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F779 and tailwheel spring

galt1074

Member
I'm having some fit issues in the tail and I know some other folks have had some similar issues.
The problem I'm having is with the spring itself. The weld at the front doesn't appear to be at the correct angle. When I try to install the aft-most bulkhead (F712 I think) it obviously requires the tails spring to be half-way in the mouse hole for the bulkhead to be installed. When the tail spring is in this position, there's a gap (probably 3/16" at least) at the top of the forward flange of the tail spring where it attaches to F711.
Anyone seen this and do I just add some shims?
I'm also having a heck of a time getting all the holes to line up but I think I just need to remove more material and make the hole bigger for the spring to pass through.

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on my 8 I did shim that location approx .032” or so.

These shims were called out in my instructions.
 
big gap

Dave,

Thank you for your reply.
My concern is that my gap is 3/16" and growing as I remove material to get F712 to seat properly over the tail spring. If it were .032" that would be easily acceptable but this seems ridiculous. Either I'm doing something wrong or this part is bad.

Anyone?
 
Greg,

Did you measure the location for the front bolt holes on the bulkhead? I don't see any marks. I'm wondering if the steel part may just need pushed down some more, making it less of an angle. But, this is where you will also need to be careful with edge distance on all parts for the bolt holes.
 
On my -8, Vans recommended using shims or a spacer to fill the gap using the tail spring flange as a pattern. My gap was quite big from memory, maybe 1/8 or so. I?ll see if I can dig up a photo.
 
I had problems in this area and ended up having the WD-409 cut and re-welded. One of the faces was not parallel to the other one and my inspector wasn't comfortable with shims of different thicknesses that could have introduced point loads. After the repair everything was nice and parallel and I just used one 0.032" shim at the forward end of the weldment.
 
Maybe bad part

Andy,

If the angles are supposed to be parallel then I'm quite certain I have a bad part. I'll call Van's and talk it over.
Thank you everyone for the replies. I skipped the wings so I don't know about them but the beginning of the fuselage with the way some parts don't fit and how vague the instructions can be has been pretty aggravating. I'm sure I'll figure it out and it will be fun again.
 
"fixed" it

So there's nothing wrong with the part, there's nothing wrong with the skins, and there's nothing wrong with the way I was preparing everything except for missing some clecos.
I went ahead and put together the whole aft-fuselage and discovered my main issue was the angle of the F711/712 bulkheads because I hadn't cleco'd the top holes in the F779 skin where it joins with the top of the curve at the bottom of the bulkheads. This meant my bulkheads weren't at the proper angle and my tail spring was at the proper angle but everything looked off by a lot.
Now I have what appears to be all the standard problems with that part of the fuselage, which makes me feel better.
Thank you so much for all the replies.
 
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