How do you measure TIR of a tool in a tool holder?
How do you, as an individual, measure the run out of a tool in a tool holder?
I use ER32 and ER16 collets for concentric and non concentric tools. I use a mag base tenth indicator to ensure the tool is spinning concentrically at the shank and the tips of the flutes (I had one drill bent like elbow macaroni). I'm aware cosine error is a thing and keep the tip as close to parallel the tool shank as possible. These are NIST certified gauges that are calibrated every 6 months. If the tool runs out I persuade it with a brass drift, spinning counter clockwise by hand, until run out is within an acceptable tolerance.
Now, the reason I'm proposing this question is because I had a tool holder salesman come in. I already didn't want to deal with this guy and his new design hydraulic tool holders but he guarantees a repeatable 2 micron run out.
The machine is a 2016 and in good repair. The holder is a CAT40 with retention knob A.
He unpackages his brand new tool holder. I put a brand new retention knob in. We put a brand new carbide end mill in the holder and I proceeded to check run out via the method above and as seen in the picture.
The end mill runs out .0009".
That's a bit more than 2 micron.
We extract the tool. I use a spindle wiper to clean the taper of the machine, he wipes down the taper of his tool holder, he says we tightened the hydraulics too tight. He loosens the tool and spins it about 30 degrees and retightens it to his acceptable torque.
We put it in the machine and, again, .0009".
He claims the end mill is defective.
We extract the tool and he suggests putting a gauge pin in.
Sure, a gauge pin is a perfect representation of cylindricity so that makes sense.
We put a class ZZ gauge pin in this brand new holder and it runs out .001". Which is still more than 2 microns but I'm also seeing a pattern develop here...
He leaves. He sends a company rep a week later.
New holder, different nominal size, same deal.
We put an endmill in and it runs out .0004"
Better, but still not 2 micron.
He leaves. He then calls, tells me I'm checking run out the wrong way and it involves equipment we don't have at our disposal in my shop, and just try the dampening affect of this new tool holder.
THIS... Is where I get offended.
I have one job in particular that is like an engine connecting rod. Tight tolerance true position hole to hole, +/-.0004 on the diameters, and 8 surface finish.
I was doing a center drill, drill, plunge with end mill, and custom ground carbide reamer*. I would have to tram in the flutes to zero run out in order to hit nominal diameter size, ensuring the tool in its holder spins concentric to the spindle. This makes sense to me because if the tool were spinning eccentrically, being a carbide reamer, it would turn into a boring bar instead of a reamer. Each .0001 run out becomes .0002 on the diameter. This theory is demonstrated true because the diameter will be oversized after the part is cut if there's any run out in the tool.
I mainly want a sanity check. I'm measuring run out the proper way, aren't I?
*I recently switched to a 140 spot, 135 drill, standard off the shelf reamer, and a roller burnishing tool. It was pricey but we get about 1500 parts holding the 8 finish opposed to swapping a reamer 40-50 parts.
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Re: How do you measure TIR of a tool in a tool holder?
I let those guys sit in the front lobby and catch up on womans world, or goodhousekeeping.
Your doing it right, the only thing I would add is you can magic marker the high spot. Remove the tool from the spindle and put it back in 180. This is how you isolate run out from toolholder to machine. Or even collet to toolholder if you index it there.
Re: How do you measure TIR of a tool in a tool holder?
When trying to measure small errors, it’s best to make the indicator setup as rigid as possible, if you have the Z, put the indicator very close to the base
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Re: How do you measure TIR of a tool in a tool holder?
Thats gonna make the tir even worse!!Originally Posted by ripperj
He needs a Noga.
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