---------------------------------------------------------- RV9-List Digest Archive --- Total Messages Posted Tue 09/28/04: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:11 AM - Nosewheel shimmy (Dale Larsen) 2. 12:17 PM - Re: Nosewheel shimmy (Clay R) 3. 01:39 PM - Re: Nosewheel shimmy (fcs@jlc.net) 4. 02:28 PM - Re: Nosewheel shimmy (Dale Larsen) 5. 05:05 PM - Re: Nosewheel shimmy (DThomas773@AOL.COM) 6. 06:06 PM - Re: Nosewheel shimmy (Bob) 7. 06:29 PM - Windshield Frame (Douglas A. Fischer) 8. 09:37 PM - Re: Nosewheel shimmy (Albert Gardner) ________________________________ Message 1 _____________________________________ Time: 11:11:26 AM PST US From: "Dale Larsen" Subject: RV9-List: Nosewheel shimmy --> RV9-List message posted by: "Dale Larsen" All, I have a problem with my 9-A nosegear. On landing, there is a shimmy in the vertical direction. This is not noticable to the pilot, but observers have commented about it. Anyone else have this problem? Thanks, Dale ________________________________ Message 2 _____________________________________ Time: 12:17:14 PM PST US From: Clay R Subject: Re: RV9-List: Nosewheel shimmy --> RV9-List message posted by: Clay R I have a feeling my nose gear is doing this to some degree, although I can't feel anything. I always keep the nose gear off the ground as long as possible on rollout. My hypothesis is that the nose wheel doesn't roll freely all the way around... there is a point in the rotation with more resistance that causes the whole gear to move back and forth. My nose wheel doesn't "spin" freely when I take the weight off of it. Should it? --clay --- Dale Larsen wrote: > --> RV9-List message posted by: "Dale Larsen" > > > All, > > I have a problem with my 9-A nosegear. On landing, > there is a shimmy in the > vertical direction. This is not noticable to the > pilot, but observers have > commented about it. > > Anyone else have this problem? > > Thanks, > > Dale > _______________________________ Declare Yourself - Register online to vote today! http://vote.yahoo.com ________________________________ Message 3 _____________________________________ Time: 01:39:52 PM PST US From: "fcs@jlc.net" Subject: Re: RV9-List: Nosewheel shimmy --> RV9-List message posted by: "fcs@jlc.net" First, consider how the nose gear is designed. What other way is it going to move? Secondly, make sure your onlookers are not confusing wheel pant movement with gear leg movement. If you don't feel it, chances are its just some small amount of wheel pant movement. Finally, make sure your nose gear leg fits snugly into the engine mount receptacle. If there is play between the gear leg and tube, you can wrap a feeler gauge blade (find the one that fits best with weight off the wheel) around the gear leg to take up the slack and secure it with a bit of silicone sealer around the leg. Regarding free turning nose wheels. This bugs the crap outta me. Yes our wheels should spin freely without sticky spots. But the design of the Cleveland wheel is such that you cannot tighten the front axle without causing bearings to bind. It should have had a machined spacer and shims or used straight bearings instead of tapered bearings. Bogus design... Because we cannot tighten the front axle bolt, and the axle bolt is the primary mounting method for the wheel pant, this leads to shimmying wheel pants, binding bearings, and scored nose gear forks. I just had a nose wheel go flat (just before takeoff fortunately) and when I removed the wheel, there was clear evidence that the spacers were spinning against the nose fork and on the axle bolt. Not good. I know others have drilled and tapped small screws to prevent the spacers from spinning, but the real fix would be a different front wheel. In short,,, don't worry about shimmy if you don't feel it, but keep an eye on your front axle bolt. Gary ________________________________ Message 4 _____________________________________ Time: 02:28:01 PM PST US From: "Dale Larsen" Subject: Re: RV9-List: Nosewheel shimmy --> RV9-List message posted by: "Dale Larsen" Gary, I'm flying without pants (on the gear that is...) and the gear fits snugly in the socket. I have watched it shimmy myself, when my buddy landed it. It looks like the front wheel is out of round (which it isn't). It moves 1 to 1-1/2 inches at about a 3 Hz rate. Maybe the wheel is out of balance? Dale ----- Original Message ----- From: Subject: Re: RV9-List: Nosewheel shimmy > --> RV9-List message posted by: "fcs@jlc.net" > > > First, consider how the nose gear is designed. What other way is it going > to move? Secondly, make sure your onlookers are not confusing wheel pant > movement with gear leg movement. If you don't feel it, chances are its > just some small amount of wheel pant movement. Finally, make sure your > nose gear leg fits snugly into the engine mount receptacle. If there is > play between the gear leg and tube, you can wrap a feeler gauge blade (find > the one that fits best with weight off the wheel) around the gear leg to > take up the slack and secure it with a bit of silicone sealer around the > leg. > > Regarding free turning nose wheels. This bugs the crap outta me. Yes our > wheels should spin freely without sticky spots. But the design of the > Cleveland wheel is such that you cannot tighten the front axle without > causing bearings to bind. It should have had a machined spacer and shims > or used straight bearings instead of tapered bearings. Bogus design... > Because we cannot tighten the front axle bolt, and the axle bolt is the > primary mounting method for the wheel pant, this leads to shimmying wheel > pants, binding bearings, and scored nose gear forks. I just had a nose > wheel go flat (just before takeoff fortunately) and when I removed the > wheel, there was clear evidence that the spacers were spinning against the > nose fork and on the axle bolt. Not good. I know others have drilled and > tapped small screws to prevent the spacers from spinning, but the real fix > would be a different front wheel. > > In short,,, don't worry about shimmy if you don't feel it, but keep an eye > on your front axle bolt. > > Gary > > ________________________________ Message 5 _____________________________________ Time: 05:05:50 PM PST US From: DThomas773@AOL.COM Subject: Re: RV9-List: Nosewheel shimmy --> RV9-List message posted by: DThomas773@aol.com Hey Guys, you solve this problem easily by replacing the thing with a tail wheel. Dennis Thomas RV-9 126 hours ________________________________ Message 6 _____________________________________ Time: 06:06:40 PM PST US From: "Bob" Subject: RE: RV9-List: Nosewheel shimmy --> RV9-List message posted by: "Bob" Yelp but why go backwards???? -----Original Message----- From: owner-rv9-list-server@matronics.com [mailto:owner-rv9-list-server@matronics.com] On Behalf Of DThomas773@AOL.COM Subject: Re: RV9-List: Nosewheel shimmy --> RV9-List message posted by: DThomas773@aol.com Hey Guys, you solve this problem easily by replacing the thing with a tail wheel. Dennis Thomas RV-9 126 hours ________________________________ Message 7 _____________________________________ Time: 06:29:18 PM PST US From: "Douglas A. Fischer" "RV Matronics List" Subject: RV9-List: Windshield Frame on mail5 --> RV9-List message posted by: "Douglas A. Fischer" I visited a local builder who had fabricated an aluminum panel at the base of the windshield and along the canopy frame on both an RV-6A and -7A. It looked very nice and neat and he said he did it because he didn't like fiberglass (I understand that!). It was screwed in place to both the cowl and the screen and sealed with silicone. Has anybody else done this? I'm considering doing this because of the neat appearance and also I think replacing a cracked screen would be infinitely easier. Any thoughts out there in RV Land? Doug Fischer 90706 Wings Jenison, MI ________________________________ Message 8 _____________________________________ Time: 09:37:35 PM PST US From: "Albert Gardner" Subject: Re: RV9-List: Nosewheel shimmy --> RV9-List message posted by: "Albert Gardner" I've had the same problem from time to time. Once, when I landed, the nose gear shadow was just in front of the wing and I could see the gear was moving fore and aft. When it does this I can feel some vibration. At first I thought it started after the nose gear first touched but now it's clear it starts when the mains touch and the nose wheel is still off the ground. It seems to be affected by tire pressure and axel bolt tightness but I don't see why since it starts before the nose wheel touches. So now I just keep the nose gear off the ground as long as possible. Why, yesterday, I kept it off until I got out and tied it down on the ramp! Albert Gardner RV-9A 872RV Yuma, AZ