which roundover bit to use

[sam]

Hi! I'm new to the group but not to woodworking. haven't used a router or router table much tho. The Problem: I need to round over both sides(edges of a five inch board. The boards actual size is 3/4 inch(1 X 4) I need to do this on a router table. My table is a floor model with a backstop adjustable on the surface in 1/16th of an inch.

What I need to know: What size roundover will I need(I have a half inch with the correct size bearing for roundover). 2. How do I set up the backstop. 3. What depth do I set the router? ( in relation to the board. I know I have to compensate for the thickness of the table.)

SOLUTION:

Thanks a lot. I hope I included enough data. If not just ask for more! Paul

[Robatoy]

After you round over one side of a 3/4" board with a 1/2" round-over bit, then the bearing doesn't have a flat spot to ride on for the flipped, second pass. I wouldn't use anything bigger than 1/4" roundover. Move the bit up high enough that the wing of the roundover bit doesn't rise above the table.

If that sounds confusing, I can make you a sketch.

[Ed Pawlowski]

Using a roundover bit is one of the easiest router chores. First, decide what radius you want. The most common are 1/4" and 3/8" but the end use is what matters. Is it to just give a smooth edge? Decorative? Functional in some way?

I'm assuming you have the router mounted and the bit inserted from the top. What you refer to as a backstop I think is what we call a fence. It is not needed when using a bearing guided bit, but some have a split fence and can be a help with dust collection.

Adjust the router height so the bit barely makes a cut. Now, with a scrap of material, make a pass and look at the result. Raise the bit in small increments until you get the desired roundover. If you want to take a full cut you can line up the bit with the wood looking at the side to get the edges in perfect vertical and horizontal alignment.

Keep a steady feed as you make each pass and keep your fingers out of the way. Hold the board on the side and not the end where you can get nipped after the pass.

If you want to get a few ore bits,

and look for the $5 deal. They are not the best bits on the market, but they are darned good for the price. Good bits are Whiteside, Infinity and a few others.

[sam]

Thanks all for responding. I tried to attach a pic but the msg wouldn't post. I need for the two roundovers to meet in the middle of the thickesss of the board with no bead or ridge in the middle. Here is a link to a pic of what I want.

just thought of another question! The board is five inches thick and I need to drill a 5/16 hole in it. I have a 6 inch drill but my drill press will not go down that far, so I can't drill a hole all the way through it. Is there any other solution other than turning it over, drill from the other side and hope it meets in the middle?

[SonomaProducts.com]

You can actually get a full half circle bit like this

but it might be kind of big and expensive and very presnickity to get it to cut just right.

Better to use a roundover bit with a radius 1/2 of the thickness of your material. and set the fenc (backstop) so it is in line with the bearing.

The most common way of doing a 1/4 radius round over in a table is to bring the bit up until it leaves just a fine line on the botton side of the board to be sure you are cutting 100% plus a smidge. Then sand out the fine line. In your case I would rather mark a center line on your board on the 3/4 edge and adjust so you cut just shy of 1/2 way. Over cutting will show much more than slightly undercutting from both sides and then sanding out to full round.

Regad> Ed Pawlowski wrote:

[Lee Michaels]

"sam" wrote

Probably the simplist approach would be to drill it as deep as you can. Then put in a longer virsion of the same bit. Long drill bits are available.

If the drill you have is slong enough, drill then put the stock up on blocks and finis the hole.

I have used a spade bit to finish a hole started with a forstner bit. With some solid backing, it was fairly smooth.

[sam]

What a clever idea! thanks

[Ed Pawlowski]

newsgroups.

What you want can be done. You need a bit with the radius of half the board thickness. You can make the first pass using the bearing, but the second pass will not be right since the bearing won't have anything to ride against. Use the fence.

Set the fence even with the front of the bearing. Make one pass, flip the board and make the second pass. Experiment until you get the perfect setup.

[Dave Balderstone]

Search for "bullnose router bit"

[CW]

[sam]

Thanks to all who replied, I think I have the solution to both problems now!

[Pat Barber]

[Bored Borg]

On Thu, 5 Mar 2009 02:05:39 +0000, sam wrote (in article ):

It might be easier (depending if your drill table winds up on a crank, or like mine is released and wrenched into a new position, thereby losing its lateral set-up) to put a big block of wood on your table and put your workpiece on that instead of raising the table, You'll need to clamp down another block or two to position it against.

[sam]

Thanks for replying! While discussing the effect I wanted on the group, for some reason, I was thinking I had to pass the wood over the bit on edge. Thinking about what someone had written, before going to sleep, I finally realized I had to pass the board against the bit Flat like I do when I put a decorative edge on a plaque. I followed the advise I was given, and lo, a perfect roundover on both sides!

Thanks again people, I will be a regular visitor from now on! Paul