Profiles


00101

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Not entirely sure if this should go here or in general talk, but I figure chances are I'll being doing the bulk of this with a power tool so....

 

I'm looking to make a box similar in profile to this piece here 

il_570xN.353372562_ihzh.jpg

 

I'm wondering how to go about making the profiles in the sides and lid. I originally was (and still am) thinking of using the table saw cove technique to get the sides roughed, but as I've been looking at this, it doesn't appear to be a cove. More of a swooshy deal. And secondly looking at the lid, the round over appears to be elongated and not the circular profile standard round overs have. Granted I'm not terribly versed in all the router bits out there, so there may be a bit that has the lid profile. 

 

More important of the two would have to be the side profile as it's much more defining to the piece, so if I have change up the lid some it's not a huge deal.

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Depending on the angle you set the fences and the angle of the blade to the table many shapes of cove are possible on the tablesaw. Think of the shape on that box as part of a cove. You might have to rig a blade guard and have part of the blade in one of the angled parallel fences to cut that shape.

As for the round over , if you cut a 5 degree bevel before you use the router bit and then sand to blend the shape it becomes more of an oval type cross section. Play with different angles , might need more or less to get the look you want. I use a random orbit sander to blend. Sand up the side of the box and pivot untill you are sanding the top, move over 1/4 of the disc and repeat in a overlapping pattern.

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Depending on the angle you set the fences and the angle of the blade to the table many shapes of cove are possible on the tablesaw. Think of the shape on that box as part of a cove. You might have to rig a blade guard and have part of the blade in one of the angled parallel fences to cut that shape.

As for the round over , if you cut a 5 degree bevel before you use the router bit and then sand to blend the shape it becomes more of an oval type cross section. Play with different angles , might need more or less to get the look you want. I use a random orbit sander to blend. Sand up the side of the box and pivot untill you are sanding the top, move over 1/4 of the disc and repeat in a overlapping pattern.

I considered that the side profile is only part of a cove, and that to cut it I'd just need to use only part of the blade. However, in thinking about that, I don't think that doing so would be all that safe. If I did only use part of the blade such that one of the edges was over the blade, I'm concerned that since there's no support on the blade side of the piece that it would be incredibly easy for it to tip into the blade and... well whatever happens when work binds in a cove cut.

 

Hmm... Would gluing a sacrificial piece of pine or something to it to make it wider, then cut the necessary cove and then lop off the pine do it?

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You do not need much material either side of the blade cut to get a good bearing surface. Rather than mess with gluing pine I'd just start with stock that is 3/8 wider than finished dimension. This would give you 3/8 to play with either side of the blade. One side would get ripped off but the top gets milled to receive the lid. You'd only be wasting 3/8 stock without the time invested in gluing. For sure try this on less expensive stock first.

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This is no different than making moulding knife patterns. Its a compound miter just draw it out on paper as a compound with 4" as your known radius and experiment with different sized circles until you find one that works best. Get out that protractor and compass you got in third grade or steal one from your kids. Once you see it drawn it will hit you how easy it is.

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Have we skipped the basic and gone straight for the advanced? Once you sketch your profile like PB suggests, I believe there are a couple online cove generating calculators. Someone who has used one could point you in the right direction. All you need is the width, depth, and eccentricity of your curve. The further off center the arc of your cove the more of a swoop you get.

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Have we skipped the basic and gone straight for the advanced? Once you sketch your profile like PB suggests, I believe there are a couple online cove generating calculators. Someone who has used one could point you in the right direction. All you need is the width, depth, and eccentricity of your curve. The further off center the arc of your cove the more of a swoop you get.

 

Dont over think its not advanced at all. Just draw a board full scale on a piece of paper. Use a $2 compass and start drawing circles and sketching in. Once you draw the circles you know where the center point is.

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Angling the sides might make making the cove easier but it's going to complicate anything you do for the interior.  I don't know if the geometry would work out but you might even be able to glue two sides together at the bottom with paper in between as a release and run the cove down the middle.

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Angling the sides might make making the cove easier but it's going to complicate anything you do for the interior.  I don't know if the geometry would work out but you might even be able to glue two sides together at the bottom with paper in between as a release and run the cove down the middle.

 

 Think crown moulding but thicker.

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I understand the concept, but I am saying when you put up crown moulding you are done.  When you assemble the sides of the box you are not done.  Are you going to be mortising hinges?  That just got complicated.  Is this a jewelry box with interior dividers?  That just got complicated.  Saving yourself 5 minutes of work now might lead to hours of work later.

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I understand the concept, but I am saying when you put up crown moulding you are done.  When you assemble the sides of the box you are not done.  Are you going to be mortising hinges?  That just got complicated.  Is this a jewelry box with interior dividers?  That just got complicated.  Saving yourself 5 minutes of work now might lead to hours of work later.

 

The inside should all be at 90 degree angles.  Stock is cut more like a wedge.

 

 

MWJB-04-open.jpg

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Hello 00101,

 

I can't back up the table saw method as it's not something I would feel happy doing. Firstly make sure you keep your stock long and don't be tempted to work on short ends, a sure way to loose to loose fingers. As I can't sign up to the table saw method I would recommend removing material with a router table and finishing off by hand. The convex shape at the top of the box would straight forward as a hand plane would easily finish off your routing. The concave shape on the lower section would be harder. A moulding plane (a round) and a scrape would get you there. If the hand tool approach is a no go you would need to splash out on some router cutters.

Last resort would be find someone with a shaper/spindle moulder who would make the profiles for you. 

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I would do something like this.

1) the top is a fingernail bit like a Whiteside 3294 that has a 1" profile width.

2) the bottom is a handrail bit like a Whiteside 3305 that has then had the bead removed. You could remove it by hand or with pattern bit.

3.) Finish the bottom off with a v-grove, point cutting, or narrow slot cutting bit. bit

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