Wings 29, Total 492 - RIght Spar nut plates done

One major difference between the right and left spars was that I did not like the countersunk depth of the rivets after I had applied the primer, so I basically ended up adjusting the countersink tool and going over each rivet hole on the right spar one more time. What a pain - literally.

I had a ton of stuff going last week so it has been a few days since I have been able to post. I had to get past a milestone birthday, and also got to go to the show Wicked on Friday night, which was fun. Yesterday was a day for oil - changing it in the cars and in my compressor, as well as the lawn mower. Spring is here in Colorado. I did manage to squeek out a little time last night to start setting the 2 additional AN4 bolt nut plates that go on the inboard sections of both spars. Thes nut plates hold additional bolts that are used for attaching the wing spars to the center center of the spar that travels through the fuselage. I had to countersink the rivet holes for these as well, add primer, and readjust the hand squeezer depth to account do the the added thickness of the spar web and the support plate.

One note about this which I added to a post on VAF talking about similar concerns about poorly written plans. Vans mentions that the drawing that contains the refences for these additional nut plates is DWG 11A. I searched and searched my large plan set looking for this particular drawing, because I needed to find the rivet call out for these additional nut plates. But, no DWG 11A was in my set of plans. Then, after thinking about it for a second, I realized that the DWG 11A drawing is not included with the Wing Kit because the center section for the RV8 is delivered with the Fuselage kit, and NOT the wing kit. The RV7 includes the center section with the wing kit I guess, but not for the RV 8. Therefore, I had to resort to the drawing in my preview plans to locate the rivets for the additional nut plates, which are AN426AD3-6 rivets. This is perhaps the longest AN426 rivet I had set to date, but there are many more that are even longer that are yet to come. THe rivet needs to be so long to get through the thickness of all of the wing spar web material.

So here is a pic of the right wing spar tank nut plates completed:

This next pic are the series of inboard nut plates that are set at angles due to the additional ribs for the wing walk area that make space in this area a bit tight.

Next is the nut plate hole prep for the two AN4 bolt nut plates at the root of the spar. It is constantly aggravating to me that as you apply the microstop countersink tool to metal of different thicknesses or densities, you seem to have to make additional adjustments to the depth of the bit to obtain the right sized countersink. I do not know why this is the case, just that it is. I had to deepen my tool another 2 clicks or so to acheive the correct depth for the rivets. Then primed them just as I did on the other ones, and readjusted my hand squeezer depth to correctly set the rivets/nut plates.

Here is a blurry pic of the nut plates and the rivets used to attach them.

Here are the tapered tipped q tips that purchased to apply the primer to each of the countersunk holes:

Next came the solution to my boo boo on th left wing spar inspection plate nut plate holes. I was able to purchase the necessary triangle shaped MS21055-L06 nut plates from a local supplier just north east of Denver. THis pick is blurry as well - not sure why - but certain it is totally due to operator error.

The method I used to drill the two new rivet holes, which you have to do since the holes are located in completely different places due to the different shape of the nut plate, was to cleco the nut plate to the outside of the spar flange so that I could use the rivet holes in the nut plate as drill guides to drill the rivet holes through the spar flange. This was not as stright forward as it might seem, since you had to cleco the nut plate initially by using the center hole where the screw goes. the problem with this is that the hole is already countersunk for the screw and so you cannot automatically center the nut plate just by inserting the cleco (#40) through the screw hole.

 So I ended up putting a cleco through the screw hole in the nut plate right next to this one, which was already riveted in place and centered. This allowed me to determine where the center of the nut plate was by checking the height of the cleco that stuck up above the edge of the spar flange. Then I did the best I could to match that same dimension of the corner nut plate but moving it ever so slightly until it appeared to mirror the position of the other cleco, adn also appeared to be centered in the countersunk screw hole. Then I drilled the rivet holes, deburred them, and countersunk them for the rivets. then primed them and set the rivets.

I think for now I will leave the other holes as is. they will be covered by the inspection plate most of the time and out of sight, and there is no issue with leaving them that way. If I feel like it later on I may fill them with rivets to close them up, but this is not necessary. There are also no structural concerns about this, since this is one of about 20 or so nut plates that hold the inspection cover in place. After the nut plate was installed, the screw hole for the nut plate was centered in the hole almost exactly, so I was pleased with that. I am just happy I was able to find the right nut plates to fix the problem that I had created for myself when I did not pay attention to wich holes I was drilling at the time.

Next up is fabricating the Wing tie down brackets. Need to go find my tap and die set.