finger nail so I don't plan on doing anything to it since it isn't broken and there is nothing to fix.
I did put the cover on it to keep the dust off of it .