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Stringer standoff

JimW

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It's been kind of quiet around here so I thought I would post a side project that has been in the background whenever we needed something to work on while hot steel cools. We decided to make the as per plans stringer standoffs but wanted a way
to mass produce a bit. We are using 5/16" X 5/8" stringer material from
ACS.



First we cut out some material and bent it u-shaped as far as we could
with a brake. We made these pieces out of .040 4130 sheet and roughly
6" long. 032 sheet would probably have been thick enough. A few of
these are in the foreground below. We then cut these into pieces about 7/8"
long. To finish the bend that the brake could not achieve, we grabbed
them with a pair of hand seamers and smacked them lightly with a
no-bounce mallet.

20080812_153650_Stringer_stando.JPG




Then we made a jig from a piece of 1/8" flat plate and some 1/4
X 3/4" bar stock, some 5/16 x 1 1/2" bar stock, some 3/16" bar stock and four 1/4" bolts and wing nuts.
All was left over form other projects. The 1/4" stock was the spacers
in the second photo. The u-shaped pieces slid onto the 5/16" bar stock
and the two pieces of 3/16" were used to clamp the hole thing together.

20080812_155006_Stringer_stando.JPG


Here you can see the 1/4 X .035 round tubing sandwiched between the spacers. There is a shim under each round tube to center it on the u-bracket.

20080812_155102_Stringer_stando.JPG




20080812_155330_Stringer_stando.JPG


Then the whole assembly is stuffed into a drill press vise for tacking (above).

20080812_155526_Stringer_stando.JPG


We flipped them around once while on the 5/16" bar to tack the other side. Then we disassembled and set each unit on these round rib gusset weights that we welded a small chunk of 5/16" bar to the top. This made it easy to spin them around for finish welding. Once they were finished we rounded the corners on a bench sander. We'll jig them once more in a drill press to drill a rivet hole in each one. The large sheet of 1/4" plate is our small parts portable welding table. Just hook the work lead from the TIG welder to it and go.

Once the jig was made, the rest of it goes pretty fast. One person can weld up a pretty big pile of these in a couple of hours.

Jim





Edited by: JimW
 

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