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.

[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]

"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

[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.

[Tom W]

John,

If you have any details on the rubber used, please let us know. I suspect 60A (medium hard) or 80A (hard) durometer rubber. They will got torn up with use. McMaster sells fabric reinforced rubber sheeting, but 12" x 12" x 1" runs about $100.

On you video, it looked like the Harbor Freight arbor press plates were under your press. If those came from harbor freight, use extreme caution as they are cast iron, and are known to shatter! Toss the Harbor Frieght ones into the scrap metal pile, as they belong in the recycle bin.

http://www.swagoffroad.com/Arbor-Press-Plates_p_7.html

$169 (check size you need before ordering) seems expensive, but a gut wound is much more costly.