Couldn't pass this up: Sukhoi su-31 .40-.46

[Doozer]

Fixed the tank, now I'm going to start setting up my throws. The only thing is, I can't find the manual for this specific plane. There are two styles of Sukhoi SU 31 presumably made by Phoenix Models. One is like mine where the wing is a one piece design and is attached via dowels and nylon bolts to the belly of the plane. The other version has the wings as a two piece design and the cockpit detaches opening up the electronics bay. Every manual I've attempted to download is for that version, and not the version I have. The throws are probably close to the same, but the CG is most likely a bit different.
So I'm going use the throws, but figure out the CG on my own. I want to fly this weekend. Probably wont have much time. Wednesday or Thursday of next week looks more likely.

[Doozer]

I watched some youtube videos about finding CG and found a cool one from Nitroplanes (aka Xheli):



So I found the spar and it was 100mm from the Leading edge of the wing. The manual for the other frame stated the CG was... 100mm from the LE of the wing. So that's what I went with. I used the Great Planes CG machine:


This is what I came up with:



I'll need to add more weight when I add the cowl. I set up my throws at 10mm aileron, 11mm Elevator, and 20mm rudder. My stunt throws are 15, 16, 30. I know that's not much more but I can always change it in my radio fairly quickly. It was fairly easy to do in my radio by going into expo and dual rates and setting the rate percentage per switch position. For example Pos 0 is my low rate, which is 35% Aileron etc etc.

So the CG is set, my throws are set, my engine works. Time to fly. I want to fly tomorrow, but I kind of doubt that will happen. I've got a lot to do. Best day still looks like Thursday.

[akphill]

yep seems like any of the planes I have built the instructions always told me to cg on the front wing chord always works too looking good
sounds great too

[Doozer]

Thanks Phil. Can't believe I was so anti-plank before. I've decided I'm going to airbrush flames on the nose (cowl and part of the fuse), and the wings, but after I break in the engine. I'm going to peel those hideous checkerboard decals then paint the top of the wings with flames.

I saw this and got inspired:


Though I'm not real sure how to go about it. I've never painted covering before, but I do believe sanding is a bad thing I'll also want to hit it with a clear and I'm not sure how to make that happen and keep the weight down. I'll have to research it. I don't like how "cartoony" those flames are. I was thinking more of a true fire look, but have the flames burning hotter (brighter) through most of the flame. Great... now I'm buying a new airbrush.

[akphill]

LOL good idea May I suggest that you go monocoat hunting for the colors you want and draw your flames out the way you want them and iron them on
Painting might not come out the best but can be done with a little prep work keeping it clean is the key

[Doozer]

Woot! Found a page that describes the process for prep. I'm doing it, provided there are no unforeseen crash related anomalies (knocks on wood).

• Buff the surface to be painted using Top Flite #000 steel wool, until all of the covering film's gloss is removed. The gloss may interfere with paint adhesion.
• Clean the surface using rubbing alcohol. Use a MonoKote Tack Cloth to remove all lint and dust. Apply a thin coat of primer. After 2-3 minutes, apply a second, heavier coat. When the primer has dried, you're ready to paint.
• Lightly sand only those areas with imperfections, such as seams and dust specs. Use Top Flite #400 grit sandpaper wet.

Lightly sand... go figure.

[19000rpm]

Good luck with your maiden!

[Doozer]

Didn't have time to pack up and go fly today. I had actually planned on it, but couldn't squeeze it in before dark. So I fired it up in the driveway just before sunset. It's idling nice, but that's not because I did anything, I haven't touched the low end needle. I did open up the high end needle a bit, two clicks, and now the transition from WOT to idle is nice. I was using tygon for the vent/pressure line, but not anymore. I switched to the tubing that came with the engine. The tygon line distorted around the nipple on the pipe and became to loose for my liking. So, I'm actually kind of glad I didn't fly because that probably wouldn't have ended well. The center bolt for the exhaust pipe came loose, as expected and needed a tightening. That should happen a few more times according to the manual.

Horizon is doing a good job watching the major forums. That is so refreshing to see. The Evolution project manager is regularly posting, answering questions, and updating information in the manual... he wrote it. Actually there are two Horizon employees in 10GX thread @ rcgroups. I guess the engine had crank pin issues in early production runs and those seem to be fixed now. The Evolution 10GX and 15GX engines open up some planes I'd really like to fly, but up until recently there was no gas power plant... .60 Super Skybolt, .46 Ultimate Bipe, .50 Sundowner.... inexpensive planes I don't have to sink a bunch of money into. If I can't fly a DLE 20 in it, I'm buying Evolution engines just because of the support and price point.

Anyway, the maiden will have to be Thursday for sure now. I might crank up the engine in the driveway if I feel like taking a break from the books. Hopefully, my camera man has the day off, or get's off work early.

[19000rpm]

Nothing like good product support. Horizon has built the largest US based hobby business based on product support and haven't lost their way.

[Doozer]

Film @ 11:00 :*(

[Doozer]

lol, I kid I did have to dead stick land it after two minutes due to the tube from the tank to the exhaust splitting and coming off, but luckily I practice those a lot in the sim and muscle memory just took over. The first part of the video, the short couple of seconds clip, I found out that I bent the tail gear in transport and it was pulling to the left. I bent it back, but it bent back on the landing. Here's the Video:

[akphill]

Alright that is really cool good save too
Looks like it handles really good

[Doozer]

Nov 1, 2013 2:25:02 GMT -6 akphill said:

Alright that is really cool good save too
Looks like it handles really good

I had it in low rates the whole time. Even the elevator on take off. I guess that's why it took so long to take off into the wind. But you're right it handles nicely. I only put a click into left aileron and a click into up elevator, but it was windy so I'm going to wait until a calm day to see if that's really necessary. The rudder was a little too sharp for my liking. I probably need some expo on the rudder, but I don't like flying with expo. I could take it out in the servo throw, but I don't know.... I guess it would be nice to get a little more than two minutes with it before I make these decisions. I was trying to do Cubans for break-in as the manual suggested, but I never really got a chance to get into a rhythm.

The wind was gusty on the landing but there was no "go around," so it was land or crash. I found some hose clamps left over from my short lived nitro days and used one on the exhaust nipple. A zip tie would have only worked as a temporary fix, because I have to pull the tank line off to fuel. I realized that as I was putting the zip tie on.

Oh btw... did you see that they're building houses :*( I wont be able to fly there for too much longer. The housing market here has really picked up. That place was completely empty six months ago and now there's about 20 new houses. There was still enough area left to fly, and the road is still pretty much a closed road, but I'm sure once they start building houses on the side I was flying on, they'll open that road up and that will be that. I guess it's back to google earth.

[19000rpm]

Many maidens have glitches and you handled that one very well. All part of the ongoing learning curve.

[Doozer]

My son get's off of work at 2 today, so I plan on a "take 2" around then. I remember thinking right before the engine died that it didn't sound good. The manual says if you take it into a climb and it starts sagging that you're running lean. If you listen around 1:40 ish you can hear the engine get raspy. Do you think that's because the line came off then and the fuel stopped pumping into the tank? And that's just air leaning the engine out? My assumption is that the last few seconds were just whatever left over fuel was in the system then it died. However, that makes me worry about the piston a little.