Wing attachment block SNX-W11-03 attach pin hole

[Sonex1517]

On page SNX-W11 there is a wing attach block, part -03 with a note about a wing attach hole. It indicates the hole is enlarged later, but I can't figure out what page to find that on. The part also indicates to make this hole with the block clamped to the extruded angle in both directions....that part was kinda difficult...

I want to know how large the wing attach pin hole going to be when it is final. so as I make the part and try to keep the hole aligned I have an idea of the tolerance -- anyone know where I can find this in the plans?

The part has two bolts to attach it to an extruded angle with a 3/16" pilot hole for the wing attach hole, and that part makes perfect sense to me. It is the horizontal wing attach pin hole that indicates it is to be made larger, and I have searched the plans but just cannot find this.

As I made my first attachment block the wing attach hole is slightly misaligned with the existing 3/16" hole in the extruded angle. No big deal if I need to re do that, but before I do I want to know how much it is enlarged to determine if I can use it as is or not....

Hope this makes sense...if not I can add photos...

[vicdelgado9]

I am not sure what page it is on, and not near my plans to check, but the two holes that have bolts that attach the block to the extruded angle, are drilled up to 3/16 for bolts. The wing alignment holes, will eventually be drilled up to 1/4 and then 3/8 at final fitting and updrilling.

[Sonex1517]

thanks Vic!

[Sonex1517]

Follow up question for all who have done the wings

I have seen several builders state that they updrilled the wing attachment blocks to 3/8" before finishing the wings. I am at a point where I cn do this if it is a good step to take, but not certain why it is - even reading ahead I am not sure if going outside of the plans here is wise.

Should I updrill the attachments to 3/8" while I can have easy access to them?

Anyone have practical experience or input on this idea?

Here's one explanation with photos:

http://websites.expercraft.com/willsson ... g_id=24051

"This would have been MUCH easier if I had done as several others had done before and had updrilled the two end holes in the attach blocks to 3/8 before building the wings...I don't know why Sonex does not change the plans to reflect this and if you are reading ahead, trust me, do it!!!!"

[MichaelFarley56]

I guess this is my .02 cents, so take it for what it's worth, but if I were to do things over I would follow the directions and not updrill anything until you fit the wings. If you updrill now you may save 20 minutes when you fit the wings, but you also run the risk of elongating holes (which would be VERY bad) and without being able to updrill to a bigger size you would have a serious issue.

When you fit your wings you set all angles, and then drill the vertical fuselage angles to 1/4" first (I think) using the spars as your guide, then as one unit updrill to final size. This way you're drilling everything at once and not using your spars as alignment tools with no room for error. As I see it you still have to drill the same holes but I liked the fact that, as soon as I drilled the holes to final size, I could tap in the real bolt knowing the fuselage angles and spars were all drilled perfectly.

I just don't see how up drilling now is really going to save you much time. :? Actually, I remember most of that job is actually fitting the aft spar first, and then after it was all set the main spar holes really didn't take much time at all.

Again, just my two cents...

[Sonex1517]

Thanks! That is why I asked...Any other opinions are welcome please. I just could not see why doing it now is a time saver and while I could see it being possibly easier to replace the blocks now if I mess em up, I don't think my opinion trumps the design of the plans....

[sonex892]

It comes down to personal choice. I thought long and hard about the rigging process then chose to drill the spars clamped together up to 3/8" using a drill press. Later when fitting the wings placed a 3/8" OD x 1/4" ID x 4" long steel bush in the spar holes for the alignment. Then using a long 1/4" drill to drill a 1/4" pilot hole into the front angles then removed bush and updrilled the angles to 3/8" Then repeat the process to do the rear angles. No more chance, I actually believe less chance, of ovaling out the holes this way.

The reason I went for the alternative method is prior to building my plane I saw the holes ovaled out using the sonex recommended method for rigging. Its just a fact that aluminium is soft stuff and using a hand drill to drill a deep hole in an awkward place is a recipe for ovaling out the hole.

Just my opinion. Ducking for cover now

Steve
Sonex 892

[radfordc]

but you also run the risk of elongating holes (which would be VERY bad) and without being able to updrill to a bigger size you would have a serious issue.

You can drill the hole larger than 3/8". Sonex told me that it's OK to drill up to 1/2"...I drilled mine to 7/16" in order to eliminate an ovaled hole.

[Sonex1517]

I'm still looking at the plans and trying to figure out where they show putting the two spars together to drill their matching holes - from the plans and poking around on web sites it appears this is best done before I even updrill the ribs...

I confess to having gotten lost in some of the details and being wary of screwing up the main spar in an expensive way.

[Andy Walker]

Having hogged out/miss drilled/enlongated/angle drilled/just plain screwed up way too many holes on this thing already, I think I'll stick to the plans method.

Just drilling straight perpendicular holes seems to be beyond me sometimes. :lol: