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SB Nose Wheel Report
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Mauledriver(at)nc.rr.com
Guest

Posted: Mon Sep 22, 2014 10:03 am Post subject: SB Nose Wheel Report

Regarding the flexing of the plate; having gotten rather intimate with 

my cracked plate, it's pretty clear to me that the plate is being 

"pounded" in 1 direction - that is from donut side.  The failure and the 

cracking is because the center of the plate is unsupported and subjected 

to being deformed.  In my opinion, it is not from repetitive bending 

fatigue.... but I'm not an engineer, so.



I wouldn't worry about the hat banging on the assembly on the rebound.



I would make sure that there is no play when the wheel is unloaded. Even 

if you plan to wait before doing the full SB inspection, it is worth 

unloading the front wheel and checking for play.  If there is play, you 

need to add washers.



Bill "almost ready for the welder" Watson

jdriggs49(at)msn.com
Guest

Posted: Mon Sep 22, 2014 12:19 pm Post subject: SB Nose Wheel Report

Since mine got destroyed when the nose gear leg weld failed, Here is what the new engine mount/ gear leg looks like:



         [img]cid:inlineImage0[/img]

     





 	  Quote: 	
		   Date: Mon, 22 Sep 2014 14:01:20 -0400

 From: Mauledriver(at)nc.rr.com

 To: rv10-list(at)matronics.com

 Subject: Re: Re: SB Nose Wheel Report

 

 --> RV10-List message posted by: Bill Watson <Mauledriver(at)nc.rr.com>

 

 Regarding the flexing of the plate; having gotten rather intimate with 

 my cracked plate, it's pretty clear to me that the plate is being 

 "pounded" in 1 direction - that is from donut side.  The failure and the 

 cracking is because the center of the plate is unsupported and subjected 

 to being deformed.  In my opinion, it is not from repetitive bending 

 fatigue.... but I'm not an engineer, so.

 

 I wouldn't worry about the hat banging on the assembly on the rebound.

 

 I would make sure that there is no play when the wheel is unloaded. Even 

 if you plan to wait before doing the full SB inspection, it is worth 

 unloading the front wheel and checking for play.  If there is play, you 

 need to add washers.

 

 Bill "almost ready for the welder" Watson

 

&gt=============
	


 	  Quote:

IMG_5393.jpg

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gengrumpy

Joined: 07 May 2013
Posts: 131
Location: Tullahoma, TN

Posted: Mon Sep 22, 2014 12:50 pm Post subject: SB Nose Wheel Report

Can you post pics of the weld failure?

Grumpy



Sent from my iPad



On Sep 22, 2014, at 10:18 PM, Danny Riggs <jdriggs49(at)msn.com (jdriggs49(at)msn.com)> wrote:

[quote]   



Since mine got destroyed when the nose gear leg weld failed, Here is what the new engine mount/ gear leg looks like:



         <IMG_5393.jpg>

     





 	  Quote: 	
		   Date: Mon, 22 Sep 2014 14:01:20 -0400

 From: Mauledriver(at)nc.rr.com (Mauledriver(at)nc.rr.com)

 To: rv10-list(at)matronics.com (rv10-list(at)matronics.com)

 Subject: Re: Re: SB Nose Wheel Report

 

 --> RV10-List message posted by: Bill Watson <Mauledriver(at)nc.rr.com (Mauledriver(at)nc.rr.com)>

 

 Regarding the flexing of the plate; having gotten rather intimate with 

 my cracked plate, it's pretty clear to me that the plate is being 

 "pounded" in 1 direction - that is from donut side.  The failure and the 

 cracking is because the center of the plate is unsupported and subjected 

 to being deformed.  In my opinion, it is not from repetitive bending 

 fatigue.... but I'm not an engineer, so.

 

 I wouldn't worry about the hat banging on the assembly on the rebound.

 

 I would make sure that there is no play when the wheel is unloaded. Even 

 if you plan to wait before doing the full SB inspection, it is worth 

 unloading the front wheel and checking for play.  If there is play, you 

 need to add washers.

 

 Bill "almost ready for the welder" Watson

 

=============

 

 

 


	


 		 	   		  

 

[b]

jesse(at)saintaviation.co
Guest

Posted: Mon Sep 22, 2014 12:52 pm Post subject: SB Nose Wheel Report

I have been wanting to make the point that Bill is referring to here. If you have play in your system and lift the plane and hold the nosewheel up and then let it drop, the hat will bang on the plate. During a normal takeoff, however, there would only be a gradual change of pressure from the elastomer pushing on the plate from the bottom with weight on the nose to the hat pressing on the top as the weight comes off the nose. I don't see almost any cases in which the hat would have an opportunity to bang on the plate unless you get to flying speed with the stick forward and then yank it off the runway, but even in that, the force would be fairly gradual. The force on landing, however, especially when landing on a rough surface, would put an immediate force up on the gear and thus the elastomer onto the plate. I'm no engineer, but that is what it sounds like is happening. The elastomer top plate is pressing hard (or banging hard) on the plate and forcing it to bend upward, eventually creating the crack.



Every condition inspection I do on a -10, I make sure to keep the pivot breakout force close to the 26 lbs called for in the plans, and I check the play in the nose gear leg, and add a spacer or two if necessary. I don't think I have ever gotten a plane beyond 3 spacers, but I have gotten several to 3.



As others have mentioned, some do have a noticeable amount of play in the bushings either where the elastomer bar bolts to the gear leg or where the gear leg bolts to the engine mount. I can see how that would wear over time, but the preload on the elastomers I always deal with if there is any.



Jesse Saint

Saint Aviation, Inc.

jesse(at)saintaviation.com

C: 352-427-0285

F: 815-377-3694



On Sep 22, 2014, at 2:01 PM, Bill Watson <Mauledriver(at)nc.rr.com> wrote:



 	  Quote: 	
		   

 

 Regarding the flexing of the plate; having gotten rather intimate with my cracked plate, it's pretty clear to me that the plate is being "pounded" in 1 direction - that is from donut side.  The failure and the cracking is because the center of the plate is unsupported and subjected to being deformed.  In my opinion, it is not from repetitive bending fatigue.... but I'm not an engineer, so.

 

 I wouldn't worry about the hat banging on the assembly on the rebound.

 

 I would make sure that there is no play when the wheel is unloaded. Even if you plan to wait before doing the full SB inspection, it is worth unloading the front wheel and checking for play.  If there is play, you need to add washers.

 

 Bill "almost ready for the welder" Watson

glastar(at)gmx.net
Guest

Posted: Mon Sep 22, 2014 1:23 pm Post subject: SB Nose Wheel Report

Thanks Danny,



so it looks like a doubler welde on or is the whole plate thicker?



Is there as well on the inside an additional ring or is that as before 

(looking from the other side).



Cheers Werner



On 22.09.2014 22:18, Danny Riggs wrote:

 	  Quote: 	
		  



 Since mine got destroyed when the nose gear leg weld failed, Here is

 what the new engine mount/ gear leg looks like:

Dick Sipp

Joined: 11 Jan 2006
Posts: 215
Location: Hope, MI

Posted: Mon Sep 22, 2014 6:31 pm Post subject: SB Nose Wheel Report

Nose gear SB Status: serial number 65, 540 hours and less than 5 grass field 

landings.



No cracks in the mount or free play in the elastomers or pivot points.



I certainly concur with Jesse and the others regarding the need to keep some 

preload on the elastomers with the spacers under the hat.  We started with 

one on the initial installation and added one at around 100 hours.



Dick Sipp



RV-10 540 hours

RV-4 750 hours sold

RV-12 40 hours

--

partner14

Joined: 12 Jan 2008
Posts: 540
Location: Granbury Texas

Posted: Mon Sep 22, 2014 7:27 pm Post subject: SB Nose Wheel Report

My situation similar to Dick's.... 650 hours, about 13 grass field landings, no cracks, no free play, but will probably keep one spacer plus the plate.

Serial # 40636



Don McDonald



        From: Dick &  Vicki Sipp <rsipp(at)earthlink.net>

 To: rv10-list(at)matronics.com 

 Sent: Monday, September 22, 2014 9:30 PM

 Subject: Re: Re: SB Nose Wheel Report

  

 

--> RV10-List message posted by: "Dick & Vicki Sipp" <rsipp(at)earthlink.net (rsipp(at)earthlink.net)>



Nose gear SB Status: serial number 65, 540 hours and less than 5 grass field 

landings.



No cracks in the mount or free play in the elastomers or pivot points.



I certainly concur with Jesse and the others regarding the need to keep some 

preload on the elastomers with the spacers under the hat.  We started with 

one on the initial installation and added one at around 100 hours.



Dick  Sipp



RV-10 540 hours

RV-4 750 hours sold

RV-12 40 hours

--

_________________
Don A. McDonald
40636

Barry

Joined: 16 Sep 2008
Posts: 108

Posted: Tue Sep 23, 2014 12:59 am Post subject: Re: SB Nose Wheel Report

I'm thinking about riveting the doubler to the top most elastomer in the stack to keep the doubler centered and make for easy inspections. I also believe that proper per-load is very important to keep all the parts in the build up free of slack, which could cause the pounding on the plates. What ya think?

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Tue Sep 23, 2014 4:15 am Post subject: SB Nose Wheel Report

I think you will have issues that you don't need. The shock disk is 

bonded together, aluminum on rubber. The only way I think you could 

rivet to it would be with blind, pull rivets of some sort. The heads of 

the rivets would have to be absolutely flush for the doubler to fit 

against the original plate.The doubler is already a snug fit against the 

tubing. I had to lightly file the edges smooth to get it to fit snugly. 

If you are worried about the doubler moving around, use some RTV or 

ProSeal to bond it to the mount. The pre-load is necessary and probably 

your best bet to keep the parts from moving around. I really don't think 

you want to be drilling holes in the doubler, which is steel.

Aluminum rivets into aluminum plate on the shock disk are not going to 

add any strength. The steel strut that the shock disks mount on is going 

to limit lateral movement of the shock disks.  The doubler is held from 

moving laterally by its fit between the steel tubes of the engine mount.



On 9/23/2014 1:59 AM, Barry wrote:

 	  Quote: 	
		   



 I'm thinking about riveting the doubler to the top most elastomer in the stack to keep the doubler centered and make for easy inspections. I also believe that proper per-load is very important to keep all the parts in the build up free of slack, which could cause the pounding on the plates. What ya think?





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=430958#430958

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

flysrv10(at)gmail.com
Guest

Posted: Sat Oct 04, 2014 5:12 am Post subject: SB Nose Wheel Report

Checked mine today and found no cracks.



880 hr flight time and I estimate about 30% of my operation is from my home grass field.

On Sep 19, 2014, at 2:13 PM, Bob Turner <bobturner(at)alum.rpi.edu> wrote:



 	  Quote: 	
		   

 

 Bill points out an alternative means of compliance: buy a new, improved engine mount from Vans.

 Has anyone priced this out? I could not find it on Vans "list".

 

 --------

 Bob Turner

 RV-10 QB

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=430792#430792

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