Matronics Email Lists :: View topic - Trike nose wheel castor spindle and yoke failure. Europa Fly

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Trike nose wheel castor spindle and yoke failure. Europa Fly

Matronics Email Lists Forum Index -> Europa-List

View previous topic :: View next topic

Author Message

g-iani(at)ntlworld.com
Guest

Posted: Fri Apr 17, 2009 6:28 am Post subject: Trike nose wheel castor spindle and yoke failure. Europa Fly

Bob



 	  Quote: 	
		   Do you mean your bird specifically or in the fleet generally


	


Our bird.  I was aware of the discussion re your accident two years ago.



 	  Quote: 	
		   The factory did load tests and gave assurances as to the adequacy of the

arrangement.
	




As far is I am aware what the factory tested was the adequacy of the roll

pin to retain the spindle.  What is called into question this time is the

bending of the spindle.



 	  Quote: 	
		   simple load tests do not represent real time operation and because of the

prising action of the friction assembly the stresses can far outweigh the
	


dead weight factors.



I agree with you here.  On the three examples I have examined there is

evidence of loads on the roll pin that I would not have expected.  This is

on the forward lower side and may compressed the casting.  This marking

indicates stress but far below what would be required to shear the pin.



 	  Quote: 	
		   BTW the application of Loctite was part of the original assembly procedure

anyway.
	




That is not what David Person (who makes the unit) said.  The three I have

examined did not use Loctite or similar.



 	  Quote: 	
		   The solution you proffer


	


I am reporting what David Person is now doing.  I believe this is an

improvement and I have no evidence to suggest a second roll pin is needed.



 	  Quote: 	
		    These forces "out of vertical plumb" also go to cause the prising/opening

action of the friction device against the
	


castellated adjustment nut holding the whole assembly together.



Basically I agree with this analysis.  As I understand it, it is this action

which is allowing the bending to occur.  I think we have very limited

understanding of the loads applied to the components in the real world of

potholes and wheelbarrow landings.



G-IANI has damping grease applied to the friction plate.  As a result the

castellated nut does not need to be very tight to provide the necessary

damping friction.  Under shock loads this means the spindle can move a short

distance vertically against the spring washers.  I have speculated that this

may be what allows the bending to occur.  Taking this to its logical

conclusion, it would be best to eliminate the spring washers.  The question

is how to do this and provide and maintain the anti shimmy damping required.

So:-

1) The point of may article was to prompt owners to keep a close watch on

their nose wheel.

2) If there a better man/woman out there, who can come up with an improved

design for the nose wheel, I am sure we will be pleased to hear from them.

What we want is proper trailing link springing, controllable anti shimmy

damping, no weight increase etc.

PS) The longer spindle does not have a Mod number at present but it probably

should have.  I will discuss this with Roger when I have time.

Ian Rickard G-IANI XS Trigear, 250 hours

Europa Club Mods Rep (Trigear)

e-mail mods(at)europaclub.org.uk   

   or direct g-iani(at)ntlworld.com

- The Matronics Europa-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List

craigb(at)onthenet.com.au
Guest

Posted: Fri Apr 17, 2009 3:21 pm Post subject: Trike nose wheel castor spindle and yoke failure. Europa Fly

I have come in on the end of this conversation. From the descriptions and

examination of the nose gear

yoke etc, am i right you are all referring to the shaft in the yoke being

pulled out the top of the fork that

holds the wheel. There is no mention of any work needed to fix this issue on

the europa site, I can see how

a wheelbarrow landing could create such loads.  Could some one point me in

the right direction for the orginal issue.



thanks



craig

VH-XSV

--

- The Matronics Europa-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List

ptag.dev(at)tiscali.co.uk
Guest

Posted: Sat Apr 18, 2009 1:51 am Post subject: Trike nose wheel castor spindle and yoke failure. Europa Fly

Hi!  Craig.

I should say I was the first to experience this problem and I'm not

ashamed to admit, it had a fair share of wheel barrow jobs. Firstly you

need to regularly inspect the castor spindle fixing in the aluminium

nose wheel yoke/stirrup casting. Unfortunately a nose wheel spat must be

removed to do this adequately. If the castoring facility needs regular

tightening you will probably have the problem. If the said castor

spindle is not plumb into the yoke, either bent or leaning backwards,

you need a new spindle and may need a new yoke. My yoke compressed

behind the spindle and I now know that the miniscule gap at the front of

the friction device is indicating a problem further down.

My fix was to have a 1" extended spindle made to project 1" further into

the yoke. I utilize a new roll pin in my new yoke AND a second roll pin

1" below the original but 180 deg out of alignment with the first. All

suitably loctite applied. 

ON reflection if I did this again I would have the entire spindle solid

instead of bored. ( I accept that the core of the spindle does nothing

to improve the bending stress but it does facilitate better continuity

of hole for applying the blessed roll pins)

I also use the friction grease on the friction damper and to date the

fix has worked satisfactorily.

Please note that any over lubrication of the pivot area will migrate

through the rubber "o" ring mod and so lubricate the friction damper

needing still more adjustment /tension applied to the castellated nut

and bingo you are on a fools errand tightening the nut still further to

get friction and so pulling on the existing inadequate roll pin.

The Europa Flyer Mag. contains an item on this problem but still

advocates only one roll pin and damn loctite on their own!

Regards

Bob Harrison G-PTAG (going where supposedly none went before !)



--

- The Matronics Europa-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List

craigb(at)onthenet.com.au
Guest

Posted: Sat Apr 18, 2009 3:05 am Post subject: Trike nose wheel castor spindle and yoke failure. Europa Fly

thanks for that bob, I have some of the anti-shimmy grease, and intended to

run it only

on the friction surfaces, not pumping the thing full as the manual suggests.

being aware of

a problem you dont know exist is a good start to fixing it. One thing my

flight instructor always

drilled me on constantly was "protect the nose wheel" most landings where he

was present he would

insist on me keeping the nose wheel off the ground as long as possible,

balancing the A/C on

just the main gear with the elevators. Hopefully his insistance will serve

me well when my baby flys.



regards and good building



craig



Do Not Archive



--

- The Matronics Europa-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List

ptag.dev(at)tiscali.co.uk
Guest

Posted: Sat Apr 18, 2009 3:52 am Post subject: Trike nose wheel castor spindle and yoke failure. Europa Fly

Craig, I would suggest that the manual requests to fill the spindle/bush

void with lubrication grease otherwise one side of the grease nipple

will not be lubricated.  As you say only use the friction grease on the

friction surfaces.

BTW I don't profess to be an authorizing agent !

Regards

Bob H 



--

- The Matronics Europa-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List

garrys(at)tampabay.rr.com
Guest

Posted: Sat Apr 18, 2009 4:27 am Post subject: Trike nose wheel castor spindle and yoke failure. Europa Fly

With no disrespect to anyone, it baffles me as to how many Europa pilots 

continue to land nosewheel first (wheelbarrow).  The first thing you learn 

in basic flight landing training is to hold the nosewheel off for as long as 

you can, until the elevator looses the power to hold it up.  The Europa 

trigear is so easy and forgiving it practically lands itself.  In 45 years 

of flying I've never touched down the nosewheel first.  Can someone explain 

to me how this keeps happening?  Again, I mean no disrespect to 

anyone....I'm just wondering if there's something I'm overlooking here.



Garry Stout

914 Trigear

---

- The Matronics Europa-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List

ptag.dev(at)tiscali.co.uk
Guest

Posted: Sat Apr 18, 2009 1:05 pm Post subject: Trike nose wheel castor spindle and yoke failure. Europa Fly

Garry it's like landing gear up! There's those that's done it and those

that are going to do it ! Sooner or later some mysterious gust of wind

will instill a bounce or some unexpected happening and you will get

caught out.

I can assure you the ones I have done were not by intent.

Probably now you have said how difficult it is to do one you may have

one destined for you, watch out !

Regards

Bob Harrison G-PTAG



--

- The Matronics Europa-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List

Display posts from previous:

	Matronics Email Lists Forum Index -> Europa-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum