Rudder Stiffeners - need Help

[BillL]

Well, I purchased an RV7 in process, bought tools, build shop, made the practice kit, and now have a question about the rudder stiffeners. The dwg says to cut the taper on the angle flange between these little notches. The line of intersection apparently needs to go through the imaginary centerpoint.

Well, most notches are on the corners which will be rounded out anyway, but the taper has one on the outeredge of the flange.

Do I leave the notch or round out the taper to eliminate it? The notch seems like a stress riser to me? Engineers don't like notches.

OK, I know you guys are way past this, but please help anyway.

Thanks,
Bill

 

[John G]

I just cut to the center of the notches and then rounded to eliminate the notch when I was deburring the edges. Seemed to work fine.

Best, John

 

[gbumga]

Go easy here and be precise

Hi, I'll tell you what I just did wrong and hopefully save you some $. I took to much off of several stiffners when using the scotch-brite wheel on the ends to remove the notches, just get ride of the notches and smooth em NO more or you won't have min. edge distance, I had to replace some. Also on the other end of the stiffner where it sets next to the R-902 spar don't leave them to long, I did and they are almost impossible to fix without bugger them up. I would cleco the spar on and put a sharpie line using the fine line type marker as close to the spar as possible then use it so you don't go to long. I have been trying to fix these things and maybe these expiereanced guys can drill out 30 or 40 of the flush rivets without damaging anything but I cannot do it now and have had to buy new parts. One little slip and the parts toast. i hope this helps you. Oh we could probably just buy a whole new emp. kit and between me you and one other person use it up in replacement parts and save some shipping, kidding but it is close. Gene

 

[larrynew]

Cleco the spar to the skin

I just finished riveting the Rudder stiffeners today. Before trimming the R-915 stiffeners, I clecoed the R-902 spar to the R-901 skin and checked how much I needed to trim off the stiffeners. I took off the least I could but made sure I took off all the "notches" when sanding and scotchbriting.

I learned my lesson after blindly following the plans without test fitting first on HS-404, 405 and 702. I had to reorder all after an edge distance snafu.

 

[BillL]

Thanks -

Thanks for the comments - no notches, and test fit well ahead of riveting. I can use this - - Thanks for building my confidence.