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Ron Springer

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Ron Springer last won the day on July 31

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About Ron Springer

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Personal Information

  • Real Name (Public)
    Ron Springer
  • Location (Public)
    Rockville, MD
  • Occupation
    Aerospace Engineer

Project/Build Information

  • Plane
    Cozy Mark IV
  • Plans Number
  • Chapter
  1. Ron Springer

    Re-do... part 2

    For details on the VariEze gear wraps, see Canard Pusher 12, page 3 and Canard Pusher 20, page 3. Notice that CP12 says it would be best to wrap it before the tabs are installed but it is not strictly required. http://www.cozybuilders.org/Canard_Pusher/
  2. Ron Springer

    Re-do... part 2

    FYI ... on the TE it is called a fence rather than a vortilon.
  3. Ron Springer

    Re-do... part 2

    Cutting off the ears and rewrapping the strut is technically what is called for in the Canard Pusher newsletters. An early VariEze builder would have had to build the strut with ears and no wraps, and much later cut off the ears and wrap with UNI, and much later cut off the ears for a 2nd time and add BID (or the other way around). On my plane, the builder chose to just apply those wraps everywhere except for under the tabs. It has been working fine since the early 1980s with the exception of the delamination, but that had more to do with the lack of a glass-to-glass bond at the trailing edge. Now, to cover myself, you should definitely cut off the ears and wrap the whole strut because that is the only right way to do it!
  4. Ron Springer

    Re-do... part 2

    I also had some delamination of the UNI and BID wrapping the strut on my VariEze. I peeled it all off and re-wrapped it. This time, every single ply wraps all the way around the strut and back onto itself at the trailing edge, which makes it a lot stronger. Using a hair dryer, it was not too hard to peel off all the glass and get back down to the bare strut. Below is a video of the delam that I discovered. The UNI and BID wrap the strut outside the lift tabs only and between the lift tabs. That is because the VariEze plans did not call for any wraps initially. The UNI and BID was later called for in two separate Canard Pusher newsletters. The builder of this plane did not feel like cutting off the lift tabs to wrap the entire strut, so he just glassed around them.
  5. Ron Springer

    Sales I've seen

    This is the same plane that is on the canard calendar this month.
  6. Ron Springer

    Newbie Questions

    I am using EZpoxy now, which you can definitely smell as opposed to MGS, and my wife can tell when it gets into other parts of the house from my basement or garage. I have had good success by closing all the doors and using an exhaust fan wherever I am working. The fan makes sure the fumes are going out the window instead of into other parts of your house. If anything, you will be drawing air into your shop from inside the house, which is the direction you want the air to move.
  7. Ron Springer

    hangar electricity and other rants

    When I bought my VariEze in Wyoming, the hangar had no power, but he had a battery, solar panel, and inverter. It was good enough to run power tools, a vacuum, lights, and a radio as required.
  8. Ron Springer

    Varieze Canard Bolt Torque and quick disconnect pins

    Unless, like on my VariEze, a bushing was used that is too short. I think both bushings are around 0.77" long which matches F22 on one side, but on the other side F22 is 0.825" thick. Tightening of that side over the last 40 years has lead to crushing of the foam and cupping of the wide area washer under the bolt head. I made a new bushing of the correct length to fix it. The reason for the difference in thicknesses is a build-up on the front face of F22, presumably to get the canard perpendicular to the aircraft centerline. Maybe the bushings were made prior to that and never adjusted to account for it?
  9. Ron Springer

    stab mod

    Regarding Todd's drag claims ... I just flipped open my "Theory of Wing Sections" book and flipped to the page where they compare a split and plain flap drag polar. The split flap does have a slightly higher max CL, but at the same CL, the split flap has the same or lower CD, at least for a NACA 23012 with a 20% chord flap. That's actually a bit counter-intuitive. But, the drag polar plot does not really address the flap deflection. I think his claim of three times the drag for the same deflection may be true ONLY for very small deflections. It is definitely not true across the board. At very small deflections, the air may be able to stay attached to a plain flap, but the split flap forces a large wake. At larger deflections, both styles of flaps have large wakes.
  10. Ron Springer

    stab mod

    I will also point out that I do know the drag of the rudder will be a lot less than the lift, but the drag force should have a moment arm of about 14 ft from the CG, and the moment arm of the lift force will be much less. So, the effect of drag on yaw will be amplified by the ratio of the moment arms compared to the effect of lift on yaw. There are some calculations that could be done here, but I'm not going to do them ... too busy!
  11. Ron Springer

    stab mod

    I am not promoting this mod, just answering the question about whether or not there would be a loss of effectiveness. But now that you bring it up, why are you only talking about lift, where the split flap makes a small difference, instead of drag, where the split flap makes a big difference? Now I will directly refer to Todd Parker's statement on the mailing list that a split flat has 20% more lift for the same deflection and three times as much drag. I haven't verified it myself, but he is usually correct. I could certainly see the drag being really high due to the creation of a large wake.
  12. Ron Springer

    stab mod

    It is more effective. This idea was proposed on the Cozy mailing list by Todd Parker on March 2, 2005. Look it up in the archives to see the discussion that took place ...
  13. Ron Springer

    Cozy IV Forced Landing

    He may be referring to Len Johnson's forced landing of a Cozy in Missouri. It happened around the time of the posting, but I am too lazy to look up the exact date! Len posted here after the accident, so that's a good sign.
  14. Ron Springer

    Cozy vs E-Racer specs

    According to my plans, the Cozy Mk IV is 141" after shortening it from 147". It would have to be shortened twice to get to 135".
  15. Ron Springer

    N200LZ: Chapter 10 - Part Two

    Mine were a little smaller than the template after hotwiring. But, after the skin layups, it pretty much matches the template size.