The EXTRA 300 EXT Build Thread

[AKfreak]

After many hours of searching and trying to find a big airplane that I can afford, I bought an Extra 300, I call it the EXT edition as in Extreme Turd. I am too embarrassed to even tell you guy much I paid or even tell you who makes it.

I am new to 3D, but I try every day to get better. I haven't been flying RC planes very long (60 days or so), but I am a fast learner. I have build 3 Balsa ARF's in my short time in the hobby along with 6 or 7 foamies, F3P to 3D planes. Like I said I fly every day (Vegas has great weather) and use Phoenix sim and fly indoors when its too windy.

I desperately want to fly bigger planes, thus the obsession for tying to find one I can afford. I know you get what you pay for in this hobby, but I rather have a Turd then nothing at all. With that said, I will start this thread to show people like me that aren't rich men that we can play with bigger planes too. Or I will show that you shouldn't waste your money on junk, and save to buy somthing better later on.

So here we go, a sneak peak of the plane that I am going to build next.

 

[AKfreak]

OK, just a little more of your time on the motor subject. My Extra build manual says the plane flying weight is 11 lbs. I am trying to pick the correct KV Motorfly 4330 motor for my 6S packs (TP 5000mah 45&70C packs). I want post stall performance and lots of power to pull out if I need it.

With 2700 watts I am leaning toward the DM4330-400 it says, "for 3D Planes up to 13 lbs". Max Watts 2700 with a 19x8 to 19x10 on 6s , for a 75.5" plane, is 19x8 prop too big?

Also with 5000 mah packs what are the flight times going to be like 3-4 mins of hard flying? Here is what I did to try and figure it out. I went here to figure amperage draw 2700 watts (Motor) and 22.5 (6s pack). That gave me 120 amps then I went to here ans used their calculator and input 5000mah and 120 amps to get 2.5 mins. I do have some 8000 mah packs in 6S, and I realize that is WOT for the whole 2.5 mims so if I mix it up I can get 5 mins without too much trouble?

So before I hit the buy button, would you buy the DM4330-400KV and run a 19x8 prop for 3D on a 75" 11 lb plane? That's 245 watts per pound (would you consider that to be ballistic performance?)

Thanks again guys, I hope to hear from you soon. AKf

 

[3dNater]

19x8 or 20x8 are great sizes for a plane that size. You don't want anything smaller than that if you can help it. The big props help post-stall performance.

Your method of finding out how long your battery will last is great on paper, but you don't know what your watt/amp draw will be until you meter it yourself. I am going to venture a guess that you will be able to get 4 min of flight time without any trouble. I would fly it 3-4 min the first few flights and then see how many mah you put back in when you charge the packs and go from there realizing that you should only be using maybe 70% of the total mah available in the pack. Keep in mind that your packs may be damaged if the cell voltage drops below 3v/cell and 3.6 or 3.7v per cell at the end of a flight is healthy. *disclaimer... this is my opinion... some people may or may not agree with me.

on the last question... 245 watts per pound is certainly ballistic. Keep in mind that the minimum is 150 watts/pound for 3d flying.

I am really hoping you are able to bring the plane in under 11 pounds in an electric version. I'll be interested to hear more about that as you complete the build.

I have yet to build an electric plane in this size. I am on my 3rd 25-26% gasser at the moment.

 

[AKfreak]

I come from the multirotor world where battery failure means everything is a failure. We use these little cheap things called Lipo Alarms. They plug into the balance connector. I set all of them to 3.6 and use my radio timer.

Btw, also I am working on micro audio transmitter (just a few grams) that I will be placing inside of my planes. Not only will I be able to hear the alarm going off, I will be able to hear my motor. At Bennett field there is so much going on the noise can be as bit much at times. You have Control line with no mufflers, huge gassers ripping around, then the helis, oh the helis. It's almost impossible to hear an electric plane motor when you are flying. you see, I like to hear the motor, I feel more immersed into the flying. When I cant hear my motor I feel disconnected a little. So lately, just so I can hear my planes. The receiver is a single ear bud, it's like a miracle ear or somthing. It's only in one ear, so you can still hear the guys on the flight line.

Sorry for going of on a tangent like that, bottom line is I fly to 3.6 max on all my big packs. Thanks for the info, I am now ready to buy $300 in electric motors now

 

[AKfreak]

Well my plane showed up today, but stupid FedEx drove a forklift tip through the double boxes and busted a hole in the fuse. What a huge disapointment. The plane is so so nice. The structure is very well built. As to customer service, I sent an email with pics, and in no lmore than 30 minutes I recieved am actual phone call from the company who sold it to me saying dont worry. When he gets home he will make it right.

 

[3dNater]

Bummer on the shipping damage! Keep us posted on how it turns out.

 

[AKfreak]

Yep a helluva way to start the build.

Besides the hole, the only thing I don't like so far is the way the canopy attaches. I will buy one like on the Extreme Flight from Redwing RC here . Also not sure why they made elongated holes for the front wing root support.

 

[3dNater]

I have had both styles of canopy attachments. On a plane this size I am a lot more comfortable with the bolts. Either one will work fine though. I recommend trying these bolts out for a while. I think you will find they don't add much time to a battery change or gas fill-up. In the end, it is your plane to mod how you like.

That hole doesn't look too bad from here. I'm interested to see what kind of structural damage there is on the inside. If all you have to do is patch the covering you might have scored a new fuse with one as a backup. That would be a sweet deal.

The elongated holes aren't a big deal the direction they go. As long as the wings can't turn around the wing-tube is all that matters.

Keep posting up the pics. It looks cool so far

 

[AKfreak]

I am sure he would of sent me a new fuse. After I tell you how much he sold this to me for you will see why I am trying very hard to work with him and save him as much trouble as possible. I have already fixed the wood damage, and I am now waiting for the covering material to finish the job. Ill post pics in a few. I did do a video to show him me opening the box (i just kept that private as I used a little bit of foul language.) However after my initial frustration, I am now officially excited again about this plane. I say it's pretty nice. Ill go out on a limb and say its every bit as well put together as my Hangar 9 Showtime 90.

Here are two boring videos (sorry I am kind of new to this stuff) of me taking the stuff out of the box and seeing some of it for the first time.

Part 1. (7mins)
[video=youtube_share;RF_4oFQznng]http://youtu.be/RF_4oFQznng[/video]
Part 2. (4mins)
[video=youtube_share;rrzYNsEhN34]http://youtu.be/rrzYNsEhN34[/video]

Please don't ask for your time back after you watch these videos

 

[AKfreak]

The video doesn't really show the true colors so I took some stills.

I need to do a little sanding to clean up the Cutouts in the Balsa ( this is a difference between a top end and entry level model)

I might have to file the top and bottom elevator notch to get more throw

The wing has a nice profile and the trailing edge root piece fits like a glove.