Gear Alignment

[BatMaule]

I've read the previous discussions on this topic and am a bit confused on how toe-in/out might affect camber. My M6 is definitely toed in (plan to get a good measurement this week) but it also really seems to have an excessive amount of outside camber. The maintenance manual doesn't say anything about camber and I'm wondering if camber gets "fixed" the same way as the toe (i.e. leverage). See in the pics the plane pushed back (all seems good) and then pushed forward (front and rear shot). The ground handling of the plane seems great - tracks true on take-off and landing. However, tire wear on the outside is pronounced so there is obviously an issue. Anyone with experience on the gear straightening exercise have some sage advice before we get medieval with this thing?

Pushed back (looks good):


Pushed forward (looks not so good):




Thanks.
Paul

[maules.com]

The landing gear geometry is such that the toe in will decrease as the tail is raised if the oleos are good as yours appear to be.
First job is to find out if you have one, or two, gear out of straight alignment.
Plumb the spinner and tail spring to the floor and draw a chalkline after rolling the plane forward with a load in it.
Measure alignment of each individual wheel relative to the centre line.
With wings level for and aft as in a wheel landing I like to see minimal toe in, this changes as the tail is dropped to the ground, up to approx 5/8" total toe in, at the outer radius of 8.50x6 tyres measured at 9.5" (axle height) fore and aft.

[N9657]

I have outside tire wear also (M5-180) My mechanic tells me it's because when in the air the wheels hang with a inward cant so you land on the outside of the tires and they have to straighten out as the weight is transfered to the tires

[maules.com]

Setting track alignment is relatively important for stability in hard surface landings.
I have encountered toe in on 8.50 tyres of as much as 2.5" which made extreme difficulty in landing then keeping the Maule straight, as the tyre receiving most weight tries to walk in under the plane (as it were).
As the plane rolls from side to side, the situation worsens.
When the oleo fully extends, it comes to a stop in its travel and thus it then pulls backwards on the inboard axle protrusion.
The oleo strut is angled rearward as it attaches to the airframe.
The twist fulcrum is where the A frame attaches to the axle and if the inboard portion is pulled back, then subsequently the outboard portion with wheel attached goes forward and inward at the front.
Therefore, the more hard landings a Maule has endured, the more likely the toe in measurement is misaligned.
This was especially the case with the old style square section oleo springs.
The later round section springs have better absorption without bottoming.

[BatMaule]

Thanks for the input Jeremy and I think I see the picture you are painting. But are you also saying that excessive outside camber can't/doesn't exist without a toe-in condition? We'll get some measurements and make some adjustments as are described in related threads. I thought I might get to this in the next week or so but fast running out of time before I have to go back to "work" but hopefully before summer is out.

Plan B is to just put my floats on and not worry about it anymore!

N56517: Ever see a C-180 with big tires on approach? That spring gear REALLY sucks the tires in and on landing it is exactly the situation you describe. But...I don't know that they wear tires much more quickly than other planes. I think most of the wear on tires happens during taxi.

[maules.com]

The camber is usually a little more pronounced with excessive toe in situation but not always.
The rearward pull of the oleo on the inboard axle is also a slight upward pull.
However, there will always be varying camber dependent on the strength of the oleo springs and dependent on the load carried.
More camber out at top with lighter loads and less with heavier loads as the A frames swing in and out.
If you wheel the airplane backwards and the wheel track increases or forwards and the wheel track decreases, it is because of toe in.
If you raise the tail to wheel landing position ie wing level fore and aft, then with loaded plane wheel it fore and aft the wheel track should not change significantly if the track is set correctly.
It is wise to unskin the gear legs and place a straight edge at perpendicular positions around each A frame leg to check for bent tubes because when the oleo reaches full extension on hard landing or weak springs, the rear tube is under compression at the same time as the axle is being twisted.
The tubes may have a very slight bow because at manufacture, the weld at bottom where tubes come together is 'pulled' in the weld process but it should not have a 1/16 gap on a 12" straightedge.