Aft Wing Spars

The rear spars are fabricated from ¼” last-a-foam and covered with BID.  There is an inboard rear spar and an outboard rear spar-- build two of each.  Print out the following drawings:

Inboard Rear Spar
Outboard Rear Spar

First let us fab the inboard aft spars. Rough cut the ¼" foam and bond in the ¼” plywood end reinforcement. I used the plywood section cut out from the BB rib to reinforce the inboard rear spar.  Layup BID,  for a total of two layers the entire length, three layers for the inside 2/3rds and four layers for the inside 1/3 rd.  Trim the spar to size.  Use a straight edge clamped to the work surface as was done for the spars in the horizontal stabilizer.

The outboard spars are roughly 52” long and about 3” wide at one end and 2” at the other. they are also made from 1/4" last-a-foam.  2 layers of BID the entire length both sides.

Trimming Inboard Aft Spar

Use our technique of clamping a straight edge to the table to creat a nice straight edge on the spars.

Trimming Inboard Aft Spar

 

Completed Inboard Aft Spars

Completed Inboard Aft Spars

Alright, good job.  Now it is onto the ribs.