GravityKnight Posted May 5, 2016 Report Share Posted May 5, 2016 My plane's tires lean out pretty far too, and the toe in was worse on one side vs. the other. I put the whole axle in the mill and machined off just a little in two directions and it came out nice (basically matches the other side- though they both still have the lean out, at least the toe in is real close now). I just eyeballed it in the mill and got lucky, your system is far more precise.. good on you for doing a nice job. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 6, 2016 Author Report Share Posted May 6, 2016 My plane's tires lean out pretty far too, and the toe in was worse on one side vs. the other. I put the whole axle in the mill and machined off just a little in two directions and it came out nice (basically matches the other side- though they both still have the lean out, at least the toe in is real close now). I just eyeballed it in the mill and got lucky, your system is far more precise.. good on you for doing a nice job. Nothing wrong with that method, I'm just not enough of a machinist to grind the axles precisely enough without ruining them. I know my limitations! Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 6, 2016 Author Report Share Posted May 6, 2016 Update...I pulled the plane out at taxied it. First off, the plane is easier to roll by hand now, which I take as a great sign. I put chalk all over the treads, but after a couple hundred yards, when we stopped the chalk was 100% gone. No help there, but at least there were no areas that had chalk left, which could indicate little or no tread contact in those areas. Overall a neutral sign. The airplane *might* be a little more wander-y in taxi, but not sure it that's my imagination. Toe in tends to make a vehicle track with more stability, so it might be a good thing as long as it doesn't go into toe out and squirrelly behavior. We did some quick measuring, and the wheels seem pretty neutral, which is the goal. Tomorrow I will do a high speed taxi down the runway, then a flight test if that goes well. Link to comment Share on other sites More sharing options...
GravityKnight Posted May 6, 2016 Report Share Posted May 6, 2016 Update...I pulled the plane out at taxied it. First off, the plane is easier to roll by hand now, which I take as a great sign. I put chalk all over the treads, but after a couple hundred yards, when we stopped the chalk was 100% gone. No help there, but at least there were no areas that had chalk left, which could indicate little or no tread contact in those areas. Overall a neutral sign. The airplane *might* be a little more wander-y in taxi, but not sure it that's my imagination. Toe in tends to make a vehicle track with more stability, so it might be a good thing as long as it doesn't go into toe out and squirrelly behavior. We did some quick measuring, and the wheels seem pretty neutral, which is the goal. Tomorrow I will do a high speed taxi down the runway, then a flight test if that goes well. Great news. I can believe it being slightly less "stable" just as you stated about toe in and tracking. But the trade off as you are very aware is better tire wear.... and.... in theory a shorter take off roll! excessive toe in is going to create some drag. Something interesting about toe in vs toe out.. on a tail dragger, a little toe out isn't as "bad"(not optimal) as it might be on a nose dragger. If the plane starts to come around heading for a ground loop on a tail dragger, the weight obviously shifts to the outside tire which if it has a bit of toe out, is pointing more so in the direction you want it to- to recover, than it would be with toe in.... kinda of interesting. I'm just not enough of a machinist to grind the axles precisely enough without ruining them I'm barely enough of a machinist to pull it off. I figured I'd have to make 2 cuts at least. Made the first, went and checked and it was so close I figured I better stop there Link to comment Share on other sites More sharing options...
Anticept Posted May 6, 2016 Report Share Posted May 6, 2016 For aircraft, there's advantages and disadvantages to either one, and has been the subject of many debates. In cars, there is more to it that firmly plants the toe choice in one camp or the other. Is it front or rear wheel drive? Are we toeing the front or rear wheels? etc. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 6, 2016 Author Report Share Posted May 6, 2016 I seem to recall from my racing days that for cars toe in increases stability at the expense of handing, and toe-out does the opposite. Link to comment Share on other sites More sharing options...
Anticept Posted May 6, 2016 Report Share Posted May 6, 2016 In general yes. But those two questions play a big role. Check this out: http://en.intraxracing.nl/techniek/camber,-caster,-toe-intoe-out/ Link to comment Share on other sites More sharing options...
207WF Posted May 11, 2016 Report Share Posted May 11, 2016 Just curious on the tire wear. How many hours were you getting on a set of main tires before you started all this? WF Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 12, 2016 Author Report Share Posted May 12, 2016 40-50hrs on a set of 6-ply, about twice that on 8-ply. Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted May 12, 2016 Report Share Posted May 12, 2016 40-50hrs on a set of 6-ply, about twice that on 8-ply. That's worse than mine. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 12, 2016 Author Report Share Posted May 12, 2016 That's worse than mine. Hopefully not anymore! My airplane definitely has less rolling resistance now, which I take as a good sign. I can pull the airplane along and if I let go it just keeps rolling. And the taxi speed at idle has increased; on a flat surface at idle my airplane used to roll along at 18-20kt, now it rolls at about 25kt. So better tire wear, worse brake wear. Link to comment Share on other sites More sharing options...
FastEddieB Posted May 12, 2016 Report Share Posted May 12, 2016 One nagging question, that I'm sure has occurred to you... Do you think your plane was delivered that far off, or perhaps something else in the gear has been knocked out of alignment and you're just compensating for it? As an aside, the designers of the Sky Arrow apparently did not adequately consider the lighter weight of the LSA version, causing the tires to have excessive positive camber and roll on the outside edges. They realized the problem, and shipped axle shims that were installed free of charge by my dealer. At 435 hours or so, I'm on my second set of tires, Desser "Monster" retreads that are wearing like iron. No great photos, but the shim is on the left here: Link to comment Share on other sites More sharing options...
Tom Baker Posted May 12, 2016 Report Share Posted May 12, 2016 Eddie, it was likely shipped that way. There were several airplanes from that era that had this same issue. There are 2 different fixes for those with the stock Marc wheels, or shimming if you have the Marco's installed. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 12, 2016 Author Report Share Posted May 12, 2016 Eddie, I have wondered, but there is no way to know for sure. My right wingtip does sit about 1-2" lower than the left, but that is common for CTs. Any hard landing event that may have caused problems must have been done by the previous owner (that's my story and I'm sticking to it!)... Honestly, I think my setup was just not right from the factory. To be as far out as it is/was is both axes, if it was pilot induced it probably would have bent, wrinkled, or cracked something. I've been over the whole gear/wheel/brake assembly thoroughly and everything appears straight and undamaged. No to mention the gear feels pretty tight with no slop or mush like you'd get with significant damage. I have landed on somewhat rough grass strips with no issues, which would have probably highlighted any issues. Hell, at Oshkosh they taxied me around the entire airport on the worst, roughest surfaces I've ever seen and nothing broke. Link to comment Share on other sites More sharing options...
Tom Baker Posted May 12, 2016 Report Share Posted May 12, 2016 Have you checked the wing tips since doing the alignment? Sometimes having to much toe on one side will pull the gear in raising the wing. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 12, 2016 Author Report Share Posted May 12, 2016 Interesting, I will recheck and report. Link to comment Share on other sites More sharing options...
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