ChrisBolkan

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  1. ChrisBolkan added a post in a topic Catalina Project   

    I am having trouble finding the particular actuator you used. Can you re-check the number? The link leads to a blank page.
     
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  2. ChrisBolkan added a post in a topic Catalina Project   

    Sweet! I'm on it! Would you mind taking a couple photos of how you did the install from a couple different angles?
    Thanks man!
    Chris
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  3. ChrisBolkan added a post in a topic TP'n Patey style!   

    So THAT's where all the toilet paper is going!
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  4. ChrisBolkan added a topic in Avid Catalina   

    Catalina Project
    Has anyone replaced the manual gear retraction mechanism with an electric linear actuator/ jack screw?  If so, did it work? What linear actuator did you use?
    I'm having a hard time sorting out the forces it would be subject to. However it looks like it would be a relatively easy install and would be a lot nicer than the manual handle.
    Mine, even though it moves freely requires more force that I want to apply every time I want to cycle the gear once I am flying this thing.
    Chris Bolkan
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  5. ChrisBolkan added a post in a topic Flaperon Flaps   

    That's a huge change in minimum controllable airspeed
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  6. ChrisBolkan added a post in a topic Flaperon Flaps   

    This is fascinating. So lets assume the system you have come up with is balanced so no flutter under any conditions and the flapperon hangars can withstand any force the system can apply. This leaves two really interesting approaches to consider in deployment of the flapperons and extensions.
    1) apply flaps with the lever in the plane, and then from there apply the extensions for even more droop.
    2) use the extensions to apply the flapperons. The internal flap handle would become unnecessary as an upward deflection of the extensions would force the flaps to deploy, more like the action of a trim tab on an elevator. 
    Either way, you gain the benefit of additional wing surface area so lower wing loading, but in #1 you are changing the airfoil shape to add more under camber and in #2 you are just adding surface area to the wing and removing the need for the flapperon mixer because the extensions would control flap deployment.
    Is this the way you see it? It would be so much fun to experiment around and see how it would behave in different scenarios!
    Hopefully you can play with both and let us know the performance differences.
     
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  7. ChrisBolkan added a post in a topic Stupid Question   

    And why are they buying up water????
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  8. ChrisBolkan added a post in a topic Flaperon Flaps   

    Part of me is saying that is the coolest idea I've seen in a ling time and I want to do it to mine. Plus to a small degree it lowers wing loading so should stall some tiny amount slower.
    The nervous Nellie part of me is wondering if the addition of the extension changes balance on the flapperons so would the lead counter weight need to be modified in order to prevent potential flutter, and The flapperon hangars are designed for a certain amount of force to be exerted on them before failure and this definitely increases the force so is there a potential problem there?
    Another thing that comes to mind is you should not need a flap lever inside the plane with this configuration, since this is essentially a trim tab. So the whole mixer could just go away, right?
     
     
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  9. ChrisBolkan added a post in a topic Chicken Stuff   

    What he said :-)
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  10. ChrisBolkan added a post in a topic Near miss with fuel line.   

    I did some not purely scientific but informative (to me) testing of various chemicals on Avid fiberglass tank pieces with various tank sealant materials painted in spots on the fiberglass. I put the pieces in Ball canning jars with whatever the chemical was. The sealants were buna “n”, proseal, epoxy resin, and some others. Av gas had no effect on the glass or any sealant. Ethanol free auto gas was good too. The worst was ethanol 10%. It softened the fiberglass and delaminated the buna n, swelled the proseal slightly and did not seem to affect the epoxy. Interestingly, pure ethanol (195 proof everclear) did not have near the bad effects of the 10% ethanol gas, although it did effect on the buna n and a very slight softening of the fiberglass.
    While the surface of the fiberglass was softened slightly it did not loose structural integrity over the two weeks, but from my experiment I will not use any fuel with ethanol in my tanks.
    i posted a lot more detail on another thread a long time ago on this site somewhere.
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  11. ChrisBolkan added a post in a topic Near miss with fuel line.   

    I am trying out a new (to me) Tygon LP1100 low permeability fuel tubing. It is clear but has a liner. The outer part seems to be urethane like regular UL fuel tubing, but the liner is supposed to be impervious to highly aromatic(sp) stuff in fuel and meets all the California rules for fuel line. Haven’t installed it yet, so don’t know how it will actually work in practice. But if it works like I hope it should have a much longer life and not get brittle and crack. I think I bought it from US plastics if anyone is interested in having a look. 
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  12. ChrisBolkan added a post in a topic Avid Plus build is on ....   

    A ratcheting system or a linear actuator will work fine. Friction as originally designed???? Not so much.
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  13. ChrisBolkan added a post in a topic Avid Plus build is on ....   

    Here are a couple of photos of my linkage. The linear motor under the passenger seat adjusts the flaps. Things may not look exactly like yours because the original builder of my plane did a lot of cutting and trimming of things I think he shouldn't have, but it is what it is. None of what he did affected location or basic geometry of any of the control system.


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  14. ChrisBolkan added a post in a topic Avid Plus build is on ....   

    I got the flu and just got back from the dead. I guess I forgot that I took quite a few photos of the mixer assembly in my fat avid thread on this site. Let me know if you want any additional pictures. I should be able to get out of the house soon!
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  15. ChrisBolkan added a post in a topic Flaperon travel parameters   

    I do not believe MKIVs came with F7s. My MKIV was a late sn very much built to plan and it did not have them. I guess I didn’t know that any avids came with them. I thought it was a part you could buy as an extra if you did not want to use the rudder. I always believed that having full differential travel provided the greatest authority even though it required more rudder input to stay coordinated. I don’t think any of my avids have F7s from the pictures I have see on this site.
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  16. ChrisBolkan added a post in a topic Flaperon travel parameters   

    Absolutely! Every one of my Avids had the issues you describe above. Once full travel is obtained by fixing all the little builder induced issues the travel is what it is by design and won't vary from plane to plane.
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  17. ChrisBolkan added a post in a topic Flaperon travel parameters   

    It's only 40 degrees down on the "down" aileron. It will be approx 15 degrees up on the other one at full deflection. I got these numbers on every Avid I have owned My original MKIV got those numbers, My Magnum was identical, and my Fat Avid once all put together came up with exactly the same deflections. That's how I got the numbers. I seldom use a lot of flaps, but in a lot of Avid time, I have never experienced roll reversal, but I have heard of it happening. I also have no experience whatsoever with the F7 mod. Maybe that makes things move too far
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  18. ChrisBolkan added a post in a topic Flaperon travel parameters   

    Flapperons should travel plus and minus 25 degrees limited by the bottom of the stick hitting both sides the little triangle pouch it lives in. pulling full flaps should displace the flapperons an additional 15 degrees down and not cause any bind in the initial flapperon travel described above. So, with full flaps pulled and full aileron in one direction or another, max down deflection should be 40 degrees. THIS SHOULD ALL BE ABLE TO HAPPEN WITH WITH NO BINDING OR TRAVEL LIMITING EXCEPT AT THE BASE OF THE STICK which is the travel limiter.
    Hope that makes sense. :-)
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  19. ChrisBolkan added a post in a topic Avid Plus build is on ....   

    I'll take some pictures of mine. The easiest way to fix the flap handle problem is to install a linear actuator. Works well and does not slip when set.
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  20. ChrisBolkan added a post in a topic What's this part?   

    So, interesting conversation about using all-thread above.
    So there I was yesterday at a friend's grass strip practicing slow short landings just above stall. I had just completed a landing, had turned around and was blasting off for another when the stick started moving around in my hand in a way that is hard to describe, but immediately disturbing. The strip is a bit rough so I thought maybe just that. It was getting worse as I accelerated so I aborted just before liftoff. I turned around and accelerated back to the starting point and it did it again. A very creepy and kind of violent but not really movement in the stick like something was broken. When stopped at the top again I moved the stick back and forth and it seemed firmly connected to the flapperons. When I moved it for and aft it felt like the elevator was firmly attached without excess slop. When I got out of the plane I found this: (photo) The strip is remote but I was able duct tape and bailing wire the trim tab in place to fly it home. The original builder used all thread for the connection and had a slight bend in it for clearance. I never thought a thing of it because I would never expect the forces to be great enough to bend or break the all thread. What I did not take into account was the infinite number of small flexes happening to that slightly bent piece of all thread led to catastrophic failure. 
    I think it could have turned out to be a much bigger problem if it had failed mid flight. I think what happened is best described as a form of flutter.
    Lessons learned for me: 1) The control arm should have been straight, not the gradual bend the original builder had in it and 2) I I will probably use all thread for this again even though I am not a fan, but it will be straight and I will sleeve it.

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  21. ChrisBolkan added a post in a topic Avid Plus build is on ....   

    I think that is the fuselage I have too. I love the room. Super fun to fly and well behaved.
    I think the control arrangement leaves a lot to be desired. While the mechanism under the seat and cables is convenient, Mine leaves a lot to be desired wrt flapperon slop.
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  22. ChrisBolkan added a post in a topic Rework an Avid Project, needed parts   

    I am wondering that too....
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  23. ChrisBolkan added a post in a topic Avid Plus build is on ....   

    Is this the same as a "fat avid"/
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  24. ChrisBolkan added a post in a topic Rework an Avid Project, needed parts   

    Does the fuselage have a nose wheel weldment? If so I have original tricycle main gear and nose wheel fork.
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  25. ChrisBolkan added a post in a topic Getting close for an engine choice   

    I vote HKS for the KFII if you want the lightest option, or a used 912 if you are willing to sacrifice a lot of useful load and don't mind adding some weight in the tail. 
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