Flanging lightening holes

[N3UW]

I purchased the plans for the Patrol at the end of August. I have been working away digesting the plans and reading everything I can on the build. All of the information here has been very helpful. I have built all of my cutting templates and have rough cut most of my wing ribs. I have started with the nose ribs. I have cut them all out on the router and have now started flanging. I decided to flange the lightening holes first then hammer the outter flange. That seems to work well for me. I did have to cut some recesses in the flanging forms to account for the flanged lightening holes.

To flange the lightening holes I took an idea from the EAA website. I used a 1" thing piece of rubber and some 3/4" steel plate and used that to form the flange in one step. Please check out my video to see what I did.

[DRLPatrol]

That is so cool, never thought about doing it that way. Any more info about the rubber, does it come in different densities.

Doug

[X'N]

Nice work! Great idea.

[Enewton57]

Wow, that's one of the most innovative things I have seen. How will the operation work with the longer ribs? Will do a couple of holes at a time? Thanks for sharing this.

[eh009us]

Pretty cool, though I'm curious to see how you'll go about flanging the ribs now that the lightning holes are done. Seems like you'd have had to make a lot of modifications to your form blocks for them to lie flat. I did mine all with plugs and a press I made from a 3 ton bottle jack. If you have the flanges figured out this looks like a great way to go. Great job, thinking outside of the box. It's the great thing about homebuilding.

[N3UW]

Pretty cool, though I'm curious to see how you'll go about flanging the ribs now that the lightning holes are done. Seems like you'd have had to make a lot of modifications to your form blocks for them to lie flat. I did mine all with plugs and a press I made from a 3 ton bottle jack. If you have the flanges figured out this looks like a great way to go. Great job, thinking outside of the box. It's the great thing about homebuilding.

I read the build log of another builder who also flanged the lightening holes first. I copied what he did. On the form block I simply cut out a grove part way through on the inside of the form block with my circle cutting jig. It could also easily be done with a router freehand or with a circle cutting jig. I left just enough room for the flange to sit inside without it be deformed. I did it on both side. I flanged a few ribs to make sure this worked before I committed to doing all of the lightening holes.

Also you can use the same process to do one hole at a time or parts of a rib at a time. The process keeps it very uniform even when done in multiple presses.

[DRLPatrol]

"Pretty cool, though I'm curious to see how you'll go about flanging the ribs now that the lightning holes are done........."
Any reason you could not do the flanges first. the form block would just have to fit inside the flanges, even could use the same form block for both the hole flanges and the edge flanges.

Also, thinking about the rubber. Any idea about the durometer rating of the rubber. A friend of mine manufactures standing mats, maybe I could try his scraps. A little harder than that, I was thinking the rubber mats for the floor of horse trailers and stalls. Maybe 3/4" thick and 4' or 6' rolls that you buy by the foot from farm stores.

Doug

P.S. I just noticed your #255. I'm #254 and you are ahead of me I am still building my new shop (roof yesterday and today) that I will build mine in. Just studying the plans in the evening so far.

[eh009us]

Gotcha, sort of a hybrid hydroforming method, which is what Avipro uses. I can see where it would be useful on the oval holes in the middle ribs. Just rout the formblock hole to 45 degress and squeeze away !

[DRLPatrol]

Eric,
Could this be moved/merged with the one in building tip/techniques? I figured one would die but they both are continuing?

Doug

[DesertBearhawk]

N3UW, that has to be about the coolest thing I have seen in a long time! I noticed that the rib was not "potato chipped" like I have seen happen with holes that are pressed with dies. All my ribs are flanged now so this step is in my rear view but you can bet your last nickel that if I ever have holes to flange this will be the way I am going to do it.

Can you give some details on the pneumatic ram you used and where a guy can get one....

Again, out-fricken-standing!

[Enewton57]

I was just at Harbor Freight yesterday and saw the 20 ton pneumatic ram for $72 there.

[N3UW]

N3UW, that has to be about the coolest thing I have seen in a long time! I noticed that the rib was not "potato chipped" like I have seen happen with holes that are pressed with dies. All my ribs are flanged now so this step is in my rear view but you can bet your last nickel that if I ever have holes to flange this will be the way I am going to do it.

Can you give some details on the pneumatic ram you used and where a guy can get one....

Again, out-fricken-standing!

Dave,
Thanks. Yea. I did not see to much "potato chipping". It was up about 1/4" in the center. Took just a it of adjusting with the "BOB" stick to correct. I did find it was more consistent to flange each hole though. When I tried to do the entire rib, sometimes the edge of one of the holes was not completely flanged. I also tried to flange the edge of the rib. I do not think I have a strong enough press and/or the proper rubber to do that. I am basically doing a poor mans version of "rubber pad forming". I found the piece of rubber off ebay about a year ago for a repair project I was doing on my Piper Cherokee 235. I think it is 1"x12"x12". I think it was natural rubber but I do not remember. It seems to be about the hardness of a tire inner tube.

Eric is correct. I got the jack from harbor freight. I have posted the link below. It was a slide in replacement for the 20 ton bottle jack that originally cam with the press.

BTW, I love your videos and facebook posts. They are helping me along with aspects of my project.

[wingnut13]

I believe I saw the same EAA video awhile back. Then just a couple days ago came across your video, and so today traded a co worker for a big thick rubber standing mat. I've been keeping an eye out on Craigslist for a good deal on a press. . . .. It would be cool to do all the bending at once though.