myn's Tuba HT Build Thread

[maxmercy]

Myn,

I'd do it in two steps, PL first and caulk afterwards, just to be sure. I know I'd feel like crap if I discovered an air leak that was impossible to get to (unless you take a side off). If you are worried about wire vibration, run and glue the wires along the inside surfaces instead of 'stringing' them in the air.

All these possible headaches are why I put the terminal posts on the access cover. Easy to get to and fix.

JSS

[Rickisan]

All these possible headaches are why I put the terminal posts on the access cover. Easy to get to and fix.

+1 !

[myn]

Yeah, I agree. I am convinced just putting the terminal plate on the access cover is the way to go. Way less to worry about and really easy to fix if there are issues.

Thanks guys

[myn]

[== 7/24/2009 ==]

So yesterday I glued panel 9 to the THT. Since it's apparently going to rain all weekend, tonight I cut out:

- Panel 8/9 reflector
- Panel 9/10 reflector
- Panel 10
- Panel 6/9 braces

I test fit the 6/9 braces and discovered that panel 6 is pretty warped. I tried taking a bit off the brace to make it fit better but it still it didn't fit perfectly, having an 1/8" gap towards the wider side of the brace that gradually gets smaller towards the middle of the brace. The rest of the brace fits perfect. Unfortunately I think the only way to get this perfect would be to trace it which is going to be pretty hard if not impossible.

With that said, Do you think I should just add some extra PL and let it do it's work? Will this cause any issues structurally or vibration wise?

Here's some pics:

Getting Panel 9 ready:


Panel 6/9 Braces prefit:

[Tom Smit]

Let PL do it's work

[gdougherty]

That's why I use the braces to square up the panels as I build. The installation and bracing on the other side of 6 should have straightened 6 out unless you had to bow 6 in to meet that corner.
PL will hold it as is.

[DJPhatman]

Read my signature line!

[myn]

Read my signature line!

Nice. So does this mean get messy with the PL and fill the gap or does it mean get the braces perfect by tracing and recutting?

[DJPhatman]

it means don't worry about making a mess on the inside. No one will see it. Fill the gap with PL and move on.

[bgavin]

Another solution is using a cleat on the inside.
The brace mounts to the cleat, which will give you considerable room for error.
As long as there is 1/2" glue area on the cleat, it is every bit as strong as the normal butt joint.

[myn]

Sorry for sounding ignorant but what is a cleat? Got any examples or pics?

[Tom Smit]

I just finished googling "cleat" w/wood and ......if you have a strip of wood, even 1/4 round, put PL on the cleat and screw the cleat to bad joint. When pPL has set, remove screw(s). The cleat only needs to be as long as the joint (gap) that needs the cleat. In your case, that might be 4-6", or as in your pic, from the end to the screw(?) that is at the end of the pencil line.

[bgavin]

I use scrap 1/2" ply for my cleats.
The flat surfaces allows use of clamps to secure the cleat to the brace.

Only one piece has to be firm... the cleat is clamped to this piece, then forced against the side wall until the PL cures.

As noted above, the dimension is not at all critical.
If a guy was going to slam these out at production speeds, the cleats could be pre-installed in the panels.
The braces can be cut close-enough-for-gummint-work and clamped into place on the cleats.

I had to cleat one side of one of my OT212 for this reason.
Somehow I dorked up a measurement on the brace, and wound up with a gap. Awwshit.
Cleating cured that problem entirely. OT212 is strong like Godzilla with these cleated braces.

[myn]

Thanks guys.

So if my interpretation is correct, it should look something like this (below)


Should I glue/secure the scrap piece to the brace first while test fitting and than proceed to secure the entire brace + cleat/scrap piece to the sides of the panels like normal?

I'm also assuming this extra bump in the bracing won't cause disturbance or extra turbulence in the mouth path?

[Bill Fitzmaurice]

Thanks guys.

So if my interpretation is correct, it should look something like this (below)


Should I glue/secure the scrap piece to the brace first while test fitting and than proceed to secure the entire brace + cleat/scrap piece to the sides of the panels like normal?

I'm also assuming this extra bump in the bracing won't cause disturbance or extra turbulence in the mouth path?

More trouble than it's worth. PL and forget it.