P-51Owners-Landing Gear Caution!  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> RC Airplanes >> ARF or RTF >> NitroModels Support >> P-51Owners-Landing Gear Caution!
Page: [1]

Login
Message << Older Topic   Newer Topic >>
P-51Owners-Landing Gear Caution! - 9/12/2007 5:29:16 PM   
arcticflyer


 

Posts: 112
Joined: 11/17/2005
From: Tuktoyaktuk, NT, CANADA
Status: offline 		Gentlemen, I purchased a P-51D (Double Trouble) ARF (Semi Built Kit in reality). Prior to completing the plane I read several posts about bracing and strengthening the area of the main landing gear. One post I read described a guy who landed for the first time and the gear popped out of the wing. Well.....being in a rush to get the thing done and get flying (because our season is so short up here) I did not want to cut the covering and the sheeting and open up the wing. Good Grief...it took long enough to build it as is was.
That was a mistake! On my first flight I was practicing landing approaches on the sand bar where we fly and the engine cut. No sweat.... I thought there are no trees up here and I've got this giant sand bar to dead stick on. Full flaperons, gear down, set her down some distance from me. Plane was sitting up right, looking good. WRONG.... The pictures below show the where the gear had popped out of the wings.
I took the plane home and did what I should have done in the first place. I cut off the covering and what remained of the sheeting and exposed the gear area. The gear had been held in place by tiny triange blocks glued to the bottom of a thin piece of poor quality lite ply (see pic below). The mounting blocks which were somewhat stronger were glued to the top of the lite ply. The problem was the lousy lite ply with small tabs through the ribs and the tiny triangles are the only thing holding the gear in the plane. I couldn't get pictures of this as the light ply was totally destroyed.
MY FIX is documented below, in the pictures. I took heavier lite ply and made six additional ribs and braced the factory ribs on each side. I then cut mounting blocks from YES....3/4 inch construction grade ply wood!! And on top of the ply wood, hardwwod engine mounting rails. This was installled in the wing with a liberal amount of epoxy. Needless to say I have had numerous hard landings since then and the gear legs bend but those mounts are not coming out of the wings. I would also suggest getting larger wheels and better quality retracts since you have to cut the wing apart anyway. The wire in the gear legs is of poor quality and bends very easy. Other than that this plane is fun to fly and SCREAMS with a ST .75!

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by arcticflyer -- 9/12/2007 5:46:53 PM >
       Post #: 1

RE: P-51Owners-Landing Gear Caution! - 9/12/2007 6:53:24 PM   
opjose



Posts: 5774
Joined: 11/26/2005
From: Poolesville, MD, USA
Status: offline 		Yup I went through the same thing with the Bobcat .52.

I purposely went with the stock setup w/o changing anything to see how well it would hold up as it comes out of the box... Mistake.

The gear popped out on a bounce that the plane should have been able to handle.

Fortunately it was an easy fix with no major damage. Even the repair is undetectable....


I would recommend at the VERY VERY least, checking the existing blocks to make sure that they are properly epoxied in place by lightly prying under the mounting blocks with a screwdriver, to see if they pop out from the underlying supports.

If so re-epoxy back in and then in either case LIBERALLY apply 30 minute epoxy on all exposed wood areas around the gear mounting blocks.

Better yet add a few pieces of ply to the existing blocks and supports to re-inforce while you are at it.

While you've gone one better on your fix, merely adding a bit more wood at the junction points on the existing wood helps a lot.

This adds very little actual weight but GREATLY improves the gear area's ability to withstand abuse.


A very very simple fix/upgrade that should be done by everyone building any ARFs.

----

Nitroplanes

Please see about making the gear area more sturdy. This should not affect your manufacturing costs, but would help the purchaser and improve your plane's reliability far over competing brands ( that also overlook these areas... even the "big boys" do so! ).

Don't worry about adding a little weight... I'll take strength over a few ounces any day.




< Message edited by opjose -- 9/12/2007 6:56:24 PM >

_____________________________

-
Build em'', fly em'', crash em'' and build more.

(in reply to arcticflyer)
       Post #: 2

RE: P-51Owners-Landing Gear Caution! - 9/13/2007 9:42:10 PM   
Glacier Girl



Posts: 6958
Joined: 7/9/2004
From: SomewhereIn, PA, USA
Status: offline 		well mine is kinda similar, I have the big P47. The bracing held up fine, the retracts didn't.
On take off. Both wires snapped off in the retracts, as she was running down the strip, found they were only in approx 1/8", in the retract body. Plowed approx a 20-25 foot set of ditches when they let go.
But the Jug lived up to her name, some scrapes on the belly pan, and didn't even break the 4 blade.
Will be yanking them out and installing better ones, soonest.

_____________________________

"The Missing Man Formation"
Looking heavenward you cannot help but shed a tear...mornful...lonesome...a hole that screams out almost as loudly as the roar of the engines that pass over head.

(in reply to opjose)
       Post #: 3

RE: P-51Owners-Landing Gear Caution! - 9/13/2007 10:19:16 PM   
Jazzy



Posts: 1106
Joined: 1/8/2002
From: Erie, PA, USA
Status: offline 		Something that may help you guys is increasing the angle the gear come down at. I was sick and tired of bending gear back and replacing them so I managed this fix:
Place two small washers or a 1/16-3/32" (1-3mmm) shim between the gear housing and the mounting block on the trailing edge of both gears. This will angle the gear forward slightly when down so that more of the stress is transferred into the wing as translational strain instead of the existing shearing force.
Here are some pics of the landing gear of my WM SuperChippy with the mods described above:


Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by Jazzy -- 9/13/2007 10:38:58 PM >

_____________________________

Aww $#!^.... I left the )@#& transmitter at home!

(in reply to Glacier Girl)
       Post #: 4

Page:   [1]
All Forums >> RC Airplanes >> ARF or RTF >> NitroModels Support >> P-51Owners-Landing Gear Caution!
Page: [1]





Jump to:


Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Member Video Posts | RCU Video Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America

Kaango.com Classifieds

0.609RCU1