rodders

I’ve read about it. Not sure if it was you that said about it but I’ve seen numerous references to this.

I like to fly aerobatics, so for me having it fly as nuetrally as possible is a must.
Im also going to attempt to fit top ailerons. I’ve seen photos of cropped ailerons, and ones that appear the same length as the bottom ones. At the moment I’m going cropped as it means less modifications to the existing top wings.

Im still trying to find a picture/diagrame of the full size tail ribs and plan to use these as a guide. At the end of the day providing the tail lift increases with increasing forward speed it can only help the situation.

Rodders.

rodders

Anyone care to reply?

With ref to the climbing issue, what have tried to correct it from climbing?
Have you added down thrust?

Has anyone used a assymetric tail plane as per the full-size?


Regards,
Rodders

BobH

My Feedback: (2)

The way to compensate for excessive climbing is to add positive incidence (leading edge up) to the stab. The stab flies higher so the nose flies lower.

rodders

Ok
Ive sort of got it and understand that the tail incidence needs to be increased ( probably to the same angle as the wings), but is there still an issue of climbing under higher power?

The use of an assumetric tail plane ( as per the full size) does counter this.

I was hoping that “ outofcontrol41” would reply and detail his problems

regards
Rodders

I was hoping that

BobH

My Feedback: (2)

You can have a greater stab incidence than that of the wings if necessary.
What that gives you is Engine Down thrust in practice. The greater Stab incidence the more effective down thrust.
I suppose you could sand the stab ribs to mimic that of the full scale. That could work too.

outacontrol41

My Feedback: (9)

I iincreased the engine up thrust too many degrees resulting in a severe climb on takeoff on last flight....did not end well. Came down a bit hard after an aborted takeoff and did some minor damage. Going to go to a seasoned builder and pilot with a wing incidence meter to figure this out as it seems that this is way over my head to tackle alone

rodders

Ok
Upthrust would have been the wrong way to go if it was already climbing.
To counter climbing climbing under power, the thrust needs to be vectored down.

Its not uncommon to have a few degrees of downthrust on certain models, especially those designs with high wings and biplanes.

I was just hoping to take the guess work out of it and get it right first time.

Out of interest is there an approximate weight of the engine and nose weight needed to balance one of these?
The reason I ask is that I thinking of using a Saito 90cc 3 cylinder. It won’t look as good as a 5 or 7 cylinder but should sound nice and mean I’m not flying with lots of dead nose weight.

outacontrol41

My Feedback: (9)

I'm using a Zenoah G62 engine which is about 6 lbs. or so and no nose weight to balance at CG. That Saito better be around 6 lbs as well or you will have to add a # or 2
I'm going to go back down a couple degrees in engine thrust before next flight....got to fix the minor damage first from last attempt

rodders

Ok
Did the Zenoah need any balance weight or is 6lb the ideal weight for the engine?

The Saito 90 radial I’m thinking of using is 7.7lb. Is this going to be too heavy?

What are other people using for engines and how much do they weigh

outacontrol41

My Feedback: (9)

The fake plastic radial engine I have covering the G62 is at least a pound or more .... lots of plastic parts and epoxy all stuck together. At 7 lbs you should be okay. If you can wait a bit, I'll dismount ny engine and weigh it along with the radial cover and send that info along so you can compare to your Saito. There is a video or two of some guys using a Moki 150 radial engine on their Flair Stearman so I really think even if you had to add a little nose weight to make it balance you'll be alright. I think your target weight should be 26 - 32 lbs.

rodders

Hey,
Are sure the Moki 150 is in a Flair Stearman and not a Balsa USA stearman?

BobH

My Feedback: (2)

I think a Moki 150 is too big and too heavy for the Flair plane.
I have an Evo 77 that is just about the right size. Maybe its an inch in Diameter too small.

outacontrol41

My Feedback: (9)

The second video I had in mind was a Ziroli kit w/ 87'' wingspan
The first video is definitely a Flair. He said so in the comments but has since erased most of the comments since first posting.

It can be done... just that the Moki engines are so expensive

barzini

My Feedback: (4)

Hello everyone,
I'm building a Flair Stearman now and using the Evolution 7-77 for power.It looks like I should add some more positive incidence to the stab after reading this thread.My plan calls for +3.5 degrees.Did anyone add more and eliminate the climbing issue?
Thanks,T.C.

outacontrol41

My Feedback: (9)

My Stearman was built for me but I wish the builder had added the pos. incidence to the stab...I think it could only have helped.

barzini

My Feedback: (4)

Correction,My plan shows +3 degrees stab incidence.Im going to make it +4 .I dont think it would hurt anything.
Thank You

rodders

I wish I could add more detail.
I noticed the climbing problem in the threads but knowone has come back with a solution.

I seem to be repeating myself here, but the full size has a lifting tail ( the model has a symmetrical section). Why doesn’t anyone copy this?

I intend to make my tail as per the full size section and still use the same incidence on the tail as the wing ( in this case 3.5 degrees). Hopefully this will reduce the power/speed induced climb.

Please report back on how you get on with the 4 degrees on the tail.

barzini

My Feedback: (4)

I added a 1/8" piece to the front of the stabilizer saddle and I'm at +4 degrees now.Im just in the early stages of the build now so if anyone who has built the Flair Stearman and powered it with an Evolution 7-77 radial or any engine please feel free to chime in with any building tips as far as strengthening the engine mounting tube,fuel tank size,servo receiver location? This is a really nice kit!
Tony

barzini

My Feedback: (4)

Here's my progress so far with three weeks into it.

BobH

My Feedback: (2)

Lots of progress after only three weeks. Good job.

outacontrol41

My Feedback: (9)

looks good so far

barzini

My Feedback: (4)

I mounted the radial to try to get an idea where I might need weight to balance the plane since the only area to access the radio gear and battery are through the cockpit once the plane is covered. It's pretty nose heavy so I'm thinking the rear cockpit.

outacontrol41

My Feedback: (9)

Hope you don't end up having to push your batteries into the tail section to make it balance

BobH

My Feedback: (2)

Looks pretty good with th radial on it, The first ear cockpit should work for the weight, hopefully.

barzini

My Feedback: (4)

Did you have to add weight?