Routing end grain?

[Bruce]

So, I've been making circular picture frames for wife.com and I'm trying to perfect the technique. I'm using various types of wood, primarily oak, walnut, and alder. These are about 1" thick, 8" ID and 10" OD.

Basically I make a hollow octagon out of strips of 5/4 wood, gluing the end grain together. These have the grain oriented such that it 'flows' around the circle. I then resaw this ring and overlap the two pieces so that the glue joints overlap 50%. Nice and strong without any joint failures, coolio!

The problem comes when I turn the octagon into a true circle. I made a jig for my router table that is basically a 1/2" post on a flat board that can be clamped to the table (think of a jig used on a bandsaw for the same purpose). I then attach a piece of hardboard with a hole in the center that allows me to pivot the unit on the post, making perfect circular cuts (and all the grooves/dados required to hold the artwork).

Anyhoo, the problem comes up when I'm routing the inside and outside surfaces. Given that the grain is alternating both 'uphill' and 'downhill', routing in the usual direction (upcut) results in lots of chip out when the bit decides to split out sections of wood. Simple solution is to vary the feed (rotation) direction to avoid this. The best solution that actually produces a perfect, split free surface is to do a climb cut all the way around. Aside from the white knuckle grip I need to avoid the setup going into 'self feeding' mode, I can live with it but would prefer something safer.

What I want to try is instead of the grain flowing around the circle, I want to cut the octagon sections so that the grain follows the radius of the circle. What this changes is I end up with end grain exposed along the inner/outer surfaces. Advantages would be I can eliminate (I hope) the need to do the overlapping since the glue joints are (mostly) long grain against long grain. I'm hoping that since I'll be routing end grain to turn the octagon into a circle, I can revert back to routing in the normal feed direction and avoid the climb cut scare factor.

I've routed miles of end grain, but never something that is entirely end grain. Any tips (i.e. depth of cut, bit type, speeds/feed rates)?

I want to avoid any grain pullout or other damage that would require patching, excessive sanding, etc

I'm using a two flute spiral bit if that matters.

TIA

-BR

[tiredofspam]

What kind of bit are you using. I suggest using a spiral bit, the shearing forces usually do a better job than a straight bit.

You might need to make a coarse pass then a finish pass (very light pass

1/32-1/16). In my experience spirals have done a good job doing this work, where a straight bit just can't. And make sure you have good backing using ply for your tearout. I would router from the top using a downcut bit. I would screw the frame to the plywood by drilling holes in the ply, then coming through the ply to the frame staying out of the cutting zone.

[routerman]

"I've routed miles of end grain, but never something that is entirely end grain. Any tips (i.e. depth of cut, bit type, speeds/feed rates)? "

******************************************************************************** Hand fed on the RT? Guess & x golly. I would hand rout (in climb) and in thickness stages. An increment of depth can always be chosen such that there will be no tear out. Might be a 1/32, might be an 1/8. Species, cutter, feed rate dependent. A climb cut is key. A light climb cut poses very little risk. There is risk, however, if you don't have control of the router. If you tip the router you may be cutting a full thickness of new wood and they could be a problem. Use a plunger, collar and new straight cutter; would not sweat flute design. ********************************** Routs all day long.

[Swingman]

Bruce,

Just in the (unlikely) event you don't know Pat Warner, his post on your question is the definitive, authoritative answer.

Take it as gospel and you won't go wrong ... :)

[Bruce]

On Sun, 19 Feb 2012 09:14:33 -0700, routerman wrote (in article ):

******************************************************************************

This is on a jig, basically a 1/2" pin that the frame pivots on as I rotate the frame against the bit. Plenty sturdy and secure.

So basically do as I was doing in the first place. I suppose I really just need to try it and see how bad things tear out. Possibly get within a 1/16" with a standard up cut (less scary), then do the final pass with shallow climb cuts.

This is on a router table so tipping, etc, is not a problem. I doubt I'd have the stones to try this with a handheld router!

-BR

[Larry Blanchard]

How about using a circle cutting jig on the bandsaw (or even freehand if you feel capable) to cut the circle just a mite oversize and then use the router to finish up and cut the grooves?

[John Grossbohlin]

This would seem to present an opportunity for an opportunist tool designer/seller... a single-point power-feed that would allow climb cutting elliptical and other non-straight items on shapers and router tables. Anyone listening? ;~)

John

[Bruce]

On Sun, 19 Feb 2012 09:24:53 -0700, Swingman wrote (in article ):

I hear ya!

Pat's website inspired me to build my first fence/router table.

I went ahead and tried my idea, went very well indeed. Small incremental cuts (1/8") followed by a full cut at about 1/32" depth seemd to be optimal.

A normal (not a climb cut) on the table with my jig went smooth as butta, very minimal tear out. I'll post some pics on ABPW tomorrow.

By arranging the octagon so the end grain is on the perimeter, I can eliminate a lot of hassle. I'll probably still resaw the frame and reglue it with some offset to avoid any wood defects from causing a split.

-BR

[Bruce]

On Sun, 19 Feb 2012 09:43:39 -0700, Larry Blanchard wrote (in article ):

I thought about that and have a bandsaw jig ready. It would eliminate a lot of wear 'n' tear on my expensive spiral bit, at least for the outside cut.

I'm being a wimp by trying walnut first, but since things went well I may have a go at the oak and perhaps some hickory.

-BR

[Swingman]

Similar to the way I had to do the top and bottom trim on this rounded corner (18"radius) "L" shaped desk (picture is during installation and prior to finishing).

curved pieces were cut from one wider board, and even though I selected the grain carefully, it is still impossible not to have an end grain routing problem in one at least area of the curve.

Actually, and from previous experiences, I had routed out a couple of extra trim pieces, but didn't need them.

[Leon]

Snip

I just looked at your pictures of what you are doing, Looks like the perfect job for a disk sander with a circle jig.

[Bruce]

On Mon, 20 Feb 2012 07:51:02 -0700, Leon wrote (in article ):

I agree (if I had one). It wouldn't touch the inside but it would be perfect for the OD cleanup. I did try a sanding drum on the drill press with a similar jig and that worked sorta ok (got a small groove where the drum first makes contact).

A disk sander is on my wish list, but not anytime soon due to limited space, etc. I might consider a sanding disk 'blade' for the table saw however. Making a jig to allow for fine tuned feeding would be somewhat complex but worth it since I will probably be making dozens of these frames in various sizes over the next year.

-BR

[Puckdropper]

Bruce wrote in news: [e-mail]:

Do you have a belt sander? That would work just as well for the outside.

Puckdropper

[Leon]

Yeah, I forgot about the inside.... ;~(

[Bruce]

On Mon, 20 Feb 2012 09:33:30 -0700, Puckdropper wrote (in article ):

Yep, a PC mini belt sander. That would work in a pinch with some form of fixture to hold it. That is one thing I like about the design of the Bosch(?) is it has a flat back making it real easy to mount.

-BR

[Lew Hodgett]

"Bruce" wrote

--------------------------- Do you have access to a spindle sander for a test run?

Lew

[Lew Hodgett]

"Bruce" wrote

-------------------------------------- For less than $100, problem solved.

A 2" oscillating sanding spindle will make you happy.

Lew