airguy

airguy

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I suspect I know the answer to this, and I'm keeping the number of cleco applications/removals to an absolute minimum - but I'll ask the question anyway. Can anyone tell me what to expect as far as enlarging/damaging match-drilled holes due to multiple cleco insertions and removals?
 
It's pretty minimal. Obviously, technique aside, enlarging a hole with the use of clecos is nothing I've observed.
 
I haven't noticed any problem so far, except where there is shear force on the clecos (such as the holes in the leading edges of control surfaces). If you're careful to remove such force before inserting/removing a cleco, you should be fine.
 
This can happen.

This can happen, but.....................

It is usually attributed to mis-alignment of the holes and still forcing the clecos in place more than once.

Be aware that when this is happening the structure is being set up to be pre stressed. Check out why this is happening and correct it.

On the fully predrilled stuff you might need to clean it up by drilling the next increment size hole. But before you do find out why.

Even if you have a reversible drill you can't un-drill it.
 
Slightly off topic, but if you suddenly notice that a Cleco is loose in the hole you might check the brand. There IS a difference and it is most noticed in holes that have been match drilled and dimpled.

Bob
 
There isn't a big problem with this but I do think there are some areas worth thinking about, if my experience is any indication.

Take the front skin on -- in my case -- a 7A...

Because the skin doesn't easily lay flat where it meets the fuselage (the skin is across a curved subpanel, of course, it's under a bit of stress when you cleco it in.

That skin, again if my experience is any indication, comes on and off a LOT when working on the canopy and canopy frame and after awhile, it's pretty tough not to have enlarged those holes.

What to do about it? Not sure. Haven't gotten that far yet.
 
Not to worry . . .

Rivets expand to fill the holes. Unless there is deformation to the point where the cleco falls out, build on. Clecos don't come close to holding things together like rivets, so these structures are quite flexible as they are being built, and alignment will change until the rivets are in. Use due care, but don't sweat the small stuff.
 
Cleco tip

Bob Collins said:
Take the front skin.......Because the skin doesn't easily lay flat where it meets the fuselage.....it's under a bit of stress when you cleco it in. That skin...comes on and off a LOT when working on the canopy and canopy frame and after awhile, it's pretty tough not to have enlarged those holes. What to do about it?.........
Click to expand...
I wouldn't worry too much about it. Not one cleco vibrated loose during initial engine runs.



Besides, if a hole does become slightly wallowed out or the cleco otherwise does not grip well; for example being subjected to significant tension forces, that situation is easily resolved by drilling a small (I prefer a #41 hole) into a small square of scrap and backing the work with it.

 
Rick6a said:
Besides, if a hole does become slightly wallowed out or the cleco otherwise does not grip well; for example being subjected to significant tension forces, that situation is easily resolved by drilling a small (I prefer a #41 hole) into a small square of scrap and backing the work with it.

Click to expand...

Now THAT I like - that's a trick I'll remember and probably use at some point.
 
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