How would you make these legs?

[Toni Ciuraneta]

Hi guys.
I am on the way to start making a table I designed a few years ago, that I didn't make because I wasn't sure how to do it. I'm not going to disclose it now, but these are its legs. (See below)
As you can see, they are curved in two directions, and I didn't want to take the easy way out by cutting them from a single board as it would waste a lot of wood and also maybe render them fragile due to the gran direction no matter how parallel to their length I could cut them. I've drawn the lines of the potential board to show the amount of waste.

Then I thought about curving them with steam, but again making a double bend like that would be quite difficult for my first time at bending wood.
So today I got a combination idea of cutting the legs following the side profile which is the one that is less curved, and once cut bend it with steam to achieve the other curve.
My question is: do you think it will work? Is it a bad idea? and last but not least, to those who are more experienced than me, do you have a better idea?
I will apprecciate your thoughts on this matter a lot.
Thanks to all.

 

[Dave Richards]

Maybe like this? The grain would run closer to the direction of the leg without requiring bending.

 

[Leo Voisine]

I may do them on CNC - BUT and there is always a but

Steam would be the better choice because of the grain orientation. Build a form with both bends. The problem would be to make 4 forms. Steam and bend one at a time would be a PITA.

 

[Darren Wright]

I might consider a laminated glue up in a form over steam bending for repeatability and accuracy, but I’ve not done a lot of steam bending. I just know that the end product tends to depend on the wood used and how much spring back you may get.

 

[Charles Lent]

I've never tried to do this on something this large, and never done any steam bending, but I frequently 3D cut on my band saw and scroll saw. I think Dave Richards has shown you how to make the cuts to achieve what you want. With something this large I would do it on my band saw. You may waste a few in the process of making 4 good ones, but I don't think it would be this hard to do.

Charley

 

[Don Baer]

I would take a lesson from Sam Maloof, he was in my opinion the "king" of templates. and make a template out of something like 3/8 MDF then I would trace the pattern and do em on the band saw. Or if you really want to do it like sam take the router in one hand and a piece of wood and have a it..just kidding.. or am I lol

 

[Toni Ciuraneta]

Thanks a lot guys. Your comment do clarify mi mind a lot.
Dave, I think I'll try your approach using two templates, one for the front side and one for the side. In this way I could make both right and left legs using the same templates. I'll get some cheap pine wood to give it a try, although I think that the trick is referencing them correctly to the piece of wood and among themselves. I'll work on that in my pc.

 

[mike calabrese]

You can create these on a router table using a pattern. It gets a bit complex as you will need two different patterns but possible. Like I sad it gets a bit complex needing spacers to atrrange the pattern parallel to the table but doable. The picture here shows the concept I used on making legs with some different detail . Ask any questions.

 

[Paul Douglass]

I would try cutting them on a band saw. Ruff cut then lots of sanding.

 

[Charles Lent]

When I do the reindeer, I use a pattern that shows the face view, a fold line, and one side view. They are kept in alignment by this paper pattern and the fold line. The fold line goes against one corner of the piece of wood, and for the reindeer, their feet need to touch the end of the piece of wood. I use stationery store rubber cement to glue the pattern onto the wood. For the reindeer, no part of the surface of the wood remains after the cut, so I don't need to worry about getting the paper pattern off of the finished wood, so using rubber cement may not be the best choice, but alcohol seems to work well to remove spills.

I use a DIY clamp to hold the pieces together during the cuts. It's important not to allow any of the cut pieces to fall away during the cutting. Some of your uncut pattern for cutting the second side is on them. You may need to stop and add some tape to keep the pieces together. Tighten the clamp each time you make a long cut that removes the blade thickness of wood, as the clamp will loosen during the cutting. It needs to hold everything tightly together and in alignment.


I follow the lines of the pattern of the side view of the reindeer, cutting all of the lines on that side to completion, and re-tightening the clamp as needed during the cuts.

I then unclamp and rotate the pieces while still keeping them perfectly aligned with each other. Then tighten the clamp with the face view showing. Then I cut all of the lines shown in the face view,. again tightening the clamp when needed.

When you are certain that all of the cuts have been completed, you can remove the clamp and loose pieces. The cut reindeer or other pattern is like a hard boiled egg. When the shell has been removed, the chicken or reindeer, or leg appears from the center of the pieces.

The DIY clamp is just two identical pieces of Baltic Birch plywood with cross holes through them at each end (see photo) and threaded rod, wing nuts, washers, and hex nuts to hold them together. Starting at the stationary end, the hardware sequence is - hex nut, flat washer, wood, flat washer, hex nut. The moveable half of the clamp starting from the assembled half of the clamp is - wood piece, flat washer, wing nut. For your leg, you may need to design a clamp that holds the wood together, but also holds the wood rotated to 45 degrees and tape each piece back on the main piece after you cut it free. This part of the deep thinking about the clamp design is up to you.

For a long leg, clamps may need to be added in several places between the end clamps, and removed one at a time as you are cutting this area, then replaced after that area is cut. I doubt that just the end clamping and plywood will remain straight enough to hold the pieces together in the center area of the clamp over such a distance. My clamp that's shown in the photo is only about 6" long and 1 1/2" wide (high), as I have never needed one to cut anything 3D that didn't fit in this clamp.

Before you start, make certain that the saw blade and table are at a perfect 90 degrees with each other, both side to side and front to back. Use high blade tension to keep the blade perfectly straight as it's cutting. If you look closely, the blade that I used for this 3 1/2" tall reindeer is a scroll saw 2-0 blade. It's the tiny black vertical line that can be seen as it crosses the rear clamping board.

Charley

 

[Toni Ciuraneta]

Hi guys.
I don't know how to proceed in tranferring those outlines on the board. If I change their position so that I waste less wood there is no way they will come out as desired because ortographic projections, do modify the length and shapes, and the only way I can cut them so that I get what I designed is by wasting wood.
So according to the ortographic projections I should use an enormous block of wood, if I take those same outlines and reorient them so that I use less wood, the leg will not match. I'm stuck as I do not find a way to draw those templates to cut them on the bandsaw, and not wasting wood. Hence my initial approach of steam bending, honestly I am lost at this point.
On Rhino I can unroll developable surfaces, but even that doesn't help much.
I hope I have explained my problem well.
Now my only guess is to create a plane as much parallel to the length of the leg on both sides and project the outline onto it, as the ortographic projections do not work as shown on the sreen shot of the right.
See screenshot below

 

[Toni Ciuraneta]

I think I got it, as Dave drew it, I put the leg as vertical as I could, then I drew those two planes and projected the leg onto them. My error was trying to get templates without changing the position of the leg and moving the projections to fit the potential board. This shot is a test, I'll make another one with the planes as close to the edges of the leg as possible and that will give me the measures of the board to cut it from
or so I think. I will have to pay attention to the position of the templates by projecting their ends to the corner of the board. or it won't work.

 

[Toni Ciuraneta]

Nope, It doesn't work! I can rotate the piece in one of the views, but not on both (Front & right) because then the view gets distorted or I am following a bad path to get this thing done?

 

[Dave Richards]

I didn't save what I drew for my example and it wouldn't have been exactly right, anyway. I'm not sure if you can do the same thing in the application you are using but in SketchUp I set up the component's bounding box, represented by the dashed lines to fit tightly around the leg. Here's an example from a chair I modeled for Thos. Moser. If you get the box to fit tightly you should be able to generate the outlines for each face. If there's a twist in the surfaces of your leg you could transfer all four patterns to the sides of the leg blank and then connect edges on opposite sides of the blank.

I think you're going to wind up with mirrored pairs of legs but after you've shaped one left and one right, you could use a duplicating just with a router to copy each of them.

 

[Toni Ciuraneta]

I didn't save what I drew for my example and it wouldn't have been exactly right, anyway. I'm not sure if you can do the same thing in the application you are using but in SketchUp I set up the component's bounding box, represented by the dashed lines to fit tightly around the leg. Here's an example from a chair I modeled for Thos. Moser. If you get the box to fit tightly you should be able to generate the outlines for each face. If there's a twist in the surfaces of your leg you could transfer all four patterns to the sides of the leg blank and then connect edges on opposite sides of the blank.

I think you're going to wind up with mirrored pairs of legs but after you've shaped one left and one right, you could use a duplicating just with a router to copy each of them.

Thanks Dave.
Are you suggesting something like this? I've placed planes as close to the piece as possible on its four sides and projected the piece onto them So, in theory I've got four flat curves that I should use to cut the templates. On the bottom shot I've hidden the piece so that the projected outlines can be seen better.

 

[Dave Richards]

I think what you are showing is what I'm suggesting. Your views should be aligned perpendicular to those faces. In SketchUp I aligned the part so the box representing the blank is vertical and aligned to the axes. It might help if you can rotate your geometry to align that way, too.

 

[Toni Ciuraneta]

But even then, the placement of the templates will have to be referenced to the point where the extension of the lines of the top and bottom ends join or arrive to the edge of the blank, won't they? If wouldn't mind helping me I'm attaching the file in sketchup format which I think you can download. If not let me know and I'll send you a PM with it.

 

[Dave Richards]

Here's a SketchUp file back along with a DXF file. Do they help?

 

[Darren Wright]

I think from a larger piece is probably going to give you the most accurate results, but I've not steam bent much either. I guess you probably can still use some of the cut-off material for other parts of the table yet, so I wouldn't look at it as a large amount of waste.

A few years back I cut some boards into several strips, keeping them in order, and thin enough I could bend tight a tight radius. I built a mold for the final shape and waxed it well, also using wax paper for an extra layer to prevent sticking. I then glued each strip back together in order and clamped to dry in the mold. The final piece held shape without any spring-back. There are a few areas you can see the layers, but mostly due to the kerf width of my table saw and change in grain directions of the wood I used. I think band sawn piece would give a less noticeable joint.

This was on my high chair project...

High Chair Project

If you have a dog, there's no need for the railing, & just lay the chair down after the kid has ate :D My brother used to take chair, kid, mess and all out on the patio and hose everything off. Especially after spaghetti, which they loved. No dog. Kids loved it and it worked in Phoenix most...

familywoodworking.org

I might also suggest a polyurethane or clearer glue if you choose to do this. I had some areas to fix after the first finish that the glue prevented the finish from absorbing.

 

[Toni Ciuraneta]

Hi Dave.
Thanks for the files one has come up showing everything in 3D and the other are the projections, (see below) is this what you pretended? I'm asking because there are always problems when converting files from one format to another, I'll give them a try. The difficult part is referencing the templates correctly on the blank.