FILENAMES:

Bending_die_with_blank.jpg
Bending_die_with_male_and_female_parts.jpg
Bending_die_for_flying_wire_lugs.jpg
Bending_Die_Crimping_tool_02.jpg
Bending_Die_Crimping_tool_01.jpg
Bending_die_results_ready_to_weld.jpg
Bending_die_flying_lug.jpg

DESCRIPTION:

These are pictures of a bending die and its use. 

Posted by John Ebensperger <jebenspe@twcny.rr.com>. 

The following description was provided:

=================================================================

Bending die for making 7/16" flying wire lugs.

This die is used to form metal straps into a 
U-shaped channel.  The female portion of the 
die was made from a 1"x3"x4" piece of mild 
steel. A 9/16" hole was drilled in the edge 
of the steel block and a hack saw was used 
to remove the material from one edge of the 
hole.  A mini-grinder and emery paper were 
used to smooth the channel.  The male plug 
was made from the shank of a 7/16" bolt and 
a 1/4" x 1" x 1 1/2" piece of mild steel.  
One side of the bolt shank was filed flat to 
provide a bearing surface for the short piece 
of 1/4" steel which was TIG welded to the shank.  
If I were to make another of these I would make 
the 1/4" steel piece about 3" long so that when 
the strap is bent and the "wings" start to come 
up, they won't interfere with the hammer, my 
hand or the arbor press which ever is used to 
provide the force.  This die will make only one 
size strap specifically for the aircraft I am 
building.  

The next step in making one of these flying wire 
lugs is to get the strap to conform to the shape 
of the 7/16" bushing.  I constructed a crimper out 
of two pieces of mild steel approximately 
3/32" x 2" x 4".  I bend the last 3/4" of each 
piece into a 90 degree angle and drilled three 
holes to act as guides for the bolts.  The lower 
bolt is tangent to the bushing and bracket formed 
in step one.  The lower part of the crimper is put 
into a bench vise and the metal strap is formed 
around the bushing stock.  I used two small pieces 
of square tubing to hold the lug from tipping but 
that isn't the best way to keep the lug from tipping.  
I plan on welding two washers to the bottom bolt 
spaced just far enough apart to steady the lug head.  
I will also weld each bolt head to the steel plate 
so that only one side of the crimper actually moves.

The ready to weld picture shows the final step in 
assembly.  A metal tab ..063" of the same shap as 
the lug is welded to the bushing stock.  The bushing 
stock and .063" tab are inserted into the  lug strap.  

The whole lug is edge welded.  The tab end of the lug 
will be drilled to accept a clevis and the bushing end 
will be trimmed and reamed to 5/16" I.D.  Prior to 
painting, the brackets will be bead-blasted.  

This was quite a bit of work to make sixteen fittings 
total.  I accept the sweat equity of having to make 
the two tools in exchange for potentially spending 
hundreds of dollars on metal benders.