John, I hope what I'm about to write is taken in the spirit of encouragement that I intend....
The key to not damaging gear legs on an Eagle is to know how to land the plane. The lightly-built Eagles are intolerant of poor airmanship, but will reward the competent pilot with a long, uneventful service life. Assure your skills are at the point where you can land a plane and not merely arrive (semi-crash) and you won't have problems with the gear as designed.
I can see how the LE could be easily flown over gross, but an XL flown over 575 lbs is a very heavy Eagle/pilot!John, I hope what I'm about to write is taken in the spirit of encouragement that I intend....
The key to not damaging gear legs on an Eagle is to know how to land the plane. The lightly-built Eagles are intolerant of poor airmanship, but will reward the competent pilot with a long, uneventful service life. Assure your skills are at the point where you can land a plane and not merely arrive (semi-crash) and you won't have problems with the gear as designed.If you fly the plane over-gross, and many do, the gear will need to be beefed up, sooner or later...
I consider the Black Max tires with solid struts to have equivalent shock absorption to the sprung struts with cycle tires. The low pressure tires absorb a lot of energy. I run a max of 10 psi in the Carlisle tires, and flew an entire summer with nearly no pressure. The sidewalls were stiff enough to support the plane but it did wear the outside edges of the tread.Sam, I plan on landing mostly on grass strips around where I live and wondered how much you land on grass. Coming from an RV-9A that doesn't tolerate rough fields I sure don't want to stand the XL on its nose. I really like your setup but concerned about the small diameter of the tires verses the bike wheels.
Hi Joe,Ebody I know who has the Black Max likes those. They are definitely top of the line. The down side is the cost and a little weight and I suspect higher drag. The complete bike wheel setup with mountain bike brakes weighs 10# the Black Max not that big of a weight penalty over the bike ones unless you're fanatical. I am. That's with the thorn proof tubes which are a bit heavy. Go with regular tubes and maybe 9# rounded off. The cost diff is big about 300$ diff but you only gotta spend it onetime so if I wanted the Black Max I wouldn't let that hold me back. If I had it and could spend it. There is a 4.00x6 Black Max setup that I put on this new thing I'm building that wud be good on an Eagle but doesn't quite have the good looks of the 600x6 that Sam is running. I wonder if that is the 13# setup that Black Max quoted you on the weight of. The weight and cost favor the bike wheels the looks and durability favor the Black Max. And the flotation...(Sam doesn't have any springs except his tars)...if doing a lot of off field landings that favors the Black Max too. No doubt for my use the bike wheels. they are part of the climb performance package on my plane. And they are tough but not good for soft ground. But I do operate off grass. sometimes soft and slick. I just go anyway no probs. Your call...
I love it. Man the LE aint no combine and I think Weasel said he went into a corn field that had been cut already. That bird looked like it belly flopped in and tried to use the prop as a blender. Holy crap, the bird is tougher than nails. You sure wouldn’t get away with this least amount of damage in a Mini-Max or too may of the other competitor aircraft flying today. Leonard sure knows how to design a tough bird.
I can now see why the gear loves to bend like an elbow when hitting the ground. Your explanation is great and it sheds light on what forces are impacting the various gear members and constantly bending them in similar ways.
I am glad you included the tail wheel along with this. I like your design and I know I can maybe do that too. It looks light weight, basic straight forward solution to a problem and durable as a nagging wife. I don’t have one of those but I have heard that to be so.
I have spent a lot of time over at the Yahoo site and I am still learning how to slide around over there. I am concerned about losing all the information contained there. It truly is a treasure trove of good information that supports the reasons for the changes that have occurred over the years.
So Joe, you would go with the 20” Murray wheels and disc brakes over the Black Max wheels? The people at Black Max said the guestimated weight of the system is around 13 pounds total. I am figuring on 14 pounds and that would be what I would use in comparison. I don’t remember any weight expressed on the bike wheels with brakes. Does anyone have a feel for what that might be?
I thank all of you for all this great information. I am fairly sure regarding the tail wheel direction but I am still in a deciding mode on the mains.
Joe, is that tar an all terrain tread or a snow tread? :) Joe, is the spring a cut down leaf spring from the junk yard?
Thanks,
John
Hi John
either one will be fine for grass strips the Eagles aren't bad about wanting to nose over at all. i ran 600x6 lawn mower tires and wheel on mine before going to the bike wheels no prob with either one unless in mud. then neither one is good SpencerI consider the Black Max tires with solid struts to have equivalent shock absorption to the sprung struts with cycle tires. The low pressure tires absorb a lot of energy. I run a max of 10 psi in the Carlisle tires, and flew an entire summer with nearly no pressure. The sidewalls were stiff enough to support the plane but it did wear the outside edges of the tread.Sam, I plan on landing mostly on grass strips around where I live and wondered how much you land on grass. Coming from an RV-9A that doesn't tolerate rough fields I sure don't want to stand the XL on its nose. I really like your setup but concerned about the small diameter of the tires verses the bike wheels.
Jim, I occasionally land on grass but don't know how relevant this will be to your situation. "My" airport has grass areas that are often used for landing zones and these areas are not groomed, just regular ol' pasture grass that is mowed down to a foot or less. The ground is rough and the XL has never had any problem with it even though the pilot gets bounced around some due to the lack of sprung struts.I consider the Black Max tires with solid struts to have equivalent shock absorption to the sprung struts with cycle tires. The low pressure tires absorb a lot of energy. I run a max of 10 psi in the Carlisle tires, and flew an entire summer with nearly no pressure. The sidewalls were stiff enough to support the plane but it did wear the outside edges of the tread.Sam, I plan on landing mostly on grass strips around where I live and wondered how much you land on grass. Coming from an RV-9A that doesn't tolerate rough fields I sure don't want to stand the XL on its nose. I really like your setup but concerned about the small diameter of the tires verses the bike wheels.
I guess I've got some time before I decide for sure on the wheels, but it's good to know I have options.You need to have your decision nailed down before building the gear legs, the Black Max gear is taller. There is an error in a major dimension for the gear on the XL drwgs, let me know when you get there.
Thanks Sam, I am sold on the Black Max setup with hydraulic brakes.The brakes are superb, only take a few minutes to rig, and never need adjusting. Being able to have a reliable parking brake is an added bonus:
Sam, I don't understand why you would ignore the 17 1/2" dimension when the drawing says on pg. 22 it is for use with the 6" Black Max wheels on pg. 28 of the drawing package . I have built mine using Hagar 4 X 6 " wheels and the 17 1/2" dimension and the gear leg measurements came out different than the drawing. I don't recall what those dims. are so I'll have to get back. I went with my gut and figured that the 171/2" level upper longeron was the key dimension for a 6' wheel.Charles, you answered your question.
there is more drag on the two small fat boys hanging out there.I wonder if that is actually the case. If the cross section of cycle tires and Black Max tiers is compared they may be very close. But the aerodynamics of the larger cycle wheel diameter with all the spokes and stuff make it hard to actually compare the two systems. Most likely differences in drag at Eagle speed is very small....and I don't know which system would have less.
Wheel Drag,can be improved on those spoke wheels like they did on the WW1 Spad, cover the spokes with Dacron .Let that wheel with the dacron covers get a little crosswise to the wind and you will have time to ponder drag coefficients while recovering from rotator cuff surgery........ :o
Stick it out your car window and see if you can hang on to it better with or without the covers.
Rodger
i found some really nice wheel covers on ebay. they fit the 20" bike wheels...made outa thin plastic. i figured they cut the drag down so put em on. painted em all up with swirls on one side of the plane and i think it was a star or something on the other wheel. looked like a pimp mobile.
Hi Joe,John I PMed you Joe
A little off topic but it is about the air craft of yester year. Were you involved with the Black Pony?