Compensating for spindle runout while calibrating OTS

How are you guys compensating for spindle runout while calibrating your OTS? My mini-mill has 0.0003" of spindle runout, which doesn't affect my parts. I'm using my probe to measure the tool radius, and then I use that to offset my cutting tools in my program. The thing is though, I calibrate with one of those Maritool masters, and it doesn't spin the master. So when I calibrate, it doesn't know about the spindle runout. I can calibrate with the master and then immediately probe the master as a tool, and it's 0.0003" oversize in its radius measurement. This causes every tool to cut .0006" too small.

I know I'm not the only one with spindle runout, so is there a way to calibrate the OTS so that the runout is compensated for? If the master was spinning as an endmill does during measurement, I could calibrate the master with the runout and be perfectly on size.

Maybe I'm not understanding something, but why cant you spin the Maritool Calibrator just like you would a tool? Isn't it just a solid shaft thingy?

As an aside to this. Measuring tool radius to the enth degree isn't really going to perfectly satisfy your Cutter Compensation needs. Especially on something light like a Mini-mill. Tool deflection, along with a fair number of other things like tool-holding/work-holding/cut parameters etc, are going to have a say as to what size the part feature measures after it's machined. Simply starting with the nominal radius or slightly over nominal and making a test cut, is ultimately going to get you where you need to go size wise.

You dont need to because the spindle probe always goes in the same way. Your haas may not be accurate within a few tenths. .0003 I would not worry about it

13engines said:

Maybe I'm not understanding something, but why cant you spin the Maritool Calibrator just like you would a tool? Isn't it just a solid shaft thingy?

As an aside to this. Measuring tool radius to the enth degree isn't really going to perfectly satisfy your Cutter Compensation needs. Especially on something light like a Mini-mill. Tool deflection, along with a fair number of other things like tool-holding/work-holding/cut parameters etc, are going to have a say as to what size the part feature measures after it's machined. Simply starting with the nominal radius or slightly over nominal and making a test cut, is ultimately going to get you where you need to go size wise.

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I don't see why you couldn't spin the master while calibrating. That's the question I'm asking. I've used other machine tools with the same masters and probes, and they all spin the master while calibrating. The programming manual from Renishaw for Haas has a bold note that says the tool doesn't spin during calibration, which is odd.


As for chasing this to the enth degree, I agree with what you're saying. I'm asking for something that's probably better suited for a different machine tool or a laser tool setter. This isn't a huge challenge to solve, at least in my mind. I'm using radial comp instead of wear, so these values multiply quickly to create more issues. .0003" of runout causes the tool to measure a total of .0006" in diameter. So if I'm cutting a square, it's always 0.0012" away from the target size. It's so repeatable that I'm trying to find a way to mitigate the issue. Since the machine does move quite a bit throughout the day due to thermal growth, I always measure every tool on tool change, which wipes out wear comp values. If I could refine the calibration of the radial measurement, I would be dead nuts on size more often than not.

Speedie said:

You dont need to because the spindle probe always goes in the same way. Your haas may not be accurate within a few tenths. .0003 I would not worry about it

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The spindle probe most definitely does not always go in the same way on a Haas, at least if it's taken out of the tool carousel. The spindle probe calibration can compensate for the runout, but I'm referring to the tool setter, not the spindle probe.

I would spin your cal tool just like you would any other. Couldn't hurt it.

How are you measuring the spindle runout?

If you follow the HAAS procedure for setting up the Spindle Probe, you absolutely WILL orient it properly prior to use and storage in the tool changer so recheck that, something like HAAS logo always pointing at you when loading, if you're not doing that with every tool you load, then tracking .0003" spindle runout isn't something you should worry about

Don't use the control to set dia if you have over / undercut issues, use wear to adjust as needed

Things pretty much never cut "perfectly" you always adjust as needed

The probe SHOULD go back in the same way every time. If it doesn't, you're creating a problem. Set it up with the logo on the front, always load it that way. Adjust the stylus in to less than .0001" runout with a test indicator, then run calibration. Calibration should rotate the probe 90 degrees a few times to account for any remaining runout.

We're totally off track here...

I'm not referring to the spindle probe; I'm talking about the calibration of the tool setter using a master. The master does not spin for some reason while calibrating the tool setter, and the Renishaw manual says explicitly that it doesn't, which is odd. Does anybody know of a way to get the Haas macro program from Renishaw to spin the calibration tool during the tool setter calibration?

daringwilliams said:

How are you measuring the spindle runout?

If you follow the HAAS procedure for setting up the Spindle Probe, you absolutely WILL orient it properly prior to use and storage in the tool changer so recheck that, something like HAAS logo always pointing at you when loading, if you're not doing that with every tool you load, then tracking .0003" spindle runout isn't something you should worry about

Don't use the control to set dia if you have over / undercut issues, use wear to adjust as needed

Things pretty much never cut "perfectly" you always adjust as needed

Click to expand...

I've never had an issue with my spindle probe. I never even take it out of the machine unless a stylus breaks.

I have to disagree with the tool setter though. I use the control to set the diameter all day long without issues. I've found that I can lie to the control during calibration and get the diameter measurement dialed in. Once that's done, I double-check that my master tool measures correctly in length and diameter by running an endmill measurement cycle. I can probe all of my tools and effortlessly get my parts within tenths. I also have a quick way of verifying that my probes are still within calibration every day after warmup.

Everybody has their own way of doing things, and this works well for me. If I could get the macro program to spin the master during calibration, I could get a proper calibration without fudging numbers. There's gotta be a way to do it.

I mean I cut all kinds of hard materials with odd conditions, like super thin walls one part none the next

They all cut differently and need various wear settings / adjustments to work in the different situations you need them in. I can use a tool, come back to use it again and it's like the first time

How you're measuring the spindle runout / adjusting to get perfect numbers on the screen doesn't really have that much to do with actually making parts, checking probes that haven't had a contact or crash event etc just a waste of time

Cutting verifies your Length and Dia offsets, not what numbers you can fudge or change few tenths throughout the day

How are you checking your spindle runout and verifying .0003" that's leading you to do all this in the first place?

JSL_MFG said:

We're totally off track here...

I'm not referring to the spindle probe; I'm talking about the calibration of the tool setter using a master. The master does not spin for some reason while calibrating the tool setter, and the Renishaw manual says explicitly that it doesn't, which is odd. Does anybody know of a way to get the Haas macro program from Renishaw to spin the calibration tool during the tool setter calibration?

Click to expand...

It doesn't spin, because that would give you an erroneous size measurement. The master is a known, precision measured diameter, which you punch in. If it spun, that would increase by the amount of the runout.

When you measure the diameter of a cutter, then it spins, and at that point the runout of the cutter is included in the diameter measurement, because that's the size it will cut to.