Cutting Small Angles

reible · Post by **reible** » Tue Feb 18, 2014 1:30 pm

I came, I read, I studied, and those plans are bad. When I see 1' 1/2" I've got to wonder why this is not shown as 12-1/2". Same goes for the 1' 2", clearly 14".

First sketch with the 3/4" x 23/32" x 3/4" and the mention of 2 degrees. Those two do not agree. A quick sketch shows the angle to be about 1.2 degrees off both sides. The drawing does not indicate anything but a symmetric piece....

Part "D" has a length and a height but no radius. If I use arc's it will be different then if I were to do a radius. No cue as to what was intended. A 10" radius does come close to what is shown but doesn't match the strips.

When I make the string of parts based on the given 3/4 to 23/32 tapered parts they do not match the other know parts of the drawing.

If we look at the sketch just below item 13 and count the slats there are 21 of them, not 24. This makes more since as when one makes a top like this it normally will have an odd number of slats so the center ends up in the center of the top slat. On my sketch up build it is really close when I reach 19 pieces.

Now I know we are missing a lot of pages but from what I see I have absolutely no confidence in what has been presented in what we have been allowed to see and thus question the rest of the plans.

The question will be what does the fit look like after taking another 1/4" off the top in final shaping.

The following sketch is done using the 3/4" x 23/32" parts and rotating each part from after the center one by 2.4 degrees. The part "D" is shown with arc's that come out very close to a 10" radius. I have no cue as to if this is correct or not.

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I think I'd be call the guy and finding out what is what before I worry about how to cut the slats. For $12.95 he owes you that.

Ed

JPG · Post by **JPG** » Tue Feb 18, 2014 2:18 pm

Interesting my butt, I thought the trunk stacking finale was hilarious!:D

As for the funky plan. There is more right than wrong. That initial trapezoid is what is most wrong.

Using a 12.5" chord, I derived the following:

10.01" radius ~~10
2.193" height ~~2.1875
13.5" arc
1.35 rad = 77.35°
2° cuts create bottom dimension of .697
19 slats on arc = 13.24

This is consistant with that pix showing 19 being short of the full arc.

Now for the coup de gras - 19 x 4° = 76° which again is short of the total arc(77.35°).

I do not know if the plans included the radius.

So as we pretty much concluded the 23/32 is not created by 2° cuts.

I hope some learned that when removing material from two opposing sides, that the amount removed from each side is half (the original minus the
final dimension).

I am always suspicious of 'plans' especially those that look resemble plans in women's magazines.

Not sure why one extra was cut.

Lotta slop once we realize that the sides will be trimmed as needed!

edflorence · Post by **edflorence** » Tue Feb 18, 2014 2:35 pm

Wow, this discussion has gotten pretty numbers intensive...So, I thought I would contribute a formula I picked up a while ago that really helps with laying out these circular segments. I found it in a reprint of Popular Mechanics "Shop Notes" from 1907.

Post # 22 includes the .pdf with the info for building the arch on which the slats are to be placed during construction. Using the dimensions given in that post, and the Popular Mechanics formula, the radius of the curve can be determined as follows: Take (1/2 chord distance), square it, then square the height and add the two results together. Finally, take that sum and divide it by twice the height. The result will be the radius of the curve, which in this case turns out to be a bit less than a 64th over 10 inches.

You now have enough information to layout a full size drawing of the arch on which you can then draw the slats and determine the correct angle for setting the table tilt.

dusty · Post by **dusty** » Tue Feb 18, 2014 2:42 pm

This is getting really funny now.

If we are not all attempting to do this with the following dimensions, if is no wonder we get different results.

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dusty · Post by **dusty** » Tue Feb 18, 2014 2:43 pm

edflorence wrote:Wow, this discussion has gotten pretty numbers intensive...So, I thought I would contribute a formula I picked up a while ago that really helps with laying out these circular segments. I found it in a reprint of Popular Mechanics "Shop Notes" from 1907.

Post # 22 includes the .pdf with the info for building the arch on which the slats are to be placed during construction. Using the dimensions given in that post, and the Popular Mechanics formula, the radius of the curve can be determined as follows: Take (1/2 chord distance), square it, then square the height and add the two results together. Finally, take that sum and divide it by twice the height. The result will be the radius of the curve, which in this case turns out to be a bit less than a 64th over 10 inches.

You now have enough information to layout a full size drawing of the arch on which you can then draw the slats and determine the correct angle for setting the table tilt.

You are right on.

bear1050 · Post by **bear1050** » Tue Feb 18, 2014 2:46 pm

I want to thank everyone for the input? I am really new at wood working and some of the suggestions are beyond my beginners understanding. Wanted to build this chest as I thought it would be simple and straight forward to do but right now I am not sure I can get the top correct which is why I picked this plan cause I liked the design. Would anyone have a simple way to explain to me how I should move fwd with this plan? I am not sure I am as far along in the wood making business as most of you and my understanding of some of the above is beyond me. thanks again for all the help and input. Bear

JPG · Post by **JPG** » Tue Feb 18, 2014 2:52 pm

edflorence wrote:Wow, this discussion has gotten pretty numbers intensive...So, I thought I would contribute a formula I picked up a while ago that really helps with laying out these circular segments. I found it in a reprint of Popular Mechanics "Shop Notes" from 1907.

Post # 22 includes the .pdf with the info for building the arch on which the slats are to be placed during construction. Using the dimensions given in that post, and the Popular Mechanics formula, the radius of the curve can be determined as follows: Take (1/2 chord distance), square it, then square the height and add the two results together. Finally, take that sum and divide it by twice the height. The result will be the radius of the curve, which in this case turns out to be a bit less than a 64th over 10 inches.

You now have enough information to layout a full size drawing of the arch on which you can then draw the slats and determine the correct angle for setting the table tilt.

((c/2)² + h²) / 2h ====== h/2 + c²/8h

Take yer pick!;)

JPG · Post by **JPG** » Tue Feb 18, 2014 3:22 pm

bear1050 wrote:I want to thank everyone for the input? I am really new at wood working and some of the suggestions are beyond my beginners understanding. Wanted to build this chest as I thought it would be simple and straight forward to do but right now I am not sure I can get the top correct which is why I picked this plan cause I liked the design. Would anyone have a simple way to explain to me how I should move fwd with this plan? I am not sure I am as far along in the wood making business as most of you and my understanding of some of the above is beyond me. thanks again for all the help and input. Bear

Please do not let our taking a simple question(how do I make this piece) and making a two day project out of critiquing the plan discourage you.(not all of the posts make perfect sense anyway since we were 'brain storming')

Set the table for a 2° bevel cut. Set the fence for a 3/4" top width at 3/4" above the table. Take a few trial cuts on short pieces. By trial cuts, I mean cut just enough to get the profile of the end and stop and measure and readjust the width(top = 3/4") if necessary.

IIWM, I would not cut the 3/4 x 3/4 strips prior to cutting the bevel.

I would cut from a wide board that has been cut to 'near' final length, the first strip. That strip will have one side beveled and three sides square. Flip the board end for end, placing the wide face facing up. This time the strip will have two sides beveled.

Repeat until the board is consumed.

Repeat until sufficient strips are made.

It would be good to consider the first strip cut from each board to be waste and not try to add the second bevel. Two could be used for the outside pieces that get trimmed.

If however they are already 3/4 x 3/4, set up using Ed's hold downs etc.. Again setup for 2° and 3/4" width across the top. Tight to the fence and tight to the table!!!

robinson46176 · Post by **robinson46176** » Tue Feb 18, 2014 3:25 pm

bear1050 wrote:I want to thank everyone for the input? I am really new at wood working and some of the suggestions are beyond my beginners understanding. Wanted to build this chest as I thought it would be simple and straight forward to do but right now I am not sure I can get the top correct which is why I picked this plan cause I liked the design. Would anyone have a simple way to explain to me how I should move fwd with this plan? I am not sure I am as far along in the wood making business as most of you and my understanding of some of the above is beyond me. thanks again for all the help and input. Bear

And this very well states why I often worry about all of the highly involved putzing around we sometimes do on this forum overwhelming folks that are somewhat new to woodworking.
Bear asked a simple question and got buried in numbers, high tech devices and formulas...

While we (yeah, me too) were having a good time exploring this subject Bear is standing there looking at a saw and a stack of wood saying "HUH!!!???

I will offer one profound piece of advice Bear and someone already said it. "Cut it"...

If you feel the need, go get a little cheap 3/4" dimension lumber like the box stores now like to call "white wood" and build it out of that first before trying one out of "highdollarwood".

DON'T BE AFRAID TO MAKE A MISTAKE... We all make them and you can almost always find something smaller to build out of your screw-ups. Either that or buy a woodstove.

The only mistake to be worried about is one involving blood or loud screaming.
About 95% of what I have built was either something out of my head, I maybe saw it somewhere or from a picture. Working like that you don't give a rats behind about exact dimensions, you just make it fit the other pieces in front of you. All of those plans come from somebody building the thing and then taking measurements or somebody else measuring another persons work afterwards.
Remember the "KISS" system (Keep It Simple Stupid) and have fun.

.

dusty · Post by **dusty** » Tue Feb 18, 2014 3:37 pm

Our numbers are close but I doubt that we will ever determine which are closest to correct.

I believe this to be my last shot at this.

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