My Fokker DVII Project

Jeff Brooks · 7 August 2006, 03:19 PM

I worked on the riveting today. the aluminum is 6061 and it appears a bit soft where the rivets close the lap joint. I may order 2024 aluminum and try again. I used a rivet pitch of 8x the dia of the rivet. I used .125" rivets, so the pitch was 1"

the rivet pitch on the top was 48mm per the plans. they look nice.

Jeff Brooks · 7 August 2006, 03:21 PM

Jim Bruton · 7 August 2006, 04:23 PM

not too shabby Jeff! will send info tomorrow?

Jim

Jeff Brooks · 7 August 2006, 05:28 PM

thanks Jim!
I have been thinking about how to do this. I belive the metal clip that hold both sides of the wing may help keep the shape in that area that is cut. hopefully your plans confirm this.

Jeff Brooks · 7 August 2006, 05:28 PM

Yeah, I think I'm gonna buy some 2024 Aluminum ... the other stuf is too soft to rivet without making a mess out of it.

scott5952 · 8 August 2006, 12:31 PM

Hey Jeff

I think what happened is that you used dead soft alum. I can't tell for sure, but it looks as if the markings on it are "6061-0", the 0 indicating unhardened. That would definitely make it feel like you are riveting through a pop can, and unfortunately, it is not to much stronger than a pop can.

If you order 2024, make sure it is T-3. 2024-0 will be just as bad as the 6061 and T-6 will be really a pain to bend.

Jeff Brooks · 8 August 2006, 04:58 PM

scott5952,
thanks for the input. when I bought the metal, the plans did not specify which to use ... so I had to guess. I wish I had consulted the forum when I bought the metal. it would have saved me the wasted metal.

Jeff Brooks · 9 August 2006, 04:48 AM

Maxim08, is this how you are going to build your fairing? did you want me to make a few ribs for you as long as I am on this stage?

Brad · 9 August 2006, 07:02 AM

Quote:

Originally Posted by Jeff Brooks

scott5952,
thanks for the input. when I bought the metal, the plans did not specify which to use ... so I had to guess. I wish I had consulted the forum when I bought the metal. it would have saved me the wasted metal.

Jeff,

You should PROBABLY be using 6061-T6. 2024-T3 is a little stronger, a little more expensive, a little stiffer (harder to bend) and a little more brittle (easier to crack). Either would serve you well... but the 6061-T6 is probably more readily available to you, and will be a bit easier to form. IIRC, 2024 is also less corrosion-resistant than 6061-T6, which is why it is available in "alclad," meaning it has a VERY thin layer of pure aluminum on the surface to protect it. (If I am wrong I am sure someone will correct me, but I am pretty sure that is right.)

Generally in homebuilt aircraft, when plans refer to 6061 they mean 6061-T6 unless it specifically says otherwise. That and 2024-T3 are the 2 most common aluminum alloys/hardnesses used in experimental aircraft construction.

0 (T0) means it isn't hardened at all... that material is used when you expect to heat treat it AFTER forming. I don't think that is an option in this case. That material will form very nicely though, so you can use it to do any formed parts you need to make... it won't all be wasted, and the construction experience will be helpful when you build the "real" axle box.

Brad

Maxim08 · 9 August 2006, 10:31 AM

Brad,
I agree re the 6061 but not necessarily about the T6. The 'T' refrers to the heat treatment stage of the alloy. 6061 will work harden. In the T6 stage, it can be bent but you must be careful to use a radius of at least 6x the thickness or it will crack. 6061 is also available 'alclad' for corrosion resistance.
I suggest that 2024 T3 alclad is the best bet here. It can be worked reasonably well and a tighter radius can be used. I believe that 2024 T3 is what the Dr1 guys are using for their axle boxes.

Jeff,
How can I refuse?
I'll be in Buffalo Saturday AM to collect my lozenge linen from UPS. Any chance of meeting up? Any other forum people nearby that would like to get together for breakfast/lunch and talk WW1 stuff?

Regards,
Maxim08