So, how am I measuring my router wrong?

[Jeff Duncan]

Yup, as David said, you don't want to measure at the bearing as they have their own play in them. Here's the thing to remember when checking tools for runout, you want to eliminate as many sources as possible. So if you try to measure the runout of bearing on a bit in a router that's mounted in a table, you have so many potential sources of error it would never be reliable. If the router base is off to the table by a fraction of a degree your going to have runout, the bearing as mentioned has runout....too many places for it to add up. The only reliable way to check IMHO is to attach the dial indicator to the base of the router, insert a known straight piece of rod, and check the collet to the base.

Anyway it sounds like you have solved your problem for now, and learned a little something along the way

JeffD

[Joe Hillmann]

What was the reason for returning the original router? Did it actually not cut well. Or did the runout just bother you?

[Rick Fisher]

I remember reading an article somewhere that said the Milwaukee routers had the most run-out .. It might have been on Pat's website, can't remember..

[Bill Bukovec]

How does the Milwaukee router cut?

[Wade Lippman]

How does the Milwaukee router cut?

Just finished the router table today; haven't wired up the switch yet. Should know in a few days.

[Marvin Wilson]

Have the woodworking magazines driven us all mad? Some of the most beautiful pieces of furniture ever produced have moldings produced by a wooden plane with a hand shaped cutter and we are talking about 3000th's of an inch. You never mentioned whether you simply tried to rout an edge or not. Did you? Was the finish acceptable? Then it is a good router. For crying out loud men we build furniture not jet engines. We are woodworkers not machinist. My suggestion is to lighten up, stop obsessing over the mythical zero run out and go build something useful. It's much more enjoyable.

[David C. Roseman]

Have the woodworking magazines driven us all mad? Some of the most beautiful pieces of furniture ever produced have moldings produced by a wooden plane with a hand shaped cutter and we are talking about 3000th's of an inch. You never mentioned whether you simply tried to rout an edge or not. Did you? Was the finish acceptable? Then it is a good router. For crying out loud men we build furniture not jet engines. We are woodworkers not machinist. My suggestion is to lighten up, stop obsessing over the mythical zero run out and go build something useful. It's much more enjoyable.

Point well taken, Marvin. But if we pay top dollar for a tool, don't we want to be sure it's built to its own manufacturing tolerances? I think that was the OP's concern. He wasn't sure he was measuring correctly, and turns out he wasn't.

David

[Joe Hillmann]

I read an article a few months ago (If I could find it I would post a link)in which they were doing a story on a high end hand to manufacture. The owner of the company said back when he started only machinist owned accurate measuring tools so when someone bought a tool from them if it worked it was a good tool. But now with cheap measuring tools from China anyone can own them and think they can accurately measure down to .0005 and they expect there tools to be as accurate as they think they can measure them. The problem with that is just because the tools may read out to five ten thousandths of an inch doesn't mean the person using it can measure to that accuracy. Because of that the company made a large investment in large slow speed grinders that act almost as random orbital sanders to make the surfaces of there tools flatter than what can be measured without specialty tools. Although the article said even with the large investment the tools they are making don't work any better but it is required to stay in business in the modern world.

[Chris Fournier]

If you're using a router bit to measure your routers runout you might as well stop right there. It really doesn't matter where on the router bit that you measure, this is not a useful exercise. You are measuring both the routers and the bits runout at once. A drill bit is no different really. You need to buy a standard of known accuracy and chuck that then measure the routers runout. Any other efforts are a waste of time and the data you get is not terribly useful unless you're using that router bit, chucked that way in the router - then you know that you are running out 0.008" for example.

[John Piwaron]

I guess you don't have other routers to measure, Wade? I mean, really, only one router in your whole shop?!

That *is* funny - one router. Those seem to collect like stray cats to a tray of milk.

[John Piwaron]

Mr. Hillmann,

For sure measuring is a science. I'm frequently impressed with the things my employers QC dept. has to measure things. Some are exceptionally clever, all are exceptionally accurate. All need training to be used to get valid results. Some training takes 10 minutes (micrometer) for some (CMM) you go to school for a while.

[Myk Rian]

Mr. Hillmann,

For sure measuring is a science.

It's more common sense than science.
I did precision tool repair/calibration for 20+ years. If you study the procedures, it makes perfect sense.

[Pete Bradley]

Chris Fournier has it right. Measuring at the bearing of a router bit is a dead giveaway that it's time to put away the dial indicator.

There's way too much emphasis on machine measurements in certain woodworking mags, and some of the "precision" measurements they publish demonstrate a complete lack of understanding of machine precision. Likewise there's endless blather about checking for "play" in new bearings when the worst quality offshore radial bearings now have runout that is unmeasurable by amateur methods.

Most likely the bit that you're using was not very accurately manufactured, but it still may work just fine. If the router works, enjoy it.