Bucking Bar Woes

smithhb · Post by **smithhb** » Mon Nov 05, 2007 2:01 pm

I was wanting everyone's help with a dilemma. A friend of mine was riveting the bottom skins on his wings this past weekend and accidentally dropped his bucking bar. The wings were in the wing stand and the bar fell through to the leading edge, third bay from the tip.

The area is accessible through the access holes in the spar but with the bottom skin riveted on, it can only be accessed from the end of the wing. Unfortunately, it is just out of arms reach.

Since this is an RV-9 wing (amazingly, the same model as I am building) I would like to help him with this problem so I am coming to the experts for ideas. Please don't suggest adding 3lbs of ballast to the other wing for balance...this has already been suggested and rejected as a solution.

Here is a pic of the wing. The bay is the third one from the left, one bay to the left of the access hole (which is impossible to reach through due to the ECM bracket and bellcrank.)

Post by **bullojm1** » Mon Nov 05, 2007 2:06 pm

Bret-

Same thing happened to my buddy building a RV-8. His solution was to go down to Home Depot's Aviation aisle and pickup a "Leading Edge Bucking Bar Removal Magnet". If you can't find one of those, a normal magnet should work fine. Get a small one and tie/duct tape it to to a string and go fishin'!

Good Luck!

clreding · Post by **clreding** » Mon Nov 05, 2007 2:12 pm

I have these small polished rare earth magnets that I could send you one which is ½ inch in diameter and about an inch long can easily pick up all of my steel bucking bars.
Put a string on it and wrap it with tape and go fishing. Might work

Craig

From: RB Lists - Screwup Chronicles [mailto:support@rivetbangers.com]
Sent: Monday, November 05, 2007 2:02 PM
To: screwup@rivetbangers.com
Subject: Bucking Bar Woes

I was wanting everyone's help with a dilemma. A friend of mine was riveting the bottom skins on his wings this past weekend and accidentally dropped his bucking bar. The wings were in the wing stand and the bar fell through to the leading edge, third bay from the tip.

The area is accessible through the access holes in the spar but with the bottom skin riveted on, it can only be accessed from the end of the wing. Unfortunately, it is just out of arms reach.

Since this is an RV-9 wing (amazingly, the same model as I am building) I would like to help him with this problem so I am coming to the experts for ideas. Please don't suggest adding 3lbs of ballast to the other wing for balance...this has already been suggested and rejected as a solution.

Here is a pic of the wing. The bay is the third one from the left, one bay to the left of the access hole (which is impossible to reach through due to the ECM bracket and bellcrank.)

Bret Smith
9A Fuse (N16BL)
Blue Ridge, GA
http://www.FlightInnovations.com

rivetbangers.com - Discussion topic http://www.rivetbangers.com/cgi-php/forums/viewtopic.php?p=21389#21389

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smithhb · Post by **smithhb** » Mon Nov 05, 2007 2:26 pm

Thanks Mike and Craig,

I will try to get a magnet at HD. If that doesn't do it I may give you a call Craig.

My friend will really appreciate it.... Boy, am I glad I didn't do something stupid like that...

clreding · Post by **clreding** » Mon Nov 05, 2007 3:05 pm

Mike I didnt see your reply before I launched mine.

Brett, one last thing if the bucking bar is Tungsten you may have more difficulty with the magenet. My rare earth magenets will barely lift one edge of a small tungsten bar. They work fine on even the largest steel bucking bar. Tungsten does not seem to have the same magenetic properties as steel

dons · Post by **dons** » Mon Nov 05, 2007 3:29 pm

I might be missing something here, but couldn't two people just lift the wing out of the cradle and s-l-o-w-l-y tilt the wing there-by sliding the bucking bar towards the main spar where you can reach it from that access hole ? I am guessing that there is a hole through the main spar, and that is how it got to the leading edge in the first place. If the bucking bar is all taped up, it likely won't even make any new scratches. The magnet idea is great as long as it doesn't keep dropping off, and it might if there is a lot of tape on the bucking bar and the magnet isn't quite strong enough. Rare earth magnets are really strong for their mass compared to regular ones.

smithhb · Post by **smithhb** » Mon Nov 05, 2007 4:08 pm

Don, we considered just picking the wing up and rolling it till the bar dropped into a "more accessible" area. But there were only two of us and we were just trying to finish riveting the top skin. I... my friend that is, didn't want to ask his wife for help because she would have never let him live it down.

This happened after about 6.5 hours of riveting... Which proves the point, don't push yourself to finish a task if you are tired or trying to beat a deadline.

BTW, I took yo'alls advice and ordered one of these puppies with 270lbs of pull force. This should work!

Wicked Stick · Post by **Wicked Stick** » Mon Nov 05, 2007 8:49 pm

Just curious, but did the skin get any damage to it ???

What if you carefully removed the wing from the jig, and laid it flat on a table, then tilted slowly so that the bar would slide back towards the opening at the spar ? Would you be able to reach it from that point ?

JOHN TIPTON · Post by **JOHN TIPTON** » Tue Nov 06, 2007 5:57 am

Has there been any damage done - I hope not

smithhb · Post by **smithhb** » Tue Nov 06, 2007 10:26 am

Fortunately, the bar only fell about 8-9 inches and the only dent was a very small one on the underside of the leading edge. All in all, it was a minor event.

As far as accessibility, on the -9 spar, there are about 5 access holes starting on the tip end and extending to about where the tanks start. You need these access holes in order to rivet/buck the leading edge to the spar. The actual holes get smaller in diameter the further inward you go so the bar actually fell through about a 3" diameter access hole just inside the third "bay" from the end.

I think the rare earth magnet on a string tied to a stick will do the trick. I'll keep you guys appraised as to my journey...

smithhb · Post by **smithhb** » Fri Nov 09, 2007 10:51 am

Just a follow-up. Yesterday I received my super-duper Nano-magnet and tied it to a string and a stick. The magnet "snapped" the bucking bar and removing it was a non-event.

Now I just need to see what can be done to remove the tiny BB-sized bumps in my leading edge...

clreding · Post by **clreding** » Fri Nov 09, 2007 11:01 am

Glad the magnet worked J.

From: RB Lists - Screwup Chronicles [mailto:support@rivetbangers.com]
Sent: Friday, November 09, 2007 10:51 AM
To: screwup@rivetbangers.com
Subject: Bucking Bar Woes

Just a follow-up. Yesterday I received my super-duper Nano-magnet and tied it to a string and a stick. The magnet "snapped" the bucking bar and removing it was a non-event.

Now I just need to see what can be done to remove the tiny BB-sized bumps in my leading edge...

Bret Smith
9A Fuse (N16BL)
Blue Ridge, GA
http://www.FlightInnovations.com
RB# 6793

rivetbangers.com - Discussion topic http://www.rivetbangers.com/cgi-php/forums/viewtopic.php?p=21511#21511

Submitted via email