BillFitzmaurice.info

Continuing with the HF module... Got a lot done today (even forgot about the football games, but I checked and my Niner's won against the Cardinals) but not as much as I wanted to. But I'm guessing that's pretty much the norm for anyone doing a cab build.

Before proceeding with putting on the sheaths, I wanted to make sure the melded arrays will fit now that the PL has set the faces and cleats. Good thing too, because it was too tight to fit through, so I had to make some trim adjustments. I used a Dremel with a plunge spiral bit. I like using it because, 1) it's easier to control freehand, and 2) it pulls the sawdust away from the work so I can see how much I'm trimming as I'm doing it. Now the MA fits in perfectly. Just a note, the MA doesn't go in straight on. You have to put it in tilted sideways and rotate it in. A close-up of the back. You can see where the routed groove in the back panel allows the fit of the tweeters. It's definitely a tight and just right fit. Started off with a rough cut of the panels and then fine tuning them to each side. I used staples to hold it all together. The front face is overhung by about 3/16" of an inch. I'll trim it with my trim router once PL has set.

(Cont.)
Front view of the sheaths installed. While the PL on the sheaths was setting, I started the work on the side braces. To keep them consistent, I made a routing template for the braces. I made it out of 1/4" MDF. I used the two arc guides that my friend made for me for the layout. Fine tuning the fit of the template before proceeding.

(Cont.)

Tracing the template to all the brace blanks. All the side braces rough cut and final shaped with the router. Again, I taped the template to the rough cut blanks and then routed them to final shape. After test fitting each brace I laid out the final trim lines for cutting as per the plans, and labeled them. I used a scrap sled jig, aligned and taped the braces and cut off the excess.

(Cont.)

All the side braces trimmed up and labeled. Drilling pocket holes for screws to attach the back end of the side braces to the back braces. With the side braces dry clamped I traced reference lines and drilled holes to secure the front inside edge of the side braces from inside the driver chamber. Back edge of the side brace attached to the back brace with pocket hole screws. Screws driven into the front inside edge of the side braces from inside the driver chamber.

(Cont.)

All the side braces installed. The PL on the HF modules have set. I was going to use my trim router to clean up the excess overhang of the sheaths. But I decided to go old-school (real) woodworking and used my small block plane to trim down the excess and then sanded the sheath edge flush with the front faces for the final step.
Because the face and cleat framework of the HF module is on the smaller side, putting on the sheaths can possibly alter the alignment a little bit. So I dry fitted the MA's again just to make sure. And sure enough, it was off just slightly, so I had to shave off a little more - about 1/32". Now everything fits hunky dorey! And just to make sure everything still fits, I dry fitted the whole HF module into the main cab. Everything was good. You'll notice I don't have the mounting nacelles installed yet. I'm debating to do what Grant did with his DR250 build (viewtopic.php?f=30&t=18214&start=60) OR what is in the plans. I like the clean look of what Grant did, but I'm not sure if I want to go through all that work, since it won't really be seen. I plan on putting grills on the opening of the horns. Side view of the dry fit. That's it for today.

Do the nacelle route. Make one long wedge-shaped piece (triangular looking), and then cut the individual parts off. Draw a base line from top to bottom on the sheath to know how far forward they go.

Now I have even more motivation to pay attention to this build - plans have been in. Went through it as a quick read, and you that doesn't mean a whole lot. Lightly reviewed Grant's tubes, and I get why he did it that way. I'd do a little different, with a smaller tube, and a Hex head (love those) instead.

I hope you don't mind if I ask you some questions of your build, as I'm mentally preparing for mine . . . and since you're on the nacelles, I've loosely had a though process similar to Grants.

Do you think it be feasible to glue the nacelles on the inside, then use a Forstner bit from the outside to drill the "tube", and come in with a smaller bit to go all the way through? Of course the nacelles would be shaped differently, actually, the exact shape of the inner bracing. I'm thinking doubling up on the 1/2" ply (if I don't have any extra 3/4" lying around, which I may) to do this. My thoughts are since the sheath is supported from the inside, the 1/8" won't blow out. What do you think?

Still trying to wrap my head around the port design - and making them adjustable. . .

If I haven't said it yet, thank you for sharing. Great techniques, great build!

Sorry, double post????

kekani wrote:Now I have even more motivation to pay attention to this build - plans have been in. Went through it as a quick read, and you that doesn't mean a whole lot. Lightly reviewed Grant's tubes, and I get why he did it that way. I'd do a little different, with a smaller tube, and a Hex head (love those) instead.

I hope you don't mind if I ask you some questions of your build, as I'm mentally preparing for mine . . . and since you're on the nacelles, I've loosely had a though process similar to Grants.

Do you think it be feasible to glue the nacelles on the inside, then use a Forstner bit from the outside to drill the "tube", and come in with a smaller bit to go all the way through? Of course the nacelles would be shaped differently, actually, the exact shape of the inner bracing. I'm thinking doubling up on the 1/2" ply (if I don't have any extra 3/4" lying around, which I may) to do this. My thoughts are since the sheath is supported from the inside, the 1/8" won't blow out. What do you think?

Still trying to wrap my head around the port design - and making them adjustable. . .

If I haven't said it yet, thank you for sharing. Great techniques, great build!

That's exactly what hifibob did on his DR280s - doubled up on the braces and then used pocket screws. Dig back in his build thread...

billkatz wrote:

kekani wrote:Now I have even more motivation to pay attention to this build - plans have been in. Went through it as a quick read, and you that doesn't mean a whole lot. Lightly reviewed Grant's tubes, and I get why he did it that way. I'd do a little different, with a smaller tube, and a Hex head (love those) instead.

I hope you don't mind if I ask you some questions of your build, as I'm mentally preparing for mine . . . and since you're on the nacelles, I've loosely had a though process similar to Grants.

Do you think it be feasible to glue the nacelles on the inside, then use a Forstner bit from the outside to drill the "tube", and come in with a smaller bit to go all the way through? Of course the nacelles would be shaped differently, actually, the exact shape of the inner bracing. I'm thinking doubling up on the 1/2" ply (if I don't have any extra 3/4" lying around, which I may) to do this. My thoughts are since the sheath is supported from the inside, the 1/8" won't blow out. What do you think?

Still trying to wrap my head around the port design - and making them adjustable. . .

If I haven't said it yet, thank you for sharing. Great techniques, great build!

That's exactly what hifibob did on his DR280s - doubled up on the braces and then used pocket screws. Dig back in his build thread...

Yup, just did. Thanks for that.

The nacelles aren't too complicated. The face of the nacelle, when properly positioned, is parallel to the rear panel of the HF module, and thus the HF module mounting surface on the cabinet. The nacelles allow a seating surface for the screw heads that fasten the HF module to the rest of the cabinet.

Superb build - not sure about the green though! Are you painting the cabs black?

ncgrove wrote:The nacelles aren't too complicated. The face of the nacelle, when properly positioned, is parallel to the rear panel of the HF module, and thus the HF module mounting surface on the cabinet. The nacelles allow a seating surface for the screw heads that fasten the HF module to the rest of the cabinet.

I agree, it isn't that complicated. I do like the look of Grant's tube, and definitely like the application of Bob's DR280. If I had paid more attention to Bob's builds, I would've caught it.
http://billfitzmaurice.info/forum/viewt ... &start=195
I didn't because I just thought his level of build was WAY beyond mine, and if/when I did DR's, it wouldn't be near his, so I figured I couldn't steal much from that thread. I was wrong. Between this build, Grant's and Bob's, I think they've covered mostly all of the basis of the DR series that anyone doing research could want. I'm sure there's more, but for the recent ones, these are very well documented.

Not sure if I'd double up on the bracing, or just double up on the "inner nacelle", but as Bill stated, those with adequate drill presses can do this. Actually, I like Tom's idea.

I should have mentioned that those individual pieces are the actual nacelles. After drawing the line, mark the locations that you want, place a nacelle butted down to it in that location that you want, and trace around the nacelle. Then, between a dab of PL and hot glue, install the nacelle.

Today was a bit frustrating. Figures. Since yesterday was a good build day, today was a trying one. Not all bad, but it had its moments.

Kekani - I liked the idea of putting the nacelle on the inside and do a pocket hole and how it would look, but as I examined it a bit, it would take a bunch of work. First, I would have to clean up the PL squeeze out on the inside of the HF module so there would be a good joint connection to both the sheath and the back. It was just too tight in there. Then you would have to be pretty accurate with your placement of the nacelles on the inside. The DR200 is the smallest of the DR's and there's not a whole bunch of room. But I did like the idea. Maybe if there is a future DR build...

Anyway, I decided to stick with the nacelles. It's in the plans and seems pretty straight forward. Tom I used your approach and it works quite nicely. Thanks for that tip.

Chris - It was a toss up between red, purple, green, and pink. I'm not a pink guy. Purple has been done. I came down to between red and green. To me green just sticks out more. It's a forgone conclusion that the sound of these puppies will get everyone's attention, but I think the bright green will compliment that more than the red. So green won out. And yes, I am using Duratex black. I plan on also using green highlights here and there for visual interest as well. I had almost thought about getting Duratex white and then blending it with the black for a mottled swirl effect. Maybe on the Tuba 45's.

On to the build for today...