Router spindle axial runout

[Steve1]

While all this metrology is an interesting exercise, in real world  use it may not make that much difference. You need to remember that adage “perfection is the enemy of good”

Good point. 
I am of the opinion that in metalworking, a micron (.001mm) does not exist.
In woodworking, a thou (.001") does not exist.

 

[Cheese]

The Milwaukee is leaving the locker room to sit on my bench full time.

If that's the case, you may be interested in this. It certainly is a nice selection of sizes.
https://elairecorp.com/milwaukeeroutercollets/

 

[Michael Kellough]

Thanks for that. It would hard to improve the readings on that particular (Milwaukee) router.

Check my thinking on this, I see PrecisionBits has collets in various degrees of precision. If my router has .0002” runout in the taper then an absolutely precise collet will mirror that instead ofimprove it. It seems I would need a collet that is also out .0002” and then I need to determine the rotational position of the collet within the taper where the errors cancel out?

 

[Cheese]

Thanks for that. It would hard to improve the readings on that particular (Milwaukee) router.

Check my thinking on this, I see PrecisionBits has collets in various degrees of precision. If my router has .0002” runout in the taper then an absolutely precise collet will mirror that instead ofimprove it. It seems I would need a collet that is also out .0002” and then I need to determine the rotational position of the collet within the taper where the errors cancel out?

That would be my thinking also Michael. Although the difference in price between Ultra Precision (.0002") and the Extreme Precision (.0001") is only $10. At that point the extra $ is more like an insurance policy. [big grin]

 

[Michael Kellough]

It seems the ultra precision collet is only beneficial if the taper is perfect. If both the taper and the collet are each out .0002” then you have a possibility of canceling out the errors, or ending up with twice the error if not measuring. Too bad the Festool collet is so uncommon and difficult to adjust.

 

[Crazyraceguy]

The Milwaukee is leaving the locker room to sit on my bench full time.

If that's the case, you may be interested in this. It certainly is a nice selection of sizes.
https://elairecorp.com/milwaukeeroutercollets/

That's pretty cool. I'm thinking about getting an 8mm collet, "just because I can"
I love the Milwaukee Body-Grip routers. They are my top pick of fixed-base routers, and the vertical clam-shell case is brilliant too. I have two of the set up and ready at all times, one with an Amana flush-trim and one with the matching pattern bit, both insert style. I use these regularly, exclusively for those bits, but a random 8mm can't hurt. As it is now, the 8mm bits are used in Festool routers, mostly OF1010 of MFK700......options  [big grin]

 

[greg mann]

If anyone wants to try these I will post contact info.

Greg...count me in, this was supposed to be a walk in the park.

It started with a simple question from Michael and it grows to this. I get it ...this is how many technical issues eventually pan out. This is exactly why Engineering is identified as "taking too long" to deliver a product.  [blink]  When evaluating new results, there are always too many results that result in endless parsing.

His name is Ross Jones, and he can be reached at (248) 640-6887. He can accept payment in several ways. You and he can work that out.
[/quote]

Greg, are these Festool compatible collets? I've looked at the Elaire line of collets and they don't appear to be Festool compatible.
[/quote]

I am quite sure they are not compatible but I can check. I have access to the collets at my day job so I will bring one home. It certainly would be nice, but I suspect no.

 

[Michael Kellough]

In the Shopsmith forum thread posted on the bottom of the previous page, there was a discussion how similar collets from different manufacturers are. Particularly whether the ER looking Milwaukee collet would fit on an ER spindle.

The answer is no, the taper is different. I didn’t measure the slope but I’ve read that the ER is 8 degrees. If that is so then the Milwaukee collet is about 6 degrees. It is quite wobbly in the ER taper and too long. Also the thread for the nuts is different.

I’m not sure the thread is the same for all applications of the same size ER collet, probably not. The ER spindle I have is on the SpinRite router Motor sold by Woodpeckers.

The thread of the Porter Cable collet is the same as the SpinRite spindle but the PC nut only engages one thread on the spindle. And the taper of the PC collet is more like 12 degrees, or more?

 

[Cheese]

Yesterday, I decided to pull apart the 1010 collet/nut and the 1400 collet/nut. I immediately noticed that they are ER "style" collets but certainly not ER spec collets. They are longer and have less draft than ER collets. ER collets have 8º of draft on each side while the Festool OF 1010 is 2º 29' and the 1400 is 2º 43' per side.

Obviously these Festool collets are manufactured by someone other than Festool yet searching the web for "2-1/2º collets" yields zero meaningful results. Just my  [2cents]  while looking for some better precision.

[attachimg=1]

[attachimg=2]

Better precision collets do exist and are commercially available, here's a chart of ER collet TIR classes per ISO 15488:2003 Collets with 8 degree setting angle for tool shanks — Collets, nuts and fitting dimensions.

[attachimg=3]

 

[Michael Kellough]

Thanks for the chart Cheese. The SpinRite ER collets have AA stamped on the tops (in my photo above, the middle nut, under the N in clamping) so they are already pretty good?

However, one SR ER collet was clearly better than the other… [tongue]

 

[Crazyraceguy]

Spindle and collet accuracy are important, but to open the next can of worms, "What about the bits themselves?"
There is certainly a quality/accuracy difference between brands. Perfectly centered and aligned spinning with a bit that is off, is just as bad as a bad spindle, isn't it?

 

[Cheese]

Spindle and collet accuracy are important, but to open the next can of worms, "What about the bits themselves?"
There is certainly a quality/accuracy difference between brands. Perfectly centered and aligned spinning with a bit that is off, is just as bad as a bad spindle, isn't it?

Well, while router bit shaft diameter TIR tolerances are important, it really all gets back to the TIR variations with the collet and the collet bore. And more importantly, the perpendicularity of the collet bore relative to the router shaft. If that's not dead nuts then anything else is really insignificant.

 

[Steve1]

And more importantly, the perpendicularity of the collet bore relative to the router shaft. If that's not dead nuts then anything else is really insignificant.

If mounted on a router table, check the perpendicularity of the tool to the table surface. Long half inch rod and a good square will do, but you might have enough fixturing to mount an indicator on the rod and tram the table.   

You might be surprised. 

 

[Michael Kellough]

And more importantly, the perpendicularity of the collet bore relative to the router shaft. If that's not dead nuts then anything else is really insignificant.

If mounted on a router table, check the perpendicularity of the tool to the table surface. Long half inch rod and a good square will do, but you might have enough fixturing to mount an indicator on the rod and tram the table.   

You might be surprised.

Worth checking out if feasible but you can (usually) compensate for that with shims.

 

[Crazyraceguy]

I did that on mine with a 4" long piece of 1/4" drill rod. I have always kept at least a couple of them around. They are very handy for all kinds of things. Never really thought about buying a bigger one?

 

[Steve1]

I got my Jessem motor installed.

The inspection report that came with it said the spindle collet taper was .0002"

I put in a piece of drill rod and measured the run-out at 2" away from the top of the collet nut.
I got numbers that ranged from .0005" to .0045", depending on how I clocked the rod.    The position of max run-out followed the rod orientation as I rotated it, so seems my rod is not quite straight.  Maybe the collet. 
I am calling it .002" runout.  Very good, but they advertise "less than .001" at 2" out".

What is nice about their controller is that it has a digital display that measures actual RPM, not 1 to 6.  It runs 9,000 to 21,500 RPM

 

[Michael Kellough]

@ Steve1 if you can rotate rod without moving the collet you can determine if the rod is bent. A slight bend in the right direction can give you a reading that seems great but disguises the fact that the collet or taper are slightly off. In your case it would be the collet since the taper is so good.

 

[Steve1]

I expect I am rotating the collet with the rod.  But collet is hidden by the nut.  Even if I mark and rotate the collet, I can't see if the collet is rotating when I tighten the nut. 
If I can't be sure of the collet's location, not worth the trouble of chasing it.

 

[Cheese]

I put in a piece of drill rod and measured the run-out at 2" away from the top of the collet nut.
I got numbers that ranged from .0005" to .0045", depending on how I clocked the rod.    The position of max run-out followed the rod orientation as I rotated it, so seems my rod is not quite straight. 

What is nice about their controller is that it has a digital display that measures actual RPM, not 1 to 6.  It runs 9,000 to 21,500 RPM

One of the issues with drill rod is that it's manufactured, sold, transported, stocked, resold and restocked in lengths from 2' to 10'. There are a lot of opportunities to put a slight tweak in it. You'll purchase a 4" cut-off length but it's a junk shoot how straight it is. Sometimes you get lucky sometimes not. It's also an annealed material, it's soft so that it can be easily machined, the hardening process comes after the machining is completed.

After running into these exact problems, for test purposes I decided to purchase hardened dowel pins. They're short, 4" max length and are shipped & stocked in small boxes, no length issues.  They're also hardened which is nice. Both Unbrako & Holo Krome dowel pins are held to .0002" TIR.

A direct RPM readout is real nice.  [thumbs up]