Maker Pro
Maker Pro

It's in the box

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Here's a few things I've been working on.

Nothing fancy in the electronic sense, but placed in custom boxes.

First is my A-B 4 wire resistance tester.

WP_20160101_09_26_37_Pro (Custom).jpg

This is simply so I can compare the readings between two 4-wire resistance meters quickly. If one can be verified as being close to "in spec" then the second can be quickly compared.

The two knobs are a pair of 10 turn pots 47k and 200R in series. The switch is a 4PDT to swap and isolate the pair of 4-wire terminals.

The kelvin connection is made on the terminals of the pots, so any variation of resistance due to poor switch contacts, grubby terminals, etc. is eliminated.


Second is my mains frequency meter. I've had this for quite a while and decided to place it in a box.

WP_20160101_09_27_26_Pro (Custom).jpg

Sometimes it reads a tad above 50Hz, other times a tad below. I have no idea if it's the mains frequency or the variation in the meter with temperature! (Yeah, I should measure the mains frequency with a known good frequency counter, but I'm lazy).

WP_20160101_09_27_36_Pro (Custom).jpg

The main reason for this box was to get the cutouts for the fuse and IEC connector right. There's three layers of MDF in the rear cover of this box to hold the power connector sandwiched in place. The screws on the front (hidden) and rear go completely into wood supports to they cannot come into contact with the mains.

You may also notice that the box has been coated with clear lacquer. This stops the MDF getting grubby and oily fingerprints all over it (the A-B tester is not lacquered).

From the practical experience making this box, I present my third project:

WP_20160101_09_28_21_Pro (Custom).jpg

I've finally got around to this! I have finally made a box for my cheap 800VA variac.

It's amazing what you can do with a laser cutter, Laser Boxie, and a few days off over Christmas.

If you're interested in Laser Boxie (it generated the box contours) send an email to laser(dot)boxie(plus)help at gmail dot com.
 

KJ6EAD

Aug 13, 2011
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Aug 13, 2011
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I recently used our laser cutter at work to make the openings for the switch and strain reliefs in this assembly. Since the cuts are on-seam, I made jigs that held the halves together and in the correct orientation on the cutter.

AWD Docking Emulator Complete.jpg AWD Docking Emulator Internal.jpg
 
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