Nose Gear Mounting

[joeflys]

Hello Everyone - I am new to this forum and have building my Long Ez for about 2.5 years. I am in the St. Paul, MN area. I bought a partially completed project from a previous builder. I have been working on the fuselage and nose section lately. (Fuselage is mostly done, wings and roncz canard done, landing gear mounted. Soon to mount wings, cs spar, and canard to fuselage, then on to strakes and canopy) Anyways, I was working yesterday on preparing to bond the nose tire cover in the fuselage so I temporarily reinstalled the nose strut and tire to check fit, and noticed a couple of things. BTW I have the wilhelmson noselift installed.

1) when the nose gear retracts it very lightly touches the instrument panel. I may be able to slip a piece of paper in between the nose tire and instrument panel, but it would drag on the nose tire. Is this normal? It seems to me with this little clearance there is possibility of getting the tire jammed on the instrument panel. Anyone have any idea how much clearance they have between their tire and instrument panel?

2) The nose gear strut seems to be mounted vertically to the fuselage, but when the tire is down to approximately the down position, the tire seems to be out of vertical by a few degrees. It is noticeable visually, and I havn't measured it. For tire wear and ground steering this concerns me. Obviously I should be shooting for completely vertical on the nose tire, but what should be considered acceptable since the casting is currently already floxed to the end of the nose gear strut.

Any thoughts or suggestions are appreciated.

Joe

[Bill James]

The nose wheel pivot pin should be approximately vertical with the airplane loaded for takeoff.

[Joe Person]

Vertical, when loaded at max gross.  Unloaded, the lower (vertically-oriented pivot shaft) should incline "aft" at the upper end, so as to make around an 85 or so degree angle from horizontal, measured relative to the aft end of the lower part of the lower nose gear components.  This caster angle ensures that the propensity to shimmy is essentially eliminated, all other configurations of the NLG components being correct.  Do NOT accept a pivot angle that is greater than 90 degrees.  This is detailed in the plans.

[joeflys]

Hey Guys- Thanks for the info. I was able to do a little more accurate measurements. The nose tire is out of vertical left to right (ie, the tire is "rolling to the right" with the fuselage vertical. I measured using a bubble (bulls eye) level, and used a digital level over the top of the nose fork bushing, and the digital level says it is .6 degrees off vertical when the bushing is completely in the vertical fore-aft position. Since it is close and would require a lot of work (castings already floxed to nose strut) I am going to wait to see if it gives me any troubles. I have talked to other builders who have a similar situation and said it was a minor annoyance at worst. Besides, with the tire leaning this way, maybe it will help take off performance and keeping it straight on the centerline.

I also had to remove a small section of foam from the instrument panel to allow for tire clearance. Originally the tire was dragging on the back side of the panel when inflated. I didn't like this and thought it could be a possible way to get the tire jammed in the up position. So I overinflated the nose tire to 50 psi, and removed foam until I had approximately 1/8" clearance during the full travel of the nose tire retraction. I am much happier with this.

Another problem I had was the strut cover and nose box limiting the retraction of the nose gear which didn't allow the tire to fully fit up into the wheel well. I think since they were sitting around for 15-20 years since they were purchased they had changed shape significantly anyways. I attempted to make cuts and repairs to the original nose box, but after a few less than ideal itterations, i used foam and duct tape mold release to mold up my own NB, and ended cutting away parts of the strut cover so it would retract fully.... Now once I get those repairs done, the nose gear is getting there... Thanks for the help, and thought I would give everyone some info on what I did to solve those problems.

Joe

[A. Bruce Hughes]

Hi Joe

Check with other people on the tire pressure because I am a Microbiologist.   Micro means
small so I know very little.

50 PSI is written on my tire as the maximum.   However others have said that is the
MINIMUM that you should use or the rubber will slide in relation to the metal and rip
the filling tube off.   NOT good.

Maybe Joe Person will post again.  He is EXPERT.

Bruce Hughes