Hurricane Nuts in plywood

[lilmike]

Just an FYI - careful with the torque you put into Hurricane Nuts that are installed in cheap plywood!!!

While installing the driver in an Autotuba, we managed to either cross-thread or damage the threads in three of the Hurricane Nuts. The individual installing the driver (NOT ME!!!) kept twisting away even though the threads were not mating right and before we knew it, he spun several of the nuts free, making it impossible to properly tighten the driver (or remove it.... )

We glued the shanks with PL Premium before placing them, and probably got some into the threads. Anyhow - it probably wouldn't hurt to test-fit screws or run a tap though each nut prior to installing the driver. As for me, I'll probably make my future baffles out of MDF or at least a better grade of ply than Home Depot's finest.

Even with a poor seal to the baffle, the Autotuba sounds good, but it is not quite right, so we get take it all apart and try again....

Practice makes perfect, or so they say....

[Bill Fitzmaurice]

While installing the driver in an Autotuba, we managed to either cross-thread or damage the threads in three of the Hurricane Nuts.
....

I always try the bolt with finger pressure only, if it doesn't go in easily I chase the threads of both the nut and the bolt until it does go in by hand.

[CBIERN]

I learned the hard way when working with stainless steel racks in photo processors to have a 10/32 tap handy for use at the 1st sign of binding or cross threading. It's saved my butt working with t-nuts too. Never, ever think that more torque will solve the problem!

[Tim A]

Never, ever think that more torque will solve the problem!

So, you're saying we should all throw out our bigger hammers?

[lilmike]

While installing the driver in an Autotuba, we managed to either cross-thread or damage the threads in three of the Hurricane Nuts.
....

I always try the bolt with finger pressure only, if it doesn't go in easily I chase the threads of both the nut and the bolt until it does go in by hand.

Someone once said "Hindsight is always 20/20"...

Anyone have an idea as to how I can undo this other than wielding my recip saw with impunity?

(You guys can have your big hammers, I'll take my recip saw, though I gotta admit, the shop does have a BFH or two ready when nothing else will do!)

I think I've figured out plenty of ways to avoid this next time around.

[Bill Fitzmaurice]

You can cut the bolt head off with a Dremel tool and an abrasive disc.

[Les Webb]

Reciprocating saw has worked for me when this exact same thing has happened on some of the larger tubas. Dremel might be better though.

[DaveK]

... have a 10/32 tap handy for use at the 1st sign of binding or cross threading.

I've learned to hate 10-32 T-nuts. Way too easy to cross thread. I use 1/4-20 whenever possible, even when it is way overkill (like bolting on the back of an Omni).

[bgavin]

I have (eight) 1/4-20 T-Nuts and L-clamps holding my 8" MCM 55-2421 driver onto the baffle of my upcoming Autotuba.



I even routed a recess into the baffle board so the driver is always centered when the clamps are applied. Gotta love that Jasper Jig.

I use a bolt to draw the T-nut into the wood. Learned my lesson long ago about not installing with a hammer. It bungs up the threads.