Template Routing Question

[James Jayko]

Hey all, I'm template routing the curved stiles of a Morris chair back (I think you'd call them stiles...the sides that the back slats are mortised into). Its basically a VERY shallow "S" shape, maybe 2" of spread between the two ends (of a center line). I've messed up two individual pieces in the same way and I'm curious what I'm doing wrong.

I'm doing blue tape / super glue to attach the template to a piece of ~1 1/8" cherry. I then band saw as close as I'm comfortable, probably a ~strong 1/8"? I then flip it over, template down, and rout it using a ~2", 1/2" shank bottom bearing router bit. As I come through that bend in the middle, I think I'm approaching the grain in an odd way and on two separate pieces the router bit tore out BIG chunks (beyond the template). Like, would probably need 1/4"+ roundover to get them out. I'm not climb cutting (though I think this would probably solve the problem if you don't kill yourself) because the material is so thick that it really feels like it could run away from you.

Am I doing something obviously wrong? Bad luck? Is there a better way to approach this? I'm sure cutting closer to the template would be helpful, but I'm not super comfortable getting much closer. Any advice?

[Jim Becker]

There are many times when you have to do part of the job with a bottom bearing bit and then flip the whole thing and do the rest with a top bearing bit to avoid issues with tearout. It can be the species; it can be the particular piece of wood; it can be the particular sharpness and/or configuration of the tooling...etc., even when you've only left a little bit of material to clear with the template. Direction does matter.

[Phillip Mitchell]

I cut closer to the finished line (~1/16” off) and use a shaper with helical head + bearing and tear out / cutting against the grain is not an issue.

I would suggest cutting closer to the finish line. What type of router bit are you using? Straight flutes, spiral, compression? The less material overall removed and the closer you get to a compression / helical type cutting the less you will have to worry about tear out and grain direction...though, of course there will be some situations that test this and you may have to flip, etc like Jim suggests.

An example -> https://www.instagram.com/reel/Cd_y9TAAwI9/?igshid=YmMyMTA2M2Y=
Caveat - enter your own risk...nothing has been as divisive as sharing video of shaper operations. Sandpaper under the workpiece, double clamps, backup block on trailing end, and push blocks mounted well away from cutter. Bearing is on the bottom in this case (with cutterhead exposed above) for simplicity of work holding and accuracy. Yes, there could have been a shop made hood to cover some of the upper side of the cutter - will probably make something for that the next time I do a lot of template shaping.

[glenn bradley]

You are experiencing "tearout" which is not unusual when routing against the grain. A top/bottom bearing bit is your answer.

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This allows the upper or lower bearing to ride the template and assure that you are always routing downhill. Here is an example of me using a finished piece as a template for a second piece.

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I route from the center, downhill to the end. Then I raise the bit and flip the parts using the bottom bearing so that I can again start in the center and route downhill to the end.

Here is an article about avoiding tearout. (https://www.woodmagazine.com/woodworking-tips/techniques/routing/avoid-tear-out-when-routing)

[Lee Schierer]

Examine the grain where you saw the tear out.
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In the future when you approach areas of grain like that you want to climb cut those areas to prevent tear out. You do need to exercise care when climb cutting to firmly control the work piece and make shallow cuts. The work piece will tend to self feed when climb cutting. Here is a guide for routing curves.
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Glenn's method works well, but doesn't solve reversed grain problems for other types of router cuts, such as edge rounding or profile cutting on curves. The Freud Quad router bits will produce far less tear out, but even they aren't a perfect solution.

[John Kananis]

You really climb cut on the router table without a power feeder? In all the years I've used my router table, I've been too terrified to try it. Just seems like a 97% likelihood of something going wrong.

[Lee Schierer]

You really climb cut on the router table without a power feeder? In all the years I've used my router table, I've been too terrified to try it. Just seems like a 97% likelihood of something going wrong.

I agree if you are terrified of making a cut, don't do it! Note that I only suggested climb cutting on the potential lifting grain areas of curved pieces. When I do routiing on any piece my first step is to examine the grain to determine whether I am likely to encounter grain lifting by the bit and direction of cut I plan on using. I often switch ends of the piece or roll the piece 90 degrees if I can to get better cuts. When in doubt, I take a first pass taking an extremely light cut or resort to hand tools or sanding. Power feeders don't eliminate tear out on lifting grain.

Even when using planers, jointers or hand tools, you need to make cuts from the other direction to avoid tear out. Again if any operation on any tool makes you nervous find another way to do it.

[Paul F Franklin]

A lot of good advice here. I'll add that swapping the bearing for a slightly larger one can allow you to minimize the stock you are removing on the first pass when you can't cut close enough to the line. I have also used a sanding drum to remove extra material in tricky grain areas so the router bit is removing very little stock on the final pass.

[Vince Shriver]

I'd emphasize Lee's advice, "an extremely light cut."

[James Jayko]

I also have a very short pattern bit (maybe ~1/2" cut length?) Would it help to just do maybe two 1/4" cuts to get to full depth there, and then switch to a longer bit to get across? IE how much is it grain direction vs amount of material being removed?

[Nick Lazz]

All good stuff here.. I would add that I always try to cut as close to the line as possible on these trouble areas on the bandsaw first. That will also help reduce any tear out etc.

[Doug Garson]

Haven't tried this so I'm curious what others think, but to take a lighter cut, wrap the bearing with several layers of tape if you don't have a bigger bearing and remove the tape for the final pass. Alternately you could put the tape on the template but of course that would require more tape.

[Warren Lake]

had a sleeve made up that slipped over the router bearing for .020 over. Id rather have a router in my hand than router table. You can control the router and do anything you want no so with the table.

[Kevin Jenness]

I agree if you are terrified of making a cut, don't do it! Note that I only suggested climb cutting on the potential lifting grain areas of curved pieces. When I do routiing on any piece my first step is to examine the grain to determine whether I am likely to encounter grain lifting by the bit and direction of cut I plan on using. I often switch ends of the piece or roll the piece 90 degrees if I can to get better cuts. When in doubt, I take a first pass taking an extremely light cut or resort to hand tools or sanding. Power feeders don't eliminate tear out on lifting grain.

Even when using planers, jointers or hand tools, you need to make cuts from the other direction to avoid tear out. Again if any operation on any tool makes you nervous find another way to do it.

Climb cutting with a handheld jig on a router table with a 2" high straight cutter is pretty sketchy in my book. Those reverse grain sections are just the areas that tend to catch and kick back. At the least the template should be solidly made with handles well away from the action.

Powerfeeds don't prevent tearout but they do keep your hands away from the cutter. That said it would be diffficult to use a powerfeed for this cut.

Holding a wide, thin piece in a jig for contour shaping is not easy. Unless firmly held to a solid jig the piece can "flutter", leading to chatter and tearout. Can you show a picture of your setup? Precise sawing from a wide blank using a template guide on the bandsaw followed by sanding might be a better option than shaping.

Cutting within 1/16" of the line and reversing the orientation of the workpiece to keep cutting "downhill" should help solve your problem.

You might consider laminating those curves rather than cutting from solid stock.

[Jim Becker]

I also have a very short pattern bit (maybe ~1/2" cut length?) Would it help to just do maybe two 1/4" cuts to get to full depth there, and then switch to a longer bit to get across? IE how much is it grain direction vs amount of material being removed?
Big bites can certainly cause issues sometimes, but grain direction is the greater evil, IMHO. Many folks who build electric guitar bodies have learned that the really have to be selective in cut direction at those places in the pattern where the woodgrain is making a change such that the bit rotation can grab the fibers rather than cut them off, resulting in tearout that can sometimes be impossible to recover from visually. Incrementally increasing cut depth can help, but how the tooling edge engages the wood is the biggie.

[Steve Demuth]

Obviously if you're afraid of the technique you shouldn't use it. I do a lot of template routing using climb cuts. But, there are rules to make it safe. First, and most impoortant, I cut a bare minimum with the router. I use a pattern guide on the band saw with the same template as I'm going to route to, to get the initial cut as close as possible to the final shape - rarely would I ever leave more than 1/16", and I shoot for and generally achieve less. Second, I use either a spiral flush trim bit, or an angles/shear cutting flush trim bit on the router. Third, I make sure I have plenty of mass in my template/workpiece combination, and good holds. Kickback when routing climb cuts is all about how much force the cutting bit develops relative to the mass and stability of the workpiece. These three things (minimum cut depth, shear cut, mass) put the equation in your favor.

[James Jayko]

Well I patched up the pieces and bandsawed as close as i dared. Then I took 3-4 VERY light climb cuts around the outside curve that was causing the problem and all is right with the world. Thanks for all the suggestions! I'm going to buy a compression bit but needed to get this done in a hurry!

[Kevin Jenness]

Well I patched up the pieces and bandsawed as close as i dared. Then I took 3-4 VERY light climb cuts around the outside curve that was causing the problem and all is right with the world. Thanks for all the suggestions! I'm going to buy a compression bit but needed to get this done in a hurry!

That's great that you succeeded. Would you mind posting a photo of your setup?

[Mike Wilkins]

Cut closer to the line so there is less to route. A spiral bit with bearing should solve most if not all of your problems. I have gone against the grain with no problems.

[Brian Runau]

Thanks for this post. I'm working on a curved leg project with a template and the information within helped me. Cut my pieces on the band saw reduce them at the oscillating sander and finish them with the template on the router table. Brian

[John Kananis]

I personally don't like going from the sander to the rt. The abrasive (I feel) dulls the router bit. If you make a template guide for the bandsaw, you can easily get under 1/16 of waste material for your rt to handle.

[Tom Bender]

Unless you are doing a production run, bandsaw then hand tools