REFLECTOR: Belleville washers

Sat Jul 4 22:58:32 CDT 2009

I had a terrible landing yesterday. Alex and I were going up to Oklahoma to see Noel's project after a stop in Fairview, OK to check on a Sonerai project. Alex was riding up front and I forgot to add 5 knots to the touch down speed because of the extra weight up front.  Plus, the winds were gusting and I should have added another 5 knots for that. Instead, I was under 75 knots and still a few feet in the air when the wind changed and the plane just fell out of the sky onto the runway landing on all 3 legs simultaneously. The airport manager was watching us land, and after seeing the airplane fall onto the runway he was sure he was going to have to drag us to a hangar. I'm sure that if I'd had a metal nose strut it would have bent or broken.

I don't know how much damage there is to my Cozy nose strut. The torsional wraps were cracked on both sides of the strut, and it looked like there may have been some small delaminating cracks in the strut itself. I won't know until I get it off and remove the torsional wraps. But the strut was still very strong. It could still pick the airplane up from the kneeling position, and I figured that was more stress than it would see during a normal landing. So we aborted our leg to Noel's house and headed for home with Alex riding in the back seat.  After a smooth landing in Denton to drop Alex off and another smooth landing, I was home. 

The silver lining is that I learned just how tough that fiberglass nose strut is, not to mention the fiberglass main gear. The Velocity puts an extra 100 lbs on the nose strut compared to a Cozy, and I've had a question in my mind about whether it was strong enough. As long as I can keep the airplane from falling on the runway, I think it's going to be just fine.

Doug Holub
N2980W, Standard FG
  ----- Original Message ----- 
  From: John Youngblood 
  To: Velocity Aircraft Owners and Builders list 
  Sent: Saturday, July 04, 2009 7:21 PM
  Subject: Re: REFLECTOR: Belleville washers

  Terry,

  I'm going to a castle nut and cotter key in lieu of the nylon nut.  I had significant shimmy on a landing in April and broke the strut at the bottom of the "taco" weld.  The incident caused a hole in my fuselage, one in the wing and ground down my nose substantially.  The nut came loose after three flights.  I'd recommend checking it before every flight.

  Further investigation found the strut had not been heat treated after welding the gussets (tacos) on.  Rockwell hardness around the weld joints was 57 on the "C" scale.  The rest of the strut was 42!  I understand a 57 hardness on 4130 steel is "glass brittle".  You may want to check the heat treat of your strut near the welds.

  I understand, if you always have good landings and experience very little shimmy, an improperly stress relieved NLG strut will probably be ok.

  John

  On Jun 20, 2009, at 3:50 AM, Terry Miles wrote:

    John,

    Thanks so much for volunteering that.  I recall that they went in originally smooth, primed and un-lubed.  The problem I have is adjusting the big nyloc to setting that is neither too loose nor too tight.  A bit of grease seems to increase the torque range tolerance.   The prime coat of paint is long since rubbed off and I thought the rust was part of my culprit.  

    If I were to say, it is steering problems I have and not so much shimmy problems.  I have an XLRG.  The only shimmy I see in when on the brakes in the latter half of the roll out, and then only when there is more wgt on the nose wheel from having someone in the right seat.  I am tempted now to take my 1/7/8 (or whatever size it is) end wrench over to the local welding shop and have then make a 1/2 fitting on it to fit my torque wrench.  The fish-scale-as-tq-wrench method is not working for me…and the end of wrench is so fat I can only get a few degrees of bolt rotation at a time before it hit the forks.  

    So people know, there are several different nose leg assemblies in the field with differing washer count.  Were I to add a nylon washer and not remove any steel washers, it would have to be in the thinner side.  As it is, I barely have 3 threads showing.  

    Terry

    From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of John Youngblood
    Sent: Friday, June 19, 2009 18:18
    To: Velocity Aircraft Owners and Builders list
    Subject: Re: REFLECTOR: Belleville washers

    Terry,  The idea of Belleville washers is to develop turning friction to subdue shimmy.  You may want to wipe off the grease in order for the washers to transfer torque.

    John

    On Jun 19, 2009, at 2:04 PM, Terry Miles wrote:

    Jeff

    Whatever you got.  1/16th or so?  This is out of sequence some, but I have been removing, polishing off corosion, regreasing (just stock marine grease) and adjusting the tq to my bellvues on about a quarterly basis.  If you have a better mousetrap I'd be interested that's all.   

    Terry

    From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of Jeff Howell
    Sent: Thursday, June 18, 2009 10:24
    To: reflector at tvbf.org
    Subject: Re: REFLECTOR: Belleville washers

    I may still have a few made I will have to check. I made them in different thicknesses. what thickness are you looking for? Jeff

----------------------------------------------------------------------------

    From: terrence_miles at hotmail.com
    To: reflector at tvbf.org
    Date: Wed, 17 Jun 2009 19:31:12 -0500
    Subject: Re: REFLECTOR: Belleville washers

    Jeff,

    Could I talk you into making a set for me?  I'd gladly trade for free banjo lessons or $5 or whatever plus shipping.

    Terry Miles

    From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of Jeff Howell
    Sent: Wednesday, June 17, 2009 17:29
    To: reflector at tvbf.org
    Subject: Re: REFLECTOR: Belleville washers

    I ordered some 2 1/2" round stock on line and opened up a hole to the right dia. using a lathe. It works great. 

----------------------------------------------------------------------------

    Date: Tue, 16 Jun 2009 14:19:50 -0700
    From: ajlz72756 at yahoo.com
    To: reflector at tvbf.org
    Subject: Re: REFLECTOR: Belleville washers

    Where did you get the nylon sheet stock that you made the washers from and how many did you use?

    Andy Ellzey

----------------------------------------------------------------------------

    From: Jeff Howell <jeffreyhowell at hotmail.com>
    To: reflector at tvbf.org
    Sent: Tuesday, June 16, 2009 2:07:49 PM
    Subject: Re: REFLECTOR: Belleville washers

    I found that a combo of a home made nylon washer and a nose wheel lock makes a great addation to any velocity. no nose wheel shimmy and awsome steering (taxi) on the ground...Jeff

----------------------------------------------------------------------------

    From: johnt at comp-sol.com
    To: reflector at tvbf.org
    Date: Tue, 16 Jun 2009 12:25:25 -0500
    Subject: REFLECTOR: Belleville washers

    I have the 'thin' belleville washers (with spacer) - and plan on purchasing a new washer kit from the factory, but I thought someone had successfully been using SS washers - and had suggested McMaster as a source...?

    John

----------------------------------------------------------------------------

    Insert movie times and more without leaving Hotmail®. See how. 

----------------------------------------------------------------------------

    Lauren found her dream laptop. Find the PC that’s right for you.

----------------------------------------------------------------------------

    Lauren found her dream laptop. Find the PC that’s right for you.

    _______________________________________________

    To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

    Visit the gallery!  www.tvbf.org/gallery

    user:pw = tvbf:jamaicangoose

    Check new archives: www.tvbf.org/pipermail

    Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

    _______________________________________________
    To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

    Visit the gallery!  www.tvbf.org/gallery
    user:pw = tvbf:jamaicangoose
    Check new archives: www.tvbf.org/pipermail
    Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

------------------------------------------------------------------------------

  _______________________________________________
  To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

  Visit the gallery!  www.tvbf.org/gallery
  user:pw = tvbf:jamaicangoose
  Check new archives: www.tvbf.org/pipermail
  Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20090704/565a0129/attachment-0001.htm>