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Large 1/5 scale SM F-86 CG ?

Old 04-10-2010, 09:43 AM
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furloughed ual
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Default RE: Large 1/5 scale SM F-86 CG ?

Thanks Anton.
Old 04-10-2010, 10:48 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

Hi, furloughed ual

I just received e-mail from my demo pilot Germany, who just test flight the Large F-86 with full 5L fuel the CG is 390mm no problem, but if the main gear too soft that trustline will be + degree, this was why need more elevator throws , as your asked , the main gear oleo air/oil struts of the big F-86 need minimum 50-60 PSI,,, this will keep the trustline at 0 degree.. and easy for take off,,


Best regards

Anton
Old 04-10-2010, 10:59 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

ANton:

We need to extend the nose gear about a half inch in order to get the plane slightly positive incidence on the ground.
Brian
Old 04-10-2010, 11:06 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

yes, but now already slightly positive incidence on the ground,,, i don't think need extend the nose gear ....

Thank you for your suggested!!
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Old 04-10-2010, 11:45 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

Mine does seem to have a little negative AOA. I'm glad the main strut pressure came up. I did not even realize it was ajustable.

Vernon
Old 04-10-2010, 01:52 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

The main wheels of that Skyblazer scheme are sitting in a hole....that's why it has the positive AOA....putting more air in the mains will make it worse in terms of a negative AOA, not better....we'll get ours dialed in and working.....no worries....
Old 04-10-2010, 07:58 PM
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Gary Jefferson
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Default RE: Large 1/5 scale SM F-86 CG ?

Anton, what has to be done to install the new tanks. I have not installed my tanks yet and I am just wondering how they are installed. Do you have any pictures of the new tanks installed?

I will send an e-mail to get a new set of tanks...

Thanks, Gary Jefferson
Old 04-10-2010, 08:06 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

ORIGINAL: Gary Jefferson

Anton, what has to be done to install the new tanks. I have not installed my tanks yet and I am just wondering how they are installed. Do you have any pictures of the new tanks installed?

I will send an e-mail to get a new set of tanks...

Thanks, Gary Jefferson
Hi, Gray

yes, the new Fuel Tank cell willl finish tomorrow, and I will post the picture here (not need modify any frame, Please e-mail to John ( [email protected] ) for advise your address with telephone number, we will start send the new fuel Tanks to all customers of Large F-86 next week ..and when we send to all customers of F-86 1/5, that we will make the new manual for the new CG position,

Best regards

Anton
Old 04-10-2010, 08:10 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

Anton,

Please can you give us the inside diameter of the "BIG" bypass duct that you offer as an option with this jet?

Thank you

Jan
Old 04-10-2010, 08:14 PM
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Default RE: Large 1/5 scale SM F-86 CG ?


ORIGINAL: Springbok Flyer

Anton,

Please can you give us the inside diameter of the ''BIG'' bypass duct that you offer as an option with this jet?

Thank you

Jan
Ok, i will let you know the diameter of bypass for P-180 tomorrow,

Best regards

Anton
Old 04-10-2010, 10:05 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

Anton:
What is the maximum pressure we can put in the struts? Is the 60 pounds min or max?
Brian
Old 04-11-2010, 08:57 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

Gary, have u flown yours yet? 390 mm is a good starting point on the CG....I'm guessing we will move this one back to end up somewhere in the 400 - 410 mm range.....390 was still noseheavy in rolling manuvers and inverted flight....

Ryan

Ryan, I have not flown mine yet. I recently took a new job that has basically stopped my progress on the plane, but it is very close. I am not really in a big hurry until Skymaster has worked out all of the bugs. Mine is covered in Flite Metal and I have allot of time invested in the finish.

I have a little play in my elevators at neutral, did you notice this on yours? Just wondering how you fixed it if so...

Congrats on getting yours flying. I was going to post some pictures of mine soon. I have an incredible hot section on mine...


Gary
Old 04-11-2010, 09:27 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

Gary, PM sent...
Old 04-11-2010, 09:40 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

Hey Gary,
I had the same problem with my F86. I thought it was little play,but mine was almost 1/8 inch up and down before moving the servo.
I found the problem to be the swivel ball links on both pushrods. When I took mine out, I put the screw in and I noticed that the ball inside was not tight
giving a little play, but when you combine both side of the pushrods, it was significant play at the elevators.
I changed both ball swivels, and the only play I have now is the servo play.
Hope this helps,
Hector
Old 04-11-2010, 09:51 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

the stock aluminum ball would not work on ours...they are more of a single axis pivot than a true 2 axis ball.....due to the angle of the elevator bellcrank (tried it 4 different ways....top, bottom, and the fliped it also), it would bind. I ended up tossing them and replacing with HD Dubro ball links that allowed pivot on the 2 axis' it needed....
Old 04-11-2010, 06:24 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

the stock aluminum ball would not work on ours...they are more of a single axis pivot than a true 2 axis ball.....due to the angle of the elevator bellcrank (tried it 4 different ways....top, bottom, and the fliped it also), it would bind. I ended up tossing them and replacing with HD Dubro ball links that allowed pivot on the 2 axis' it needed....
I did the same thing and used the DuBro ball links since I could not make the factory links work either. I still have allot of play that seems to be in the control arm pocket in the stabs. I am thinking about putting a thin layer of epoxy on the pockets buy I don't know if it needs it on the top or bottom and I am afraid I might make it worse. I know the stabs need to be tight to prevent any flutter so I have to figure out some way to fix it...














Old 04-11-2010, 06:29 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

our slop was in the rod/torque tube, not the pockets.... FWIW...
Old 04-11-2010, 06:29 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

BTW, how did you guys attach your stabs to the fuselage? You can either glue them or attach with the 2mm screw thru the carbon rod on the stab. When I use a 2mm screw I have a gap between the fuse and stab and it also wiggles up and down. On the other hand if you glue it in place then you cannot remove the rudder for service. Not a fan of the design at this point, too many problems in this area of the plane...
Old 04-11-2010, 06:33 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

The factory needs to address the inevitable elevator flutter that is built into the plane due to the slop in the elevator linkage. Many guys think this is an ARF the way it is marketed. But so much of the plane has to be re-engeneered before it could ever be classified as safe. The elevator linkage is only one example.
Brian
Old 04-11-2010, 06:35 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

Gary, I embedded a piece of 1/8 ply laminated with .015" poly ply in the root of the stab that stuck down about 3/8"....I glued it so it's flush with the side of the fuselage on the underside of the stab, then drilled it and sunk a 4-40 blind nut inside the fuse....now pulling the stab takes about 30 seconds...
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Old 04-11-2010, 06:42 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

Gary, this is what I did (pic in previous post)....only used a single tab, made it smaller, and of course used a button head bolt to make it pretty...
Old 04-11-2010, 06:44 PM
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Default RE: Large 1/5 scale SM F-86 CG ?

Brian, I agree. If one of these is assembled with factory parts and specs it has a high potential for elevator flutter.

In addition, i would suggest that the wing tank mounting be redesigned because the hard points glued in the wing are marginal at best. The rear one is nowhere near any former, and the wing is very soft in that area. In addition, the soft ply mounting tabs on the tank itself are less than adequate for a wing tank this size. My belief is that they will easily pullout of the wing. There has been one incident of this already and I think there will be more if this is not changed. I won't run the wing tanks until I figure out some other mounting method.

At the very least, if tanks are used with the current design I would suggest adding something similar to the scale side braces for the tanks. This will help keep them from moving around in the air at higher speeds...
Old 04-12-2010, 01:20 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

ORIGINAL: thunderbolt-RCU

The factory needs to address the inevitable elevator flutter that is built into the plane due to the slop in the elevator linkage. Many guys think this is an ARF the way it is marketed. But so much of the plane has to be re-engineered before it could ever be classified as safe. The elevator linkage is only one example.
Brian
You're so right Brian.
This is why is am holding my order on that plane. A lot of areas need to be addressed and the most critical in my point of view is the sizing and design of the wing tube/spar system.

BTW I think that the elevator lack of authority is amplified in your case by the fact that you are flying at high density altitude. You can loose up to 15% lift on a thin control surface like this one at 6000ft da.
I noticed this fact as well here in Dubai. The flight controls response decreases noticeably in the summer on some nose heavy setup.
The F-84 is optimized for 6000 ft density altitude...
Old 04-12-2010, 04:43 AM
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Default RE: Large 1/5 scale SM F-86 CG ?

ORIGINAL: thunderbolt-RCU

Anton:
What is the maximum pressure we can put in the struts? Is the 60 pounds min or max?
Brian
Hi, Brian

Please Meassure the total length of the stroke of the main oleo legs. When the F86 is fully loaded and fueled, it should compress to 2/3 of the total stroke. If not then increase the air pressure from 50, 55 to 60 psi, where 60psi is max.

Best regards

Anton
Old 04-12-2010, 05:16 AM
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Default RE: Large 1/5 scale SM F-86 CG ?


ORIGINAL: Springbok Flyer

Anton,

Please can you give us the inside diameter of the ''BIG'' bypass duct that you offer as an option with this jet?

Thank you

Jan
Hi, Jan

the binside diameter of theig bypass is 143mm (5.6") for P-180,

Best regards

Anton

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