Brief Description: Cutout HS603 Spar for Elev Horn Clearance
Well I am getting down to the final details of the completing the empennage.
Plans require that you cut out a portion of the rear HS 603 Spar in order to give the elevator control horn clearance. There is actually a stop on the fuselage that will limit the elevator so the removal is precise but not critical. The only critical part of the process is making sure NOT to take material off any of the spar reinforcements.
To do the job I do two things. First, I decide what radius I want to put in the corners of any cutout. Radius is important since a "square" corner sets up stress point that can lead to cracking through vibration and movement. After I decide what radius to put in the corner, I double it to give me the size drill to use. Then I measure and mark the distance from the finished edges and then using a center punch and center drill I start the hole. Then I finish it with the proper size drill. Next I used the Dremmel tool with a cutoff wheel to remove the metal, followed up by a little filing to blend it all in. It comes out very good and is easy.
On a side note, I have a nifty little tool that was really handy for putting the bolts in the elevators when attaching them to the horizontal stabilizer. Really works great. Have had it in my tool box for years....it is really helpful for the use I just stated for putting bolts and nuts in tight places as well as fishing out something when you drop it in a confined space. Not a tool used often.....but worth its weight in gold when you need it!
