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Balsa Forum Fall Build Along

#1
The fall build along will be geared towards the rookie balsa builder, however everyone is encouraged to participate no matter the amount of experience. The idea of the build is to get people to experiment with building a balsa kit who may otherwise be intimidated to give it a try on their own. I encourage all the experienced builders to check in often and try to give as much advice and help to the new builders as possible.

We are going to be building the Mountain Models EVA Sport (link below). The projected start date for the build is Dec. 1, this hopefully will give participants ample time to purchase the kit and supplies required. A list of additional tools and build supplies will follow this initial post, as well as suggested electronics.

http://www.mountainmodels.com/product_info.php?products_id=215
 

Joker 53150

Mmmmmmm, balsa.
Mentor
#2
I'm in for the build, however I'll probably build the EVA Bipe instead of the Sport. This is one of the great things about this kit from Mountain Models, you can build different wings for it and get drastically different flying styles. They make a 3D (ish) wing, a sport wing (with dihedral for general flying) and the bi-plane setup with 2 wings. The rest of the components remain the same, so you can start with a Sport wing, and then buy the bi-plane wings or 3D wing later on when you want to fly something different. By the way, "EVA" stands for Extremely Versatile Aircraft, due to the wing options.

For those who have never built a balsa kit, MM was picked for a couple reasons.
- It's a US based company (located here in Wisconsin).
- The quality of the laser cutting is very good, meaning you won't spend half the build trying to remove parts from the sheets.
- The quality of the design is fantastic - parts actually fit together as they are supposed to.
- They include most of the hardware needed to complete the kit (wheels, pushrods, etc).
- Their kits have been built by hundreds of people and there is a strong fan base online always willing to help (mainly RC Groups).
- Their finished kits actually fly well - kind of an important point.
- MM sells accessories if you want to buy from them. I strongly recommend their So-Lite covering material.

One other HUGE point regarding this kit - if you've built a few DTFB planes in the past you've already got many of the tools required to build an EVA. When I get a little more time I'll make a list of tools that would be needed to build this plane, and many will be surprised how short that list will be. Again, a big reason the EVA was picked for this build.

With all that said, there are a couple things to keep in mind for those wanting to join the build-along. MM is a very small company, run by one person who does all the cutting, packaging, and quality control. Brian has been in this industry for many years, and is well known in the balsa world. He's also a full time student and family man, who has had some health problems over the past few years. I've ordered from him 5-6 times and it usually takes a few days before the package ships. As we approach the holiday season I expect his business to ramp up and lead times to go up as well.
 

Joker 53150

Mmmmmmm, balsa.
Mentor
#3
How about a roll-call of those who either WILL join in or those who MIGHT join in? Here's who we've got so far:

Mountain Models:
Easy Built Models:
Herr Engineering
Dumas
Guillow's


(I'll edit this list and add people to it as they join, and will also link to their build-threads if they want to create one)
 
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TexMechsRobot

Posted a thousand or more times
#4
Man I want to but I just can't. I love the idea though and hope this catches on. I'd like to participate in the future.
 
#7
I just ordered the Mountain Models ACE and will hopefully keep up. I was planning on using the 9g servos from FT as well as a power pack C set up.
 

Joker 53150

Mmmmmmm, balsa.
Mentor
#8
For those who have built DTFB planes that are interested in trying balsa, there are a few tools that may need to be purchased. A selling point in choosing the EVA is that tools needed are minimal.

Many tools you'll already have:
- X-Acto type hobby knife
- Soldering iron for motor/ESC connections
- Small screwdrivers or allen wrenches for pushrods, motor mount, etc
- Needle nose or small pliers
- Wire stripper and/or cutter

Other supplies you may need to buy:
- Sandpaper and a sanding block. 220 grit paper should be all you need. The sanding block helps you get a nice even sanding job. You can easily use a paint stick with sandpaper stuck along one side or you could buy a sanding block. Both will work. $3.00 and up.
- Some people use building boards you can stick pins into, or magnetic boards to hold pieces together. This shouldn't be needed here, but you'll still want a good size work area, and you'll find some thin pins useful to help hold pieces while glue cures. $2.00 or less for some pins.
- Glue. No hot glue will be used on this project! You can use either THIN CA glue or a wood glue like Titebond II. I prefer the Titebond for most construction unless I'm in a hurry. It's more sandable than CA and more forgiving. DO NOT OVERUSE IT! A little bit will work, and you don't want to sand it unless you have to! I use thin or thick CA as needed, they each have their strong/weak points. $3-5 depending on brand and size of container.
- Epoxy is good to use for securing the T-nuts on the firewall to the firewall. Not required, as thick CA can be used, but epoxy is stronger.
- Wax paper or plastic wrap to put down under parts being glued. From my experience, plastic wrap is better since the CA glue sticks to the wax paper. Either way, protect your building surface. $3.00
- Iron for covering material. $20 or so depending on source. You'll use this to secure and shrink your covering film after the structure is built. I'd suggest buying a "sock" for it. The sock protects the face of the iron from the film, and keeps from getting coloring from the film on the iron which could then get transferred to other colors later on. I try to have a sock for each color I'm using. $3.00 for a sock.
- Covering film. There are plenty of brands available and a wide range of prices. However, don't be tempted to buy the cheap rolls from Hobby King! Don't get me wrong, it's actually good covering, but it's too heavy for the EVA. When I say it's too heavy, it's actually too thick and strong. Shrinking it on the delicate tail or sing structure could easily snap the balsa you're covering! DON'T DO IT! For this build I strongly recommend buying covering from Mountain Models when you get the kit. Get their SoLite covering, it's much lighter and won't break the balsa. It's not as strong, either, so check the covering if you make an emergency landing in tall brittle grass or a field. I've punctured the film like this, but it's super easy to fix. $16.00 per roll. For your first build you'll probably need 2 rolls to account for do-overs. Covering ain't cheap, but the right material makes all the difference.

You'll also need the standard parts for any build, servos, a receiver, motor, speed control, battery pack, etc. As you can see, there isn't that much you'll need to try balsa. If you do it and find it's not for you it should be easy to sell off the covering iron and getting some of your funds back. I see them on Craigslist occasionally as well, you may get lucky and save up front!
 

Turbojoe

Active member
#9
Joker just let me know about this build along project. He knows I'm a HUGE Mountain Models fan. I couldn't be happier to see you guys taking on what I'm certain you'll find to be the best building, best flying and most versatile kit you'll ever come across. I am and always will be a MM SwitchBack fan having built 10+ of them but way back in 2004/2005 Doug Binder (the founder of Mountain Models) sent me an e-mail telling me to "retire the SwitchBack" and that he was almost done with it's replacement. I thought he was nuts and nothing could ever replace my beloved SwitchBack. Those that have built and flown the SwitchBack regard it as the best parkflyer kit ever produced. While I'll never retire my SwitchBack's I have to admit the EVA is in every way an upgrade from the SwitchBack. I forgot who won the naming contest but EVA stands for Extremely Versatile Airframe. And for good reason. 3 wing sets are available. As long as you have servos in all of them then swapping wings at the field shouldn't take more than 5 minutes tops! You're then flying a completely different plane! You DON'T have to buy three different planes. Sheesh! Look at how much money you just saved. :D

I've made a few mods to the kit but mostly just to personalize it. Honestly the only mod I strongly suggest is at least a 1/8" ply plate between the main landing gear and the fuselage. If you bolt directly to the balsa fuse bottom the gear will compress the balsa and loosen up. The one and only oversight I've found in the design. Also, I never have been and never will be a fan of 3D planes. The tail feathers on the EVA remind me of 3D so just for grins I whacked off the tail feathers of my original build, resized and scratch built the SwitchBack tail feathers for my EVA Bipe. Strictly a personal thing but I prefer the rounded look. Of course I did do the trike geared EVA too but that's only because I prefer trike gear over tail draggers. The trike EVA is now my favorite flyer.

Joker has done a fantastic job of letting you know what you will need for the build and he knows the Mountain Models lineup. He'll be an excellent guide. While I have another NIB fuse kit I don't have an unbuilt wing kit. I'm also in the middle of something else so won't be able to build another EVA right now but I plan to watch this thread mainly to see just how much you guys are enjoying the build and flying this amazing kit! I usually take lots of build pictures so maybe myself or someone else will have a shot that will help when a builder has questions.

I'll add a few pictures so you can see how easy it is to modify the EVA to suit your needs. AFTER you build and enjoy it stock! ;)

Joe
 

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Joker 53150

Mmmmmmm, balsa.
Mentor
#10
Good call on the landing gear reinforcement. I was going to surf threads on the EVA to see if anything else was needed.

I also agree with you on the Switchback, it's an amazing plane especially with how long ago it was designed.
 

Turbojoe

Active member
#11
I'm really glad you let me know about this thread. Thanks to your insight I've just put that poorly cut *#%$@# Hobby King Little Bug kit back in the box and maybe forever. That thing is becoming a real letdown. Good thing it was cheap. :mad:

For a long time I've entertained building an EVA with retracts. It'll take some fuselage side beefing as the fuse was never designed to absorb landing loads transmitted from the wings. Wings will need a bit of reinforcement as well but I think it would be a cool mod. The plane will never notice the extra weight if I don't overdo it. Only $31.00 for a new set of 3D wings from Brian but I'm a cheapskate and I'm going to post some wanted ads to see if I can find some for even less in case I have to toss a failed attempt in the trash. The 3D wings having no dihedral will be the easiest to make the 90 degree retracts work with. ;) I already have some electric retracts so stay tuned. This could get interesting......

Joe
 

Joker 53150

Mmmmmmm, balsa.
Mentor
#12
Ha! I was thinking of taking the 3D wing and trying retracts as well, but with the L-19 and other work going on I wasn't sure if I'd have the time to engineer it.

Like it or not, I've added you to the list of builders in this build-along, and I'm really looking forward to what you can do with the EVA! Too bad I wasn't able to get ahold of Brian to work out some kind of group discount.

Glad the info on the Little Bug may save you from a lot of headaches. It's certainly an interesting design and it draws a lot of attention, but typical with Hobby King balsa kits the effort needed to actually build it is far greater than the reward. That's why I lobbied hard for this build-along to use a kit from Mountain Models - you pay more, but it's ABSOLUTELY worth the extra cost.

With that said, the Hobby King kits can make good 3rd or 4th balsa kits for those who want a cheap building challenge that you aren't afraid to throw out when you've finally had enough of it. I did learn a lot by building their Red Swan and Sun Bird kits, and then their DLG and the thankfully discontinued horrible Cessna 182 kit. You learn to think 3 steps ahead, how to fix broken pieces, make missing pieces, how to interpret horrible instructions, and how to make a bad design fly (hopefully). I became a better balsa builder by suffering through those horrible kits, and the build threads I did appear to have helped many people over the years, which was good to see. My guess is that most people who try these kits as their FIRST balsa build will never finish the build and never try balsa again.
 

Turbojoe

Active member
#13
You just HAD to bring up that Hobby King Cessna didn't you! :mad: I should have just flushed my money down the toilet. After punching all the pieces out of the sheets and weighing them I knew I would never build or try to fly that over weight abortion. I gave it to a friend at work. After fighting the thing and "finishing" the basic build he gave it back and asked why I hated him so much. I still have it in a cabinet in my office. Maybe one day we'll take it out and burn it just for fun.

While we're on the subject of Cessna's, the MM Cessna 180 (Dave Blum design) is an AMAZING slow flying easy build scale kit. IPS gearboxes are impossible to find now but a small outrunner would be perfect. I may have to build another with an updated power train. One of these days I should get around to putting the wing struts on her. :eek:

Waiting to hear from some of the EVA build crew. Don't let Joker and I hog the thread with our stories. :D

Joe
 

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Turbojoe

Active member
#14
I just ordered the Mountain Models ACE and will hopefully keep up. I was planning on using the 9g servos from FT as well as a power pack C set up.
You are going to LOVE the Lucky Ace! Make sure you start a build thread. It's a point and shoot monster. It loves to go fast so hang at least 200 watts on the nose to make it ballistic! The Scorpion 2215-18 or equivalent with a 10x5E APC prop is the ultimate motor for her. It still slows down like a trainer for landings though. Just switch to low rates. ;) I lost mine due to unseen damage suffered in the car on the way to the field. (Had to brake hard for an idiot that pulled out in front of me.) Elevator separated in flight. You know what happens after that. Nothing but lots of tears. Only salvaged the motor. Brian sent me a prototype 150% Ace kit. I flys just as good as the original only my old eyes can see it even better. Doesn't look like he's going to kit the 150% version though. Too bad. It fits real good with the Tyro 150 and the SwitchBack Sr (150% version).

Joe
 

Turbojoe

Active member
#15
We need a face palm emoji. I pulled down the 3D wings and found the electric retracts. Started looking at where I could fit the gear and still clear the CF spar. Then it hit me. I was looking at gear position based on trike gear. For conventional gear there is no room in the wing to put the main gear forward of the CG and to go trike the nose retract would require SERIOUS fuse re-engineering. Retracts are out unfortunately. I do love twins though.Wink wink.... ;) ;)

Joe
 
#16
MM ACE

You are going to LOVE the Lucky Ace! Make sure you start a build thread. It's a point and shoot monster. It loves to go fast so hang at least 200 watts on the nose to make it ballistic! The Scorpion 2215-18 or equivalent with a 10x5E APC prop is the ultimate motor for her. It still slows down like a trainer for landings though. Just switch to low rates. ;) I lost mine due to unseen damage suffered in the car on the way to the field. (Had to brake hard for an idiot that pulled out in front of me.) Elevator separated in flight. You know what happens after that. Nothing but lots of tears. Only salvaged the motor. Brian sent me a prototype 150% Ace kit. I flys just as good as the original only my old eyes can see it even better. Doesn't look like he's going to kit the 150% version though. Too bad. It fits real good with the Tyro 150 and the SwitchBack Sr (150% version).

Joe
I had posted a month or so ago about the best one to start with and the MM ACE came up... and up... and....

I had ordered it, got the shipping notification and then this thread popped up. Looking forward to contributing in some noob fashion.
 
#17
Is the Solite weight covering necessary or can we use Monocote on the EVA? Getting ready to place my order for the kit and wondering if I need to also buy covering.
 

Turbojoe

Active member
#18
Is the Solite weight covering necessary or can we use Monocote on the EVA? Getting ready to place my order for the kit and wondering if I need to also buy covering.
Don't try Monokote on the EVA. It shrinks so much I can guarantee you'll warp or even crush the tail feathers beyond use and will likely cause problems on the wing as well. Plus it's really heavy. Solite is great if you want to keep it really light. The only negatives for me personally is that Solite is not very opaque and it sticks to itself after removing the backing. You can rub baby powder on the adhesive side to eliminate the sticking though and it doesn't affect adhesion. I'm a HUGE fan of SolarFilm. It's a little heavier and stronger than Solite but the color is opaque and it goes around corners and on wingtips better than any other covering I've used. Either Solite or SolarFilm will work great. Solite is also available under many different names. Coverite Microlite comes to mind and most LHS carry it. Buy it from Brian though.

Joe
 

Joker 53150

Mmmmmmm, balsa.
Mentor
#20
First off, to TurboJoe, that Cessna is pretty sweet looking! I've skipped over the scale planes from MM but maybe should give them another look.

I'll also agree with you 100% on using SoLite for the EVA. It's actually my favorite covering to use because it shrinks so nicely it makes me look like I know what I'm doing! I may be the only person who really loves using SoLite. :) It does have a tendency to stick to itself when you peel the backing off, but I'm usually pretty lucky with it and don't need to do the baby powder trick.

As Joe said, the tail structure on the EVA is very lightly built and the heavier coverings will crush it with ease. Don't think that beefing it up so you can use the heavier covering is an option, it'll add too much tail weight and ruin a great design. The EVA my dad bought (he got it used, never flown) was built by somebody who thought he knew better than Mountain Models. The guy cut away structure to use pinned hinges for the tail instead of just using the recommended tape (I prefer Blenderm tape by 3M) for the hinge. The rudder and elevator had to be completely re-built just to get the plane ready for a maiden flight. If he just followed the instructions.......

The SoLite is slightly transparent, but it never really bothered me much. For this plane I'm thinking about using their clear covering, which I've never used. My dad built the MM Switchback recently and used it for the entire plane. He does nice clean balsa work so it looked great, although he had no markings on it so orientation was tricky!