[Syzygies]

Here are some pictures of my bloodwood PIMETA.

The end panels are 1/8" bloodwood, as described in the thread Exotic Hardwood End Panels:

The Hammond J16 case just fits in a sturdy pocket:

The battery pack is a set of three RadioShack 270-413 AAA battery holders, holding 12 NiMH AAA cells:

The usual drill, one pairs red with black in a daisy chain all the way around for the battery pack. It seems one is wiring the 9V snap connector backwards, but this is ok because it's being used backwards, it's pretending to be a battery, not connecting to one.

I'm using external charging circuits. I attached two snap connectors to a "normally closed" switched power jack, so inserting a plug disconnects the amp. One can then charge the battery pack, or steal power from it for a dying iPod.

Here I got very, very lucky. I bought the last nine $5 18V RadioShack trickle charger wall warts for $3 each from my local store, on spec. It turns out that as 12 NiMH cells reach full charge, the trickle current from one of these drops below 100 mA. Perfect for the 1000 mAh AAA cells I'm planning to buy, ok for these as long as I watch.

The fancy cable I've interposed allows me to watch voltage and current on two multimeters. This is the second one I've made, and this time I thought to heat shrink it in a way that leaves the wiring pattern apparent:

 

[d00dz]

FINALLY we get some creativity around here...

VERY VERY NICE....I love the exotic wood end pannels. I'm planning on doing a complete encloure using exotic wood...I just need these exams to be over...but before i do a complete one...I just might steal your idea with the end panels...hope you don't mind.

 

[digi01]

Quote:

Originally Posted by Syzygies The usual drill, one pairs red with black in a daisy chain all the way around for the battery pack. It seems one is wiring the 9V snap connector backwards, but this is ok because it's being used backwards, it's pretending to be a battery, not connecting to one. I'm using external charging circuits. I attached two snap connectors to a "normally closed" switched power jack, so inserting a plug disconnects the amp. One can then charge the battery pack, or steal power from it for a dying iPod.

nice amp,smart ideas.

 

[n_maher]

Beautiful work - nothing more needs to be said.

Nate

 

[Syzygies]

So 1/8" hardwood panels were a bit trickier than I expected to work with, and I already knew exotic hardwoods could be a bear. I'm hoping if various of us make tries, we can figure out a decent system.

A "Unibit" makes short work of making the holes. However, the thread is too short on each of my panel components. One could shop components, hoping to beat this, but particularly for small pots, there isn't much choice.

For starters, one could thin the boards a bit. Every 1/64th matters here, I'd thin the 1/8" boards down to 3/32" next time. They're plenty strong.

I used a conical bit to bevel the back side, so the stereo jacks could snuggle into the wood a bit. This bought me just enough thread to attach the nuts. Unlike the Unibit, my conical bit seriously chattered and left a rough cut, a better option is needed.

For the Alps RK097, I beveled, I cut the nib that keeps it from rotating when it isn't board mounted, and I also sanded down the PIMETA board a bit so the pot was truly on the edge. This mattered.

Don't overtighten any nuts or screws. With so little thread in play, the nuts will just strip the thread. The screws will just split the wood. Sure, the wood is tough, but a screw enjoys a tremendous mechanical advantage, working against the weakest component of wood strength.

I cut the boards after drilling. This way, I could make practice holes just off-board, for fine-tuning the screw holes. Also, cutting is a bear, why invest the time before you know the holes are a go?

Better to cut right the first time, using precise power tools, than rough cutting and sanding to shape. This wood is tough as nails! I have a Proxxon hobby drill press, but not their matching miniature table saw, which would be perfect here. Perhaps a Dremmel tool would do the trick, cheaper. I used a Japanese pull saw and sandpaper, one makes do with available tools.

As an alternative, I'm tempted to use Forstner bits to countersink holes for the component nuts into the front of the panel. This could allow thicker wood, e.g. 1/4" stock. One could instead countersink the back, but this doesn't solve the pot issue, because the PIMETA board itself gets in the way.

I'm hoping that we can collectively make the above more routine, by improving the technique. That said, I'm used to futzing with wood, this was one of your basic futzing sessions, the job got done.

I oiled with almond oil, a nut oil I had handy in the kitchen. I like minimalist finishes, otherwise might as well use plastic?

 

[jnewman]

EDIT: I need to read posts more carefully.

I think your forstner bit idea is a good one - that's what I'd do, plus maybe route it out with a chamfer bit so it's a tapered hole.

 

[Syzygies]

Quote:

Originally Posted by d00dz I'm planning on doing a complete encloure using exotic wood.

The whole DIY debate applies again in spades. I've been considering this too, because I love wood, but unless you have a decent workspace, extra time, and all the right tools, buying a case is a whole lot easier.

Wood end panels let us reconfigure at will without buying expensive 12 packs of Hammond end panel inserts, they (mostly) free us from worrying about what to ground, what to isolate, and they give a great wood accent for the least effort. End panels can be worked without a decent workshop, and they're a problem we all face anyway.

On the other hand, making your own case you can design around the battery pack. I'd insert a metal cage around the amp board, to isolate from interference. Don't glue it to the wood, they have different expansion rates. See the thread Possible issues with all-acrylic casing? for more on this.

Quote:

Originally Posted by d00dz but before i do a complete one...I just might steal your idea with the end panels...hope you don't mind.

Please! Tell me how to better cut and drill them!

 

[USER NAME:]

Here is a wood amp of walnut and Figured maple.

 

[phobus]

holy crap thats nice

 

[USER NAME:]

Thanks. It's too bad I'm limited to posting 25k images, because the finish on this is top notch.