Heavy Hauler carry-through sizing

[dcstrng 0]

What size tubing (diameters, wall…??) is used for the fuselage carry-throughs on the heavier-hauler Avids and or KFox… I’m beginning to round up material for an Avid-eque stick-built and see the spar and lift-strut sizing in this forum, but so far have not stumbled across what I assume would be corresponding up-sized tubing on the carry-throughs…

All notions gratefully accepted…

Thanks…

-- Larry

Edited 24 Feb 2011 by Larry

[Av8r3400 1179]

You'll never get anything from Kitfox.

You might get Brett from Airdale to comment for you, but for liability reasons maybe not.

There are plenty of bent or uncompleted kits out there. Why not go that way?

[dcstrng 0]

You'll never get anything from Kitfox.

You might get Brett from Airdale to comment for you, but for liability reasons maybe not.

There are plenty of bent or uncompleted kits out there. Why not go that way?

OK thanks – Just starting to get together a materials order…

Worst-case scenario I’ll SWAG off of a Buttercup or Tailwind which should be handling more or less the same or slightly more athwart-ships compression loading, and have about the same distance to span between spar attachments…

Unless someone has a better recommendation… whatever, I’ll error on the side of safety; seems like not a good place to be pound foolish…

-- Larry

[Av8r3400 1179]

Weren't there some Avid-Fox clones out there available as "plans built"? The Canadian "Raven" comes to mind as being one...

[flattie45 17]

Weren't there some Avid-Fox clones out there available as "plans built"? The Canadian "Raven" comes to mind as being one...

Can't say I know much about them, but weren't the Ravens from the B or C model era? I'm not sure how beefy they are compared to something like the Avid+/Airdale.

-Nate

edit: Sorry, I was thinking of the Mohawk.

Edited 27 Feb 2011 by Nate

[dcstrng 0]

Weren't there some Avid-Fox clones out there available as "plans built"? The Canadian "Raven" comes to mind as being one...

Yes, indeed those are the plans I’m working off of; however, the Raven is essentially a stick-built A/B-model with an 850-900 pound gross, and I’m planning to mimic the Avid/KFox metamorphosis to the 1100 +/- gross on the earlier 2-cycle birds – I have found pretty much all the upgraded wing specs (spars, struts, drags etc…), and finally found a couple of sources for the 0.083 wall 6061-T6 spar tubing, but haven’t got the exact specs on the CT upsizing…

However, if all else fails, I’ll probably mimic what a couple of Avid rebuilders have done and up the tubing to 1.0 and 1.125 diameter 4130 (front and rear respectively) for the CT, with 0.065 or so wall… that may be a touch heavy, but if so only pound or two…

Since I plan to build at the later 39†cabin width rather than the Raven/A-model-esque 33â€, I don’t want the compression loads on the CT to get anywhere close to problem areas at the planned HH-esque gross weights… But, I don’t want to end up fifty pounds heavy either…

Cheers…

-- Larry

Edited 27 Feb 2011 by Larry

[dholly 718]

Larry -

Pretty sure my 1200 lb. MTOW Avid Mk-IV HH had 1" dia. spar carry through tubes, but I don't recall the wall thickness. The KF-III 1050 lb. MTOW and KF-IV 1050 lb. MTOW use 1" dia. x .035 wall for both front and rear spar carry through tubes. The KF-IV 1200 lb. MTOW uses 1" dia. x .049 wall for both front and rear spar carry through tubes. More info HERE on lift struts, etc. Hope that helps.

-Doug

[dcstrng 0]

Larry -

Pretty sure my 1200 lb. MTOW Avid Mk-IV HH had 1" dia. spar carry through tubes, but I don't recall the wall thickness. The KF-III 1050 lb. MTOW and KF-IV 1050 lb. MTOW use 1" dia. x .035 wall for both front and rear spar carry through tubes. The KF-IV 1200 lb. MTOW uses 1" dia. x .049 wall for both front and rear spar carry through tubes. More info HERE on lift struts, etc. Hope that helps.

-Doug

Thanks Doug; that helps considerably – sorry to be slow on the response, was out of the loop for a week… guess I don’t need to go quite as heavy as I thought…

Appreciate it…

-- Larry