Router Table Top Keyhole

[Mark Vago]

Hi -

Question regarding a router table top that I am assembling (part of a table saw work center). The fence I have requires keyhole type slots through the top. How do I make these? Do I need a special bit(s)?

Many thanks

[Paul Johnstone]

Hi -

Question regarding a router table top that I am assembling (part of a table saw work center). The fence I have requires keyhole type slots through the top. How do I make these? Do I need a special bit(s)?

Many thanks

We need some more details. How long are the slots? Are they for fence adjustment or something else? A photo would be very helpful.

[Doug Shepard]

Yep. You need a special keyhole bit. It has a cutter on both the end, as well as a bit of the shank. You plunge it in, lock the depth, then continue the cut so as to let the shank portion cut the narrow diameter slot while the large diameter portion stays below. The trickey part is not forgetting to leave the depth set (or just shutting off the router) before trying to remove it from the cut. A google search for router keyhole bit should find you tons of hits.

[Brian D Anderson]

What they said. Keyhole or T-Slot bit. Something like these: http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_keyhl.html#T-slot_cutter_Anchor

Or you may have the option of embedding a T-Track. Something like this:
http://www.rockler.com/product.cfm?page=21967

-Brian

[Rob Woodman]

Hi -

Question regarding a router table top that I am assembling (part of a table saw work center). The fence I have requires keyhole type slots through the top. How do I make these? Do I need a special bit(s)?

Many thanks

"Keyhole" may be the wrong name used for this application.
Often slots in router tables are made with a completely through slot of a size to allow the threaded 'bolt' to pass through and a recessed groove or dado to contain the head of the bolt.
This can be achieved using two different sized straight router cutters. As posted before pics may assist a clearer form of advice.
Regards Rob.

[Mark Vago]

Sweet, thanks! Is a preference to have a t-track vs no track for the fence slots. Sorry, no photo yet. The tables that I have seen have the slots right through table. I guess at 1-1/2" thick, it might not make sense.

[Myk Rian]

Before using the keyhole bit, use a straight bit first. Makes it much kinder on the keyhole. I've broken them off because I expected the KH bit to do all the work.

[glenn bradley]

I agree that "keyhole" is misleading here. You would not want a round entry hole into an upside down shaped groove. Debris would collect and you would be sad. I have a round hole adequate to allow the t-bolt through, then a slot wide enough to allow the shaft with a wider groove below (open to the bottom) to allow the t-head to travel and grip. The slots basically look like a t-track with no bottom (http://www.sawmillcreek.org/attachment.php?attachmentid=116263&d=1240354709).