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David Paule 07-04-2022 10:00 AM

Added the glass to the front of this bulkhead.



And then separated the hatch from the fairing and trimmed the bulkhead.



Put it together again and back on the fuselage for a fit check. So far itís fine.



The front of the fairing is about where the cowl cheek bulkhead goes. Iíll need to tweak the aluminum bulkhead, which was just a bit oversize on the right had side, and remove the hatchís fiberglass one.

Before then, though, I laid up the beginnings of the flanges for the aft portion of this cheek extension. At this point, Iím only using two layers of bid and a cover of peel ply, because I wasnít sure how well this would work out. So far it seems okay. I expect to add more when this has cured.



Although I have no photo of it, the aft end has been finished off and after adding a third layer of fiberglass, I trimmed the flanges. Iíve added the flanges on the right hand fairing, too.

Have a great Fourth!

Dave

David Paule 07-12-2022 04:28 PM

Added the glass to the front of this bulkhead.



And then separated the hatch from the fairing and trimmed the bulkhead.



Put it together again and back on the fuselage for a fit check. So far it’s fine.



The front of the fairing is about where the cowl cheek bulkhead goes. I’ll need to tweak the aluminum bulkhead, which was just a bit oversize on the right hand side, and remove the hatch’s fiberglass one.

Before then, though, I laid up the beginnings of the flanges for the aft portion of this cheek extension. At this point, I’m only using two layers of bid and a cover of peel ply, because I wasn’t sure how well this would work out. So far it seems okay. I expect to add more when this has cured.



Although I have no photo of it, the aft end has been finished off and the flanges trimmed. I’ve added the flanges on the right hand fairing, too, including the area at the aft end. Not shown, they are trimmed. I needed to use a small bit of foam to help shape the aft end, unlike the right-hand side.



After measuring and trial-fitting the battery in the right hand fairing, I moved that cowl bulkhead forward a couple inches. The aft end of the battery didn’t fit comfortably inside the hatch - had to make a flange extension piece to do this. Fortunately there’s room - so far - in the cheek area behind the engine.

Here’s the bottom battery mount. The flange extension is on the right side of the battery inside the cowl cheek itself. The brass nut stack is the pass-through for the ground forest of tabs, which is just inside. The ground forest has two bolts. The other one is into a nutplate riveted inside the cheek extension out of sight.



The red pads are some silicone baffle flange material that I had on hand. I used Pliobond to glue them on, this is a somewhat industrial contact cement that’s been available for probably upwards of 50 years. The two horizontal strips nicely account for the mild curve of the fuselage side.

*** Later - Don't use Pliobond for red silicone! The peel strength is approximately zero. ***

With the bottom mount on, I could not resist seeing what the whole battery mount assembly looks like. The orange dots are the magnets I’m using to hold it all together. These are very convenient and I strongly recommend having a couple dozen of them. You can get them here.

There will be a few changes and some obvious trimming. For one thing, the stack of magnets to the immediate left of the battery is just an aft stop. The battery is an empty dummy. EarthX sells these and it’s been very useful for mocking-up the assembly.



Dave

David Paule 07-25-2022 01:10 PM

The battery mount is in and the photo shows it latched.



Dan Christian, whom we we know as Dan 57, flew in for a brief visit. He was traveling from Switzerland to Oshkosh and back in his RV-6. This was not a direct flight, with stops all around the U.S. and Canada. Quite an interesting visit, and a very nice RV-6.



The fore-aft battery stops were not yet in. I had added a short extension forward for the cowl cheek bulkhead, and after some time jiggling this and that, got the right-hand cowl cheek bulkhead installed. Here it is with the battery mount open. That stack of magnets between the silicone strips and the ground forest pass-though is merely acting as a temporary stop.



The silicone pieces can be attached reasonably securely with Ultra Blue silicone gasket sealant.

I removed the forward molded-in bulkhead from that RV-4 cowl cheek extension as it was in the way of the battery. Not to worry, thereís plenty of fiberglass work ahead.

Speaking of that, I trimmed off the cowl core from the bottom right-hand cheek area of the cowl for an inch or so, to provide space for the parts that the quarter-turn fasteners on this side attach to. Later I decided to use nutplates for the cowl cheeks.

A small setbackÖ. The hatch did not clear the battery latch. I removed all the stainless latch assembly and replaced it with aluminum and a screw. Everything fits fine now.



Iíve started prepping for the hatch hinges - the upper hinge pin can be removed to open the hatch, but the bottom one stays in place. You can see the upper one in the photo. The bottom one, also shown, needs further adjustment.

Dave

David Paule 08-22-2022 04:59 PM

It’s been a while since I’ve posted, sorry. I’ve worked on a small variety of things on the cowl and its cheek extensions, making minor progress. Here’s a rough summary.

I figured out an imperfect but satisfactory approach to safetying the hinge pin that’s the battery access hatch lock. It had baffled me for too long. I’d hoped to be able to use safety wire but it appears as if using McDaniel’s safety cable will be a lot easier. Hint, if you’re planning on buying this plane when I sell it, get one of those things; you’ll eventually need it. The red ellipse and arrow identifies the cable and the restrained latch.



I installed the inlet ramps in the upper cowl. As is standard for RV-3B parts, they fit poorly. I used foam to block most of the gaps, and a bit of trimming got me this far. The left hand one fit better than the right hand one. Here it is while still fitting and thinking about it.



For some reason, I had more trouble with the right hand one. No idea why. Here it is at the same stage.



Once I finally decided to press ahead with these, and tweaked and fussed until the lower cowl’s flanges joined okay, I glued the inlet ramps in and after some foam fitting and grinding, used micro to smooth out the joints. After that, a bit of 3 oz. glass over the foam and here we are, with all the ends and edges smoothed and sealed.



I can't say that I particularly like the slopes of the ramps. The right one is steeper than the left, but I suspect that both are too abrupt and steep to be optimum.

Dave

David Paule 09-18-2022 12:06 PM

It was time to ensure that the cowl cheek extensions were fair to the cowl cheeks. My shop is a small two-car garage and I needed to be able to step back to get a better perspective on this, so I pushed it out. It hadnít been outside since before the engine went on and I added some other things since, too. It was heavy enough and the driveway sloped enough that it was a handful keeping it under control. I should have asked for help from a neighbor, but I didnít. I got the tailwheel up against a handy stump and was glad that I hadnít had that stump removed - itís the only stump I let remain so there was an element of luck here.



On the right side, I didnít have the stand-off distance Iíd have liked, but it was adequate.



Now Iím filling and smoothing the cheek extension fairings where I had to extend the distance they stood off the fuselage, the RV-3B cowl being different than the RV-4 cowl these fairings were made for. Itís the business of adding micro, sanding, adding a touch more, etc. No up to date photos but thatís whatís going on.

One thing Iíve noticed is that in past years, my shop would never get warmer than 80 F. This year thatís not the case. I knocked off today at 84 F. Still, thatís better than outside, where it was well above 90 F. One reason for the higher shop temperatures is that there had been an ash tree shading the windows. It would leaf out in the Spring and the leaves would go away in the Fall, a perfect seasonal sunshade. Like nearly every ash tree in Boulder, it got the ash beetles and died. Had to remove it. Yeah, that was one of the stumps removed.

With the beginning of the school year, I started mentoring an RV-12 project at Boulder High School. I had earlier met with the teacher associated with it and agreed to do that, but later bowed out. Then he got killed on the way to Oshkosh, would have been his first visit there. Turns out the remaining staff have no idea of any of the organization of the project and know very little about it. And I was the only mentor they knew of. As a result, Iím spending some time there trying to get other mentors (volunteers welcome, PM me), finding funding (donors welcome, PM me), arranging for work space (like pulling trees through a keyhole), and somehow getting some organization done. So far itís taking me more than the 2 days a week I signed up for. I must admit that I enjoy this. There has been and will be somewhat of an impact on this RV-3B project, at least for now. I do plan to bow out if and when they are going smoothly.

Still, Iíve made some slight progress. My list of things that need to be done before I can bond on the left cheek fairing is growing but Iíve figured out how to do some of the secondary details which had mystified me, and Iíve made some progress finishing the fairings.

Dave


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