Replies

1. 
   Steinmetz | Jul 27, 2005 03:38am | #1

   Wanda, What you need is a straight router bit and two temporary 'rails' to guide the router and center the bit over the slot.

   Instead of 'Plunging', just gradually penetrate as you (at the same time) traverse the router forward. this will eliminate any tearout.
   Of course, you'll have to 'Backtrack' a bit to remove the small 'Ramp left at the starting point. since you are using a 1/4" bit, and you need 5/16", just move the rails apart each 1/32".
   Steinmetz.

1. 
   ram | Jul 27, 2005 07:22pm | #4

   Another vote for router.  I used two straight bits, 3/4" and 1/4" (5/16" would be better but I don't have one yet) to make a t-bolt hold down recess on a couple of jigs.  It was extremely easy and results were perfect.

1. 
   wendy | Jul 28, 2005 01:21am | #5

   Hi guys,

   I'm going to have to see if I can find my edge guide. Otherwise I'll just have to find 2 straight pieces of wood to guide the router while counterboring.

   Can I use a 1/2 inch dado bit for the counterbore? Not sure dado blades are used to plunge I've only used them to do dados for shelves.  I need to look for a large straight bit.  ( just finished checking out LeeValley) So it appears I'm looking for a straight plunging bit   approx. 1/2 inch diameter. Should I pay a little more and get the 1 1/4  inch depth bit?   Would it be better to use a Panel Pilot bit rather than a straight 1/4 inch spiral bit  for plunging though the material once the counterbore is made? (never knew such a bit existed till I saw it on the Lee Valley website.)

   Great pics routerman. Thanks 

   Wanda

    

   Edited 7/27/2005 6:29 pm ET by wanda200b

   Edited 7/27/2005 6:37 pm ET by wanda200b

1. 
   ram | Jul 28, 2005 08:08pm | #6

   I used one straight board as a guide/fence and routed carefully to pencil lines in one slow pass for the 3/4" recessed groove, then several shallow passes for the 1/4" through slot. Two boards would make it goof proof. I don't remember why I used just one. Routerman is the guru in this area.  Whatever he says I would consider gospal.

1. 
   wendy | Jul 28, 2005 08:41pm | #7

   Hi Ram,

   You're right about making it foolproof using 2 boards. That way the router won't steer away from the edge guide. It will be supported on both sides.

   When you cut countersunk grooves do you use a  plunge router or fixed router?   My countersunk groove starts in the middle not at the end of my workpiece.  But the only router bits I have are spiral 1/4 inch and a dado 3/4 inch diameter bit. Not too sure about using a dado bit in a plunge router to make this kind of a cut. Think what I need is a plunge straight router bit.

   Yes, I have to agree with you. Routerman is the expert when it comes to  routering. Only routering experience I have... dadoeing, (bookshelves) trimming,  rounding off corners (adirondak chair) and cutting gooves for drawer bottoms. The router is my 2nd favorite tool in the shop next to my Table saw. :)

    

2. 
   ram | Jul 28, 2005 10:32pm | #8

   I don't claim to be an expert, so keep that in mind. This particular operation went so well I am confident I understand it.

   I believe it will be confirmed by more experienced folks that you should avoid using a fixed router for plunge operations such as this. It's fair to say anytime you lower a spinning bit into the work it is a plunge operation, and I did it with a plunge router. I would not feel safe doing this with a fixed base handheld, but on a router table would not be worried so long as the long edge of the workpiece had adequate fence contact.

3. 
   wendy | Jul 29, 2005 02:41am | #10

   Hi Ram,

    I  never intended to use my fixed router  to make the countersunk grooves. I have a plunge router for that. Sorry for the confusion.

   Wanda

4. 
   Routerman | Jul 28, 2005 10:56pm | #9

   You may be at risk here, Wanda.

   Email [email protected] for some details if you'd like.

   If you'd like to post analysis, I would have no problem.

2. 
   Patto | Jul 27, 2005 06:43am | #2

   If the shape you are looking for is as per the attached, the easiest way to get the slot and countersink on the same axis is to use one fence and two bits. The first the width of the countersink, and then follow up with your 1/4" bit on the same fence setting. Guven a choice, I would size the top slot to take a washer under the head of the carriage screw, this will significantly increase the life of the jig.

   David

    

   
3. 
   Routerman | Jul 27, 2005 03:34pm | #3

   I think this picture is an example of what you're after. The rest of the link will give you some idea how to get there.

1. 
   wendy | Jul 29, 2005 02:47am | #11

   Hi,

   Routerman, I clicked on your link (picture)... that is a wonderful pic of a countersunk groove. Just what I am attempting to do.  I need to know what type of router bit that is on the left hand side.... The router bit on the right side is obviously a straight 1/4 inch bit by the look of it. 

   Thanks for the links.

   wanda