|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

02-10-2018, 07:39 PM
|
|
|
|
Join Date: Feb 2007
Location: Mpumalanga, South Africa
Posts: 1,065
|
|
When I fitted the SB plate, I had great difficulty getting the bolt in. I finally realised that the "top hat" had not gone fully down on its stem. A technical tap fixed it.......
__________________
Paul
Mercy Air, White River FAWV
RV-10 ZU-IIZ - "Zeus"
Building Bearhawk Bravo - RV-18 not available
2019 Donation Made
|

02-11-2018, 07:44 PM
|
|
|
|
Join Date: Aug 2005
Location: Atlanta, GA
Posts: 4,219
|
|
Quote:
Originally Posted by paul330
When I fitted the SB plate, I had great difficulty getting the bolt in. I finally realised that the "top hat" had not gone fully down on its stem. A technical tap fixed it.......
|
That technique came in handy for me too. I'd have sworn it was seated, but no.
Thanks for the tip.
__________________
Kyle Boatright
Marietta, GA
2001 RV-6 N46KB
2019(?) RV-10
|

05-03-2018, 09:38 AM
|
|
|
|
Join Date: Mar 2018
Location: Snead Island, Florida
Posts: 205
|
|
Nosewheel leg slop
Quote:
Originally Posted by Paddy
I still had considerable play in the nosegear leg after properly compressing and preloading the elastomer discs. This turned out to be because of the sloppy fit of the VA 143 ans VA144 bushings in the nose gear link and engine mount weldments. I ended up turning some new bushings that fit better but Vans also sells oversize bushings to fix this problem. The VA143 bushing fit was poor enough to make me think the elastomers were loose at first because of the vertical play in the gear leg.
|
Paddy, I wish I had seen this post before I bought all three bushings new from Vans only to find out they were the same size as the old ones (no wear) There is still vertical slop in the nosegear leg from the loose fitting bushings. This movement adds a pounding effect to the bolt with each landing that is transferred to the weakest link, the welded on bracket that attaches all this to the nosegear leg. It will eventually elongate the holes requiring welding or replacement of the gear. Did someone say that Vans has oversized bushings that actually fit properly? Why would they still use the undersized ones at all?
Mark, new RV-10 owner.
|

05-03-2018, 09:46 AM
|
 |
|
|
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,035
|
|
Quote:
Originally Posted by MConner
Paddy, I wish I had seen this post before I bought all three bushings new from Vans only to find out they were the same size as the old ones (no wear) There is still vertical slop in the nosegear leg from the loose fitting bushings. This movement adds a pounding effect to the bolt with each landing that is transferred to the weakest link, the welded on bracket that attaches all this to the nosegear leg. It will eventually elongate the holes requiring welding or replacement of the gear. Did someone say that Vans has oversized bushings that actually fit properly? Why would they still use the undersized ones at all?
Mark, new RV-10 owner.
|
Do you know for sure that the sockets the bushings go in haven't worn at all?
They should be lubricated occasionally.... maybe yours never have been.
There is also a tolerance to both parts (the socket and the bushing). Add to that a slight amount of wear and you can have what appears to be a lot of play if you take into account the long length of the gear leg.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.
Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
|

05-03-2018, 08:39 PM
|
|
|
|
Join Date: Jan 2018
Location: Magnolia, TX
Posts: 14
|
|
Play in new nose gear
I have play in my nose gear bushings and they have never been down a runway. I am having a friend who owns a machine shop make me bushings with very close tolerance.
|

05-03-2018, 08:59 PM
|
 |
|
|
Join Date: Nov 2006
Location: Waco, Texas
Posts: 1,658
|
|
Kyle,
Use a ratchet strap between the nose gear and your motor mount or possibly even over the top of the motor (if you have a decent spot to put load on it without damaging anything). With a few cranks on the strap, you can get enough compression to slide the bolt through.
Phil
|

05-04-2018, 09:28 AM
|
|
|
|
Join Date: Jun 2010
Location: Portland, OR
Posts: 337
|
|
Slop
I just did my condition inspection and have the slop from the VA-144 bushing. For me, it appears to be the pilot side bushing since the play is vertical and to the passenger side. I spoke to Vans about this and they could only give me specs on the minimum and maximum difference between the bushing outer diameter and weldments inner diameter. For reference, here are the numbers so you can check yours against these:
Max difference between OD of bushing and inner is 0.016?, minimum of 0.004?
I?m probably going to order the oversized bushing and have a machine shop turn it down.
__________________
David Halmos
RV-10
Flying - 570+ hours
Portland, OR
|

05-04-2018, 09:49 AM
|
 |
|
|
Join Date: Jul 2008
Location: Prosper, TX
Posts: 373
|
|
Bushings
I think what we have here is a question of serviceable vs optimal in terms of fit. I would guess that primary reason the original bushings provided with the kit are somewhat undersized is to account for production tolerances in the weldment socket. My observation was that that socket within which the bushing fits isn't perfectly round, some are more round than others and none of them are reamed after welding, so there's always going to be a variance in fit (and wear for that matter) because of that. An undersized bushing will fit them all without having to up the tolerance on the weldment. In my plane, the slop was more than I was comfortable with, so I made my own bushings to improve the fit. There's still clearance for the lubricant interface, but the clunking in the nosegear when lightly loaded is greatly reduced (as is the impulse loading that accompanied the clunking). Incidentally, I only replaced 2 of the 3 bushngs, the 3rd was close enough to leave it alone. For what it's worth, I also replaced some (not all) of the bushings in the flight control linkage because of the same variance in fit.
__________________
RV-10 N415JS
Slow build kit #40874
Homebuilt Kit Champion Oshkosh 2019
Atlantic crossings: 2
|

05-04-2018, 10:07 AM
|
 |
|
|
Join Date: Jul 2008
Location: Prosper, TX
Posts: 373
|
|
Ratchet Strap
It has been suggested a number of times to use a ratchet strap to pull the nose gear up to compress the elastomer discs and insert the top cap bolt. This makes sense, but the amount of compression applied can very easily be overdone (ratchet straps can be quite powerful!). Consider that if you want the maximum amount of travel and cushioning that was designed into the system, you'll want to compress the elastomers just enough to eliminate free play and no more. In my build, there was easily be enough compression on the discs with the normal weight of the engine plus a moderate pull down on the prop by a helper to get the bolt in. If there's more force than that required, there might be too many washers in there, especially after installing the elastomer plate doubler from the bulletin... Of course if you don't have a moderately calibrated helper, a strap might be a good option ;-)
__________________
RV-10 N415JS
Slow build kit #40874
Homebuilt Kit Champion Oshkosh 2019
Atlantic crossings: 2
|

05-04-2018, 07:56 PM
|
 |
|
|
Join Date: Nov 2006
Location: Waco, Texas
Posts: 1,658
|
|
Don?t over think it. Just do it and move on.
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 06:36 AM.
|