Shop Equipment Calibration

May 1st, 2009

Shop Equipment Calibration

There are several factors that affect shop equipment calibration. Sharpening of saw blades is perhaps the most noticeable. Most table saw fences have wear plates which affect alignment. Cast Iron can change slightly as it ages. Leveling shims can compress.

I’m sure there are earthquakes or settlement of foundations, which change the way equipment, was originally installed, or maybe it was a forklift.

How do you check your production equipment for accuracy? I would suggest a calibrated tape measure and a calibrated level.

www.lixertools.com makes a tool for calibrating tape measures and levels. They call it a Super Lixer. The Super Lixer allows for precise adjustment of your tape measure. This tool also has adjustable feet on the level for easy adjustment of accuracy. Their website, www.lixertools.com has excellent tips for use on their helpful hints link.

Once you have an accurate reference to check calibration with, it is up to you to periodically check and make adjustments to your scales or equipment. Seasonal changes in temperature and humidity are a good time to check. I like to check at the start of new production segments. It would also be necessary when ever you change saw blades as saw kerf varies from blade to blade. I also use a tilt box from Beal Tool Company to calibrate angle settings on my table saw.

On a shaper you need to align the spindle perpendicular to the table surface. You will need a precision straight edge to do this. I clamp this between the spacers on the spindle and rotate the spindle to determine what needs shimming. I use a One Way dial gauge to check spindle run out.

Is your tape measure accurate?

April 10th, 2009

Tape Measures

Accurate Tape Measures are indispensable. Tape measure accuracy is questionable unless you check it. A Lixer is the best tool to check and calibrate a tape measure. You can order a Lixer from www.lixertools.com.

I’ve seen tape measure errors form bent end hooks as much as 1/8”. The Lixer has a slot designed to straighten bent tape measure end hooks.

Accumulation of error from bad tape measures is the real problem. On a 20-foot run of cabinets, errors as small as 1/64” show up quickly. There could be ½” or more of total accumulated error.

Another common problem with bad tape measures is when two or more tape measures are used on the same project. An example could be two craftsmen, who work together to cut and install molding. It could be a shop that sends measurements to a sub contractor or fabricator. We have encountered these situations frequently in our shop. One of the tape measures could measure short, and the other could be measuring long. The combined error could be doubled!

The Lixer will deliver better accuracy from tape measures. Their web site is filled with more useful information. Visit them at www.lixertools.com.

New tape measures are not necessarily accurate either! I’ve seen new tape measures off 1/16”. You should use a Lixer to find an accurate tape measure to begin with. Use your accurate tape measure to mark inside and outside measurements, radius, and straight line marking. We even use it as simple calculator ether adding or subtracting fractional measurements. One of our contractors even uses it for a plumb bob (not recommended).