Reproduction Back for Admiral Models 19A1X & 17T1X

[Winky Dink]

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.



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.



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.



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.



Tracing complete, holes marked, and ready to cut:



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.



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.



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.



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).



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.



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

[vts1134]

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

[bandersen]

Outstanding work
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

[Phil Nelson]

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

[Kevin Kuehn]

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.

[Reece]

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.