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previous: Hamish Hubbard I like to use at least 2mm aluminiu... -- 12/18/1997 7:24 PM

Re: Amp Chassis and Construction and ranting

12/19/1997 10:00 AM
R.G.	Re: Amp Chassis and Construction and ranting >But I cannot get good drilled holes. They always >have nasty burrs around the edges and I cannot >find a satisfactory way to deburr them. Try this: get a wooden dowel of 4-6MM, and saw a split into one end of it. Chuck the un-split end into your drill, and fold a bit of medium sandpaper and stick it into the split, grit sides out. Place the sandpaper end into the drilled hole and key the drill. Bingo! Smoothly deburred hole. For centering, centerpunch and drill a small (1-2 mm) guide hole, then drill the main hole. Better yet, invest in a drill press. A bench drill press can be had for well under US$100, which sounds stiff, but is cheaper than another amp, and will make a huge step in your satisfaction in your work. >I suspect I have answered my own question, but >what do you need to get good looking, accurately >lined up chassis holes? You have answered your own question. Good tools, good operation, care in layout. If you get greenlee chassis punches they will make nice holes, but 2MM may be two thick for them. >And, is there a standard hole size for octal and >9-pin tube sockets? The old radio guys used 3/4" and 7/8" for 9 pin and octals, --- I think ---. The easiest way to tell is to take some sockets out of equipment and measure the holes. >but I like rack gear and printed circuit boards, >especially for construction ease and quality. So do I. However, construction gets much easier if you use turret strip for holding components instead of lug strip or point to point. T-nuts (the clamps with threads) are a HUGE advantage in many cases. There is a version of that for metal. It's a threaded insert with a knurled edge that you press into a steel or aluminum sheet with a vice. No more stripped threads in sheet metal.

12/19/1997 10:00 AM

R.G.

Re: Amp Chassis and Construction and ranting

>But I cannot get good drilled holes. They always >have nasty burrs around the edges and I cannot >find a satisfactory way to deburr them.

Try this: get a wooden dowel of 4-6MM, and saw a split into one end of it. Chuck the un-split end into your drill, and fold a bit of medium sandpaper and stick it into the split, grit sides out. Place the sandpaper end into the drilled hole and key the drill. Bingo! Smoothly deburred hole.

For centering, centerpunch and drill a small (1-2 mm) guide hole, then drill the main hole. Better yet, invest in a drill press. A bench drill press can be had for well under US$100, which sounds stiff, but is cheaper than another amp, and will make a huge step in your satisfaction in your work.

>I suspect I have answered my own question, but >what do you need to get good looking, accurately >lined up chassis holes?
You have answered your own question. Good tools, good operation, care in layout. If you get greenlee chassis punches they will make nice holes, but 2MM may be two thick for them.

>And, is there a standard hole size for octal and >9-pin tube sockets?
The old radio guys used 3/4" and 7/8" for 9 pin and octals, --- I think ---. The easiest way to tell is to take some sockets out of equipment and measure the holes.

>but I like rack gear and printed circuit boards, >especially for construction ease and quality.
So do I. However, construction gets much easier if you use turret strip for holding components instead of lug strip or point to point.

T-nuts (the clamps with threads) are a HUGE advantage in many cases. There is a version of that for metal. It's a threaded insert with a knurled edge that you press into a steel or aluminum sheet with a vice. No more stripped threads in sheet metal.

Replies:

Charles Hi RG,>> If you get greenle... -- 12/19/1997 4:51 PM