Acceptable runout?

I guess my first issue would be how you measured the runout...... I hope you are not doing this with a router bit in place and the router running.....

I don't know how the "offical" way of measuring is done but I can tell you what I do.

Static testing is normal the safest way to do this. I have a steel shaft that is designed for use in a drill press or router to mark the center of where the drill/router is. I also use it to check wear. I test at 5 spots around the base to make sure I'm getting a good reading, and I rotate the "bit" at least 3 times ( loosen then twist retighten). I make sure the indicator is giving a value as I rotate the shaft I see what the range is. The min. might read 5 and max 10 (thus the runout is 5). I then force a block of wood into the "bit" 180 degrees away and do the same rotation. I index around and repeat the tests. Some times you don't have to go very far as the bearings are worn and you get readings that very a lot.

Bit are in the range of +/- .002 to .008 but any single bit should be off by more then half of that ie + the range or - the range. The total of the router and bit should be maybe .009 or .010. You can not use the bearing of a bit to do the measurements they will indicate higher numbers. You also must measure close to the collet nut as if you measure further up the shaft the numbers will also be larger.

This is not offical but what I do to keep track of wear.

A bent motor shaft would most likly vibrate a lot and I think you would feel that buzz. I would look to the collet assembly for a burr or dirt on a new router, something that would keep the bit from tighnening in the center.

I would also think about the bit as a possible problem some times they are not very well made....... or may have gotten damaged in shipment or dropped at the store before you purchased it.

If you are feeling a lot of vibration then things are wrong and you should not be using the router or bit until you know what is going on.

I have no specifications but I know that all of my routers have a run out of less then .006.

Ed

Thanks for the info.

First off, I didn't try measuring the runout while the router was running! What I did was secure the router in a vise and placed the indicator's magnetic base on the same vise. I placed the indicator's plunger on the end of the bearing, and slowly spun it until I found the furthest variation on the dial. Then I set this position to zero. I continued to spin the bit, and noted the total runout to be .015. You mention that I shouldn't use the bearing though? I thought that that would be the best place to try it as it is closest to where the actual milling of the wood will take place.

I have looked for burrs on the collet. None. (This in both the adapter and the actual collet. I've also tried a 1/2 inch bit without the adapter... still runs out)

The bit used in measuring was nearly new. I also tried another, with the same results.

There is no abnormal vibration or sound.

What I may do is bring it back to the store, along with my dial indicator.

Hi again,

I have heard of people trying to use a bit in a running router and just want to make sure that was not what you were doing..... thanks for being safety minded.

The measurement at the bearing while it sounds like a good idea adds the tolarance of the bit and bearing into the picture and will not tell you how good or bad the router is.

To find if the collet and or other parts above that are "off" you need to mark the shaft at the high and low points then loosen the collet and rotate things 1/3 turn or so and see if the high and low spots are in the same place... repeat and see if those spots move. If you see movement then it points to something above or inside the collet area. If you see no movement then you are looking at the runout of the router motor/shaft.

You might try contacting the manufacture and see if they will tell you what the runout should be on a new router. My guess is that it could be as much as .008 or so, measured at the shaft.

If you happen to have a 1/2" drill bit that might be a easy way have an accurate shaft to measure to.... drill bits are normal right on the money, that being less then .001 off size. The "adapter" can be used with a 1/4" drill bit.......

If you do take the dial indicator to the store and find one that is "better" let us know what you found. It would be interesting to see what other routers have for runout.... they don't list that on the "features" list now do they????

Ed

Okay, now I'm feeling a tad bit foolish. Let me explain...

I found about 45 minutes in the shop today, and wanted to do a decorative edge on four boards needed for a project. I decided that I would use a simple chamfer. I took the v-groove bit out that was last used (it had produced a groove that wasn't as sharp as I would have expected at the bottom of this groove, but not too bad either... I believe the less than perfect point was caused by some runout). I took the adapter out and cleaned it up. I cleaned the collet out as well (some good advice from this forum).

I put the chamfer bit in, and by eye it looked good. I decided to check things out again with the dial indicator. On the collet tightening nut (again, the round part), I recorded next to no runout (on the unit I exchanged, it was around 0.005").

As I said, my time was limited, so I didn't have a chance to stick the ogee bit back in, and try again. So, I'm thinking that either the ogee bit is bent, or the collet had a small wood chip in it. At least at this point, I'm not condemming the router.

I do want to say though that the first unit I had deffintitely showed a runout at the collet nut.

I'll put some more thought into it, and try the ogee bit again. Now, if the bit is bent, could that have been caused by runout of the original machine... or vica-versa? Is there a danger of damaging the bearings on the router by using a bent bit? As I said, I don't hear any different sounds with it, or feel any vibrations.

Thanks to all so far who have helped clear up this bit of murkiness that I wouldn't otherwise know where to ask.

aniceone2hold said:

There is a reason this router sells for $120 Canadian versus $350 US for a Porter Cable 3-1/4HP. It's called quality and YOU GET WHAT YOU PAY FOR!

Click to expand...

... And also why a fifteen pack of router bits sells for less than 50 simolians!

In a later post, aniceone2hold reports, "Let the buyer beware!" Well, received as a gift, I wasn't really aware! Not my point though.

What I want to say is that the ogee bit is indeed out of true. Actually, the cutting edges themselves are decent enough... it's the bearing on the end that is funky. And of course, when the router is mounted in a table, the bearing on the bit is the most obvious piece showing. I saw it wobbling, and grew concerned.

I was convinced when I brought back the original router that the shaft was bent.... am I still? Not as much as I was. It could have been a case of newbie over-concerns I suppose. Then again, my dial indicator doesn't lie.

As for runout measuring, I've seen another idea that may be of interest to others. It's actually really simple. All you have to do is clamp a piece (I used some scrap 1/4" ply) to the base plate so it is very close to the bit's shaft. Turn the router (by hand of course, Ed!) until the bit is as close to the piece as it will get. Now move the piece until it touches the bit. If, as you rotate the router, a gap forms between the bit and the clamped stock, that idicates rounout. It is easily enough measured with a simple (and cheap!) set of feeler gages.

There it is. I hope no-one is more confused after reading this!

I remember truing or what ever it is called my bike tires using this sort of method. You held a stick near the rim and against the frame and found the spot where it was bent then adjusted the spokes to fix it..... to bad the router and bits don't work that way.

Now take the bearing off the bit and see if that is what is wrong..... I had a Whiteside bit that they forgot the washer on and screw got to mess with the race of the bearing.... If it just the bearing you can buy new ones and keep using the bit. The bearings are a week part on some bits and need to be replaced from time to time. That is one reason to use a table and fence with the bearing not being used (isolate the bearing).

I'm sorry I questioned the running bit but people do some odd things...... just didn't want you to have to change your name to lefty or????

Just remember even if the router reads no runout now it will in the future so if you use it a lot check it again in a year or so.....

Thanks for the follow up.

ed