2 x DR250 (melded) + 2 x DR250 (CD horn) March 2012 plans. Completed

[Grant Bunter]

Day 6.

3 hours including cleanup time.

Started out cleaning up PL on the first cab.

Then cut more hardwood up to use as straighteners/dewarpers.
I bought a Merbau decking plank (heavy dark redwood hardwood) 90mm x 19mm (err not quite 4" x 3/4") when I started the T39 builds, specifically to cut up as dewarpers. Cut to length, slice down the middle to end up with 45ish x 19. I use them on their edges, clamp the ply and merbau together to pull the warp out, insert heavy screws, done.
I know it's not 2 x 2, but it does the job.

So, dewarped second cab and finished it to the same stage as the first cab:

Called it a day, haven't slept much after working last night and on again tonight... so chill time

[Gregory East]

Baltic birch users are some lucky fellows.

I had my pine ply go its own way after I cut it. I got the worst of it out by dampening it and laying it flat on the concrete with a big pail of water on top. It still took a lot of wrangling with clamps and logs to mate the horn panels on my little BAT.

[Grant Bunter]

Baltic birch users are some lucky fellows.

I had my pine ply go its own way after I cut it. I got the worst of it out by dampening it and laying it flat on the concrete with a big pail of water on top. It still took a lot of wrangling with clamps and logs to mate the horn panels on my little BAT.

I hear ya Gregory.
It would cost me almost as much to get BB to me as it would to buy it!
And why would I bother when I found a nearby source of locally made radiata ply at $15/sheet.
Laughing all the way to the bank!

So far my builds have been not overly bad with warping.
However, when you have to make critical measurements to cut more pieces to put into the build, as is the case with the DR's, I figured the extra half hour to sort it was well worthwhile...

[Gregory East]

Now you're making me jealous with your cheap warping radiata, I paid good money for mine.

[Titanium Hand]

$15.00 Ply ? Good find. Speaking of "Finds"; warped merbau is a right P.I.T.A bain of my existence when building 'economic' decks for clients who wont spring for good aussie hardwood!

I'm surprised you could find a piece straight enough. To avoid exorbitant straight edge prices in the hardware, I've resorted to a local aluminium fabricator/supplier. I purchased a 6m length x 100 x 25 and cut it up into a 3 , 1.8 & 1.2 Straight edge's for the price of a 1.8m straight edge @ bunnings

DR's are looking flash by the way -so bloody intricate though

[Grant Bunter]

Day 7,

2 hours including cleanup time.

I've been busy with work and feeding cattle and getting more hay. So the build has been quiet for nearly a week.

Today, drew up the additional half circles and attached 1 pair to cab 1. Cut and installed sheaths to cab 1.

You have to read the plans fully. More than once!
It seemed natural to me, that if the horn throat area requires a light stuffing of pillow filler, then the time to do that is before putting on the sheaths. Stuffed (pun intended) if I know how you'd do it if you missed this...

More planned for tomorrow...

[Chris Betancourt]

Day 7,

2 hours including cleanup time.

I've been busy with work and feeding cattle and getting more hay. So the build has been quiet for nearly a week.

Today, drew up the additional half circles and attached 1 pair to cab 1. Cut and installed sheaths to cab 1.

You have to read the plans fully. More than once!
It seemed natural to me, that if the horn throat area requires a light stuffing of pillow filler, then the time to do that is before putting on the sheaths. Stuffed (pun intended) if I know how you'd do it if you missed this...




More planned for tomorrow...

Good job brother its looking sweet. In this pic, "the sheath" did you glue it on right there where you have it placed?? Cuz it must be glue touching the half circle and reaches the front brace not the end of the front edge?? Just a concern of mine. Maybe your just showing the stuffing before close the hole I guess. Anyway keep those pics coming cant wait to see it finnished.

[Grant Bunter]

Hi Chris
Thanks mate...
You can breath a sigh of relief lol. That's pic is just showing the stuffing in place. The sheath has been glued in the correct position!

More to follow later today...

[Grant Bunter]

Day 8

5 hours including cleanup time.

Installed half moons to cab 2
Cut out and installed sheaths to cab 2.
While I waited for the PL to set some, I trimmed and installed Reflectors on Cab 1.
Then trimmed the sheaths on cab1 at the front.
Bondo'ed screw holes.
Sanded sheaths.

Then trimmed Reflectors for cab 2 and installed.

I scratched my head for a short while about how to champfer/channel the reflectors.
Hand file, be there for days.
Out with my trusty POS 4 1/2" angle grinder with super thin (1.5mm or 1/16") steel cutting blade. Man that made the job a total breeze! A few swipes on each edge did the job.

So at the end of today:

Apart from ports for tuning, I feel like I'm at the end of stage one.
I need to get 2" joiners and pipe and the correct size hole cutter for the ports as I'll go with the adjustable tuning option for smaller gigs without subs.

When building Bills's designs, it seems with each cab there comes a time when everything goes from stable to firm, IMO with these cabs, putting on the reflectors just made everything tighten up. Sure, adding the sheaths made a difference, it was the reflectors that stopped everything moving...

[LelandCrooks]

For sure. You start in and what's this rickety thing I'm putting together. One more piece and all of a sudden it's a tank.

[Grant Bunter]

For sure. You start in and what's this rickety thing I'm putting together. One more piece and all of a sudden it's a tank.

Well put Leland!
And from that point on, every extra piece you add just makes it stronger and stronger...

[Bill Fitzmaurice]

The back braces should be butting the throat horn divider. I wouldn't tear them apart to fix it, but viewers should be aware that's how it should be done.

[Scott Brochu]

I think it could be fixed by taking the horn divider out using a knife and a small hand saw and repositioning it. But definitely getting it fixed now IS the way to go like Bill mentioned.

[Grant Bunter]

The back braces should be butting the throat horn divider. I wouldn't tear them apart to fix it, but viewers should be aware that's how it should be done.

Damn!
I thought I was doing so well...
More haste, less speed.

Bill,
If I was to PL in a small piece of scrap to secure the middle braces to the throat horn divider (ie on the underside of the throat horn divider, just wide enough to touch each of the middle braces, say 1" x 1") would that be of any benefit? Or leave well enough alone?
Does me having done this the way I have affect the benefit in offsetting the throat horn divider and it's consequent improvement in mid range response?

I think it could be fixed by taking the horn divider out using a knife and a small hand saw and repositioning it. But definitely getting it fixed now IS the way to go like Bill mentioned.

Scott,
Since I've left all the screws in, I'm thinking to do what you have suggested would be very difficult to achieve, but I agree

[Bill Fitzmaurice]

Does me having done this the way I have affect the benefit in offsetting the throat horn divider and it's consequent improvement in mid range response?

Yes, though I can't say by how much. It's one of those theory things where I never tested it the 'wrong' way to see what would happen.