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  #381  
Old 08-29-2018, 08:53 AM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,555
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Hereís a photo of the rivet holes in the side skin that are hidden by the wing. The row at the top of the photo doesnít need to be flush. The plans are a bit vague about this area - Iím sure that other people have built their planes a little differently here. But for me the ease of riveting is more important than the extra work dimpling them. I could have gotten the AN442 flat protruding head rivets for this but I didnít. Those are as easy to set as flush ones and are otherwise like universal-head rivets, but with a flat top. While weíre thinking of easy-to-set rivets, if you go back to reread that riveting spec MIL-R-47196 thatís on Vanís site, Iím pretty sure it says that flush rivet sets can be used on universal-head rivets. Thatís also easy. But thereís a small dimensional window between a proper shop head and going too far squishing the factory head, so I havenít been doing that.

The area outlined by the red dashed line will not be glued.



I rechecked the twist of the fuselage. Once the cockpit side skin goes on, no other tweaks can happen. This is it.

Hereís the longerons at the spar bulkhead:



And the longerons at the seat bulkhead:



I also checked the firewall and itís aligned, too.

I was unable to check the aft end of the tailcone due mostly to not being able to see the level.

Rod Woodard dropped by the Boulder airport for a visit. It was great to see him again and to examine his new RV-3. Itís a very pretty airplane and I got to look at a number of things that Iíd wondered - throttle quadrant location, seating height, fuel selector position, fuel vent position and configuration,, antenna locations, etc. Details.

Here, here, and here are the backup photos.

Dave
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  #382  
Old 09-04-2018, 07:29 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,555
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Sunday before Labor Day was kind of a big deal. With the help of Charlie Stein and with Rod Woodard observing, we glued the LH side cockpit skin to the frame.

This marks the final skin while on the jig.

This skin, like the entire RH side, tailcone and cockpit sides, are as yet unriveted.

Rod Woodard took the first four photos.

The day was interesting and fortunately, uneventful. It went pretty much according to plan. It took 77 grams of mixed epoxy and there was a little left over. In the photo, the lids were ajar because I wasn’t sure if I’d need to mix another batch or not. As you can see from the cans, I’ve been using them.



I’d already put the tape on the inside of the skin.



Charlie Stein and me,



Once the exoskeleton and clecos were off, I stood back for a few minutes to look at it.

Incidentally, for this skin I countersunk the longerons .012 deep, using a rivet as a gauge. This gave me a noticeably smoother surface than the dimension of .007 that the factory recommends for non-glued joints. On the bulkheads I've been using the tank dimple dies and they work very nicely for glued joints.



Then I removed the front part of the jig that had supported the firewall. The plan was to install the engine mount and then the main gear legs, but the bottom front cross member of the jig isn’t removable and was in the way. Here’s the firewall without the jig obscuring it. Yes, I did remove that bump in the center of the cross member.



I also learned that, as I had rather thought, that the belly round-over will need trimming. Might even need removal but it’s too early to be sure.

The photos are also here, here, here, here, here, and yes, here too.

Dave

Last edited by David Paule : 09-04-2018 at 07:33 PM.
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  #383  
Old 09-05-2018, 07:54 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,555
Default It's a Canoe

I bought a couple sawhorses and unfastened the fuselage from the steady, reliable Fry jig. Man, that’s a good tool. I lifted the fuselage on to the sawhorses, one by one. The RV-3B fuselage, in this state, is light in the tail and not so much heavy up at the firewall as it is awkward. It was not hard to do it myself,

Folks, I present the canoe.



While I really would have liked to put the main gear on and get it aligned and rigged, there just wasn’t enough room before hitting the jig. If I’d have known, I would have raised the fuselage up from the jig 2.00” at the start of assembly. That would have made some things considerably easier as well as permitting the gear to go on.

If I’d done it, put the gear on, I’d have removed it shortly, too, to facilitate other things. Other things like moving it around on the sawhorses and working around it, since my shop is small. I still think that’s the best time to do rig the main gear.

No, I’m not going to try to add 2” shims and reinstall the fuselage on the jig now. Thought about it and decided against it. You might say that canoe has paddled off.

Heck, yes, there's a backup photo right here.

And yes, the Fry jig is for sale. See the ad in the Classified section. It also fits an RV-4. In fact, it was intended for an RV-4.

Dave
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  #384  
Old 09-06-2018, 07:40 AM
RussellT RussellT is offline
 
Join Date: May 2016
Location: Albany Western Australia
Posts: 34
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Good stuff Dave, a milestone to enjoy.
Russell
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RV 3B. Very slow build
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  #385  
Old 09-16-2018, 07:03 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,555
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The Fry jig is sold and gone. It will be used by a repeat RV-4 builder in the area.

The concept of installing the main landing gear legs is still on the table, since I could do it with the canoe upside down on the sawhorses. I asked some of the local builders and Eric Lanning volunteered to spray them with Azko Nobel primer for me. I included the tail spring too. Azko Nobel is one of the better primers and frankly, Iíd have been better off to have used it myself throughout. Itís very tough, resistant to aircraft chemicals, and epoxy sticks to it. It was ideal for the landing gear legs.

Hereís Eric spraying the legs in his priming booth.




And here they are during the first hour, while they are still soft to the touch.




After that I was able to put them carefully into my car and drive them the 90 miles home.

At this time, the entire right-hand side is unriveted, as is the left side forward of the seat back. The glue is keeping things together, and a few clecos ensure than no edges lift and start unzipping. I was reluctant to do much interior installation or install the main gear until that riveting is done. Itís scheduled for next week. One of the things I could do now was hang the engine mount, which requires trimming the hot air exit fairing at the bottom of the firewall. Thatís the titanium belly overlay I added on earlier. The titanium is one of the things needing riveting, though, so I had to be careful not to accidentally rip it loose.

Trimming the exit fairing was relatively simple: fit the engine mount, trim any of the fairing that interfered, repeating both steps as necessary. Took a few hours. Hereís the trimmed fairing.



However, the engine mount has a teensy problem. When it was built, the bottom cross-member was welded on somewhat lower than the engine mount bolt holes to the firewall. The plans show it, drawing 29, as being in line with those holes.



Compare to the actual engine mount. Iíve drawn a thin centerline between the mounting bolt holes.



And observe that the bottom cross tube is a bit forward of the firewall, too. The fairing, youíll recollect, curves upward there. As a result, thereís interference along the entire bottom cross member as it rests on the fairing.



If I press the engine mount down to the correct position, the fairing bends down around 1/4 inch or so. And that doesnít include the clearance that Iíd need to prevent the mount from chafing on the fairing, due to the three dissimilar metals which would be in contact.

Turns out that this isnít a new error. Hereís that tube on an RV-3 built 15 to 20 years ago.



Elsewhere on the fuselage, looking towards the top tailcone skin, I found that the aft four bulkheads, F-305, F-306, F-308 and F-309, do not line up well at all. The two middle ones are high and all four are slightly narrow. This isnít too much of a surprise as they were fitted for fairness along the sides and bottom (the accessible areas whilst in the jig), getting the top be as it would. Still, it was slightly encouraging that the bottom 3Ē or so is the only areas too narrow.

Stay tuned for the next episode, folks.

Alternate hosting: here, here, here, here, here, and here.

Dave
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  #386  
Old 09-20-2018, 06:19 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,555
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The canoe was only glued together when I took it off the jig, not yet riveted. Still to be riveted were the entire right-hand side skins, firewall to tail, the left-hand cockpit side skin, and the titanium belly overlay.

With the help of Glenn Potter, I got these done this week. Having the canoe off the jig and on sawhorses really helped as it was possible to rotate it to a convenient position.

The riveting came out decently enough. I'd been worried that I'd screw something up but it looks like we did okay.

Dave
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  #387  
Old 09-30-2018, 07:27 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,555
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Glue Technique Tip -
As the total thickness builds up, you may need longer rivets. Buy them early and you will have them when you need them.


When that riveting work was done, I really truly had a canoe.


Back when I ordered the finish kit, I ordered a clear Toddís canopy. More recently, I decided that a light tint would be better. Lance Logan now has canopies available. He took over Toddís equipment. Lance Logan is the supplier to Spruce, so I had the option of ordering direct or through Spruce. I discussed it with Lance and decided to get it directly from him. The quality of the pre-purchase assistance was terrific.

I chose the 2515 Light Smoke, which blocks 88% of UVa and 99% of UVb. The other easy option was 2094 Gray. Lance sent a sample of both and the decision was pretty easy. The 2094 is pretty dark.

I sent a check and very shortly afterwards, a canopy arrived. And I do mean shortly.

First, hereís the earlier canopy that Toddís sent, the clear one.



Next, hereís the new one that AeroCanopy sent.



There were some differences in how they were packaged and in a few other things, but all in all, Iím very satisfied with the new one.


Way back when I was assembling the firewall, what I should have done was take the engine mount and the firewall to a machinist friend and have him match the firewall holes to the engine mount. Then I could have used bushings to hold them to the 1/4Ē hardware on the jig.

But I didnít. None of the firewall holes were drilled, of course, since this is an RV-3B, but they were center-punched to mark their location. That was nice of them. I determined that the middle two hole locations were somewhat close and that I could use them as a starting place to align and drill the outer four holes, which were, if not located properly, at least on the same firewall.

Drilling them from 1/4Ē to 3/8Ē was easy. For the two middle mount holes, I used a Harbor Freight Unibit clone and that left holes just slightly under 3/8Ē. I finished them with a reamer and those fit the engine mount. Since I lost the AN6-53 bolts that itíll take to bolt them to the firewall, I bought some hardware store bolts for the job. No worries, theyíll be replaced. This wonít be permanent for a while yet anyway.

The outer four holes were visible through the engine mountís attachment holes but thatís about all I could say for them. What to do?

I discussed it with the aforementioned machinist friend and decided to get some bushings.

First, I bushed the holes down to 1/4Ē and used a slightly undersized twist drill to walk the firewall holes closer to center, followed by the 1/4Ē reamer.

Second, I removed that bushing and the remaining bushing had a 5/16Ē bore. I did the same thing, using undersized twist drills to get close, and then the 5/16Ē reamer.

Last, I repeated the process with no bushings, ending up with 3/8Ē coaxial holes in the firewall and engine mount that the bolts would go into.

How was it? The first bolt with the bushings was very slow but not especially difficult. Learning curve, you know. The remaining bolts went quickly. At the conclusion, the engine mount was temporarily bolted to the fuselage.

Goody - a convenient place to grab when moving the fuselage around.



I rotated the fuselage upside down - geez, that looks familiar - and discovered that with a sawhorse under the upper longerons forward of the panel, I could level it by shifting one sawhorse end fore or aft. When level, I marked the location.

Upon trial fitting the main gear legs, guess whatÖ they donít go in their sockets. I had to decide whether to reduce the legs or open the sockets. Turns out that the gear legs are 1.375Ē diameter but the ends of the engine mount sockets are about 1.365Ē, or .010 smaller for the diameter. I thought that this was due to some excess cadmium plating that migrated into the sockets. The plating company assured me that theyíd mask those holes. Looks like they gave me a headache instead. Later I discovered that the plating made a minuscule difference, and that the fit is what the factory sent. No worries, it's an RV-3B, and I signed up for this.

I bought a brake cylinder hone tool. I had never used one of these but heck, itís a tool right? And Iím a proud member of a toll-using species, right? Plus I have an aptitude for mechanical things. How hard can this be?

Turns out that it wasnít hard, just tedious. First, the tool.



I dipped the stones in alcohol and ran it on partial speed at about 40 psi, for about 30 seconds at a time. I didnít want to burn out the stones but I really didnít want to have the sockets get too loose. Hereís a photo of my doing the honing thing on the top of the right-hand socket. One thing to be careful about is to stay on the internal boss and neither get past it nor remove the tool while the stones are spinning.



It took about fifteen passes to get the top end of the right-hand landing gear strut past the bottom part of the socket. I was still about 1/4Ē shy from being able to insert the strut all the way. One more thing that I wanted to avoid was getting the strut stuck in the socket so that I couldnít remove it or adjust it. I made a couple more passes with the hone and then put it all away. I ordered a replacement set of stones and theyíre about a week out.

But no worries, there are plenty of things to work on. I started one of those.

Also at Todd's canopy, AeroCanopy canopy, Engine mount attached, hone tool, and actual honing.

Dave
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  #388  
Old 10-15-2018, 10:02 AM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,555
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Iíve been sort of roaming around the fuselage, doing things that looked interesting.

I put together the pitch servo mount, following the Dynon RV-4 mount arrangement. It also holds the elevator bell crank. Here it is from the front, looking aft. I need to touch up the primer slightly and then the baggage floor skin fits under the forward end. I used nutplates under the mounting bolts.



Itís looking like Van is a lot bigger man than I am in several ways, and one of those ways is simple body length. The RV-3 has depressions built into the seat ribs for butt room. Neither of the two RV-3s that Iíve sat in demonstrated a need for that recess, so one of the alternatives Iím thinking about is revising the ribs to make them flat on top. I checked with Vanís Support and they say thatís acceptable but wouldnít specify rivet spacing or type (I'll probably use blind rivets). The major load is the downward crash case, if youíre interested.

The red lines show where the new flange will be.



Another easy fit-up was the aft deck. The orange dots are magnets with mating ones underneath. That does a fine job holding the deck in place. I needed to locate and cut the openings for the stabilizer mounting bars and trim one side to fit, but the stock piece that came with the kit, fit pretty well.



Since the RV-3B isnít a prepunched kit, there are no holes in the deck yet. Before locating the access holes that are in the plans, or the fastener holes, it seemed prudent to see if the stabilizer actually fits. Remember that the fuselage was built to fit the bulkheads and skins and more or less follow the plans. When people say that all RV-3s are different, thatís not an exaggeration. Letís just say that there was some question - would the stabilizer fit at all?



The answer, Iím happy to report, is ďyes!Ē

The stabilizer came down from the rafters, sat in place for ten minutes, posed for some photos, and then went back up where itís been safe for the last several years.

I marked the front spar and the front spar mounting angle positions and realized that the access holes in the deck will need adjustment. The rear-most hole in the deck allows for the elevator horn to extend down into the fuselage, so I marked the elevator hinge centerline position on the deck. I was going to mark where the aft hole needed to be when I realized that the horn is an RV-4 part. Okay, no problem, Iíll deal with that some other day. Iíll need to bring the stabilizer and both elevators down and assemble them and measure stuff.

With a small bit of epoxy curing somewhere else, it seemed like a great time to leave the project for the night.

Same photos located elsewhere here, here, here and here.

Dave
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