XXL Polaris scratch build

[Larry3215]

Just checked out your build on BE 103 - very cool! A twin pod setup! Nice looking plane

[larryross]

Good... someone did build one without a HS, but he hasn't answered me on how it flys without it yet.

You didn't say if you saw my BE 103 build or not. Ooops I guess you did before I could post this.

I have a close friend whos name is Larry also and we would have fun when we're together and in a group of other people.

[Larry3215]

Im sure it would fly fine at speed but I suspect the low speed handling would suffer some. I can see CG being more of an issue as well but not a big deal probably.

[Larry3215]

Well, Ive only completed 587 of the 643 items left to do before I can do the maiden, so tomorrow is out. Sunday still looks good though.

I decided to add a little color to the vertical fin before gluing it in place so thats slowed me down some too. I bought several rolls of colored packing tape and Ive been experimenting with the best ways to apply it. Its not too bad to work with, but not 100% easy either. The black covers very well. The red covers ok but the white doesnt cover worth a darn.

The results are good enough for my purposes though as long as I remember to apply the colors in the correct order. Over al its still easier than covering or painting by a mile

I also found a liquid soap bottle that looks like it will make a decent cowling.

[CHELLIE]

Hey Larry, paint it like this







It will be as nice or nicer

[Larry3215]

I wont get it looking that nice, but thats the scheme Im going for

[larryross]

I like the cowling, but you didn't spend as much time on yours as I did on mine and it's going to look better. Guess I'm going to have to start thinking plastic bottle.
Looking good Larry.

[CHELLIE]

Hi Larry and Larry I thought you guys might enjoy this video, Take care, Chellie

Sky king

[Larry3215]

Thats was cool Chellie! I got a kick out of it

That cowl bottle was easy - but it took me several trips to the store and about $20 worth of dish soap, shampoo and hand cream to get one that works! There were several ladies at the store wondering why I was looking so closely at the bottoms of all the bottles in the beauty section for all that time! I got some strange looks!

[CHELLIE]

Originally Posted by Larry3215

Thats was cool Chellie! I got a kick out of it

That cowl bottle was easy - but it took me several trips to the store and about $20 worth of dish soap, shampoo and hand cream to get one that works! There were several ladies at the store wondering why I was looking so closely at the bottoms of all the bottles in the beauty section for all that time! I got some strange looks!

Its Funny what we will do for our Hobby Huh even dive into dumpsters Take care, Chellie

[CHELLIE]

I found some info on Cowl Construction, hope it helps, Chellie


Maybe this info might help, make a pattern cowel from balsa, then vacuum form, hope that helps, Chellie


Vacuum Forming with your Kitchen Oven and Vacuum Cleaner


http://www.wattflyer.com/forums/show...hlight=vaccume

http://www.instructables.com/id/Make...-plastic-vacu/

http://www.youtube.com/results?searc...rch_type=&aq=f

http://www.ffscale.co.uk/page4f.htm

http://www.cstsales.com/tutorials/fiberglass_mold.pdf

http://www.rcgroups.com/forums/attac...mentid=1379325



http://www.rcuniverse.com/forum/m_3209607/tm.htm

http://www.ffscale.co.uk/page4g.htm

[Larry3215]

LOL Thats some cool stuff you found there Chellie! I am waaaay to lazy to go to that much work though.

If I cant find an old bottle or jug or soda can or steal one from another plane then too bad. I just do without or do something ugly

[larryross]

Ha ha ha Funny video... thanks for sharing it Chellie. I haven't looked at the links yet.

[Larry3215]

Well, Im about ready for the maiden BUT I have a bit of an issue.

I got the tail section all done with all linkages on and assemble the plane for another CG check and - OH NO!

Im 4" behind where Steve recommends the CG to be!!

So I did some calculations and where Im at now is around the 25% MAC point. That's if I include the fuse portions where the wing is in the area calcs. If I add in the forward fuse area Im more like 30-35% and thats pushing things a bit.

I think I will still be fine - I hope! I fly most all my planes with the CG pretty far back any way. I'll dial in some extra expo and keep my fingers crossed.

I could always do what Larry suggested and toss an old motorcycle battery up front too

Seriously though, all the flat bottom fuse up front will act sort of like a fixed canard and the CG may well need to be further forward.

Hmmmmmm. I hate to do it but I may put some lead up front for the maiden.

Ok, off to cut the batery hatch and charge up the Tx and a couple of packs for tomorrow!

Hopefully I'll get some video too

[larryross]

Take a motorcycle battery with you. Keep the nose up when you get close to the ground.

Good Luck
Larry

[CHELLIE]

Originally Posted by larryross

Ha ha ha Funny video... thanks for sharing it Chellie. I haven't looked at the links yet.

Glad you enjoyed the video I cracked up when i saw it, and every time i see it Good luck to you Larry on your Maiden, fingers crossed Chellie

[Larry3215]

Thanks!

[CHELLIE]

Ok I will show off my Blooper/Mistake what was i thinking Ok I really am Blond, I was making my elevator for my Giant bi plane, and i am going to add some wire braces on the elevator and rudder, so i epoxied some basswood into the stabilizer,for the brace wires, so i thought, it was the elevator, I am adding some helper areas to the tip of the elevator and rudder to help the servos along, and i was thinking conventional build rather than with the helper ends, and i made a Blooper, Silly me, it will be covered up with some tower covering, so no one will ever know Take care, Chellie


BTW the elevator is 30" long

[larryross]

30" elevator... that is going to be a big bipe. Are you building from scratch 3 view or from a pattern? Do you have a picture of what it will look like?

[Larry3215]

Thats funny Chellie! You have actually come up with a blooper I havent done yet and I thought Id done them all!

[CHELLIE]

Originally Posted by larryross

30" elevator... that is going to be a big bipe. Are you building from scratch 3 view or from a pattern? Do you have a picture of what it will look like?

Hi, here is a build thread on it, its going to have a 9mm flat Depron foam wing and a full fuselage, made from 6mm depron, wish me luck, Chellie

Originally Posted by Larry3215

Thats funny Chellie! You have actually come up with a blooper I havent done yet and I thought Id done them all!

LOL What was i thinking

http://www.wattflyer.com/forums/showthread.php?t=42680 giant biplane build thread

[CHELLIE]

I am building this biplane from scratch and pictures and TLAR Method

[Larry3215]

It flys.....great!

Its not perfect but one heck of a good start. I am jazzed

Video and details to follow............

P.S. CG was fine where it was - for me. Some folks might consider it pitch sensitive, but its just the way I like it. You will see in the video it flys great!!!

[CHELLIE]

Originally Posted by Larry3215

It flys.....great!

Its not perfect but one heck of a good start. I am jazzed

Video and details to follow............

P.S. CG was fine where it was - for me. Some folks might consider it pitch sensitive, but its just the way I like it. You will see in the video it flys great!!!

YEA Glad it flies Great, Waiting on pins and needles for the video Chellie

[Larry3215]

Thanks Chellie The video is "processing" on YouTube now.

Ok, first things first - the cg. I flew it 4" behind where Steve suggested and it flew fine. The elevator is somewhat sensitive, but keep in mind I also have my ailerons set up as elevons so I have way more than twice as much "elevator" as the original design.

You will be able to tell in the video that the plane tracks very well so its not tail heavy in the conventional sense at all. Also, inverted flight still takes a fair amount of "down" stick to hold level. Its just that the elevator is very sensitive or maybe I should say very effective.

I have large 3D type throws programmed in as well - almost 45 degrees each way on all surfaces. But - my one bit of rationality - I had 75% expo dialed in on elevator and aileron.

Over all - its just about where I like it. Most people will probably prefer to keep it like Steve has with just the elevator controlling pitch and probably use reduced throws AND keep a good bit of expo. It is a close coupled bird and will tend to be sensitive in pitch anyway - especially with the elevator in the prop wash.

It feels like it could easily be made to do a Cobra maneuver if you buried the elevator at speed. I didnt want to try that just yet until Im more used to how it handles I also didnt try any spins.

It loops very well and even knife edges! Take off is easy and smooth as are landings.

At the end of the video you will see I go dead stick when the pack gives out. I didnt do the smoothest landing and kind of flopped it in but no damage at all.

It handles hi alpha very well. Once you get the nose up to 45 degrees or so you get a good bit of wing rock but its not bad and you can steer with rudder easily.

Ground handling is excelent. It will litterally turn in place! You will see that at the start of the video and I think it looks kind of cool

Things that need improvement:

1)The power system needs to be beefed up. Im only getting 3+ minutes of flight on my 6S1P A123 packs and thats running them down to 2150 mahr put back in!

The plane will fly easily at 1/4 throttle and in fact I did the first take off (not in the video) at just a hair over 1/4 throttle. However, Im spending a lot of time at full throttle and when I back off its only down to 1/2 and then back up to full.

It just looks better going faster and feels like it should be flown fast Thats eatting up the electrons at a heavy rate though.

Im going to have to run 2P packs to get any run time. I need to do that any way as I want to go to the 13" prop. because of the next issue

2) I barely have 1:1 thrust to weight. It struggles to do a big loop from level flight. So I'll jump up to a 13x7 or so for the next trials. That should give me a good bit more thrust and mabey a bit more speed.

That means more amps though, so I will definately need to go 2P on the packs.

3)Once I do that - I may need to go to a larger motor. It came down today at about 145 deg F after a prolonged full throttle run. The Mega is safe at that temp but this was a cool day - 40 deg. So summer time running could be an issue - especially with a larger prop.

4)The packs came out of the plane at 150 deg which is the upper limit for me on the A123's as well. I had no air flow at all to begin with so I cut a hole fore and aft to let some air flow get through. That helped a bit but it needs better air flow. Going to 2P will help a lot too so that may all work out ok.

Thats about it. The video wil be up shortly and you can see how well it flys. The video is a bit jerky - I think I turned off the stabilization some how. Oh well