Phil Nelson's recent 19A12 restoration showed a superbly finished Bakelite cabinet, but the back was missing. Since I have an almost-identical back for a 17T12, I thought I'd try to do a reproduction that would fit Phil's set. The only difference between the two cabinets is the rectangular cutout for the 17T12's Rotoscope antenna.

https://lh4.googleusercontent.com/-oXMAu7IBEl0/UElyBLJq_KI/AAAAAAAAKAo/5hIgOF-4rYg/s800/19A1%2520Back%252003.jpg

All modesty aside, it turned out great. The tools were simple and the materials were cheap. All I used was a saber saw, electric drill, sanding block, ruler, paper, and patience. And a 35-year old Black and Decker Workmate.

https://lh6.googleusercontent.com/-QE1wV7XfwBA/UElyE0D5kBI/AAAAAAAAKA0/39JTSClzOfo/s640/19A1%2520Back%252004.JPG

The original material was Masonite, a composite wood product first used in the 1920's. Home Depot calls it "temp board," and others refer to it as a variety of hardboard. One side is smooth and burnished; the other side has the imprint of a screen. A 2x4-footx1/8-inch piece cost about eight dollars.

https://lh5.googleusercontent.com/-_jA9uTINZAw/UElqrDE_C7I/AAAAAAAAJ_0/MesPmGKL0co/s640/19A1%2520Back%252007.jpg

To make it appear authentic, it has to look machine-cut. To be sure all the holes lined up perfectly, instead of tracing it directly on the Masonite, I made a paper template. Then I triangulated the hole circles to get each hole center placed perfectly. I used a small drill bit to mark the hole centers through the paper.

https://lh6.googleusercontent.com/-xajE792bEqw/UElqRiZqJqI/AAAAAAAAJ-k/hwcAy8I1aJQ/s800/19A1%2520Back%252010.JPG

Tracing complete, holes marked, and ready to cut:

https://lh6.googleusercontent.com/-wPp8w8kZUZ0/UElqUbkL14I/AAAAAAAAJ-s/_9ZmkWDbXbg/s800/19A1%2520Back%252012.JPG

The next challenge was to get cleanly cut holes and edges. After some experimentation I rejected the sawblade and drill bit that I would usually use. For saw-cuts and drill holes without furry edges, I used a scroll blade and a "brad point" wood boring bit. The holes measured 11/32 inches, and I had to go to a woodworking store to find bits in 1/32-inch increments. That was another four bucks.

https://lh6.googleusercontent.com/-nAUihIhQ9nQ/UElqk0RtetI/AAAAAAAAJ_c/GjtmD2Bsxms/s640/19A1%2520Back%252015.JPG

The brad point bit will cut a clean circle it's run at very low speed. I made the holes at about 100 rpm. If it ran much faster than that, it would tear the wood fibers on the surface and leave a fuzzy hole. Also, the point of the bit is excellent for accurately centering the hole.

https://lh4.googleusercontent.com/-VrlCdq1RJX0/UElqoZE1kiI/AAAAAAAAJ_k/8AZgV4lfSIA/s640/19A1%2520Back%252020.JPG

Here's the finished product. Since I had the original power cord, I tried to make a metal interlock bracket. The result was only fair, so I temporarily positioned it for this photo.

https://lh3.googleusercontent.com/-8Aotdsy7x58/UElqX6ZiqQI/AAAAAAAAJ-0/UMG6k_is6Qg/s800/19A1%2520Back%252050.JPG

This is a comparison of the original with the reproduction (I later drilled the one missing ventilation hole and the hole for the top middle screw so it would fit the 19A1 without a Rotoscope antenna).

https://lh3.googleusercontent.com/-CaTuNDXZNlY/UElqQtpvCGI/AAAAAAAAJ-c/MEQmA6N4IiQ/s800/19A1%2520Back%252060.jpg

Total cost was 12 dollars, but I still have plenty of Masonite to replace the damaged back on this Motorola 12T2 with 1,700 holes. And after that I'm going to climb Mount Everest in shorts, a T-shirt, and flip-flops.

https://lh4.googleusercontent.com/-kGXec_4-oKk/UElqdoyUubI/AAAAAAAAJ_M/SGagZCS8y7w/s800/19A1%2520Back%252090.JPG

If you know anyone who needs a back for an Admiral 17T1X or 19A1X, here are links are for a template in two parts. If the Flickr download in original size is used, it'll give you two JPEGS which, when printed on letter-size paper, will give right-side and left-side prints that can be joined to make a perfectly-sized paper template.

https://flic.kr/p/WEYyor

https://flic.kr/p/WP6rU7

-Winky

That's looking good. Lots of patience lining up and drilling all of those holes :yes:.

Outstanding work:thmbsp:
I need three of these backs and was gearing up to do the same experimenting you did including trying a variety of drill bits. You just saved me a lot of time and effort :yes:

Very nice job! I need to make a couple of backs, too, but I have been holding off because I didn't want to make something with fuzzy edges and vent holes.

Phil Nelson

Excellent job.

[edit] Was just thinking, since they likely didn't have CNC routers or laser cutters back in the day, I suppose the originals were made with a stamp and die set. I don't know how else they'd of mass produced these.

That's a beautiful job. The tough part of these is making them accurately, and you solved that by triangulation. I copied the layout picture for future reference. Thanks.