New Build of Old-style T39s

[Bruce Weldy]

Time to start two additional T39s. Like the last ones, they'll be 25" wide.

I considered going with the new style build, but after looking at the plans, it looks like the old style is easier - so I'll stick with it.

Just got back from picking up 5 sheets of Baltic Birch at $25.34 ea.. We are lucky to get it so cheap in this part of the world....

My cut sheets (and cutting order) are complete and the ripping starts tomorrow morning. I'm also expecting a large box from Leland tomorrow.

I know it's the old style, but I'll post some pics along the way anyway.

[shawn_g]

Time to start two additional T39s. Like the last ones, they'll be 25" wide.

I considered going with the new style build, but after looking at the plans, it looks like the old style is easier - so I'll stick with it.

Just got back from picking up 5 sheets of Baltic Birch at $25.34 ea.. We are lucky to get it so cheap in this part of the world....

My cut sheets (and cutting order) are complete and the ripping starts tomorrow morning. I'm also expecting a large box from Leland tomorrow.

I know it's the old style, but I'll post some pics along the way anyway.

That's a ridiculously cheap price for Baltic Birch. What drivers are you going with?

[miked]

Cool! I knew you'd get them done before the new outdoor music season started. Good luck and please post lots of pics.

[Bruce Weldy]

That's a ridiculously cheap price for Baltic Birch. What drivers are you going with?

I felt it was my civic duty to post the price......nah....I was just rubbing it in.

I'll put in the 3012LF again.

[88h88]

That's annoyingly cheap for BB... I'm about to get a few sheets myself and the best price any place local (ie; without pulling a 100 mile round trip) is selling for is still over $60 a sheet for a 8'x4'.

[Grant Bunter]

Looking forward to seeing the pics Bruce!

And the smile on your face when you run them up with your existing pair...

[sine143]

4x8 bb is 50 here. 24 for 5x5 of top quality, 21 for the lower grade (about 7 footballs per sheet in the low grade stuff).

[Bruce Weldy]

Got started cutting panels today. Had a major disappointment with my baltic birch. Oh, it was straight, flat and beautiful.....only, it wasn't square!

3 out of 5 pieces were too far out to even try to use, so I had to square up one corner before I could even start. First time that's ever happened. Usually, its just picking which corner is the most perfect....out of 20 total corners, only two were close enough to use...and they weren't perfect.

One of the things that I do is to not only produce a cut list, but I also set up a cutting order. It's a speadsheet that starts with ripping all the sheets, then crosscutting. By planning this out in advance, every rip of any certain width is done at one time - thus, they are all exactly the same. This certainly helps in keeping the boxes square.

By not having four square corners though, it made me do more cutting with my circular saw jig than I wanted. With square corners, I would have made every cut on the table saw, but due to not being square, I had to do any cuts over 25" with the sled. Fortunately, that was only a few.

Nothing to really take a picture of yet....tonight and tomorrow I'll start prepping the tops, baffles, spacers, and all the bevel cuts on the horn panels.

A little snag on hardware, so I can't get my speaker mounting t-nuts and access panel nuts installed. I will have some downtime until they come in. But I'll get all the woodwork finished that I can.

[miked]

You know what, maybe MY BB wasn't square either...and I didn't bother to check. My skills are half what yours are, but I certainly know how to use a table saw. I've been scratching my head for weeks now wondering how my cabs are so far out of square. I know I screwed up the horn panels on a couple, but they should be better than they are. My BB was probably not square either.

Oh, and my BB has probably 5-8 footballs per sheet too. And here I thought I bought the good stuff. Definitely was flat and void-free though...a real pleasure to work with compared even to $60/sheet 4x8 3/4" oak ply.

Looking forward to seeing progress pics!

[Bruce Weldy]

You know what, maybe MY BB wasn't square either...

That's probably exactly what happened. I always try to find the most dead-on corner to cut from. And usually it's a toss-up. I just couldn't believe how bad this was. The stuff looks great - it just ain't square.

[Bruce Weldy]

Since there is plenty of T39 builds documented....and I'm building the old style, I'll try to focus more on process instead of just progress. Most of this will be useful on the new style too.

First out of the box - draw it out. Then place the other side behind it, clamp it together, then drill your holes through both boards at once - now the other side is ready to slap on at the end.

Cutting the handholds was a pain last time, this time I built a jig. You only have to cut the handhold one time in the jig. Clamp it or screw it to the top, then rough cut inside the hole with spade bits and/or a jigsaw - then use a pattern bit and a router. You only need to use the jig for one top panel. Then use that panel to be the template for the other top and the back panels (you'll have to use a spacer to get the alignment right on the backs, then clamp it and start cutting).

Here's the finished product...

The backs....leaning on the old T-39....

I'd like to give credit where it's due, but I can't remember who suggested this approach to the access cover panel cleats.....this is much easier than cutting and putting in separate strips. Just cut the panel with the same bevels that you would the strips...do a little measuring, then cut out the middle.

[Bruce Weldy]

Cont'.....

Here's the baffles. I did all of the "holes" in the tops, access cover cleats, and baffles on the table saw using a "rising" cut by bringing the blade up slowly into the wood. Makes really nice internal cuts...

And last, but not least.....one day I may buy one of those expensive circle-cutting jigs for my router. But for now, the old piece of scrap paneling and a 3/8" dowel works just fine.

[miked]

Very nice, Bruce. I like the "process" approach/pictorial. I'm already taking notes for my T48 builds. Keep the pics coming and continued good luck to you. Looking great so far!

[doncolga]

Dude I'm jealous. I wish I was building right now.

[biggerrigger]

Looking good!