Bending Aft Fuselage Sides
Posted: Mon Sep 03, 2018 9:29 pm
by GordonTurner
The forward edges of the aft fuselage sides bend in toward each other 14 degrees.
This edge is longer than my little harbor fright brake, so curious before I screw it up how others have done this. Can I clamp the inch or so that gets bent between two boards and just bend it?
Gordon
Re: Bending Aft Fuselage Sides
Posted: Mon Sep 03, 2018 10:05 pm
by WesRagle
Hi Gordon,
I just radiused the edge of my build table with some sand paper. Then I clamped the piece to the edge of the table using the largest piece of angle aluminum I have (2.5 x 2.5) . Then I used either a rubber mallet or a dead blow hammer to tap the bend into the skin.
The only danger of using this method is not going slow enough. That is, you should make a small bend from one end to the other and repeat as necessary to achieve the desired angle. If you try to make too large of a bend in one pass you might end up “stretching” the edge. In that case the edge will be wavy.
Best of Luck,
Wes
Re: Bending Aft Fuselage Sides
Posted: Mon Sep 03, 2018 11:19 pm
by onex28
I did what Wes didnby clamping the piece to my work bench at the desired bend line then used either a broom stick or iron pipe to progressively run it along the piece to obtain the proper degree of bend.
David
Re: Bending Aft Fuselage Sides
Posted: Tue Sep 04, 2018 8:23 am
by Bryan Cotton
I also did what Wes did, except I used a router to make the radius. At the time my tennsmith brake was across the airport at the EAA hangar and it seemed like a hassle to transport the sides over there. After doing the job I was wishing I had used the brake as the bend looked poor. Now that it is riveted up, I have to say it looks nearly perfect.
Re: Bending Aft Fuselage Sides
Posted: Tue Sep 04, 2018 6:37 pm
by SP1
Well timed thread! I am reading the notes of the previous builder on this area. He used a torch to heat up the piece before bending. Did a similar thing to get the bend in the elevator spar. I take that technique is a no-no, because of loss of temper? Thanks!
Re: Bending Aft Fuselage Sides
Posted: Tue Sep 04, 2018 10:34 pm
by Bryan Cotton
No way should you be heating 6061-T6 to bend it.
Re: Bending Aft Fuselage Sides
Posted: Wed Sep 05, 2018 12:02 am
by Rynoth
SP1 wrote:…used a torch to heat up the piece before bending. Did a similar thing to get the bend in the elevator spar. I take that technique is a no-no, because of loss of temper? Thanks!
Absolutely should not do this for anything structural as it weakens the material strength substantially. The only time that might be OK is when it’s non-structural/cosmetic parts like fairings. I shudder at the thought of a spar being heated for bending in this manner. The fuselage sides are definitely structural as well.
Re: Bending Aft Fuselage Sides
Posted: Wed Sep 05, 2018 1:06 am
by SP1
Rynoth wrote:
SP1 wrote:…used a torch to heat up the piece before bending. Did a similar thing to get the bend in the elevator spar. I take that technique is a no-no, because of loss of temper? Thanks!
Absolutely should not do this for anything structural as it weakens the material strength substantially. The only time that might be OK is when it’s non-structural/cosmetic parts like fairings. I shudder at the thought of a spar being heated for bending in this manner. The fuselage sides are definitely structural as well.
I thought as much. Thanks for confirming this.
Re: Bending Aft Fuselage Sides
Posted: Wed Sep 05, 2018 6:42 am
by GordonTurner
Thanks for the pointers. Doesn’t sound so hard after all.
Gordon
Re: Bending Aft Fuselage Sides
Posted: Tue Sep 11, 2018 7:03 pm
by Spaceman
Here are some pictures of how I did it:
http://paegelow.blogspot.com/2017/09/af … -2-35.html
Like the other guys, I just clamped it to the table, and then I used like a foot-long scrap of 2x4 to just press on the flange and form the bend. It took a little trial and error but in the end it was easier than I expected!
Re: Bending Aft Fuselage Sides
Posted: Wed Sep 12, 2018 1:29 pm
by WaiexN143NM
hi all,
just read the sbpf newsletter for sept. jeff mentioned a mentorship program. i think its great.
relative to the post in this thread from sam sp1. about bending alum. by heating it first. he bought a partially built sonex. on other threads hes showed pictures of extra holes, misdrilled holes, no rivets etc. ive reached out to him in a PM. i believe any parts that were heated then bent need to be replaced. thanks ryan(and bryan) for offering good advice. ive offered to take a look at sams project.
what do the rest of you think? maybe the factory will chime in on this issue too. are you of the advice of us that these parts NEED to be replaced?
WaiexN143NM
Michael
Re: Bending Aft Fuselage Sides
Posted: Wed Sep 12, 2018 10:10 pm
by peter anson
As several people have pointed out it is a bad idea to heat structural parts for forming. Heating 6061 at above 200°C will eventually get the material back to something like T-0 temper. Higher temperatures will do it faster. T-0 yield strength is around 55MPa compared with T-6 yield strength of 276MPa, so you can lose around 80% of the strength. The only way to get the strength back is to go through the whole heat treatment process again: heat the part in a furnace at around 500°C for a period followed by a water quench after which the part will naturally age to T-4 strength followed by around 10 hours in a furnace at about 200°C to artificially age it to T-6 condition. Since most of us don’t have the equipment to do that Michael’s advice to bin the part is correct.
Hope we don’t have any heat treatment experts here to tell me I’m wrong, but that process is roughly right.
Peter
Re: Bending Aft Fuselage Sides
Posted: Thu Sep 13, 2018 10:34 am
by racaldwell
Sorry folks if you wanted to heat treat your parts yourself. Last month I just sent our last age oven to the scrap yard. It was 50 ft x 10 ft so size would not have been an issue. I tried to give it away with the new owner taking the removal costs but no luck with that.
Rick Caldwell (proj. eng. at Hydro Aluminum)
Xenos 0057
Re: Bending Aft Fuselage Sides
Posted: Thu Sep 13, 2018 3:29 pm
by SP1
Hi All,
Greatly appreciate you guys chiming in and looking out for me.
My new rivet removal tool is getting its workout, though I’m fitting it in between a very busy work schedule.