Router bit shank install depth

[Taylormade]

Hello,

I just purchased an OF 1400, which I like.  Very quiet and handles on the dovetail jig well.  Dust extraction is excellent.  However, I seem to be installing the router bits too far into the collet and always have to loosen and readjust the bit depth.  I did not have this problem on my Porter Cable but perhaps that was because bit install and change was a huge pain.  What is the recommended installation depth for a router bit - half of the shank?

Thanks!

 

[rrmccabe]

I normally drop the bit in all the way and lift up about 1/4".  More shank is better but you don't want it bottomed out.

I only cheat it the other direction if I need more depth in my cut.

Since all my shanks are different there is no way to base it on 1/2 a shank, etc.

 

[tbellemare]

Some router bits, Festool and CMT bits included, have a mark on the shaft indicating proper burial depth.

Whatever you do, don't bury them to the bottom of the collet. If you don't know how far to go, you can bottom them in the collet and then pull back a 1/4" or a little more.

Tom

EDIT:
It looks like another of those simultaneous posts...

 

[ScotF]

One easy fix you can try that will help you ensure proper depth is to install an o-ring in the bottom of your shaft -- that provides 1/16th or so clearance which is adequate and it will prevent the bits from bottoming out.  As Tom mentioned, several manufacturers have a line on the shank that tells you how far to install them.

Scot 

 

[Rick Christopherson]

If memory serves me, this whole misconception of bottoming out router bits began way back with the Hitachi M12V router, but later morphed into everyone "trying" to bottom out their bits.

The Hitachi M12V had the shallowest spindle of any router I have ever examined (I think it may have been less than 1 inch deep). Because of this, it was very easy to accidentally bottom out the bit. So there were a lot of internet discussions about how to prevent that from happening (because the bit could come loose).

Unfortunately over time, these discussions morphed from how to prevent it with an Hitachi, into discussions about inserting any router bit in any router to full-depth and then backing it out slightly. This was necessary with an M12V because the spindle was so shallow, but it is not necessary with most other routers.

As a matter of fact, it is virtually impossible to bottom out a router bit in a Festool OF1400 or OF2200 router. The OF1400 has a spindle depth of 2.25" and the OF2200 has a spindle depth of 3.5". So it will be very rare that you will find a router bit with a shank long enough to bottom out in these routers.

The bottom line is that there is no reason to ever fully insert a router bit into a any router. Once the bit extends into the collet enough to be fully gripped by the collet, inserting it any deeper will not make it grip any better.

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So the only decision a woodworker needs to make regarding how deep to insert the bit, is how much of the shank they need/want exposed above the collet. This relates to the stability of the bit, not about the gripping power of the collet.

For a 1/2" shank bit, it hardly matters how much shank is exposed. It will be very stable at any depth as long as the collet clamping surfaces are fully engaged. (For Festool collets, this is 1" insertion.) 1/4" shanks are a little less rigid, but then the cutting heads are also smaller.

So the really simple answer is, stop inserting your bits so deep! Base your insertion depth on how big the cutter is and how thick the shank is. For most router bits, 1" insertion is sufficient. For large panel raisers and profile cutters, leave enough shank exposed to not cause you other problems.

 

[Taylormade]

Thanks to all! I wasn't bottoming out the bit, but with 1/2 inch shanks I was probably inserting them farther than necessary.

Cheers!