Chinese ???

[ieezitin]

I have a Rabone machinist level which I fooled with on the leveling jack and inadvertently threw it out of spec ,it was made in 1945, great tool just don’t have something to re-calibrate it with.

Now I installed a new lathe in my shop this weekend and want to take the twist out of it and level it, I own one of these incredible place anywhere accurate to ½ a degree doo-dads and it reads zero one direction and minus 2Deg the other.

I have the right tool that was made with pride in front of me and I have a tool that lies to me. God daam im pissed off.

Sorry for the rant.

Anthony.

[f350ca]

Anrhony, you should be able to recalibrate it your self. Use the lathe bed, check the level then rotate it 180 degrees. Adjust the vial to split the readings. Continue till it reads the same as you rotate it. Then start adjusting the lathe to level. As you get the lathe close to level you may have to readjust the vial. By turning the level 180 you self calibrate it.

[TomG]

Yup, levels are one of few tools that are self calibrating. The more you use and tweak them, the more accurate they become.

Tom

[Sunset Machine]

Could a guy make his own by grooving a bar lengthwise & filling with a liquid, then using a depth mic measuring from the top of the bar to the surface of the liquid on both ends? Make the top and bottom parallel. Like laying a miniature water trough across the ways.

[TomG]

It would be tough to measure to the surface of the water, so the bar would need to be very long to compensate. As soon as the depth mic rod touches, the water will wick up the side affecting the following measurement. What you would need is a non-contact method to sense the surface of the water like capacitance, or maybe resistance using a needle as a probe.

Tom

[Sunset Machine]

The water snaps as the surface tension breaks; it's a repeatable phenomenon and easily visible. Needs more investigation, but I used a variation once (with green grinder fluid) and was surprised how repeatable it was - within a tenth or two. This thread made me ponder its use as a semi-portable level.

[TomG]

Yes, but if some of the water sticks to the rod, it will influence the following measurement. Not a good thing if you are comparing two measurements to determine if something is level. Maybe you could take several measurements and average them out.

Tom

[Sunset Machine]

Yep, you must dry the depth mic off with a clean rag or paper towel between measurements. No floating oil either. The other thing to avoid is the edge where the water creeps up the sides of the trough. So far I've seen no need to average the measurements - everything was very repeatable the ONE time I tried this using clay dams and plastic tubing. In that case I referenced from a machined surface instead of the worn ways. That may have been a blunder. Wanting to check it and having no level, I'm driven by need, so to say...

[TomG]

If you dry the rod between measurements you are changing the level in your trough. Unless you know exactly how much water was removed, that will make the following measurement meaningless. That's why I suggested a non-contact method of sensing the water level.

Tom

[Sunset Machine]

Well, sounds like a wider, deeper trough is needed to make the error negligible. Reminds me of a neighbor lady who overfilled her car's engine with oil and was trying to draw it down by repeatedly wiping the dipstick clean... <chuckle>