RV-3 landing gear help please

Good afternoon folks. It seems that I have made an error in my judgment with the engine mount and landing gear on my now certified RV-3. at the time I choose to use a traded for used mount and gear, with the assumption that all RV's were drilled and bent at the factory, They are not on the RV-3's. First taxi test at around 20 MPH the thing started to shake an vibrate so bad that my first thought is my prop lost a blade. Gear bent wrong and drilled wrong.

Long story short (I know to late) I have now ordered new Vans landing gear for the 3. Not drilled but is bent.

My questions are: is there a fixture to drill the mounting hole perfect? If so does anyone have one that I can borrow, rent, steal.
I do not think that I can free hand drill this hole straight and keep the hole sized right, through the engine mount and gear. Just using an hand drill on round soft stuff that thick is tough enough to keep straight and come out the other side at the same radius point.

There are a lot of these 3's flying so I am sure there is a way to drill the gear properly. Tony, Randy, Fred, Rob Any builders of RV-3 I really need some advice and hopefully pictures.

Thanks in advance

Perry

Perry,

First, how much air pressure in the tires? If it was more than 20 psi, drop it down to 18 psi and try again.

Tires squeak a little or a lot when you push it forward on a smooth surface?

How have you determined that your gear is not properly aligned? To be sure that's what the problem really is, here's what I would do. Build a sawhorse that will just barely slide under the bottom cross tube on the engine mount. Make it narrow enough to fit between the exhaust pipes. Put horse in place and pick up tail until fuselage is level. Put something under the tailwheel to maintain fuselage position. Wheels will now be off the ground. Remove what's attached to the axles until there's nothing but bare axles remaining. Lay a long, very straight 2x4 against both axles and check the alignment. A quick and dirty check before you pull everything off the axles would be to clamp some angles or lumber at least 4' long to the outside of the tires and measure the distance across front and back.

If that's in fact the problem and the gear legs need to be replaced you have several choices, but let's leave that for part two.

Tony

GEAR

Perry- Tried to send you a PM but your mailbox is full.
The best Goodyear or Michelin tires will make a difference. The wheel assemblys should be balanced. Hardwood stiffners clamped or fiberglassed to the trailing edge of the gear help. Is the gear tight in the lower portion of the socket tube? If not a clamp can be fabricated from a short piece of 5/16 I.D. tubing welded to the gear socket in line with the short area where the gear leg is supposed to be the same size as the i.d. of the socket. Weld the tube in place and then slot through the middle of the tube and the landing gear socket with a die grinder or hacksaw. Cut far enough up the socket tube so that when an AN5 bolt is installed and tightened there is no play between the gear leg and socket.
The gear can be moved by filing out the holes in the gear socket and welding 1/8 thick washers over the elongated holes. This can be done with a mig or tig even with a heat treated gear. One tiny tack weld at a time, let things cool completely between tacks. This does require pulling the engine and mount. If you have someone who is an artist with a tig, you can probably leave the mount on the engine. Short pieces of tubing can be used instead of the washers. In either case the washer/tube should be a tight fit on the bolt. Some Wittman Tailwind builders have been sucessful in rebending the gear in place on the airplane. This is done with a long heavy wall tube that slides over the axle. Lots of muscle, it takes a lot of bending to permanently move things 1/16". I don't know if the RV3 gear mount and or fuselage would survive this. If you decide you need a drill jig I will tell you how I made one.

RV-3 gear

Tony, I tried down to 15 lbs air pressure, just a slight change from 30 lbs. (what I run on my Cassutt) The bolt hole is elongated and the left gear is off by 1/2 the hole when toe in is zero. Right gear about 1/4 hole. When in flight attitude and off the ground both axle's tilt down (over the length of axle) 5/8 inch.

An RV-4 out of Chicago was at our airport today, with no gear covers or wheel pants. His tires were vertical while sitting on the ramp. Mine on the 3 really tilts out at the top by at least 1.5 inch over the height of the tire.



Jrs. The lower fit is snug. although I would not say tight. I like the idea you have to make a clamp on the lower end.
Plans are to weld holes closed and weld on a plate to both sides of tube and re-drill.


Thanks again Perry

GEAR

Perry- It is much easier to drill and ream the washers before you weld them in place. The camber(5/8" dimension) is excessive, mbut I don't believe this is a factor in shimmy. The Tailwind uses 3/8" camber, measured the length of the axle. The Sukhois with the flat gear have a huge amount of camber. This requires the tires to be reversed due to wear on the outside, but doesn't seem to have any other negative effects.