Horizontal and Vertical Stabilizers

March 13, 2014 and I am picking the Horizontal Stabilizer back up.  In the first post, I completed the spars having riveted on the stiffeners.  I have already made two mistakes.  The builders manual says that if you are using flush rivets, you MAY rivet in the stiffeners after aligning and updrilling the skins.  I did not understand why, and thought it would be easier.  Since the plans gave me a choice, I chose to rivet now.



That was my first mistake.  I did not understand the consequences.  So now,  when I go to dimple the flange on the spar channel that has the stiffener riveted inside it, I am going to be very short on space and will have to shave off my rivet squeezer and dimple die to get it to fit in there.  Tony Spicer has a picture of this on his site, and I will too as soon as I get to that point on this part.

The second mistake was that I did not pay attention to the rib attach holes in the stiffener and channel.  For two of these on each spar, there are only two holes pre-drilled, so I made a template from one of the ones that have all three pre-drilled and used that to drill the additional hole.  You can save yourself this trouble, if you also have the same issue, by sliding the stiffener to that place and use it as a template.

I built the frame for the HS, and here you see that I am having to bend the nose rib away from the cleco, to be able to insert it.  This is because I was doing it wrong, but at the time it was the only way I could see to do it.  Dan sent me a picture that shows the way it should be.














Here Dan shows putting on the nose rib prior to attaching the main rib to the aft spar.  If I have this problem again, I think I will first try using solid rivets and a squeezer.  Am thinking this will come up again with the wing kit.

Here I am laying out the HS frame on the wood supports that are screwed to the bench.  The frame is to be attached firmly to the wood supports.  First, I must insure that it is all on the same plane, and square.  Checking for square is simply measuring on each diagonal and adjust the frame until the measurements are equal.










Here on the right you see that I had to turn that hole into a slot.  When you drill into wood, sometimes the grain wants to take the bit off to a place not of your choosing.  So, the slot allows for that movement and 20140313_SM_11still allows me to adjust the frame properly.

The picture above right shows the slot and is also showing the HS turned over after the top skin was attached.  These pictures below show attaching the skin starting at the aft spar and proceeding as instructed in the builders manual.






This is as far as I could get with the HS because I ran out of #40 Clecos and the next step is to up drill to #31 and my #31 bits will arrive tomorrow.  I had thought all along that for the flush rivets that I was supposed to use #30 and have a bunch of them, but found out that #31 may stop the stems from pulling thru.  So I will run some tests on that to be sure because I don’t know how I am going to remove the protrusions of those 20 or so that pulled thru.  You may have noticed that my rivet gun started out as a red one and is now a blue one.  That is because the red one had already been thru building an RV 12, and I thought it might have been the problem for the pulled stems.  I really expect that it is operator error, but the new gun at least rules out the old gun.

The first thing with the VS (Vertical Tail) is the same as with the HS.  Build the frame and this time don’t make the same mistakes.  Put it in a jig of sorts, on a flat surface, and put on the skin the same as before.


20140313_SM_2120140313_SM_23The picture with the wood supports clamped on is to show that you need to be sure to leave as much room on the end at the top of the VS, as you possibly can.  Otherwise, you will be re-placing the supports.

So as of today, March 16, 2014 I am finished with the tail kit, excluding updrilling, deburring, dimpling and riveting.  Yes, that is about another week.  I have placed on order the spar, wing, and aft tail section.  So there will be no rest for the weary.