Scratch building formers

[lstinthot]

Anyone out there scratch build their formers for the turtle deck? I have the blanks. I am working on former #5 and it is not very straight at the center where there are no fluting marks due to the center brace and rivets. I am thinking about making a box to press them in. Like the EAA video called hydro forming. Anyone else try that?

Mike
Scratch building #1604
Tail dragger
Looking at corvair power
www.mysonex.net

[gammaxy]

I think you can probably add extra flutes. Make sure to put them offset so they won't interfere with the rivets you mention. I think I added extra, but it's been a while and I don't have a picture that shows them. Also, the skin back there is so tight that it will help remove any imperfection in the former.

http://chrismadsen.org/2012/06/turtledeck/

At the Sonex workshop, they showed off their hydro forming machine. It was cool and I'd like to try it myself sometime, but I think you should be able to make great ribs without it.

[Gripdana]

#5 former is that the most aft former? I'm not near the plans and don't remember? I scratch built Sonex 1534s. I did not have the issue you are referring to. Can you email me a photo so I can better understand what your issue is? My email is gripdana@ yahoo.com.

[Gripdana]

I looked on your website at the photo of your #5 former. I see what you are talking about. Here is the process I used to make mine. I took the blank and sandwiched in the forming block and bolted it together. Then I hammered it to about 45 degrees. I did not use the edge of the block for the final angle. Then removed it from the blocks and worked the flanges with fluting pliers and the hammer while holding the former flat on the table. The angle of the flange varies along it's length. Here is a link to my building page for the formers. The photo is taken before it was finished. Hope this helps.

[lstinthot]

Thanks for the advice. I will try to make the part again using Dana's technique. If I do not get it again, I will add extra flutes.

[Gripdana]

Have you seen the video on making wing ribs? It is a 6 part series from Sonex on the EAA hints for homebuilders website? I used that video and basic process to make all the parts that required forming blocks. Here the link. Hope this helps.
http://www.eaavideo.org/video.aspx?v=1772030477

[lstinthot]

I have gone through the video series. Just not having flutes along the top edge is messing it up. I did make a sandwich block to hold the part flat as I hammered it down. When I took it out, it sprung up like it is.

[gammaxy]

I just looked at the picture on your website and noticed a couple things. It seems like you are fluting further into the corner than I did. This slightly deforms the corner at the location of each flute and can make it harder to finesse a good fit.

Sonex recommends these pliers: http://aircraftproducts.wicksaircraft.c ... pliers/500 These allow you to make tighter flutes than the ones you are using. I used both kinds, but for tight bends it seems the recommended ones work better. It will also make it easier for you to squeeze in a couple extra flutes if you decide to do so.

[Gripdana]

Are you using fluting pliers? That is what I did after it was removed from the blocks. I would only "squeeze" the flutes in with the pliers until the bend came out.

[Gripdana]

If you decide to add flutes make sure you do not add them at a rivet location I did and had to fix it.