landing gear piano wire angle    Gallery
View related threads: (in this forum | in all forums)

Logged in as Guest



Users viewing this topic: none
    Search This Thread  
 
Printable Version


AZ Model Aircrafters 1/4 Scale Albatross D.V - RTF
Seller:  Dumb Thumb
Details:   $2,500.00   |  5/16/2013   |  Classified Ad
We will rotate YOUR AD in this spot if you select "Forum Featured" when placing or editing your ad!

All Forums >> RC Airplanes >> Beginners >> landing gear piano wire angle
Page: [1]

Tower Hobbies Get Coupon Codes Brands  
Login
Message << Older Topic   Newer Topic >>
landing gear piano wire angle - 12/31/2012 6:15 AM   
chadxp1


 

Posts: 117
Score: 105
Joined: 2/2/2010
Last Login: 5/24/2013
From: perrysburg, OH, USA
Status: online 		 I was wondering if anyone knew what a good angle to use for my rear landing gear. The plans did not show the landing gear details. Going of pictures they look to be around 45 degrees. I would guess that if this angle was to wide the gear would belly out or flex to much. On the opposite side if the angle was to acute I would not gain any spring or dampining effect. I searched high and low for such information but did not come up with anything. 









Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures
       Post #: 1

RE: landing gear piano wire angle - 12/31/2012 6:42 AM   
Gray Beard


 

Posts: 12554
Score: 314
Joined: 4/21/2003
Last Login: 5/24/2013
From: Hemderson, NV, USA
Status: offline 		The front of the wheel should be about even with the LE and the side angle can be 90 degrees or you can bend in a bit of angle. There is no real fixed rule I have ever heard about for the side angle. All I have ever built and bent are at 90 degrees. They don't really act as shock absorbers.

_____________________________

Drinking and driving are illegal, why do bars have parking lots
Daisy Air Guns, keeping kids off your lawn for 100 year

Hide Signatures

(in reply to chadxp1)
       Post #: 2

RE: landing gear piano wire angle - 12/31/2012 9:04 AM   
JohnBuckner



Posts: 8323
Score: 342
Joined: 12/23/2001
Last Login: 5/24/2013
From: Kingman, AZ, USA
Status: offline 		Chad what you have there is an old standard tricycle gear arraignment using a torsion box setup. All the spring action is from that short length of the gear wires that is in the slots on the wing gear blocks. That is why I cringe every time I see someone fill in those slots with epoxie. The wires must be allowed to spring fore and aft in those slots, that is why it is called a torsion box.

Over the years that design has been an old standard and the angle as noted by GB can be ninety degrees straight down or you can splay them outward as you have done although I would discourage over doing that. The primary reason for splaying the gear outward is not springing but just to acheve a wider track landing gear for perhaps a bit more stability.

John

_____________________________

"Keep your controllines tight"

Hide Signatures

(in reply to Gray Beard)
       Post #: 3

RE: landing gear piano wire angle - 12/31/2012 2:45 PM   
KW_Counter


 

Posts: 1414
Score: 141
Joined: 2/11/2003
Last Login: 5/19/2013
From: Lake County, CA, USA
Status: offline 		John,

What about the angle of the wheels in relationship to the plane?
Here you talk of the angle to ground being 90 degrees.
What angle to the center line of the plane? Pointed in or out?
I have heard this can affect ground handling?

Thanks,
KW_Counter

Hide Signatures

(in reply to JohnBuckner)
       Post #: 4

RE: landing gear piano wire angle - 12/31/2012 4:23 PM   
JohnBuckner



Posts: 8323
Score: 342
Joined: 12/23/2001
Last Login: 5/24/2013
From: Kingman, AZ, USA
Status: offline 		Yes as you know the castor and the chamber angle of the wheels is a continuation of further landing gear geometry but I feel this posters question was more basic than that and perhaps did not understand the actual function of the torsion bar arraingnment of the wing mount wire type gear legs and this type gear can be perfectly straight down from the bottom of the wing or it can be splayed outward a bit as he showed to widen the track a bit.

The actual castor as well as the chamber of the axles themselves (wheels) is of course furthering adventures in the fascinating subject of aircraft landing gear geometry.

John

_____________________________

"Keep your controllines tight"

Hide Signatures

(in reply to KW_Counter)
       Post #: 5

RE: landing gear piano wire angle - 12/31/2012 7:28 PM   
Gray Beard


 

Posts: 12554
Score: 314
Joined: 4/21/2003
Last Login: 5/24/2013
From: Hemderson, NV, USA
Status: offline 		John, that's the first time I have ever heard anyone call them torsion box. Even on the plans I only see them called landing gear blocks? Even in the instructions they just call them the landing gear blocks. Torsion box does explain the operation a bunch better. I have never seen anyone fill them but I have run into a lot of them that are too tight for the wire rendering them inoperable.

_____________________________

Drinking and driving are illegal, why do bars have parking lots
Daisy Air Guns, keeping kids off your lawn for 100 year

Hide Signatures

(in reply to JohnBuckner)
       Post #: 6

RE: landing gear piano wire angle - 12/31/2012 8:46 PM   
goirish



Posts: 5045
Score: 305
Joined: 12/7/2005
Last Login: 5/24/2013
From: Litchfield, MI, USA
Status: offline 		Hey Gene, glad to see you are up and walking around. Have a happy New Year

_____________________________

DX-7,RDS8000. big Bingo,1/4 Scale Cub, SeaMaster 120, Forget the health food, I need all the preservatives I can get

Hide Signatures

(in reply to Gray Beard)
       Post #: 7

RE: landing gear piano wire angle - 12/31/2012 9:22 PM   
JohnBuckner



Posts: 8323
Score: 342
Joined: 12/23/2001
Last Login: 5/24/2013
From: Kingman, AZ, USA
Status: offline 		You don,t see the torsion bar expression much anymore but it was a big deal when that type of gear first appeared in the sixties. Not just the wing mounts either as a great many different trainers have and still use the torsion setup in a gear block down inside the fuselage.

I have run across many both the wing and fuse types where the fellow filled the channels with epoxie, Go figure

John

My recovery is going well and hope the same for you.

_____________________________

"Keep your controllines tight"

Hide Signatures

(in reply to goirish)
       Post #: 8

RE: landing gear piano wire angle - 1/1/2013 12:48 AM   
Gray Beard


 

Posts: 12554
Score: 314
Joined: 4/21/2003
Last Login: 5/24/2013
From: Hemderson, NV, USA
Status: offline 		Thanks Gene, today I'm feeling human again.If we can stay awake long enough I may take the wife over to a hill over looking the strip and drink something with bubbles and watch the fire works?
I have been making my own LG blocks for different size wires for several years now sense I have access to such good table saws It's nice having 10 foot lengths of the stuff on hand. Just never heard it called anything besides LG blocks. Even in the 50s and 60s. Then again, I may have just forgotten, that's happening a lot lately!!

_____________________________

Drinking and driving are illegal, why do bars have parking lots
Daisy Air Guns, keeping kids off your lawn for 100 year

Hide Signatures

(in reply to JohnBuckner)
       Post #: 9

RE: landing gear piano wire angle - 1/1/2013 4:34 AM   
chadxp1


 

Posts: 117
Score: 105
Joined: 2/2/2010
Last Login: 5/24/2013
From: perrysburg, OH, USA
Status: online 		John, you are right. I should have thought this through a little more. I did more research and came across a picture depicting the torsion section of the landing gear. My old car had had torsion springs for the trunk lid, so its basically the same concept. Thanks for clearing this up for me. 

Hide Signatures

(in reply to Gray Beard)
       Post #: 10

RE: landing gear piano wire angle - 1/1/2013 3:31 PM   
KW_Counter


 

Posts: 1414
Score: 141
Joined: 2/11/2003
Last Login: 5/19/2013
From: Lake County, CA, USA
Status: offline 		John,

What I am getting at is simple:
Should we have toe-in or toe-out on our mains? How much?
Do we need to have camber? In or out?
I'm sorry I wasn't clearer on my first post.

Thanks,
KW_Counter

Hide Signatures

(in reply to JohnBuckner)
       Post #: 11

RE: landing gear piano wire angle - 1/1/2013 4:08 PM   
JohnBuckner



Posts: 8323
Score: 342
Joined: 12/23/2001
Last Login: 5/24/2013
From: Kingman, AZ, USA
Status: offline 		Chad thanks and you are welcome.

KW I have always advocated particularly for a taildragger that concerning the wheels castor and chamber if used will provide a little more directional stability.

In other words first castor, the toes of the wheels are not directly in line with the airframe but actually toed in and pointing toward the front of the airplane somewhere in the distance. This is a direct paralell why all automobiles use this exact same trick. I would hesitate to put an exact figure on how much except to say that it only takes a degree or so and enough to just be visually perceptable.

Now the other side to this is the wheels chamber. This is nothing more than the top side of the wheels is actually further apart than the bottoms of the wheels. Another way to describe this is the tops of the wheels are splayed outward more at the top than the bottom of the wheels. Agine this is to provide a bit more directional stability on first contact with the runway. I will make no attempt to explain why simply because I am no engineer.

Now look at photos of most any general aviation full scale airplane in flight in the right angle you can readily see that with the weight off the gear there is substancial positive chamber that I described above. OK during landing at first contact exactly when the most directional stability is desired this positive chamber is at its highest angle and does just that. As weight settles onto the mains this chamber is reduced to the point is only just perceptable when the airplane is at rest on the ground.

While normally our models will not go through as great of chamber changes during landing as a full scale that does not mean we cannot enjoy the directional benefits buy using agine not much more than a degree or so in other words just perceptable.

John

_____________________________

"Keep your controllines tight"

Hide Signatures

(in reply to KW_Counter)
       Post #: 12

RE: landing gear piano wire angle - 1/1/2013 9:53 PM   
kwblake


 

Posts: 320
Score: 110
Joined: 8/24/2009
Last Login: 5/24/2013
From: Gunton, MB, CANADA
Status: offline 		Hey Chad.  Could you post the picture of the torsion box that you found.  I haven't been at this all that long, so I don't know that I have ever seen one.  I always try to learn as much as I can.  You never know when knowledge might come in handy. 



_____________________________

Kevin


Hide Signatures

(in reply to chadxp1)
       Post #: 13

RE: landing gear piano wire angle - 1/1/2013 11:03 PM   
JohnBuckner



Posts: 8323
Score: 342
Joined: 12/23/2001
Last Login: 5/24/2013
From: Kingman, AZ, USA
Status: offline 		KW if you have ever had a low wing airplane with wing mounted main gear then you probably have seen a wing gear block for torsion gear.

Also the longer wire in the photos is wire for a fuselage mounted gear box for torsion type gear just two of them are mounted in a wider slot on the bottom and the short end of the wire is secured through a hole for each.

John



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


_____________________________

"Keep your controllines tight"

Hide Signatures

(in reply to kwblake)
       Post #: 14

RE: landing gear piano wire angle - 1/2/2013 12:17 AM   
VCScott



Posts: 93
Score: 100
Joined: 8/10/2006
Last Login: 5/24/2013
From: Valley Center, CA, USA
Status: offline 		Hey, great subject. I didn't realize there was so much misunderstanding of how wire torque gear worked. This may explain why so many people hate and discard them in favor of stiff fuse mounted gear.
I've found that properly set up they work very well and will take a lot of punishment. I think 90deg is best and farther it's spread out the more stress you put on the upper bend into the gear block.
chadxp1, what plane is that in your photo?
Scott


_____________________________

Ultra Sport Brotherhood #49 Carl Goldberg Ultimate Brotherhood #16Tiger Club #44
WATCH THIS!.............oops.

Hide Signatures

(in reply to JohnBuckner)
       Post #: 15

RE: landing gear piano wire angle - 1/2/2013 9:20 PM   
kwblake


 

Posts: 320
Score: 110
Joined: 8/24/2009
Last Login: 5/24/2013
From: Gunton, MB, CANADA
Status: offline 		Hey John.  Thanks for the clarification.  I guess my Twinstar has a torsion box for the main gear?



_____________________________

Kevin


Hide Signatures

(in reply to JohnBuckner)
       Post #: 16

RE: landing gear piano wire angle - 1/4/2013 12:09 AM   
chadxp1


 

Posts: 117
Score: 105
Joined: 2/2/2010
Last Login: 5/24/2013
From: perrysburg, OH, USA
Status: online 		Scott, I am building an AK Models Simple Flier. I like the way it flys in Real Flight so I bought one. Its pretty cool. Im almost done with the build. I need to cover it yet and a few other things. 

 

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to kwblake)
       Post #: 17

RE: landing gear piano wire angle - 1/4/2013 1:14 AM   
Gray Beard


 

Posts: 12554
Score: 314
Joined: 4/21/2003
Last Login: 5/24/2013
From: Hemderson, NV, USA
Status: offline 		Very cool looking plane, I have never seen one before.

_____________________________

Drinking and driving are illegal, why do bars have parking lots
Daisy Air Guns, keeping kids off your lawn for 100 year

Hide Signatures

(in reply to chadxp1)
       Post #: 18

RE: landing gear piano wire angle - 1/4/2013 3:32 AM   
VCScott



Posts: 93
Score: 100
Joined: 8/10/2006
Last Login: 5/24/2013
From: Valley Center, CA, USA
Status: offline 		Thanks chadxp1, very nice build. It should be a standout at your field. Please post pics when your finished.


_____________________________

Ultra Sport Brotherhood #49 Carl Goldberg Ultimate Brotherhood #16Tiger Club #44
WATCH THIS!.............oops.

Hide Signatures

(in reply to chadxp1)
       Post #: 19

RE: landing gear piano wire angle - 1/5/2013 3:19 PM   
KW_Counter


 

Posts: 1414
Score: 141
Joined: 2/11/2003
Last Login: 5/19/2013
From: Lake County, CA, USA
Status: offline 		John,

Your description of the castor and Chamber was very clear and a big help.

Thanks muchly,
KW_Counter

Hide Signatures

(in reply to JohnBuckner)
       Post #: 20

RE: landing gear piano wire angle - 1/5/2013 3:30 PM   
JohnBuckner



Posts: 8323
Score: 342
Joined: 12/23/2001
Last Login: 5/24/2013
From: Kingman, AZ, USA
Status: offline 		Thanks KW Its always a wonderful feeling is one can help is some small way

John

_____________________________

"Keep your controllines tight"

Hide Signatures

(in reply to KW_Counter)
       Post #: 21

RE: landing gear piano wire angle - 1/6/2013 2:22 AM   
KitBuilder



Posts: 1571
Score: 131
Joined: 2/17/2007
Last Login: 5/22/2013
From: Palm Harbor, FL, USA
Status: offline 		You need a slight outward angle. The torsion box provides fore and afte movement only. The slight outward angle provides shock absorption above what compression of the tires offer. This way you have fore, aft and outward.

_____________________________

Mike -
I was born a pilot... 100 years to late.

Hide Signatures

(in reply to JohnBuckner)
       Post #: 22

RE: landing gear piano wire angle - 1/6/2013 2:20 PM   
Villa



Posts: 1943
Score: 133
Joined: 8/12/2003
Last Login: 5/23/2013
From: Wilson, NC,
Status: online 		I have been bending my own torsion bar type landing gear for many years and would like to point out one serious problem in the method of making the bend in the wire. At first I mearly put the piano wire in my vise and then bent the wire over the jaw with my hand. Well, one day the wire naped; it broke. The break was extreamly jagget!. It could have torn my hand. I was shoked!. I studied the problem and realized that the sharp right angle of my vice jaws was sevearly stressing the piano wire during the bend. I used my Dremmel tool to gring a groove in the vice jaw, that the wire will bend arround, so that the wire will have a "bend radius". That "bend radius" should be equal to the diameter of the wire. I have since made perhapse 100 bends, and not once has the wire broken. I use a special pair of pliers for bending smaller diameter wire, and I also made small grooved in the plier jaws as described above for my vice jaws. I welcome any comments on this method for bending piano wire. By the way, I NEVER heat the piano wire. Plus I always use a leather glove on the hand making the bend on the vice jaw, just in case the wirs snaps.

Hide Signatures

(in reply to chadxp1)
       Post #: 23

Page:   [1]
All Forums >> RC Airplanes >> Beginners >> landing gear piano wire angle
Page: [1]





Jump to:


 
Google 



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

Photo Gallery | Instructor Search | Field|Track|Marina Search

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

SITE MAP!   : :   FORUM RULES

RC Universe is a service of Internet Brands, Inc. Copyright © 2001-2013.

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


1.500RCU1