And because this piece is narrow and the guide nail is gonna slide off the end, I'll just tack the pattern temporarily to another piece of material until the ellipse is drawn. The pattern piece needs to be big enough so that the two guide points can follow both edges. I don't need to make these marks because they're built into the stick, but I'm drawing them on here for reference. I'm gonna lay out a nominal 9-1/4 inch width. It's extra nice 'cause it's easy to see and use and mark on. The only adjustment is in the major and the minor axis distances to change the proportions of the arc. The process is a same for drawing any ellipse. The goal is to have the pencil firmly in place and the guide nails to extend further through the stick than the tip of the lead. And then the pencil gets inserted through the drawing hole, and because the pencil fits a little bit loose, I'll add a piece of masking tape to snug it up. I do a little fussing around up front to get a nice accurate ellipse stick for a more accurate pattern.Ġ4:05: Now, I simply drive a straight hardened nail through each of the guide points. Using the drill press assures the hole go straight through the stick.įor the two guide nails, I use a small drill bit to create a straight pilot hole and then drive a nail through. Redpoint bits are good for this because the center spike holds the drill bit accurately on the mark. I'll drill a hole at the center mark for a pencil. The caliper tells me this pencil is just slightly over 5/16 of an inch. That way I can set how much the lead extends so that it will draw a good mark but not snap off. This is the kind I like, these Paper Mate ones that have a twist-out lead instead of a clicking lead. To draw this elliptical pattern, I'm just gonna use a mechanical pencil. And the other one is the minor axis, which is 6-1/4 inches. One is the major axis, which is 10-1/2 inches. I'm just gonna draw a reference line along the stick.Ġ2:27: I need to make three marks on here. I have a dimension of 6-1/4 for the minor axis and 10-1/2 inches for the major axis, and those are the two dimensions I need for laying out a pattern for drawing the ellipse.Īnd when someone asks me how do I draw an ellipse, I say, "Well, with an ellipse stick." Right? To make an ellipse stick, I just need a scrap of wood, preferably somewhat straight, and the length of the stick needs to be a bit greater than the sum of the major and the minor axes. An ellipse has major and minor axes that give it the elongated shape, and the pattern we're making is for one-fourth of the ellipse which will form the cut on the joists for this pergola. I started out with the 2x12s in this large pattern, and I'll use the same process to create a slightly smaller ellipse of a different proportion for other 2x10 numbers on the pergola.Ġ1:21: The first thing we need for laying out an elliptical pattern is the major and minor axes of the ellipse, where a circle has one center point and one radius. Because I'm using a range of lumber sizes for the pergola, starting with 2x12s, going all the way down to 2x4s, I need to make a separate elliptical pattern for each so that the proportions look nice on the width of material. I want to show the process I use for laying out and creating this pattern and then using the pattern to produce consistent, accurate results. In this video, I want to show the process I use for creating smooth, consistent, accurate results considering the method uses basic shop tools. One of the design elements is an elliptical cut making the sweep in the bottom of these haunches that will hold other parts of the pergola. I'm in the shop today making parts for this backyard pergola. Or, come up with a way to use posts and beams down to earth to support your pergola.Make a pattern using elliptical sticks, and then use a router with flush-cut bit to replicate onto the big stock hang 360# from the center of one rafter tail and see if it breaks. I would load up one of your rafter tails to 4x that load (a factor of 4x is often used for safety factor with lumber) to test out your idea. Whether your roof's rafter tail can support 75# + 15# is a function of the length of your rafter tail, the size of the rafter tail, and the depth of the rafter notch. That is an added Live load of maybe 150# / 2 = 75 lbs on the rafter tail. Remember that kids may want to do pullups off of the open pergola rafters if they can jump up and reach them. 15# dead weight will be carried by each rafter tail. Don't use OSB, it is crummy in tension.Īn 11' treated 2圆 weighs about 30 lbs. The method you suggest to hang the load off of the rafter tails using a plywood sandwich might be feasible, if your rafters are over-sized. 11' is a reasonable span for 2圆 pergola lumber that will not carry any roof load.
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