jrCessna O-1 Bird Dog (Intermediate Build Trainer)

[Garret234]

if you would like to see the rear turtle deck piece I deigned and how I put in the servos I would be more than happy to build a quick rough design so that you get the main idea.

 

[JohnRambozo]

OMG! What a sweetheart to fly!! ok, here's the scoop, it flies awesome! Very gentle, very forgiving and well behaved, it acts just like you'd expect a high wing trainer to act. It was off the ground in about 10 feet and just lept into the air! At about 50% throttle it was really predictable and had good self correcting tendencies. After 3 batteries or so, I was right at home in this plane! It had no strange characteristics whatsoever. I will say, it's does skid in the banks, so it likes to fly coordinated with the rudder. Tip stalls were noticeable only in higher banks but they were pretty minor, and only required a little up elevator, and if you let go of the stick it leveled off and settled right down. At full throttle, it was a whole nother animal and was able to do some pretty aggressive stuff! I was pretty impressed! Just for the love of the game, on my fourth and last battery I disconnected the ailerons from the receiver and plugged the rudder into the aileron slot and flew it as a 3 channel. No problems, and flew as advertised!
What did I learn today: Shimming the the power pod to keep the thrustline centered is a must!!! after my first landing and battery swap the plane had a lot of trouble taking off because the out of whack thrustline was pulling it hard to the right, and put the wing tip in the ground, I did have to keep adjusting it. 2nd, this plane is a blast to fly, sweet and gentle at medium throttle settings and a fly's like a war bird at higher speeds! very cool indeed! 3rd, If I would have added flaps I could have landed this plane in the palm of my hand! LOL
Very Sweet plane! Awesome for beginners and agile enough for a pro! Sorry no video, it was just me out there today, I did manged to score a couple before and after shots though. View attachment 68933 View attachment 68934

I too got to fly the birddog this weekend it was awesome! it did every thing Paxbot's did. Unfortunately all of my pics I had for the BD where not saved when I transferred them to my computer!!!! I gave mine to my friend as I said I was going to and never got a picture of the finished product. With all of my minor problems it sounds like there is no need to change v2 and that it flies great! When I flew it we had a good 15-20 mph wind and no bad tendencies. I did end up flying mine with a 1800mah 3s if it makes any difference.


Thank you very much JohnRambozo for all of your time and thought that you put into this little guy!

That makes me really happy! I'm overjoyed to hear what a good experience it was for both of you. Now I can't wait to fly mine!

I appreciate the very thorough (and glowing) review, Paxbot. Garret, that's very generous of you to pass it on to a friend. I'm sure anyone building would enjoy seeing how you installed your servos (as would I).

Nice job building (and flying) guys! I appreciate you both taking a chance and beta testing it for me.

 

[Garret234]

Here is the video on how I installed my servos.https://youtu.be/kL7OE9Vhglg

 

[Paxbot]

I too got to fly the birddog this weekend it was awesome! it did every thing Paxbot's did. Unfortunately all of my pics I had for the BD where not saved when I transferred them to my computer!!!! I gave mine to my friend as I said I was going to and never got a picture of the finished product. With all of my minor problems it sounds like there is no need to change v2 and that it flies great! When I flew it we had a good 15-20 mph wind and no bad tendencies. I did end up flying mine with a 1800mah 3s if it makes any difference.


Thank you very much JohnRambozo for all of your time and thought that you put into this little guy!

Yeah Garret, I flew the bird dog again today and the winds were fairly high, it got blown around a little. good job!

 

[Paxbot]

That makes me really happy! I'm overjoyed to hear what a good experience it was for both of you. Now I can't wait to fly mine!

I appreciate the very thorough (and glowing) review, Paxbot. Garret, that's very generous of you to pass it on to a friend. I'm sure anyone building would enjoy seeing how you installed your servos (as would I).

Nice job building (and flying) guys! I appreciate you both taking a chance and beta testing it for me.

Hey thanks John, super plane dude! I'm finishing my second one for my girlfriend, she'll have a lot more dihedral cause she's a pretty new pilot. She wants to paint it pink with hello kitty's on it. I'm trying to talk her out of it. But I'll send pics when I get em'. I flew it again today in higher winds, it did good. no problems.

 

[mesolost]

Dude! Do it! Paint it hello kitty pink Put a little kitty in the cockpit C'mon! You know it'd get the looks.

 

[JohnRambozo]

Dude! Do it! Paint it hello kitty pink Put a little kitty in the cockpit C'mon! You know it'd get the looks.

I... uh... huhwhat?

 

[JohnRambozo]

I finally got to maiden my Bird Dog yesterday. It flew really well and gently. It was pretty aerobatic, too. Good rudder authority and plenty of elevator. Of course I didn't get video either. I didn't want to break the trend.

 

[jpot1]

Planning to build this next. A few questions - in the latest version there is now a center section for the wings, any dihedral or maybe polyhedral? Not sure which is the right term. If so perhaps a gauge added to the plans? Also where is the cg? On one post a thought was about an inch from the leading edge. Is this correct?

Thx!

 

[Garret234]

I did about 1" of polyhedral on mine and it worked well. polyhedral is two breaks in the wing, dihedral is one break in the middle, and polydihedral is three breaks in the wing.

As far as CG goes I went about 1/3 back from the LE of the wing it was perfect.

Good luck and have fun flying

 

[jpot1]

Thanks Garret234. I'm still struggling. Cut out half the wing and the center section based on the v2.5 plans. In the picture below did you add the polyhedral at the side of the center section (#1) or out further along the wing at (#2). As well any spar or carve out of foam to recess the servo? When I tried out the bend, the bottom of the airfoil is not flat like other FT builds, just curious if I am doing things correct or if I need to carve out foam.

 

[Garret234]

I did the polyhedral at point #1, and to add that I used a BBQ skewer and mashed the top of the wing after I folded the wing parts.

I am sorry if you are more confused now....I am horrrrrible at describing things.

Good luck with the build!

 

[jpot1]

Focused on the fuselage tonight. So far a few mods. I found that the top plate with cockpit written on it was not wide enough. I had to add 5 mm to get it to work. I then doubled the top plate to make the swappable area more rigid. I run a shortened power pod and was able to notch out the doubled plate to fit the tabs in my power pod.





I also had to widen the rear top plate. Not sure if I didn't cut something correctly but I was not even close originally. Picture of where I'm at so far below. Rear top plate is not glued in. Planning to hide the servos like others in this thread.



Will be working on the wing and will be including a spar like other FT builds and will upload pics when done. Thanks Garret234 for answering my earlier questions.

 

[Garret234]

I posted a video on how I installed my servos a few pages back.

Good luck on the build!

 

[jpot1]

Progress on the wing. I decided to go standard FT so due to the airfoil I notched first notched out the foam to recess the servo.

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I then placed a line approximately 1.5 inches from the leading edge for a spar. I cut the spar 2 cm wide with a score cut at 1 cm, folded it over as typical other builds and glued it on the line.

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I also in the above have glued the bottom of the wing panels together, edge to edge. I then folded over the center section, glue on the leading edge, spar, and edge of the bottom airfoil.

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Lastly I cut out a little foam from the sides of the other panels so that after the fold over there was room to add polyhedral.

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Pushed glue into the crack and added about 2" of polyhedral on each side of the center section. End result...

​

 

[JohnRambozo]

Progress on the wing. I decided to go standard FT so due to the airfoil I notched first notched out the foam to recess the servo.

I then placed a line approximately 1.5 inches from the leading edge for a spar. I cut the spar 2 cm wide with a score cut at 1 cm, folded it over as typical other builds and glued it on the line.

I also in the above have glued the bottom of the wing panels together, edge to edge. I then folded over the center section, glue on the leading edge, spar, and edge of the bottom airfoil.

Lastly I cut out a little foam from the sides of the other panels so that after the fold over there was room to add polyhedral.

Pushed glue into the crack and added about 2" of polyhedral on each side of the center section. End result...

Great mods. Its coming along nicely!

 

[JohnRambozo]

Thanks Garret234. I'm still struggling. Cut out half the wing and the center section based on the v2.5 plans. In the picture below did you add the polyhedral at the side of the center section (#1) or out further along the wing at (#2). As well any spar or carve out of foam to recess the servo? When I tried out the bend, the bottom of the airfoil is not flat like other FT builds, just curious if I am doing things correct or if I need to carve out foam.

View attachment 70864

Sorry I'm catching up going backwards a bit and I know you already solved this, but it is possible to have a flat airfoil without recessing the servo, you just have to put some effort into keeping the bottom flat.

Also, the split in the wing bottom toward the ends was not intended for polyhedral, it was just a way to manage the scale wing shape since the leading edge tapers back a bit, the bottom should meet up with the adjacent bottom once the wing is folded correctly. Mine did.

Having said that, what you've done looks perfectly acceptable.

 

[jpot1]

Sorry I'm catching up going backwards a bit and I know you already solved this, but it is possible to have a flat airfoil without recessing the servo, you just have to put some effort into keeping the bottom flat.

Also, the split in the wing bottom toward the ends was not intended for polyhedral, it was just a way to manage the scale wing shape since the leading edge tapers back a bit, the bottom should meet up with the adjacent bottom once the wing is folded correctly. Mine did.

Having said that, what you've done looks perfectly acceptable.

Thanks John. Can you attach a picture of the underside of your wing?

 

[zee5001]

Hi! man great plane, plans and work can you send me the blue print at (taha7001@gmail.com)or upload it again!

 

[Tsavah]

Provided On First Page

Hi! man great plane, plans and work can you send me the blue print at (taha7001@gmail.com)or upload it again!

Maybe I am missing something in this request, but what you are asking for is on page 1? Do you have a copy machine, or printer handy? I must not be catching on to a detail in your request since I see everything on the first page.