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Ron Springer

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Ron Springer last won the day on July 31

Ron Springer had the most liked content!

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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

    Sales I've seen

    This is the same plane that is on the canard calendar this month.
  2. 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.
  3. 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.
  4. 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?
  5. 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.
  6. 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!
  7. 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.
  8. 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 ...
  9. 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.
  10. 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".
  11. 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.
  12. Ron Springer

    How hot can it get?

    TMann, I used a pair of twin size electric blankets on my canard in my garage (back in N. California) where the garage temps were still colder than your basement. I measured the temp under the blanket with a remote thermometer. I gained about 10 deg when I topped the electric blankets with space (survival) blankets. It is mylar (?) which is orange on one side (with survival directions) and aluminized on the other side. I picked them up at REI. Ron
  13. Ron Springer

    Canard top spar cap

    You might try this trick next time. As you go along and pull out the cross fiber for each ply, put each cross fiber in a pile and line them up. You will know the number of plies by counting the number of piles. You can't lose count that way. I think I even took a photo of my piles when I finished. I didn't do that for the canard, but I did for the main spar, where it is a lot easier to lose count.
  14. Ron Springer

    fixing axle camber

    OK, that explains it!
  15. Ron Springer

    fixing axle camber

    I don't think that the camber problem is the fault of the builder. It is just a result of the plans methodology. In the plans (and my direct experience is with a Cozy), the toe is precisely set but the camber just happens. The axle flange is bolted to the gear leg flush (in the vertical sense), so the gear leg angle becomes the camber angle. A flox pad is used to adjust the toe. Since the axle is usually mounted early in the build, the builder can't take into account any changes in camber due to loading. They only have an incomplete tub at that point and it is upside down on sawhorses. But, this is a good thing to keep in mind, and when I am done I will go back and check the camber.