Part II: CTH Casework
(Continued from Part 1
Well I got some more work done on the CTH case last night which really helped relieve some of the work stress I've had all week.
So last I night I trimmed the mitered pieces to get the height down to around 2-1/8”. Btw I made a last minute decision and did a minor change from my original design/plan. I really like the recessed knob on my SOHA II
so decided to do the same for the CTH. The change does not affect the overall dimensions, only the look of the knob where it now also protrudes on top of the wood instead of it being centered.
With the pieces all trimmed down, the housing is high enough to keep the tall PCB parts (caps/heatsick) remain under when I install a lid, but it’s low enough for the tube (with socket saver) to stick out far enough for the heat to dissipate.
Next step is I drilled the holes for the jacks. Edit: If you prefer, you could also route out the back panel first (see couple of pics below) before drilling the holes.
I used a caliper to measure the diameters of the input/output/AC jacks, fuse holder, and heater switch then created a printable layout in Sketchup
. The pot I plan to use is the Alps RK97 which comes with an on/off switch built-in, therefore a dedicated pwr switch is not needed for this build.
Printed the layout using 1:1 scale, then taped the print out to the wood piece which will in turn becomes the case back panel.
All set now for the drill press:
After drilling the holes using standard drill bits, I removed the paper template and followed the holes with a Forstner bit to recess them… only a wee bit.(Edit: thefragger left a comment about this step and he makes a good point.
"thefragger: I would've done the drilling operations in reverse; forstner first then the thru holes, for the sake
of concentricity. The forstner leaves a little dimple in the centre which is perfect for drilling the thru hole.")
Before I can mount the jacks to the back panel, I need to carve some of the material out using a router with a ½” bit. A little over ½” deep should be sufficient.
Made good progress I thought. The switch, fuse holder, and jacks all fit nicely and after a couple of hours in the shop the case is currently at this stage.
I’ll finish up the case by glueing the pieces together next time, clamp it tightly and then start working on the top/bottom lids next time.
Well I hope so far some new builders will find this log of value and get a few ideas from it when finishing/building their projects -- again, thanks for reading.
(Continue to Part III