Digital Levels

[cr17]

Lately I've been eying the digital levels/protractors that are available just about everywhere now. I'd like opinions on whether or not they could be used in lieu of a machinists level for levelling lathes and other machinery. Thoughts?

[JIMinPHX]

If you can make due with 0.1 degree increments, then the digital ones will do the job & are nice to work with. If you need .001"/foot, then you probably need to get a machinist's level.

[Bret4207]

No, certainly not the consumer grade stuff anyway. Check Ebay for used levels.

[trevj]

My feelings on precision levels, is, save your money. Borrow one if you feel the need. It'll be the only time you ever use it.

Having the lathe dead nuts level, is secondary to having the lathe set up so it cuts a straight part, rather than a taper. Google for "Rollies Dad's Method" or look in the South Bend Lathe book and see the two rings method for setting up the lathe to turn straight parts.

But the chip pan drains so much better if it was lebvelled with a $200 level eh! <--- (sarcasm! )

A flat surface, and a ball bearing ball will get you as close to level as you are likely to ever need. A loop of string to stop the ball from rolling off the edge is of some use.

But fill your boots, if it'll make you feel better about how the machine is set up.

Can you tell I am not enamoured of precision levels? I have one here at work. In truth, it has spent more time out of it's box during calibration, than it has in use.

Level is nice, but cutting straight and true, trumps level.

The digital levels and angle gauges. Good enough for carpentry, unless you have a means of calibrating the angle readings against a known standard.

Cheers
Trev

[cr17]

Thanks guys I'll save my money. Trev - great tip on the "RDM"

Take care

[JIMinPHX]

I use a true machinist's level frequently at work to tram up rollers that handle long web paths. For that stuff it's necessary. I have also seen some guys that calculate angles on a milling machine using a level & a protractor. For that kind of stuff, you need to have your table dead nuts level. Other than that, machine tools run fine even if they are a few degrees off.

As for calibration -
1) put the level on a surface that reads level
2) reverse the direction of the level on the same surface.

If the bubble is still centered, then the calibration is good. If not, then make an adjustment of the vial screw & go back to step 1. It's that easy.

[trevj]

We were taught to use a surface plate. Doesn't matter if it's level or not, at least nowhere near perfectly level.

Place the level on the plate, and rotate it around until the level reads level, and stays that way, hands off long enough to stabilize.

Tape a rule or straightedge alongside the level's body.

Rotate the level 180, and place back in contact with the straightedge. Adjust as required, repeat as required, until it reads same on both directions.

Then use the level to get the darn surface plate level again....:) (joke)

It makes a pretty good demo to show just how sensitive these things are, to get it set up and calibrated, then to hold your hand on various parts of the level, and watch the readings change as the various bits warm up. Sorta demonstrates just how bad you will be chasing your tail trying to use one to level up a lathe outside of a climate controlled lab, let alone how much things will change in use (insignificant amounts, in practice, but huge on the tool that magnifies the difference as much as a decent precision level can) when the machine heats up from the pile of hot chips in the pan, or from heat off the motor or headstock bearings, etc.

Cheers
Trev

[Bret4207]

Good post Trev. Reminds me of the pics of guys using 3 to 6 foot mics that have insulating material wrapped around the frame to keep the guys hand heat from altering the measurement. THAT is machining!!!!!