I'm not sure I understand the benefit of the greased plates as used for main gear alignment.  I measured the toe-in of each of my main wheels when sitting on pavement and then made shims with the required angles.  After installing, I lower the plane, rolled it back and forth and measured again.  The change in angle was pretty much exactly what was predicted.  It's not a matter of tweaking, measuring and tweaking again, so the value in going to the trouble of sitting the gear on greased plates escapes me.  I did go to the trouble of measuring each wheel with respect to a centerline drawn on the floor instead of relative to each other - that keeps the plane from dog-tracking.  Whether that is important or not, I don't know.

Gary Casey

ES, used to have excessive tire wear, now doesn't

Re: [LML] L-IV Alignment

January 22, 2010 3:08:55 PM MST

From:

"Matthew Collier" <ivdiggs@gmail.com>

To:

"" <lml@lancaironline.net>

Bill,
This grease plate method works pretty well. You can just use any kind of metal plate, it doesn't need to be that thick and the plastic sheet between them isn't necessary either. Just two metal sheets, aluminum or steel .125" or thicker with a good coating of grease between them is great. I like to make the bottom plate a couple inches larger than the top, and make sure the edges of the top plate are well deburred. Place one under each main gear and load the aircraft with the same weight you would like the wheels to align with. They will change angle slightly with load. I like to go toward the heavy side of where I think the plane will be most of the time since the tires will wear more under greater load anyway. 

Matthew Collier
Fibercraft Inc.