Help - Need tubing size

[Luked 71]

Hey everyone. I just realized that I forgot to order one tubing size for my project, and I'd like to start on it this weekend. My plane is at home, so I can't measure the size.

 

The tube I need is the one that the front spar attach bolt goes through. I'm pretty sure it's a 5/16 inch bolt, so I would guess the tube would be 7/16" OD tubing with a .065" wall. Then I could ream it to the correct ID. Could someone confirm this so I can order this today?

 

Thanks,

Luke D.

[EDMO 1078]

some may disagree with me - but I burned up a reamer on the 5/16 ID 4130 tube after it shrank with the welding - I would use bushing stock or 1020 tubing 2.250 long, and then trim it to 2.125 after welding. 

EdMO

[Luked 71]

Thanks Ed. That's a good thing to consider. I'll do some testing on some scrap first. Are my dimensions correct otherwise? I mean is the tube a 7/16" OD?

 

Thanks

Edited 23 Sep 2014 by Luked

[Luked 71]

Well, I went ahead and ordered the 7/16" x .065" tubing. Should be here by the weekend 

[akflyer 1427]

sorry, I am 800 miles away from the plane right now so I cant get measurements for you

 

[1avidflyer 1983]

Sorry, I could have measured it, but now it's to late.  Without checking, I think you are right though.  Jim Chuk

[Luked 71]

No problem guys. I should have remembered to measure myself. If I'm wrong it's not the end of the world though. I'll check when I get home tonight. May have to re-order with faster shipping. Pretty sure It's right though.

[EDMO 1078]

Luke,

    The 5/16 ID is correct - you wont be wrong on the 7/16 OD.

EdMO

[Luked 71]

Thanks Ed!

[EDMO 1078]

Luke,

     When you get ready to drill the holes for the little 7/16 tubes into the cross tubes, it is very important to get them absolutely vertical in both directions with each other - I set mine up in a milling machine to drill them both at the same setting.   And make sure the tops of the little tubes are at the same height above the crosstubes before welding them in.   Mine were set to .312 (5/16) above the 1 1/8 inch diameter crosstibes.

     When you set the crosstubes up for welding to the fuselage tubes, and to the headache tubes, you should make some sort of fixture to make sure your vertical tubes are exactly 27 1/2 inches apart on each side, and that the little tubes are vertical

 - I forget what the width should be, but think it is about 36 inches - I will try to check on that if you don't have it.

EdMO

[1avidflyer 1983]

I measured my Avid right after I posted my last message, and before I could repost that 7/16" is correct, I got a phone call that lasted till I had to leave home.  Back now so I figured I would tell you you are okey on the 7/16".  Jim Chuk

 

PS  I also kind of measured a Kitfox hub.  Now if I can find that post......