Kitfox 2 frame strengthening

[skelly 12]

Hi everyone,

While I have my kitfox 2 stripped down to its bare bones I wondered if there are any fuselage mods that I can carry out to make things a bit stronger / stiffer ?

I would be interested to see what people have done to their carry through tubes and strut mounts.

Is there also a longeron mod ?

I intend on keeping the original landing gear so no need for grove type mods.

Anyone got any hints or tips or photos ?

Cheers,

Skelly.

[1avidflyer 1944]

I would think it would be a good idea to infill the seat truss with .040" steel to strengthen it.  Also, maybe under the door frame where landing gear pressures are.  And for sure I would widen the fuselage at the doors.  I went 4" on my Kitfox 4, and 3" wider overall on my Avid MK IV.  Here is the Kitfox 4 fuselage.  The doors are twisted to fit the new opening shape before you install the windows in them.   JImChuk

[TJay 1040]

First off Jim I like your Tail wheel.

And Skelly what kind of gross weight you plan to do? If your leaving it 950  Not sure I would do much at all.

[skelly 12]

Ooh, interesting stuff,

I forgot to mention, I am in England so anything I do will need approval from the LAA.

My kitfox is actually classed as a 3 axis microlight here so I need to be under 450KG which is 992LBs in English..

I will save some weight by covering it on Oratex 6000 and making some bits from carbon fibre.

Cheers,

Skelly.

[1avidflyer 1944]

Well for sure the seat truss infill is a good idea.  Lots of them have been bent with a not so hard landing.  And TJay, nothing but quality at my place....or something else if it will workJImChuk

[skelly 12]

Cheers guys,

Have any of you ever beefed up the wing carry through tubes ?

Looking at it, there is not alot of bracing around them.

Any ideas ?

Cheers.

Skel

[Allen Sutphin 704]

Talk to TJay, the man has a master's degree in hillbilly engineering!  And several on here are waiting for their diplomas to show up in the mail.

[akflyer 1422]

Jim posted up the biggest thing you need to do.  Have not seen any failures in the wing carry through.  The seat truss area for sure needs to be beefed up.

[Firesteve 5]

Hi Skelly,

 

Don't forget your MAUW for the Kitfox 2 is 950lb or 430.913kg, this weight cannot be increased without a serious amount of testing or paperwork. You may be able to get the factory to back you up on a weight increase but I wouldn't hold my breath!

[ricocb121 0]

To co-sign on the need for this modification, here is what a gopher hole on the taxiway of a grass strip did to my seat truss.  Having 4130 Chromoly welded in throughout this whole section on both sides.

v/r

Rico

[1avidflyer 1944]

Looks like the second time damage was done there.  Or maybe there was a crack at the bottom  that started with the first incident.  Infilling the area should strengthen it up.  Wonder if there is any other damage??

Edited 16 May by 1avidflyer