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T3 suspension on a Patrol

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  • T3 suspension on a Patrol

    Dan Dufault (T3 designer) has made a T3 suspension for the Patrol. We’ve been working together for a couple of months now, tweaking things as needed. I was able to install and fly it this week on my Patrol and am very happy with the results. If you’re not familiar with the T3, my opinion is that it’s a game changer when it comes to operating off rough surfaces. I had one on my Rans S7 and was really missing it on the Patrol. You know those times when you feel your tail hit something hard and you do the involuntary “ouch” facial expression? The T3 dramatically reduces those moments, the shocks are amazing and they soak up the bumps with great ease. It performed flawlessly for the 175 hours that I owned my S7, no issues whatsoever. That being said, this is obviously a completely different animal due to the Patrols stinger tailgear.

    The basic design includes a short section of solid tubing that inserts into the fuselage tubing and is secured with an AN5 just like the standard gear, except this is a longer bolt that goes through the T3 side plates and spacer bushings on each side of the fuselage tubing. The tube extends about 3-4 inches below the fuselage and is retained by a large solid clamp that spans the distance between the side plates. The remainder is classic T3 and a leaf spring tailwheel is required. The lower arm that attaches to the tailwheel is 1 1/2” wide.

    I ordered a 10” Bearhawk leaf spring tailwheel for this project and am very impressed with Eric’s work. The T3 and the 10” worked extremely well but the geometry of the design resulted in a conflict between the lower arm of the T3 and the 10” tire when the tailwheel is broken free and swiveled 180 degrees out like required for ground handling, as in pushing the aircraft backwards (see Eric’s forum post about this). I used the new leaf spring tailwheel body and installed the old 8” fork, wheel, and tire. Perfection! I’ve got around 20 landings on it so far and am very happy. It’s that familiar “squish” feel on landing that I became accustomed to with my S7. As for the conflict with the 10” tire, I can’t speak to the T3s compatibility with other tailwheels, I’ve only tried the Bearhawk 8” and 10”. I’m not sure what Dan plans to do with the design but I am very happy with it as is. With this suspension, personally, I don’t need the larger tire for shock absorption, the T3 does all of the work.
    Mike

    Edit (12/2): If anyone is interested, Dan said he would be happy to build up more of these. Contact him at: supercubsnorth@gmail.com
    8” Bearhawk tailwheel
    Last edited by m.mooney; 12-03-2018, 12:09 AM.

  • #2
    Love the concept of the T3 on the Patrol, and this looks like a good solution to adapting it. But in looking at your pictures, it looks like the wheel significantly trails behind the vertical axis of the swivel point – line a shopping cart wheel. According to the tailwheel rigging discussions I've seen, that's a recipe for severe shimmy. Have you experienced any noticeable shimmy? Is the angle of the tail spring adjustable at all with the T3 setup?
    Jim Parker
    Farmersville, TX (NE of Dallas)
    Patrol Quick-Build Serial # P312

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    • #3
      Good observation. It actually is almost straight vertical with a slight positive angle. It’s hard to take a good photo of this because the angle of the camera has an impact on what you see. During install, I took a good look at this because the orientation of the king pin to the vertical axis is important, as you obviously know. My eye has it slightly positive. As for shimmy....Zero thus far. I plan to explore the envelope a bit more and see what I get, just need the weather to cooperate.
      Last edited by m.mooney; 12-02-2018, 12:10 AM.

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      • #4
        Do you know if Dan will be making more of these, or was this just a one-off for your Patrol? I have the B-Model 4 Place and I believe it shares the same stinger tailwheel as the Patrol. I had ordered a T3 in June, but returned as the Alaska Airframes people were not offering this for the B-Model 4 Place.
        Rob Caldwell, EAA Chapter 309
        Davidson, North Carolina
        BH Model B Quick Build Kit Serial # 11B-24B / 25B
        Build Log: https://bearhawk4place.blogspot.com/

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        • #5
          Hi Rob,
          I can’t really answer that but will look into it for you. I do know that Dan initially made only 2, maybe 3 of them. The first one was delivered to a gent that is still building his Patrol. He and I must have pestered Dan at around the same time and he decided to give it a shot. The other person involved had emphasized his desire to have it be a dual shock system which means it’s overbuilt for the Patrol. I’m glad he asked for that because I was expecting a single shock T3 like you see on the Airframes Alaska website for experimental Super Cubs. Overbuilt is good. This means that the T3 that I’m running will probably be able to handle a B model’s weight. An important consideration is whether or not the B model’s tailgear attach measurements are the same as the Patrols?

          My personal experience with Dan has been exceptional, he was committed to doing this and he has been so easy to work with. None of this has been through Airframes Alaska, it has all been personal interaction with the designer. Actually, this is how I bought my T3 for my Rans S7, directly from Dan, before he partnered with Airframes.

          I did some measurements before and after. Reference point is the center of the AN5 bolt that retains the tailgear.
          Standard Patrol with 8” Bearhawk tailwheel is 15”
          T3 Suspension with 8” Bearhawk tailwheel is 14.5”
          T3 suspension with 10” Bearhawk tailwheel is 15.5”
          The T3 suspension weighs a little more than 3 pounds greater than the Patrol’s standard tailgear.

          Generally, the T3 might be regarded by some as somewhat untested and in its early stages of development; however, look at the innovation that is going on here! Thankfully we are Experimental and can embrace this innovation. I encourage anyone interested to go to the Airframes Alaska website or YouTube and watch the before and after videos of what is happening “back there” on rough surfaces, it will make an impact on you... I think.

          Mike
          Last edited by m.mooney; 12-02-2018, 11:33 AM.

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