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Zenith XL601. Main gear position.

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Don Hodges

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Battery is behind pax seat. Have light weight Alt. Will look into starter. I'm stuck with the Sensenitch for now. The extensions moving the main wheels forward a few inches are starting to look like a viable alternative. Move the step fwd of wing and don't start eng until everyone on board. Probably a wheely bar in the tail. Could sell the 0235 and look for a lighter eng.
 

wsimpso1

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Not mentioned is that some birds have the mains placed to keep the small wheel on the ground when empty and when loaded... Others accept that and deal with empty other ways. Vari-EZ, Long-EZ, and its derivatives retract the nose wheel for parking, Rans S-12 has a teeny tail wheel for parking, etc.

Moving the mains to keep the small wheel loaded when parked is done, but can result in the nose wheel going on rather firmly most of the time.
 

Don Hodges

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Moving the mains forward will reduce the weight on the nose. The downside is that you have an aircraft that looks a little weird with the nose gear and the mains so close together plus the problem of trying to enter it without banging the tail on the ground. Could move the step to the front of the wing. I looked into the idea of ballast, as suggested earlier. A container of water in the cargo area or even ballast added to the tail. Had some issues with weight and balance. So I had a conversation with Dean Wilson, some of you may know who he is, and my takeaway is this, I need to look at enlarging the elevator and of course increasing the strength of the mounting to see if I can get more authority to raise the nose for rotation and landing. Of course, I'm concerned about the stress to the airframe. Control cables and attachment strengths. Would like to hear everyone's opinions. I would have to determine how much larger the elevator needs to be and of course the structural integrity of the mounting. Would love some help on those calculations. So here we go. I also need to whine a little, why so much grief with an airplane designed by Zenith for the lyc 0-235? The wing mods were bad enough, now this.
 

Victor Bravo

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How much further can you lighten the engine, propeller, accessories, etc.? Magnetos weigh a lot, EI weighs less. EI and smaller alternator might allow you to move the engine further rearward (shorter engine mount), making a large difference not only in the ground handling but also the flight handling, decreased aircraft weight, etc.

You also might solve your problem more eloquently by converting it to tailwheel configuration, which is an option on the 601 series.
 

Don Hodges

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Lewiston Idaho
Already have the smaller Nippondenso alternator. And one of the magnetos is electronic.
Anyone here flown a tailwheel version? If so what was that like? I think increasing the elevator size would be better. (?) As to moving the eng back, there is no room.
 

Don Hodges

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Lewiston Idaho
That is my thoughts as well. I realize I'm asking for opinion rather than engineering data. Given the weight on the nose, what kind of increase in the size of the elevator would I be looking at? I can make two more that are longer pretty easily. Making a new stab and elevator would be a little more work but doable.
I think that I would shift my focus from the LG to mods to make the horizontal stabilizer more effective.


BJC
Do you mind telling me a little more detail about making the horizontal stabilizer more effective? Tip extensions, longer front to back? Just the size of the elevator itself?
 

Victor Bravo

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The larger stabilizer and elevator will be able to apply a lot more force onto the airplane, allowing it to generate greater stresses on the airframe at lower speeds. So you are likely going to have significantly lower maneuvering and/or max control deflection speeds.
 

BJC

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That is my thoughts as well. I realize I'm asking for opinion rather than engineering data. Given the weight on the nose, what kind of increase in the size of the elevator would I be looking at? I can make two more that are longer pretty easily. Making a new stab and elevator would be a little more work but doable.

Do you mind telling me a little more detail about making the horizontal stabilizer more effective? Tip extensions, longer front to back? Just the size of the elevator itself?
What I would do,

Read Rockiedog2’s posts about mods to his 701,
Look for extant successful mods that have been made. If none, then,
Look at gap seals
Look at vortex generators,
Look at stabilizer strakes a la the Sportsman 2+2,
Look at elevator trailing edge add-ons with rebalancing,
Look at a new design, longer span, stabilizer and elevator,


BJC
 
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Pops

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First put the CG by the factory specs. Then after that is done and you still have to much weight on the nose gear and its hard to get the nose wheel off on takeoff work on the placement of the main gear. Look at post 11.
 

GeeZee

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Feb 25, 2019
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Indianapolis, IN
Just wanted to post an update on my neighbors efforts to reduce the nose gear weight on his O-235 powered 650. He started with 290# on the nose gear. His battery was already mounted aft of the cabin so after consulting with another local 650 builder he decided to flip the gear around. Note that if the gear has already been installed the gear doesn’t just “flips around” you have to grind new notches for gear attach stud clearance and the brakes have to be modded. Anyway he now has 200# on the nose gear and is pretty happy.
 
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