TitleGarrison

No bird ever flew nonstop from New York to Tokyo, or raced 15 miles high at triple the speed of sound.                                                                                                   
  But birds do something else.
  They do not conquer the air; they romance it.
.”

  Peter Garrison

HoursAndCounting

Jur's RV7 Aircraft Factory
2917 hours
and counting
Some decisions in life are bare of any obvious logic

 

More work on the F704 center bulkhead section.

Clecoed the F704-C and D in place. The manual calls for usage of at least 2 of the NAS close tolerance bolt to insure proper alignment when matchdrilling.
These bolts fit really thight. Whe you put some boelube liquid on, they slide little better but still it's a very thight fit. Had to give some of them a light tap with the hammer to get them out again.

Matchdrilled all holes to #30. There's lots of em,  the part looks like a nailboard.

Then bolted the F704-G vertical bars in place and bolted them. The AN4 holes in the vertical bars come predrilled. All you have to do is drill the two holes to #30 for the two AN426AD4 rivets that hold the bar in place.
Vans calls for AN426AD4-14 rivets to rivet these vertical bars to the center section. These rivets are way to small and will not lead to compliance to military specifications. But... these are non structural connections. They only serve to keep the bars in place until the two larger AN4 bolts are installed. Anyway, I need to order some stuff end of this month so I'll throw in some 16 rivets but if you don't have them, it's ok to go with the 14 size.

Here's a picture from the other side with the two holes in the vertical bar drilled.

Then you countersink the holes for AD4 (flush head on the vertical bars forward side.

Center bulkhead with both sides matchdrilled.

Deburring the parts is next. I took this picture because it shows nicely the nice edges on these holes after deburring.

Next job on the aft center bulkhead is to mount the control column mount brackets.
I measured the first hole as per the plans and then drilled it on the bench press. This will be the alignment hole. 

Once drilled, you put a AN3 bolt through the reference hole and square the mount on the aft side of the aft center section.
The picture shows me 'being anal again' and pushing the measurement to the limits of absurdity.
As I said... you can bever be sure enough on these parts. Measure and measure again and then double check.

Here is the reason why you need to double check what you do. The picture above shows the screw-up of the day.

The squaring and positioning is fine, but the angle is inverted. I accidentally took the right bracket for the left side on the bulkhead.
I only realised when I tried to mount the control column bar.
Fortunately for me, the CNC machining by Vans is close to perfect and by just inverting both angles after matchdrilling, the match still worked as good as if I would done it the correct way. Thank you Van.

The picture below shows the corre t alignment with both angles installed.

Same work of matchdrilling for the forward side. Check the nice green poinsonous coloured label saying that you can 'by no means' touch those close tolerance holes on the sides.

Then continuted on countersinking the nutplate ear holes on the top side of the bulkheads.
This feels familiar as it's the same as on the wing spar work. I used the same technique of clamping a fat piece of aluminum to pilot the countersink pilot drill.

Worked like a charm.

The installed all the nutplates on both sections.

The plans look simple on this part but there so much little detail jobs on this that it actually takes a lot of time to complete.

How to use

Use the kit buttons in the top ribbon bar to see a chronological overview per sub section per kit. For the full chronological article list, see chronological build link in prelude menu here below. The easiest way to lookup information is by typing in some part numbers or keywords using the search option in the ribbon bar

 

Caution !

Some advice on reading my log for fellow builders !

In some articles, I made corrections at later date on the original article to rectify my own stupidities or faults. Read through the entire article if you intend to use my findings/experiences on your own project !

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Legal Mumbo-Jumbo

It’s possible (not likely) that I’m not as smart as I think I am. (Occasionally, I have moments when I know this to be true. Fortunately, the feeling passes quickly.) Although I have tried to make this information as accurate as I can, it is not only possible, but also quite likely, that erroneous and misguided information lurks within these pages. I cannot and do not warrant these pages to be error free and correct. Furthermore, I accept no liability for the use of this (mis)information. And, as many would say, your mileage may vary. If, after reading this, you are intent on proceeding, please be aware that the contents of this site are protected by copyright (copyright © 2011 and 2012). Nonetheless, you may copy this material subject to these two conditions: (1) any information used is for non-commercial purposes, and (2) the source of the material is properly credited. Of course, you may link to any page herein. At some articles, snippets of the plans from Vans are visible. These are for educational and illustrations purposes only and should never be used as plans for part construction or assembly as plans may have changed since the picture was taken and more important they are protected by Copyright by the Vans Aircraft Mothership company.

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