February 15, 2016 - Cut/Fit Forward Cross Members and Tack Weld

OK, now comes the fun part.  Well, not really.  I have to cut and fit the big 7/8" diameter cross-member tubes on the forward part of the fuselage.  These cross-member tubes should be fairly straightforward to fit as they are perpendicular to the longerons, and they are all the same length.  The forward part of the fuselage is 28 inchs wide, from outer edge of longeron to outer edge of longeron.
   
I rough-cut nine tubes -- five on the top and four on the bottom -- using the abrasive chop-saw.  If only the rest of the tube fitting was that quick and easy.
   
I used the notching tool to notch one end of all nine tubes at 90 degrees.   Then I used the angle-grinder to manually notch the tube again to fit around the vertical side tube.  Next I used the notching tool to notch the other end of the top five tubes, all at the same distance, a little less than 28 inches.  Again, I used the angle-grinder to manually notch the tube again to fit around the vertical side tube.  As always with notching, there was a lot of back and forth between the fuse and the workbench vise, trimming a little with the angle-grinder, checking the fit on the fuse, repeat.
   
I went through the same procedure on the four bottom longeron (top in the picture) cross-members.  For fitting, I needed the fuselage sides perfectly vertical.  I did this by screwing performated steel angle to the fuselage sides and then using wood blocks and wire to secure the fuse sides to the vertical steel angle.
   
A better look.  All the nine cross-members are notched.
   
I am using wire and turnbuckles to keep the sides pulled together tight.
   
I am ready to tack-weld.
   
Lighting up the torch.  I had practiced my tack-welding before hand as it has been awhile.
   
Here we go!
   
Intense concentration.  Under the shades, I have on a pair of glasses that are optimized for welding; focused to about six inches or so away.  I have learned -- the hard way -- that being able to see well is conducive to good welding.
   
 
   
The front-end tacking went relatively quickly and came out well.
   
 
   
Previous
Home
Next