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Avid A: Plans for the fuselage, particularly the Cage

31 posts in this topic

Posted (edited)

I'm a new member on the forum.

I'm requesting to get a copy of the fuselage plans from anyone that has them. 

I recently bought a avid flyer A and while backing up hit the 

pilot wing (while in the transport position) push it forward. The result was the

cage cross member broke, and also the cage front member (where the front main 

spar attaches broke.

I live in the Boston MA area, any  assistance would be appreciated.

If someone is familiar with tubing repair, I'd be willing to travel for

help to fix it - of course I'm willing to pay. Just remember I'm on a shoe

string budget.

David

 

Edited by dee
typo

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Posted (edited)

Sorry about you bending up the plane.  There really never were public drawings for the Avids that I'm aware of.  If the damage is just on one side, perhaps you can measure everything on the opposite side to get the dimensions you need.  On the positive side, repairing a steel tube fuselage is nearly always possible.  Cut out and replace, or straighten bent tubes, and do a good job of welding.   It started out as a bunch of small pieces, so most things can be fixed.  Got a picture?  JImChuk

Edited by 1avidflyer

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Posted

fuselage2.jpg

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Posted

Seems like I'm going to have to go that route.

 

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Posted

Looks like the front is bent to the right. The door posts could be cut and spliced if they are beyond straightening.  When  TJay replaced his front wing carry through with a slightly larger one, he used a hole saw that was just big enough to go over the carry though tube.  That cut away the welds and about 1/16" of the tubing over the top of the doors where they meet the carry through tube, and the larger carry though tube fit right up to be welded in.  Maybe he will see this, and put up some pictures.   Probably be a good time to replace the diagonal cross tube with the newer design as well.  Gives equal headroom for both sides.  You can kind of see the newer style cross brace in these pics.   JImChuk

Photo0605.jpg

Photo0610.jpg

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Posted


Here is an educational video that I made for this Not the best quality but might give you some inspiration. Any local welding shop could help you out with this fix too. https://www.youtube.com/watch?v=ipAmL6fzW1I

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Posted

thank you much

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Posted

Could you please take two more pics for me please

1. looking down at the fuselage cage

2. a pic of the two members at the cockpit windshield (for the attachment 

at the bottom)

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Posted

Chuck

could you take a pic so that I can do what you said

"Probably be a good time to replace the diagonal cross tube with the newer design as well.  Gives equal headroom for both sides.  You can kind of see the newer style cross brace in these pics. "

thanks for all the help.

David

 

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Posted

Found this picture of my fuselage after painting.  It shows the birdcage area better.  JImChuk

 

Photo1006.jpg

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Posted

 

Chuck

1. what  size (OD) & wall thickness should the new carry though tube be for 4130 alloy round steel tube

2. what  size (OD) & wall thickness should the new design diagonal cross tube  be for 4130 alloy round steel tube

?would you know the size of the old stuff?

thanks 

Dee

 

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Posted

I forgot to check when I was out in the hangar this evening, but I'm almost positive the bracing/cross tube stuff is 1/2" and most likely .035" wall.  I suppose you could jump up 1/8" from what you had for the carry through, and then it would fit the cut out from the hole saw better.  I would use the same thickness as what was there before.   JImChuk

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Posted

Could you give me the dimensions for

Cage.png

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Posted

I forgot to get the dimensions again today, so I just now walked back out to the hangar and did some measuring.  Here is what I come up with.  "A" dimension is 4".  "B" dimension is a center to center dimension, and it is 6".  I ran a straight edge under the front and rear carry through tubes and the tube that is parallel to them is 1 3/4" higher then they are.  That is  center to center dimension as well.  I did not get a dimension for C or D, because the 8" tube (parallel to and about 5" behind the front carry through tube determines all the other lengths.  I would make up that 8" tube and the two short ones that come off it going forward and meet in the center of the front carry through.  Position it so it's 1 /3/4" C to C above the carry throughs and centered side to side, tack in place, and then fill in the rest of the tubes at the length they need to be to reach where they need to go.   Hope that's clear and understandable.   JImChuk

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Posted

thank very much

dee

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Posted

Chuck

I forgot to mention, I also have a kink on the left longeron that really concerns me

Any comments

fuselage4.jpg

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Posted (edited)

That is a common spot for bent tubing,  likely it can be straightened once the fabric is removed.  If you look at my fuselage photo again, you can see that I added some  tube to stiffen that area.  Basicly, a tube comes down from the top of the seat area to the mid point of that section of longeron, goes across the fuselage to the other side and then goes back to the top of the seat area.  Here is another picture showing that area of the fuselage.  Maybe you can pick out the tubes I'm referring to.  JImChuk

 

Photo1005.jpg

Edited by 1avidflyer

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Posted

TJay

What was the size of the new cross member you put in (OD and wall thickness)?

Also are you willing to lend me your jigs you made up?

thanks

Dee

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Posted

TJay

 

Thanks for the video

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Posted

TJay

One more question, where did you get that long circular bit from?

Dee

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Posted

fuselage3.jpg

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Posted


just a standard dewalt hole saw I welded to a pipe

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Posted

TJay

could I borrow the jigs you used to make that modification. That is if you still have

them. my left side is bent pretty bad

dee

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Posted


you can,  I'm not sure they will work for an avid but you may try. And the hole saw is shot there about a 1 time use deal.

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Posted (edited)

TJay,

Is it possible you send me the jigs you made for your front spar  carry thru replace

 

 

 

Edited by dee

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