Hi
I have build a number of headphone amps, some in entirely custom made cases and some in popular 2107 aluminium chassis from fleabay.
The enclosures I want to discuss here have pretty thick front panel, about 7-8 mm.
The 6.5mm phone jacks and the pots (cheap Chinese DACTs, I like them a lot!) have about 7 mm long threads, take away 2mm for a nut and you can use them in max 5mm thick panels.
I case of wooded panel I use my router to thin the middle section of the front panel and I can use my sockets and volume pots.
Once (for the pot and 3.5mm 4-pole socket) I drilled the panel with a large diameter drill bit I I glued with epoxy a small piece of 2mm aluminium to provide a mounting surface for the pot.
Today I undertook thinning of the middle section of the 8mm aluminium front panel.
I have made a jig to hold the panel securely. The panel drops in flush with the board surface providing flat surface for hand held router.
It kind of works. But it is soooo harder than working with wood front panels. I have achieved my goal. The finish is not so great (poor mans hands held cnc ;-) ). Luckily it is all inside so will not be visible.
Still i wonder if people have better ideas for pots and sockets in thick panels.
I have build a number of headphone amps, some in entirely custom made cases and some in popular 2107 aluminium chassis from fleabay.
The enclosures I want to discuss here have pretty thick front panel, about 7-8 mm.
The 6.5mm phone jacks and the pots (cheap Chinese DACTs, I like them a lot!) have about 7 mm long threads, take away 2mm for a nut and you can use them in max 5mm thick panels.
I case of wooded panel I use my router to thin the middle section of the front panel and I can use my sockets and volume pots.
Once (for the pot and 3.5mm 4-pole socket) I drilled the panel with a large diameter drill bit I I glued with epoxy a small piece of 2mm aluminium to provide a mounting surface for the pot.
Today I undertook thinning of the middle section of the 8mm aluminium front panel.
I have made a jig to hold the panel securely. The panel drops in flush with the board surface providing flat surface for hand held router.
It kind of works. But it is soooo harder than working with wood front panels. I have achieved my goal. The finish is not so great (poor mans hands held cnc ;-) ). Luckily it is all inside so will not be visible.
Still i wonder if people have better ideas for pots and sockets in thick panels.
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The remaining thickness is not enough for a screw...
But I drilled a couple of holes through the aluminium so that the glue forms "rivets".
Epoxy should be strong enough to make your comment invalid, but unfortunately you are right: I have seen epoxy giving up.
Still I take this risk. I do not sell these amps so i can fix them.
But I drilled a couple of holes through the aluminium so that the glue forms "rivets".
Epoxy should be strong enough to make your comment invalid, but unfortunately you are right: I have seen epoxy giving up.
Still I take this risk. I do not sell these amps so i can fix them.
A thru hole can be drilled in the thick front panel. Diameter large enough for clearance for volume knob or socket over nut for h/p jack. For thick metal, clearance for pot shaft/nut would be adequate, and can be covered by volume knob.
Attach the pot or jack on a small plate, to be mounted from the rear. Attach to front panel with screw or bolt and nut. A singe mounting plate could be made for both pot and jack.
Here is my example on a wood front plate but could be adapted to (thick) metal.
Attach the pot or jack on a small plate, to be mounted from the rear. Attach to front panel with screw or bolt and nut. A singe mounting plate could be made for both pot and jack.
Here is my example on a wood front plate but could be adapted to (thick) metal.
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I applaud your effort. I've cut aluminum t-slot extrusion up to 1.5" and plate up to 3/8" on tablesaws and miter saws with great results and have considered doing some router based machining but haven't tried it yet. I did make a rather clean cut into the top of a steel wing table on my saw when I misjudged my cut line and clamped the work piece too far inboard. 3/8" wide and about 1/16" deep. I felt the drag but thought I was cutting into a knot.
On the subject of counter-boring for individual components versus routing out a large section, I'd try a forstner bit if you have a drill press. They leave a nice flat bottom cut and are widely available in suitable sizes. I'd start with a pilot hole for the forstner center point to follow but that's probably not necessary.
I might also try a bottom clearing router bit, again, in a drill press.
Since I don't have a tool capable of thinning the thickness of a wooden panel and I prefer reliable and robust solutions, if the piece were mine I would think of extending the potentiometer thread with a brass adapter like the following
https://www.ebay.com/itm/296060940977
https://www.ebay.com/itm/334835204352
Then I would think about an extension for the potentiometer shaft like this one
https://www.ebay.com/itm/294683941500
Lastly, I would think of using long thread (almost 40 mm) barrel jacks like these
https://www.amazon.com/KAISH-Stereo-Copper-Guitar-Cylinder/dp/B0768SPYVR
Then - if everything worked as expected - I would be satisfied with the reliability and robustness obtained.
If the piece were mine...
@seventenths Yes, I was thinking about forstner bit. I usually use then in wood hand held. I though it might be too challenging in aluminium. I have a cheap drill press which indeed (even being cheap) works better with forstner in wood. So maybe it would be just up to the task in aluminium. After all I need to remove just 4mm or so.
@ulogon I am aware that people use extension shafts for pots, I did not want to go that route here. Thanks for the links, good to know what is out there and where to get it!
In any case, as mentioned above, next time I will try to avoid routing large areas in aluminium. Wood is a different story.
@ulogon I am aware that people use extension shafts for pots, I did not want to go that route here. Thanks for the links, good to know what is out there and where to get it!
In any case, as mentioned above, next time I will try to avoid routing large areas in aluminium. Wood is a different story.