Van's Air Force
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WD-814 Roll bar
- Thread starter DaAV8R
- Start date
ColoRv
Well Known Member
With the side rails on, sliding the outside panel into place once assembled would be interesting as I recall. I assume you're going to rivet the half moons to their support structure in place rather than on a bench? A few of those rivets might be a bit of a challenge near the sides under the angle. Look into putting the nutplates on first...again from memory those can be challenging after assembly.
Upon re-reading my OP, I don't think my question was clear. I was using the term "installed" very loosely. Should have said fit and match drilled. Sorry
I haven't riveted the rails. I have only fit the fuse skins and rails for match drilling. It all needs to come apart for deburing and dimpling.
My question is whether the roll bar can be fit at this stage of initial assembly. I don't see fitting and match drilling the roll bar in this portion of the instructions. Is there any reason not to fit and match drill the roll bar at this point?
Thanks.
Don't be in a big rush to drill and cleco this item on. You will only get one shot at doing it. Screw it up and you've ruined the top longerons. Due to the use of AN3 bolts going through the F-887 longerons, edge distance here is critical. The mounting holes going into the F-887s must be dead nuts centered, or you will not have proper edge distance here.
Being that this structure is all that will keep your noggin from getting squashed in the advent of a tip over, you want this to be right.
Make sure you've gotten the instrument panel properly fit and the glare shield skin at least drilled and fit before attempting to mount this part.
Also make sure that you have the proper dimension [31.5" comes to my fuzzy memory] across the fuselage before fitting this. Once this is fit, you can not fix several potential issues which could crop up and are not to bad to fix, BEFORE that weldment is installed. Ask me how I know!
Charlie
Being that this structure is all that will keep your noggin from getting squashed in the advent of a tip over, you want this to be right.
Make sure you've gotten the instrument panel properly fit and the glare shield skin at least drilled and fit before attempting to mount this part.
Also make sure that you have the proper dimension [31.5" comes to my fuzzy memory] across the fuselage before fitting this. Once this is fit, you can not fix several potential issues which could crop up and are not to bad to fix, BEFORE that weldment is installed. Ask me how I know!
Charlie
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Fixing a to wide fuselage
On my early 8A kit, after riveting the fuselage together, I discovered that my cockpit sills were 3/8" or 1/2" to far apart. I only learned this when I went to install the Wd-814 on. I did a LOT of measuring to figure out what the problem was. I was lucky, that I had another 8 builder who only lived a few miles from me. I measured his fuselage width dimension where the Wd-804 goes. His was correct [31"] and my Wd-814 fit his fuselage properly [as did his] I fixed my problem by fluting all four of my F-804C vertical bulkhead pieces. In this way I was able to correct an error that would not have been repairable once the Wd-814 was drilled on. [At least not without ripping out the F-887s!
Vans had advised me to simply stretch out the Wd-814 to fit. Even I KNEW that was wrong, as it would create more problems down the line. The canopy will not fit correctly if the cockpit is to wide or to narrow. Remember, the carpenters, roofers, plumbers and electricians all work to hide the mistakes of the bricklayer who lays the foundation. Ignore a problem now, and it will bite you in the a$$, later!
You can see that the Wd-814 does not meet the left F-887, after being drilled and clecoed to the right F-887. Tape measure shows this, too.
Cave man method of getting the fuselage to the correct width, using a carpenter's clamp and blocks of wood. The Wd-814 was stiff enough that simply installing it brought the fuselage width within 1/16" of being correct. However, that left the structure under tension, which is not best practice.
The solution was to flute the F-804Cs [all 4] on their inboard edges. After doing this, I could remove both the Wd-814 and the carpenter's clamp and the fuselage was the correct width at this point. These flutes are not visible after the F-804N caps are installed.
Right side F-804Cs after being fluted. The silver bar is the carpenter's clamp. Simply fluting this area cured the entire problem.
Charlie
On my early 8A kit, after riveting the fuselage together, I discovered that my cockpit sills were 3/8" or 1/2" to far apart. I only learned this when I went to install the Wd-814 on. I did a LOT of measuring to figure out what the problem was. I was lucky, that I had another 8 builder who only lived a few miles from me. I measured his fuselage width dimension where the Wd-804 goes. His was correct [31"] and my Wd-814 fit his fuselage properly [as did his] I fixed my problem by fluting all four of my F-804C vertical bulkhead pieces. In this way I was able to correct an error that would not have been repairable once the Wd-814 was drilled on. [At least not without ripping out the F-887s!
Vans had advised me to simply stretch out the Wd-814 to fit. Even I KNEW that was wrong, as it would create more problems down the line. The canopy will not fit correctly if the cockpit is to wide or to narrow. Remember, the carpenters, roofers, plumbers and electricians all work to hide the mistakes of the bricklayer who lays the foundation. Ignore a problem now, and it will bite you in the a$$, later!
You can see that the Wd-814 does not meet the left F-887, after being drilled and clecoed to the right F-887. Tape measure shows this, too.
Cave man method of getting the fuselage to the correct width, using a carpenter's clamp and blocks of wood. The Wd-814 was stiff enough that simply installing it brought the fuselage width within 1/16" of being correct. However, that left the structure under tension, which is not best practice.
The solution was to flute the F-804Cs [all 4] on their inboard edges. After doing this, I could remove both the Wd-814 and the carpenter's clamp and the fuselage was the correct width at this point. These flutes are not visible after the F-804N caps are installed.
Right side F-804Cs after being fluted. The silver bar is the carpenter's clamp. Simply fluting this area cured the entire problem.
Charlie
Thanks Charlie and Bill.
I will set aside the roll bar and fit it later. I'm glad I asked as I apparently do not understand everything that is going on at this location.
I think I am 1/16 wide out/out at the longerons according to the dimension referenced. I'll take a close look at this area after the balance of the parts are fit.
Thanks again.
Edit: I was posting at the same time as Charlie. What is the correct dimension at the top of the longerons? A search finds another thread which states that 31.5" is the correct dimension. I don't think the current documents provide a dimension.
I like your analogy Charlie. I am in the steel business so I spend many days chasing repairs for incorrect concrete. I understand what you are saying all too well.
I will set aside the roll bar and fit it later. I'm glad I asked as I apparently do not understand everything that is going on at this location.
I think I am 1/16 wide out/out at the longerons according to the dimension referenced. I'll take a close look at this area after the balance of the parts are fit.
Thanks again.
Edit: I was posting at the same time as Charlie. What is the correct dimension at the top of the longerons? A search finds another thread which states that 31.5" is the correct dimension. I don't think the current documents provide a dimension.
I like your analogy Charlie. I am in the steel business so I spend many days chasing repairs for incorrect concrete. I understand what you are saying all too well.
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Robert,
1/16" is an extremely small discrepency. You can draw that in using a carpenter's clamp temporarily, while you drill the Wd-814 to the fuselage. Once the holes are drilled and you cleco the Wd-814 on, it will hold the fuselage to the correct width. It's very rigid. You can always flute the F-804Cs later. Go easy with the fluting pliers. It will not take much to fix your small error. Be advised that the fuselage width may change slightly, once the F-803A/B/C instrument panel and the F-821 glare shield skin are drilled and clecoed on. Best to have them at least mounted with clecos before fitting the Wd-814. Worry about final dimensions with them in place.
The real issue is not to drill the mounting holes for the Wd-814 to the F-887s and have insufficient edge distance for the bolt holes in the F-887s. You are using AN3 bolts here. Make sure you have minimum edge distance from the center of those holes to the inboard edges of the F-887s. Best to draw center lines on the F-887s that you can sight on through the holes in the Wd-814s before you drill.
You might have to file or grind a small amount off of the AN3 Nyloc nuts to get them to clear the vertex [radius in the corner] of the F-887s to get the nuts to lie flat. I think I had to do that on a few of mine.
Charlie
