Eagle Project T24s

[bassmonster]

Hi all:

I'm a Life Scout working on my Eagle, and I only have a project and Board of Review to go. A couple of weeks ago my church announced they were moving to a new campus, and needed offerings for new equipment and such. I inquired if I could build them a pair of speakers to help ease their costs, and as an Eagle Project for me.

They wanted subwoofers for the youth worship room. We decided on two 21" wide BP102 T24s. I inquired about T39s but they were too big. The two T24s are overkill for that 40x40 room anyway, but what's wrong with extra power?

It must be noted that the Eagle Project is a sheer leadership project. I am not supposed to actually do the building, but to instruct other Scouts and my friends to build it under my leadership. This is a considerable task especially with the mandatory airtightness of Bill's subs. This thread will only be added to every weekend because that's the only time we can build. I expect the build will take about 4-5 more weekends, they go up fast when 6 people are working at them on a time.

[bassmonster]

What's this? A box from Leland?



It looked like it went through a war. I was nervous about what might have happened to the things inside, but opened up and everything was fine. Impeccable packaging from Leland!

Here's everything sitting on my TT. 8 tubes of PL.



Horn paths drawn. You can't see them that clearly but they're there.



Panels cut. Exterior panels are BB, internal panels are Arauco. I got my BB from Interstate Plywood, 5x5 sheets, 9 ply, $50 a sheet. Great quality BB, it's great to work with. Heavy though.




Actual construction begins next weekend.

[Gregory East]

Are you sure you got enough PL??

[Titanium Hand]

Good Job Bassmonster! EIGHT TUBES OF PL Outstanding, cant be too careful can we.
Nice to see a pair of T24's being built, haven't seen any for a while, I'm really interested to hear your in depth review upon completion.

Good luck

[Grant Bunter]

I'm looking forward to the week to week progress of this thread.
I'm sure you have the skills to lead this project to satisfactory completion, and attain your goal.
Occassionaly, leadership may require leading by example, as many people have different learning methods.
You may just have to get your hands dirty lol.
If your frustrated (and you may be at times) while instructing others, take a deep breath, count to 10 in your head, and proceed calmly.
All the best!

Grant

[SoundInMotionDJ]

I am looking forward to the updates.

--Stan Graves
Eagle Scout, 1984

[Traijin]

As am I.

--Chris Flook
Eagle Scout, 1997

[Haysus]

Be patient with the young ones and you can instruct adults as well. Good luck.

Dave Delfel
Troop 25
1994

[bassmonster]

Sorry for the late updates everyone. While working on the T24s Saturday I was reading plans off my laptop and the hot sun was beaming on the back of the laptop screen. I took it inside afterwards and opened it up a few hours later, and the screen was cracked! Heat shock? So my computer has been in my school's tech center for the past couple of days getting a new screen.

Anyways, I planned to get through panel 7 but I had to instruct the Scouts how to jigsaw, teach about kerf, how to countersink, how to lay a nice bead of PL, how to attach panels. The way I always do it is lay a bead of PL, set the panel on the horn assembly where it is to be attached, making sure it is square, and then someone lies down underneath the sawhorses and drills pilot holes straight up under where the panel is sitting. The person above is holding the panel to make sure it doesn't walk. Of course the whole assembly is predrilled before any panels are attached so we know where the panel is being attached. After drilling pilot holes the person underneath then drives drywall screws into the panel from below. Then we screw the panel into the panel sitting next to it. This way no clamps are needed and each panel keeps the other square. We could probably build the whole thing in a build marathon if we had enough time.

Everything was going well up to the baffle. I made the mistake of not measuring the diameter of the actual cone on the BP102. I'm such an idiot that I didn't measure it, cause we were behind and I was sort of in a rush. Notice how most all stupid mistakes happen in a rush?

So I mistakenly instructed two people to cut a 10" diameter hole in the baffle (actual BP102 cone diameter is 9"). Completely my fault. That was good BB too.




It was a learning experience. Luckily we had enough BB scrap to cut two more driver baffles. Friday night we are recutting the driver hole and installing the hurricane nuts. We will be using JB Weld epoxy. I fear the 5 minute epoxy included in the Speaker Hardware T24 kits will not go well.

Here's what we finished. Panels 1,2, and 4. Yes I know out of order from the plans, but I test fit Panel 3 and it will fit in perfectly, so no worries. We could have attached more panels, but we decided the fubared baffle was a good stopping point to not get too ahead of ourselves. Yes, one of the pair of sawhorses isn't level. They were two different brands of sawhorse, we borrowed them from my neighbor so I'm not complaining. The good pair of sawhorses are used for the actual assembly while the other horn assembly sits on the uneven sawhorses while waiting for more panels to be attached.



I keep the Scouts moving by playing some good tunes on Dual TT that I had lugged into the garage for demos. Before firing it up they asked how many watts and when I said less than 300 watts and two eights they crinkled their nose, until I turned it on. They were stunned!

Thanks for tuning into this thread, I appreciate the support. Good to see some past Scouts on this forum! Next big building session is Saturday 10am-2pm, after finishing the baffle Friday night.

[doncolga]

Everything was going well up to the baffle. I made the mistake of not measuring the diameter of the actual cone on the BP102. I'm such an idiot that I didn't measure it, cause we were behind and I was sort of in a rush. Notice how most all stupid mistakes happen in a rush?

I keep the Scouts moving by playing some good tunes on Dual TT that I had lugged into the garage for demos. Before firing it up they asked how many watts and when I said less than 300 watts and two eights they crinkled their nose, until I turned it on. They were stunned!

On my last two T30's I botched *two* 30 x 30 panels of BB when I miscut the access panel *twice*. Luckily I was able to still use those pieces for other parts. I don't think there's any turning back from all the marketing hype has completely warped people's thinking on this...unless they happen to be some of the lucky ones who get to hear Bill's designs.

[bassmonster]

Lots of stuff done last night and today.

Driver baffles recut and hurricane nuts attached, drivers attached.



The drivers are completely attached with the latex caulk around the edge and all. I installed the baffle panels into the subs with the drivers still attached, except for the drivers were protected with plastic grocery bags sealed around them. The drivers will stay on. No flames please, these are the third and fourth drivers I've done it on and never had a problem. Yes a little caulk on the surround but I got that off later after it was dry.

This is what we did today. I had plenty of help too which was nice. Got through panels 7 on both of them. Panel 7 was about 1/8" too long but no problems with being a tad long IMO. You can't see the difference and if PL squeezeout doesn't affect the horn path I think 1/8" of extruding wood won't affect it either.



Next work session we will install the rest of the panels and the casters, and hopefully paint the inside of the horn mouth. Then the following session we will sand it all up, paint, and solder Speakons and do the driver access door.

[bassmonster]

Well, we didn't get as much done as we planned today, but a lot of progress was still made. We attached Panel 8 and did Panel 9, the panel we attached casters to. Panel 9 is the rear panel of the sub when it's standing up normally, so we attached the casters there so the user can just flip the Tuba on its back and roll it out.

Here's the two Panels 9, we didn't use hurricane nuts for attaching the casters because 1) I hate working with hurricane nuts in general, and 2) The thick bolts are more sturdy IMO, and they don't spin at the drop of a hat and ruin everything like hurricane nuts do.

The red stuff on top of the bolt assemblies is Loctite Threadlock, the red level threadlock, which means these nuts will never come out again. Even though we used lock washers as well, the extra insurance can't hurt because being on the back panel, these won't be accessible if they ever fall out. They won't fall out.



Close up of the bolt assemblies.



Here's one of the subs. Clamp reversing a small warp here.



And the other.



We've had a few minor errors and mis-measurements, but all in all assembly is going pretty smoothly. Next workday we hope to finish the actual assembly.

[bassmonster]

Quick question. What can I do, if anything can be done, to help reduce the casters rattling at high volume? Rubber bushings?

[88h88]

I'm sure I've read that people wrap string around the bearings.

[Tom Smit]

Quick question. What can I do, if anything can be done, to help reduce the casters rattling at high volume? Rubber bushings?

these perhaps?