Dana's DR250 Adventure

[Grant Bunter]

Good to see you back into it again!

One finished is a good target

[ripNdeb]

Trimmed, nicely aligned, and ready to go to the next big step


Glued, screwed, and tattooed





This was a few months ago but, I was very pleased at this point.

[ripNdeb]

Soon to be obsolete OTop 112s in the background; not really. I'm sure I'll find something to use them for.


I've been getting super nice BB from a local store but, this one piece had a weak ply that split in a couple of different places. No problem really; an easy fix.

[ripNdeb]

Many different and varied clamps along with sturdy guide boards for the tweeter baffle backers:



Q: Do you guys put gasket material on the array or on the cab tweeter baffle?

[Scott Brochu]

Mine goes on the baffle.
Nice build.

[ripNdeb]

Thanks Scott; a great compliment from a great pro.

20 wonderful tweets from Leland; ready for sealing and assembly.



I found the Elmer's Rubber Cement to be quite messy and ineffective after the first two tweets so I tried
Locktite All Purpose Adhesive Caulk and it was easy to apply and the white on black gave me more assurance
that the seal was a good one.

[ripNdeb]

Time for some little pieces:


Attaching said little pieces:


And for some half moon pieces (PITA half moon pieces)


Yay! Ready for throat fillers and sheaths:


And here they (the sheaths) are, finally:


Reflectors (by Leland)


And, some side braces, bondo and other cleaning up chores...butt cheeks and sides next; very exciting!

[LelandCrooks]

Did you have to trim them much?

[ripNdeb]

Did you have to trim them much?

Leland, I trimmed them a half inch at the very most - more like a quarter inch after I botched the first longer one. The three degree angle you sent them with already made this job very easy.
LOL, I told my wife, "Do you think he's made these before?" - showing her, an inch of gasket tape left over from the build - top and bottom access covers and tweeter array gaskets.

P.S. do you have any more pre March 2012 throat fillers left?

[LelandCrooks]

No, I don't.

I've done one or two in my time.

[Tom Smit]

ripndeb, you've got a good woman! She lets you build cabs in the kitchen and livingroom!

[ripNdeb]

Did you have to trim them much?

Here's some shots of the second cab which I've been able to work on while I get the first sealed up properly (tweets are still leaking a little).
The second set of reflectors you sent, Leland, I trimmed one of them about an eighth of an inch or less and the rest fit with only some sanding.


My square wasn't too happy about this but, I had made the gap in the center just enough too wide to warrant
an extra little bit of spacer besides the 1/8" scrap piece down the middle. It turned out just fine in the end after
the second cheek was in place, the two pushing against each other adequately.




And, here's a coffee table full of tweets. I'm low on funds so I bought the unmatched tweets
from Leland - they were all great except one slightly weak one.


I was very happy with cab #1 and cab #2 is even better. Here's the other butt cheek glued
and cured, one side on and one to go.


The more you make the better they get. This array is very nice - very straight, leak free and fits
in the cab beautifully. I had put layer after layer of ABS down the middle/back seam and still kept
seeing light through it with the flashlight test. So, I ended up putting a coat of ABS right down the
middle of the front seam and voila - no more light - all good! That's 22 gauge bare copper wire you see on the back
with the alternately rotated element housings - works really well and makes the soldering a ten minute job.

The ugly ABS line will of course not be seen after the diffuser is in place.




Side two, cab two going on with the obligatory squeeze-out pics.

With the exception of current cab #1 pics this brings us up to date. Cab #1 needs finishing and a decision on what to do about the backs.
I'm sort of regretting not making full sides but I thought of perhaps gluing a piece of 3/8" ply from butt cheek apex to butt cheek apex and
filling from the ends of that piece to the ends of the sides overlap - also 3/8" - with fiberglass. Any fiberglass folks out there care to
comment on what would be involved with that? Thanks,
Dana

[ripNdeb]

This better demonstrates what I'm thinking about in my question
in the post above - fiberglass filling the area where the red arrows are.
That's just a scrap of 1/2" that I'm holding up with my foot. That piece would actually be 3/8" and a match for the back
end of the sides overlap.

[LelandCrooks]

Nice. Nicely done on the arrays also. That's precisely how I wire them, except I put heat shrink between each tweeter. In a DR unnecessary, because it's enclosed.

[Robin_Larsson]

RipNdeb, you probably could fill it with fiberglass, but, as a boatbuilder, I wouldnt recommend it actually. If you made it in solid fibreglass, it sure would be strong, but, rather heavy. You could make it with sandwich material, say 5-7mm foam (divinicell or similar) and 1-2mm fibreglass.
But it would still be a lot of work, and with messy materials! I do like to laminate myself, but I hate to cut and sand fibreglass.. and you need a lot of protective gear, you dont want polyester or epoxi resin on your skin, and maybe even more so, the dust..

I´d say, do it the way I did on my DR 280s, I did as you have done so far, short sides, the I put a filler piece in the middle as you are suggesting, (I made mine in 12mm, but 6 or 9 should be fine)
The, to fill the area you´ve marked with the arrow, I simply put two more layers of 4mm plywood! I put one layer from the sides, ending just before the centerfill piece, which was leveled to that second layer of 4mm ply, and the we routered out at bit of the side panels, so that the last layer of ply overlapped the side panel by about 20-30mm, and that last layer wrapped all the way from one side, around the back,and to the other side.

Thanks to the overlap, we got that last layer nice and straight, and it all looked very good:) We could then make a 9mm radius on all edges It looks great, and the bended backcorners are probably the stiffest and strongest part of the cab

Ours are built in pine btw.

//Robin