acerc

Woo Hoo! I have figured it out, you know, why the ele is trimmed down. I have been racking my brain over this as it just did not make sense to be with it not being tail heavy. Well, turns out it is tail heavy. Here is what happened. I was trying to figure out how to send the spreadsheet to a friend where he could open it, turns out it is his computer and not the spreadsheet. Anyway, while I was working with it I decided to run the numbers one more time. Yea, I'm anal enough to have wrote down the figures. And the first time I looked at it and thought "Yep, it says I am nose heavy". And just as I cleared it something went "Whoaa dum azz". So I punched them in again and it turns out I was reading the results wrong, the spreadsheet was telling me what the tailwheel should weigh and for some reason I was reading it as to what it does weigh. I have no idea why, I mean come on, I just typed in the actual weight, but somehow. Duhhhhh!!! It is a tad bit tail heavy which for this plane is very tail heavy as it really needs to be nose heavy. So, next week I will move as much possible forward but until then I will add some nose weight and see how it goes.

Argggg, I'm an idiot.

John_M_

Your not an idiot Ace, but you are very lucky it was manageable in the air... what about using a weight & balance sling and see where she actually hangs?


John M,

acerc

I knew it was close one way or the other so no worries there. As for a Vanessa rig, not happening on these trailing edges. There is not much there for support.

Melchizedek

Glad the mystery has been solved.

Kevin

acerc

I just finished adding up the electronics behind the cockpit, remember I had them up from, and they are 2lbs. I guess sometime next week I will move them back to the firewall. Go figure.

WacoNut

Congrats Robert,
She looks great in the air. May you have many fun filled flights ahead.
Anthony

John_M_

Vanessa rig, that's it... I couldn't remember the name of it.

Wow, that is definitely some light construction for the size of the aircraft... reminds me of those old rubber band models with stick and tissue paper construction.



You could always fashion a rig off the upper wing cabane, along with a small double pulley block.


Either way you do it Ace, double check it... I'm just glad the maiden went as well as it did, a bit more tail heavy could have been disastrous.



John M,

acerc

The weight method is the same manner as full scale is done and I really like it. I just need to not look at things wrong.

acerc

Thank you Anthony. I very much respect and appreciate your opinion. And I sure hope so.

John_M_

I am familiar with that method... if I was more of a wiz kid with math and maybe 20 years younger, I would give it a try, but I like to hang them from the CG... I understand your dilemma with the weight and lite construction though, you have no choice really.


You got the fire burning under my kettle now Ace... my next build is going to be 1/3 scale (or bigger) of something or another... the wife has already been made aware of it ; more or less its going to happen !... not something as hotdog as your pitts, I don't think my heart could take all the excitement ... I'm getting a little tired of high wings; I may get into a giant scale WWI biplane, something different and slow enough I can keep my mind ahead of... so I may need to calculate the CG rather than hang it, but I'll enlist someone to help me with that, but I need to get this J3 finished first, its not too far off now.


***EDIT***

I knew I had come across calculating weight & balance using scales somewhere... I think this is the same method you are referring too.

http://www.flyinggiants.com/forums/s...ad.php?t=13553

John M,

acerc

I don't know without looking if it is the same, but, what I am talking about is a spreadsheet that does the calculations you just put in the measurements and weights. I can give this spreadsheet to you if you want it. I can not post it here but can email it to anyone.

Cub Flyer Fresno

Just this last weekend I was at our IMAA event at Castle Airport (formerly AFB). Someone tried to fly a Cessna Sky Master that was way to tail heavy. He made it around the patch one time, tried to land but ran out of runway. Upon climbing out and turning away from the crowd he started losing control, over corrected and went in inverted. Such a shame, but not as bad as yours would have been. I'm so relieved you made it through!

How about some more video once you get the CG corrected, that is such a beautiful plane!

And Jacquie, if you're reading this, you're a lucky lady to have Robert modeling your Pitts! He did it right for sure!

acerc

Uhhh, David! It is I that was lucky to have Jacquie's support, input, and advice. She has answered every question, done every request, a few I thought for sure I would get a "I don't think so", but not once from Jacquie. Without her support this model would not have been nearly as well done.

John_M_

Well that method posted on the Flying Giants site is based on the RW aviation method... there is no spreadsheet, you place the aircraft in its level flying position (tail Up), with the prop spinner up against a wall (or vertical surface)... then you take measurements from the vertical surface out to the center of the main wheel axles, and the tail wheel... that gives you your "moment" measurements... then you place a scale under each wheel keeping the aircraft level in both directions and take a reading of the weight... that gives you your weight per axle / tailwheel.

From there its just some mathematics that gives you a value in inches where the CG is on the model.. then you cross reference your plans / build book, for the recommended CG location.... if your calculated CG location is off, then you add weight to the nose or tail depending on which way you need to correct the CG, then recalculate the new CG position, and so on until you get a calculated CG value that falls within the desired location on the model.

It all sounds good, and I fully understand how it all works, but you have to be accurate with taking all the measurements, and of course the math calculated correctly... with the way my eyes are, I'm a bit weary of making some mistakes.




John M,

Cub Flyer Fresno

Then it was both of you that were lucky. For Jacquie it was to have someone intent enough to do her Pitts in such fine detail and to re-do what was not perfect. Take a compliment, you did an outstanding job!

jacquieb

Hi guys. I am reading now. And I think what Robert did was outstanding in every way. It was really eerie at first to see what he was building, but what better way to remember her as she was! I LOVED that airplane and really do miss flying her. It just wasn't in the cards for me to have her forever. But she flies again!!! The detail is incredible and I'm so proud of Robert for all the work he has done. I WILL see it fly in person one of these days so don't bust her up Robert!!!

acerc

Ok, Fine. Thank you my friend!

jacquieb

I couldn't agree more!!!

jacquieb

From the very beginning I thought his idea was a great one. I was very happy to help in any way.

acerc

Hello Jacquie,
Welcome to the thread. Thank you for all your support in this venture. Without your input it would not have been possible to finish it in such grand fashion. I am truly humbled that you approved of my building your Red Eagle and amazed at your willingness to assist. People on here have no idea to the extent you went when I asked. Thank you so very much!
We will meet and do a photo shoot, if anything next year when you come to Sun n Fun. And I will do my best to keep this beautiful bird as it is. After the ugly (unwanted) take off Monday I have no doubt it will be a joy to fly and a crowd pleaser to boot.
Again,
Thank you very much for allowing me to build your aircraft and for participating.

acerc

See everyone, I was not nuts, Jacquie has been with me from the beginning via email.
Many of us scale builders often ask the owner or previous owner and I was graced with a yes. This has been the best build and the most joy from completion I have ever done.
Thank you to everyone for being on this journey with me. I will post more video as it comes and I assure you the flying will be scale, hee-hee, I have several of Jacquie's performances downloaded.

jacquieb

Yes guys it's true. I've been 'in his camp' from the very beginning. I was honored to say the least! Now to see her flying, well makes me a little 'girl like'!!

acerc

I just had a thought, think about this guys. I can put Jacquie on a buddy box, if she is willing of course.
Jacquie, a buddy box is a second transmitter connected via a cord that allows a second person to fly the aircraft while the first has can take and relinquish control in flight.

John_M_

Well I'll be!... nice to have you onboard Jacquie, both with Roberts build and here on the thread... his recreation of your outstanding Pitts biplane was an enjoyable journey he took us all through... to have you here participating at all levels, is the icing on the cake!!


John M,

John_M_

That would be something Ace... Jacquie flying her Pitts again would be something special... not to mention, she would experience the skills of an RC pilot; I can only imagine what it would be like in the cockpit flying the real Piitts... she would fully appreciate what it takes to fly an RC model.


John M,