Gauss and the DR200s

[Gauss]

All right, now I've got the divider and top and bottoms attached. When screwing these pieces to the others, I broke through the sides of the plywood. The screws didn't come out, but the wood pushed up. I've pulled the screws out, now should I fill the holes with PL, or bondo them?

Thanks

[WB]

PL

[Harley]

now should I fill the holes with PL, or bondo them?

Clue 1 - Bondo is a primarily a filler and PL is primarily a glue.

PL will fill up gaps between joints to some extent but large gaps can sometimes leak - as I found out in my recent 2 from 1 T39 exercise.

So, use Bondo to fill those holes and you'll be 100% sure.

[Gauss]

Thanks. My concern was in making it airtight, and I wasn't sure about the bondo. I'll fill the holes with bondo and sand down the part where the screws pushed the wood out.

[Gauss]

New snag. My throat construction is too big. I got some help making the curves on the top and bottom panels, and laid out the inside curve and access panel. The throat is about 3/4 inch past the access door line. What should I do?

[David Carter]

You've done it exactly right. That's how it's supposed to be. The overhang is part of the access cover flange.

[Gauss]

Thank you. That brings joy to my heart.

[David Carter]

Thank you. That brings joy to my heart.

Glad to help. I had the same concern when I built my DR250's, but the sketchup model confirms that this is how it's supposed to be.

[Gauss]

Okay, stuck again. I'm cutting the horn braces, including the curved pieces that bisect the horn path, and the numbers in the plans don't make sense. THe curved piece in the diagram on page 19 show a 23" radius that starts at 4" and ends at 6 11/16",( where the width is 12"). I used my 23" compass starting at 4" and after traveling to the 12" point, the length isn't 6 11/16", but over 7". I re-checked several times (compass length, measurements, squareness of board, etc.) and everything is right, but the numbers didn't work. I cut it out and test fit it. It's too big by a half inch or so the whole way. The point where the 4" seems to go is 3 5/8" according to page 14.

I really want to finish this by the weekend after next.

[David Carter]

How did you pick your pivot point for the 23" radius arc? You're suppossed to mark the the 4" and 6 11/16" points, then draw two 23" radius arcs using those two points as the pivot points. Then, where those two arcs intersect becomes the pivot point for the arc that connects those two points. If you're following that procedure (which is the same procedure you should have used to draw the arcs on your top and bottom panels), I don't see how your final arc can fail to connect those two points.

Also, remembering back to my DR250's, the horn braces will intentionally be a little wider than then need to be so that you have room to trim for a perfect fit. This is explained at the top of page 23 in my plans.

If none of this is news to you, and you have other issues, sorry I misunderstood...

[Gauss]

Thanks. In my rush I missed that. I will go back and try with that method instead of assuming that the compass starts aligned with the edge.