The TNH Amp, 1.2

Okay, I picked up some glasses for him to wear today, but this table saw pic was from yesterday. After cutting the sides of the cabinets to length, and routing dovetail joints, the next step was to rip the boards to dimension. We settled on a head cabinet and speaker cabinet (open back) with a 10" depth. This ripped about 1-1/2" to 2" from the boards and usually involved ripping both sides. This is so that the dovetail joints ended up nicely on the corners. It is incredible how much lighter this thing is with that little bit of wood removed. You can see the little push stick (black/yellow tape on the end) that I use for ripping smaller pieces. He learned to hold the wood against the fence and not bind the blade. Actually, he did very well at this stage and ripped 80% of the boards.

I learned on my other builds that any hardware connections that mount through the wood should be drilled before glueing the cabinets together. On my first build, I must have spent 45 minutes trying to line up where the holes should come up through the bottom to meet the receiving threads in the chassis. It turned out just fine, but it was a headache. With the piece unassembled, it is a 45 second job. The bottom has four holes where socket cap screws mount the chassis to the cabinet. The top has two holes where the handle is mounted though the wood. I don't trust wood screws for stuff like that. I will screw the feet on with screws, though, as well as all of the corner protectors.

Here is a picture of the amp chassis bolted to the bottom of the cabinet. Note that I have a t-nut counter-sunk (3/4" forstner bit) for a solid connection. I use 1-1/2" or 2" hex socket cap screws for this (10-32 thread). The mistake that I made on my first build was to leave the threads in the t-nut. This means that the screw has to thread the t-nut as well as the thread-sert in the chassis. While I like that I can back out the cap screws and have them hold in place, it is better for them to just fall down. This makes mounting the chassis a lot easier because you can feel just the threads of the chassis, and not the chassis and the t-nut. It was very hard drilling out those little t-nuts. I should have used a larger size and not worried about the threads at all. However, now they look and feel fine.

I like to use these hex cap screws for this, but I don't care to use an allen wrench. There are these little plastic thumb knobs that stretch perfectly over the tops of these guys so that you don't need tools at all to remove the chassis from the cabinet. Judging from this pic, that screw is at least 1-3/4", and possibly 2" (the dimension of the chassis side). Sorry for the bad picture here, but you can see that the bolts meet up with the chassis using the nut-sert or thread-sert that is mounted to a hole drilled in the lip. This makes such a positive match to the cabinet and I am very pleased with it. It is a little detail that I think makes the whole project a little higher quality. The quick and dirty way that some builders use is to mount an angle bracket on the outside. However, this means the whole cabinet needs to be wider, and then you have to hide the edges. This method is one way to have the cabinet inside dimension match the chassis.

--gh