There’s a common problem with anything in the world that spins. In machining we call it runout. Runout refers to the inaccuracy of any mechanical system that spins. Simply, the tool or shaft doesn’t turn in complete alignment with the main axis. Common problem. Really big problem. Often solved for 5C collets with a simple collet wrench.
You’re Only as Accurate at Your TIR
If your drill chuck, does not hold the drill bit in the center, as the bit rotates, it will turn on a secondary axis. This is runout. Total indicator runout (TIR) is a measure of concentricity of the collet. It’s how you measure runout. Use a dial indicator pressed against the rotating bit while it is turning. The dial indicator amplifies the minute variations, so they are obvious enough to be seen with the naked eye. Basically, it is just making the very slight deviation from true concentricity large enough for you to see and measure it. You can’t adjust what you can’t measure. You can’t measure what you can’t see. Once you can see and measure it, you can adjust for it.
Sometimes the solution is as simple as cleaning. Open the jaws all the way up and blow out with compressed air. One iota of any type of shop crud in the jaws can be the source of the problem. Next, check the drill rod to make sure it is true. It doesn’t hurt to check the runout on the spindle as well as checking the bearings on the spindle.
Correcting Runout on a Brake Lathe
This boils down to taking care of the arbor. Periodically inspect the arbor and spindle for metal chip buildup or rust. You can clean the arbor with fine steel wool and a little WD40. Never use sandpaper or a wire brush. If you remove metal, you only make the runout worse. Also, check the spindle bearings. If the lathe was set up properly and the arbor is in good shape this is probably the source of the problems.
Protecting Collets with a Collet Wrench
The easiest way to correct runout is to prevent it. Collets that aren’t properly tightened produce runout. Runout can also damage the collet.
Tighten all three jaws evenly with a collet wrench. Just align the three prongs into the top of the collet. Next, turn the wrench to thread the collet into your machine.
Why didn’t you do this before? You didn’t know better. Now you do. So where do you get a collet wrench?
Sierra American Multi-Systems Collet Wrench
It’s got a concaved face. So, you get perfect alignment the first time. The large tapered handle feels good in your hand and the bright fluorescent orange stands out. That makes it easy to find in the shop.
But, where do you find a Sierra American collect wrench? Only where the finest CNC tools and accessories are sold. If your supplier doesn’t carry Sierra American, ask for them to order it for you. This collet wrench is made in the USA for machinists like you. Protect your collets, stop runout before it stops, get a Sierra American collet wrench for your shop today.