Router set up for curved leg

[Brian Runau]

Good morning. Two questions

1. I actually cleaned out the dust bin on my router table and found this aluminum, I think bushing, inside the dust bin. No idea what it is or how it got there. I have a Kreg table, Kreg lift with a Bosch router. Lift seems to work fine, so if it is missing a part...

2. Setting up to run a curved leg using the plywood template shown. Running a top bearing bit. The grain on the walnut does not look too coarse after trimming the profile out of the blank. My plan is to run them through an oscillating sander to reduce the excess to a minimum and then use double sided tape, both ends and middle, to clean up the edge. I'm hoping the prep on the oscillating sander will help me eliminate any potential tear out. I will use a sacrificial piece on the back side where I need to in order to prevent tear out.

Anything I haven't thought of or where I am off base?

Thanks for your input.

Go Bengals. Sorry I lived in Northern Kentucky years ago and got to see the Rams with Dickerson play the Bengals. I got my Father to come up and took him to the game.

Brian

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[Steve Jenkins]

Can’t tell from the pic but it’s best if the pattern is longer than the leg do your bearing is against the pattern before the cutter engages the wood

[Brian Runau]

Can’t tell from the pic but it’s best if the pattern is longer than the leg do your bearing is against the pattern before the cutter engages the wood

Since it is a flat on both the top and bottom, I couldn't figure out a way to cut them square after routing them. So I cut the blank square to length so the ends would hopefully be close to square/parallel. Thanks. Brian

[Brian Runau]

Well, I'm learning what not to do.... Top bearing flush trim bit. Outside of the curve cleaned up the band saw marks well. Inside of the curve not so much when I got to the bottom 1/3 of the leg. I see how the grain is more exposed here. I did sand the leg on the oscillating sander so I minimized what needed to be removed, but...

Is the solution to do the outside curve with a top bearing bit, then the inside curve with a bottom bearing bit? If yes, can I do one on the router then the other with a hand held router as long as the piece is properly held in place? My goal would be to be able to do one leg at a time both sides since the template is on it without changing the router bit each time between passes.

Thanks for any help.

Brian

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[John Kananis]

Top and bottom bearing and just flip the work on the router table. You can do it handheld but results likely won't be as good.

[Lee Schierer]

Well, I'm learning what not to do.... Top bearing flush trim bit. Outside of the curve cleaned up the band saw marks well. Inside of the curve not so much when I got to the bottom 1/3 of the leg. I see how the grain is more exposed here. I did sand the leg on the oscillating sander so I minimized what needed to be removed, but...

Is the solution to do the outside curve with a top bearing bit, then the inside curve with a bottom bearing bit? If yes, can I do one on the router then the other with a hand held router as long as the piece is properly held in place? My goal would be to be able to do one leg at a time both sides since the template is on it without changing the router bit each time between passes.

Thanks for any help.

Brian

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Exactly the same problem you encountered on the outside of the curve occurs on inside curves. You have to be aware of the grain ends and if the router bit cutting edge is going to lift them you need to make the cut in the other direction either by climb cutting or flipping the piece. If the ends of the grain are pointing towards the cutter go the other way. The same is true when running wood through a planer.

[Brian Runau]

Top and bottom bearing and just flip the work on the router table. You can do it handheld but results likely won't be as good.

JOhn, sorry, thick headed this morning. Use a bit that has a top & bottom bearing on it in the router table. In my mind I will have to adjust the bit height after each pass. Less work than changing the bit, but trying to make sure I am clear on the process.

Thanks.

Brian

[Edwin Santos]

How much material were you removing?
Grabbing the wood when routing against the grain is always a risk, but you can reduce it if the cut is very light. I try to be 1/32. No more than 1/16.
You can also reduce risk by taking care at layout, when selecting where your parts will come from. Here if you're willing to have flat sawn grain on the face, it would reduce the risk of grabbing.

Otherwise, the top and bottom bearing bit, flipping the workpiece over is a good way to always be routing with the grain.
I'd like to second the advice to have a template that is longer than your workpiece so you can engage the bearing before hitting the work. And I hope you are not routing the ends because that's asking for trouble.

[John Kananis]

Brian, exactly that. Raise and lower the bit accordingly. Yes, an extra step but just remember how many revolutions to crank the lift up or down and you don't have to stop the machine every time (assuming your lift mechanism doesn't require your hands near the cutter while cranking).

[Brian Runau]

Brian, exactly that. Raise and lower the bit accordingly. Yes, an extra step but just remember how many revolutions to crank the lift up or down and you don't have to stop the machine every time (assuming your lift mechanism doesn't require your hands near the cutter while cranking).

John, OK. Having trouble understanding why reversing the piece top to bottom would make a difference. On the inside curve of this piece it tore out on the cut near the end on a top bearing bit. Let's say I use a two bearing bit and use the bottom bit for the inner curve cut. I still have the grain exposure on the last 1/3 of the cut? The cutter head is still in the same rotational relationship to the wood & grain at this point. Thanks . Brian

[Jim Becker]

Yes, you need to flip to avoid coming at the grain from the wrong direction and having it tear out at the least and do what happened at the most. Tooling with both top and bottom than can handle the typical thickness of material plus the template removes the need to change out the tool, but in some cases, swapping tooling may be required for thicker material.

[John Kananis]

Just try and remember the straw analogy and cut along the "length" of the wood (or straws) and not where it (the grain) terminates. Rubbing your hand on the flat of a broom is smooth but rubbing along the bottom you'll get a catch.

[Mel Fulks]

To make sure that’s not gonna happen , you just sand a round- over on the corners. Try it NOW …FREE! “On some scrap to install the app”
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[Cliff Polubinsky]

John, OK. Having trouble understanding why reversing the piece top to bottom would make a difference. On the inside curve of this piece it tore out on the cut near the end on a top bearing bit. Let's say I use a two bearing bit and use the bottom bit for the inner curve cut. I still have the grain exposure on the last 1/3 of the cut? The cutter head is still in the same rotational relationship to the wood & grain at this point. Thanks . Brian

Brian,

You don't route the entire side with the same pass. When you're routing the underside of a curve the grain runs downhill from the right side to the center. When you cross the center the grain now runs uphill from the center to the left. So you route the right half with top bearing and the template on top you. Then flip the piece over which makes the grain of the unrouted section, which is now going from the center to the left, run downhill. Raise the bit to use the bottom bearing and route the remaking part from the center to the left.

Hope this makes sense.

Cliff

[Brian Runau]

Brian,

You don't route the entire side with the same pass. When you're routing the underside of a curve the grain runs downhill from the right side to the center. When you cross the center the grain now runs uphill from the center to the left. So you route the right half with top bearing and the template on top you. Then flip the piece over which makes the grain of the unrouted section, which is now going from the center to the left, run downhill. Raise the bit to use the bottom bearing and route the remaking part from the center to the left.

Hope this makes sense.

Cliff

Yes, thanks. Should I do this for the outer and inner curve or just inner? Some days I am "thick as a brick. " Brian

[John Kananis]

Do it any time you're going to run into the grain.

[Brian Runau]

Do it any time you're going to run into the grain.

Thanks. Brian

[Jim Becker]

Yes, thanks. Should I do this for the outer and inner curve or just inner? Some days I am "thick as a brick. " Brian

You really have to look at the grain direction to decide what parts get routed with the template up vs which get routed with the template down. It's not about the curves as much as the grain direction and the way the tooling spins against it.

[glenn bradley]

JOhn, sorry, thick headed this morning. Use a bit that has a top & bottom bearing on it in the router table. In my mind I will have to adjust the bit height after each pass. Less work than changing the bit, but trying to make sure I am clear on the process.

Thanks.


Brian


Yes. You use one bearing to route downhill for part of the cut, flip the part and template, adjust the height of the bit so that the other bearing comes into play and finish the cut going downhill. Did that make sense? Just pet a cat from tail to head and you will get the idea of what your router bit is doing when you route uphill.

[Brian Runau]

Thanks to everyone for the help. Learning new skills, 1st curved leg project. Think I salvaged the damaged piece. I planed the break flat and glued it up. Joint looks good and I think I have enough meat to trim smooth. Brian

[Brian Runau]

So I bought a top bottom bearing flush trim bit 1/2" shank. The gap between the top bearing and the top of the cutting edge is fine, but the clearance on the bottom is much larger and I am uncomfortable running my 1/4" thick pattern on this. By the time I lower the bit so I am trimming the bottom of the wood, I am almost off the bottom of the pattern with the bearing. So I think my only choice is to remake the pattern and I don't have any 3/8" or 1/2" scrap ply around to do this. I do have a piece of quarter sawn oak that is left over from a project and is flat and is 1/2" thick. Any reason I can't use the oak as my pattern? Thanks Brian

[John Kananis]

Can you just double up the 1/4 material? So just glue (ca is good and quick) another piece to the existing template and trim it down.

[Steve Jenkins]

How about just gluing another piece or two of quarter inch to your pattern and flush trim. I type too slow

[Brian Runau]

How about just gluing another piece or two of quarter inch to your pattern and flush trim. I type too slow

Good thought. Thanks brian

[Brian Runau]

Well I now have 8 walnut curved legs. Thanks to everyone for your help.

Brian

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