Re: Measuring tool holder runout
hy to trully check a toolholder, you have to apply kind of a similar quality check procedure as the toolholder producer does
a faster way, to target only er chuck runnout, in respect to taper, is to simply clamp the toolholder, gently, on the flange, because taper, flange diameter and flange frontals are all machined during same operation; flange frontal and er chuck frontal may not be paralel
once clamped, simply put the dial on flange diameter, flange face, and inside er chuck; is not needed to tap/center the toolholder diameters to target 0 tir, is enough to simply adjust flange face tir, then compare diameters runnout : for example, if 2 different diameters have a runnout of cca1mm, with peeks at same spindle phase, and 0 face tir, then that part is coaxial ... thus, on other words, diameters are coaxial if their tir is identical, and phases are matched
instead of a chuck, you can also use your cnc mill spindle, as long as it delivers consistent clamping position
thus, there are tricks to check runout, without necessarily dialing the part,towards 0, but by using a comparison
besides runout, taper surfaces need checking also the angle : for the outside taper, use a toolholder as reference, and calibrate on it 2 dials, as far as possible one from the the other; they will load more on less in respect to contact point height, but the diff between them should be consistent : again this is a relative measure, not absolute, but pretty fast and easy to replicate
for the inside taper, is a bit more tricky, because it is small, but you can jog a dial inside it, and look for similar values at similar travels, thus, how i like to call it, similar drops; is not needed for the dial palpator to be exactly on the plane of simetry of the toolhilder, but more important is to achieve consistent clamping for all measuring all toolholders; again, if mill spindle delivers consistent mounting, use it, and create a nice low feed program to create contact between dial and toolholder
such relative measurements don't say that a group of parts are good or bad, but that they are identical within the deviation that you found during measuring / kindly
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