Mountain Models EVA Sport Build Thread

[Try-n-glide]

Guys, thanks for answering my questions. I got the kit on the 3rd after a couple week wait due to a backorder. Spent the afternoon of the 4th building. Totally different experience than I remember with my seniorita. Seems to have one fuselage side out of square by .020-.030", but other than that it is going well. I can't believe how light the parts are even for balsa! I am going to add a LG support to the bottom and about 2-3 grams of braces to the nose. I went flying yesterday evening and had 4 horrible landings to 2 good. Scared to fly this thing already.

 

[rockyboy]

Looking good! I don't think that amount of twist will cause any problems - just keep an eye on the horizontal stabilizer when you install it to make sure it's parallel to the wings, and sand the saddle a tiny bit with an emery board if necessary to level that out.

And don't fear the landing - she floats in beautifully at low speed with the power cut. She does seem to float forever, so don't try to force her down, just start the approach a little further out each time and power out for another pass if you run out of runway.

If you have a rough landing field you might consider the tricycle nose gear option too - that can help prevent nose-overs.

 

[Try-n-glide]

Yeah the carbon wing support rod still goes through with a little finesse, a little tight, but it goes. Based on that I'd guess it won't cause any big issues.

 

[rockyboy]

Excellent! I found that sanding a little chamfer on the ends of the carbon support rod really helped with getting it to go into the wings nicely too.

 

[Turbojoe]

Great tips from rockyboy. If I may add another tip be particularly careful when building the wings. The "D" box design gives it amazing strength but it also locks in any twists you may create while adding the sheeting. Weight the wing to a flat surface with anything that holds it firm. Lead shot in bags, books, iron bar etc..... I have square and flat solid T6 aluminum bars 12" long in many sizes that work well for me. The wings are not hard to build. Just use care not to build in a warp.

You're moving along quickly. Adding the ply support for the main gear is a must do. rockyboy gave good landing instructions. Floating is one of the EVA's many positives. Get the CG just right and landings become almost a non event with a little glide slope planning. As long as you don't point her directly AT the ground you should land on the mains every time. You're going to LOVE this plane!

Joe

 

[Joker 53150]

Like Joe said.... Don't worry about how light it seems, the design is sound. My MM Switchback has about 125 flights on it and other than a lost signal crash has never needed any repairs from landing or flight. It's about the same size with similar construction.

 

[Try-n-glide]

I hope this might be helpful. I had a slight flash of inspiration when putting the wing together. I noticed that the inner rib is tilted in two planes so that it meets flush with the fuselage. I wanted to make sure the rib was as exact as possible. So I installed the carbon rod in the fuse, the put a piece of wax paper over the side and with the carbon rod through it (keep from gluing the rib to the fuse). Then I put the wing on the fuse. Once I twisted the inner rib so that it met as close to flush as possible I tacked it with CA to the spar, LE and TE. If you look close you can see gaps between the rib, spar and TE. If I had simply glued up the inner rib flush to the spar and TE I think I would've ended up with an unsightly gap between wing and fuse to sand out later ( if possible). I think my way saves a lot of sanding and fitting later and keeps the meat on the inner rib.





Still ended up with a slight gap but I think the attachment screw will pull it snug.

 

[rockyboy]

That's a great idea! I ended up with a little extra fitting work on one of my wing panels cause I didn't get it aligned perfectly, and this would have solved that problem.

I'll remember this when I start on the EVA Bipe kit - thanks!

 

[Joker 53150]

Certainly a good tip. My on-going recommendation for people is to keep looking 3 steps ahead on the build process, and test-fit parts ahead when possible to avoid problems. The scratch-builds even more-so.

My bipe is SOOOO close to being done, I should push hard this weekend to finish it in time to maiden it at Flite Fest. About all that needs to be done is mounting the ESC, RX, wheels, and cowl.

 

[rockyboy]

That would be great to see!! Sadly I don't have enough packing room to safely bring my EVA to FF...

 

[Try-n-glide]

The end is in sight and I'm feeling the desire to rush to the end instead of doubling down on attention to detail like I need to. Made a dumb mistake today. Didn't realize that the D box balsa has a top and bottom piece which are different sizes. I reversed it on my 2nd wing. Seems fine regardless, but I wish the manual mentioned that detail.

Just had to do a mock up before bed.

 

[Try-n-glide]

Rockyboy I've pretty much hijacked your thread at this point I hope you don't mind. Didn't think these questions deserved their own thread.

So as my build is coming near the end. One wing left to cover then assembly and electronics. I painted the cowling last night with Tamiya lexan paint. It came out very very flat. I guess that makes sense it's supposed to go inside a clear body not outside a piece of white plastic. So anyone have any sugguestions to get it glossy to match? Is there a hardware store clear anyone has used that won't react poorly to the Tamiya paint?

 

[TexMechsRobot]

I've had good success with Krylon acrylic crystal clear over Tamiya.

I get mine at Michael's hobby store. Weirdly enough, the Home Depot and Lowe's near me both exclusively sell Rustoleum brand.

 

[rockyboy]

@Try-n-glide - I'm very happy to have you here! Don't feel bad about thread hijacking at all!

I'd go with Tex's recommendation on the paint - while I do have a can of Tamiya black I used on the inside of the canopy, I've never shot anything over it and don't know what would or wouldn't react.

 

[Try-n-glide]

Thanks guys. I'll see if the local hardware has the Krylon in stock.

 

[Try-n-glide]

Couple of minor jobs then maiden. This build has been very humbling in some ways. I have a love hate relationship with Solite. Tape hinges are the spawn of the devil. Anyway a few flaws that you mostly can't see from 10 feet away. It is straight so far as I can tell.

 

[Joker 53150]

That looks fantastic! So-Lite is a strange film that many hate, but it's still my favorite covering.

 

[Try-n-glide]

That looks fantastic! So-Lite is a strange film that many hate, but it's still my favorite covering.

Thanks! There are a few issues that don't show up in the picture. The worst is one of the tape hinges on the wing got messed up, and I used VERY sticky clear tape (Gorilla tape - I would NOT use it again for aileron hinges). If I try to re-do it it's going to mean recovering the wing. Anyway you don't notice it much except up close, but I find it very annoying.

Still need to clear coat the cowl, and cover the wing tips. I also have a roll of 1/4" white pin striping. I can't decide whether to use it.

Came in a little heavy I think - about 22-23oz with a 1300 3s.

The So-Lite was actually no problem on the sheeted areas. On the open areas I would do one piece no problem and then next piece it would bunch and wrinkle on the sticks, then smear. I have no idea what I was doing differently. I did find out the hard way that it is so thin that you better be spot on with your sanding. I missed some CA bubbles and they really stand out.

 

[TexMechsRobot]

Blenderm tape is my go-to for tape hinges. Sticks really well, stays flexible, and comes off when you want it to.

 

[rockyboy]

She looks beautiful!! Congrats!! :applause:

Yeah, Solite takes some practice for sure - it's all I've been using since I got back into the hobby a couple years ago (some previous experience with Monokote in the late 80's). There are lots of tips and pictures of how to use it out there, but a lot fewer videos - and it really takes a video or in-person instruction to get past a lot of the headaches I think. Maybe I should talk Joker into filming one