BillFitzmaurice.info

Gah. Spent the weekend doing wife maintenance instead of working on speakers.

Did now just get in an hour or so. Have one top and baffle glued up. Aside from putting in the baffle upside down and backwards and having to reglue (what a mess!) and disposable gloves falling apart (see my other thread), and the baffle sliding around like it was greased, it was cake.

But, I think I've figured out that I need a gluing jig. I've got a design in mind that should make things much easier next time around.

I got a boatload of honey-dos out of the way, and got some time in tonight. All the jigs people have been showing off got me thinking.

So now I have a glue-up jig for the speaker chamber, made from 1/2" Arauco and scrap pine.

I cut a 1' x 2' chunk of Arauco, marked off a line 3" from one end, and used that to mark off the lines for the baffle and the next 2 panels. Working with 1/2" ply, the edge next to the baffle would line up with the front edge of the top.

Then I screwed the pine scraps in place, and cut out holes for clamps, and added cut outs at the panel intersections to keep the glue off the jig. We'll see how it works tomorrow night.

Nice, and worth the effort for a run of four. Pretty bold doing the whole chamber at once though.

You know you can bang screws into the panels from the underside and back them them out just enough so their points will locate the panel when you plop it back down with PL?

Gregory East wrote:Nice, and worth the effort for a run of four. Pretty bold doing the whole chamber at once though.

I think it makes dry fitting much easier than it was before.

Gregory East wrote:You know you can bang screws into the panels from the underside and back them them out just enough so their points will locate the panel when you plop it back down with PL?

Tried that. Flopping ply around that is a PITA.

My next jig will hold a set of 1-piece spacers on 5-1/4 centers.

More progress. Here is the glue-up jig in action:
I've got stuff dry fitted, no glue yet, so you can see some sizeable cracks.

The jig itself works pretty well. However, it needs some stiffening, as it does tend to twist a bit. Some strips glued strategically across the top would help. Also, I need to put cauls across it and the bottom and clamp them instead of clamping the jig and the side directly.

I discovered where the top got bowed a bit because I cranked down too hard on the top when I was gluing in the baffle.

I have tango classes for the rest of the week, but I should be able to get 6 or 8 hours in this weekend, which means it's time to get the brad nailer set up.

All 4 cabs now have speaker chambers.

I also did my first round of leak checking shining a light right at the seams and looking for the glow coming through. Found a few, mostly between the baffle and panel 4.

Also started in on flanges. Scraping out PL squeezeout is no fun at all, but we want the flush fit.

I won't be able to work on speakers until Friday, but I expect that I'll be able to finish the flanges and start in on panel 5.

In other news, the 12 one piece braces I made, are all the wrong dimensions.

el_ingeniero wrote:In other news, the 12 one piece braces I made, are all the wrong dimensions.

Can you cut away anything or do you have to add? If adding you can always add a wedge or something in the bracing track. There is always a solution. Take a step back and think it through.

Scott Brochu wrote:

el_ingeniero wrote:In other news, the 12 one piece braces I made, are all the wrong dimensions.

Can you cut away anything or do you have to add? If adding you can always add a wedge or something in the bracing track. There is always a solution. Take a step back and think it through.

The main problem is that I mismeasured the point where panels 3 and 4 intersect an inch too far towards the bottom panel. The bottom part is roughly correct.

The way I see it, there are 2 ways of dealing with the issue:

* cut them up to be separate braces
* figure out how to salvage them as 1 piece braces

If these things can be fixed up so as to remain 1-piece braces, that would be a big time saver. The braces are 1/4" ply, and I was counting on draping them over the speaker chamber and holding them down with gluing cauls and ratchet straps until the PL stops expanding, which would let me fly through panels 5, 6 and 7 in a weekend.

I guess I'll have to post pix tonight.

Next time I do this, I'll use 1/2" Arauco on all the internal panels and 3/8" BB on the outside of the box. Would have been so much easier than refiguring everything for 3/8" ply everywhere, and would come out the same weight.

Here you can see where I screwed up.

Are you able to cut that joint apart, pry it apart and then insert a thin strip?

For the tiny amount of lost of chamber volume involved, I suggest just bringing the next panel over to match it where it is, making the mouth very slighty wider at its entry and less tapered, which I'm guessing would be inconsequential also.

There is really nothing you can do to move the panels that are PL in. Unless you cut them out and start over.
IMO I would leave the one brace unit the way it is wedge it where you can in the track and continue the build. It will still work and produce bass. Lesson learned for next builds

I measured and remeasured, drew, erased and redrew the lines on the sides.

They are within 1/16" of where the plans say they're supposed to be, after adjusting for the thinner ply.

It's the braces that are messed up.

I think I'm going to end up cutting them up, fixing each section and gluing them back together. I'm thinking of making jigs I can use in combination with my saw sled so I can get consistent sizing. After that I'll just tape them down on some pink insulation board (I need a a small chunk anyways for another project) while the glue dries.

That middle section where they show a gap at the bottom of panel 4, I'll probably need to make completely new pieces for. Fortunately I have a huge amount of scrap lumber.

Some more progress. I decided to forego the 1 piece braces and follow the plans word for word.

Last night the new Makita rail saw came in handy cutting 4 #5 panels and a set of 12 2/5 braces.

This evening I spent a little time before and after dinner hogging out the braces. The plans show 4 holes, I put in 7.

Tomorrow, I'll put in the #5 panels, and install the braces.

A question: due to working with 3/8" ply, I have to put in 3 sets of braces. Should I round off the section of the middle brace that hangs across the driver slot?