109jb

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About 109jb

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  1. 109jb added a topic in "other aircraft your working on"   

    109JB has another project
    So I should probably stay off Barnstormers. Found a  Glasair project with engine for a good price and got the boss's blessing to pursue it since this is an airplane I have wanted since it first came out. It was 1000 miles away from me so I jumped on a commercial flight, rented a 26 foot Penske truck and brought it hoe. Got it unloaded today. Came with an O-320-E2D. No logs or history, so will need at least a teardown and inspection but lots of work to do on the airframe anyway.


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  2. 109jb added a post in a topic Hauling a 912 rotax in Kitfox 4   

    Are you willing to pull the cylinders and put the casewith just rods sticking out in the passenger seat? Then the cylinders and pistons can go in a box in the baggage compartment.
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  3. 109jb added a topic in Avidfoxflyers General Hangar   

    Oil cooler or not?
    Hi guys. Working on my Kitfox 4 project with the 80 hp 912 UL and got to thinking. The airplane has an oil cooler installed, but looking at the Kitfox install manual, it has you just run 2 hoses. One from the tank pickup to the pump, and one from the bottom of the engine to the tank inlet. No oil cooler. I have also read about having to put on oil thermostats, tape over the cooler in winter, etc. I have also read about one at least that didn't have an oil cooler on a 912  UL.  If the temps don't climb too high without an oil cooler in the summertime, I would rather not even put it on for simplicity, and not having to mess with anything for winter flying. Just wondering about those that have experience with running a 912 without an oil cooler. How do the oil temps behave in summer temps. does it stay below the 230 top end for the normal range?
    Thanks,
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  4. 109jb added a post in a topic Bush gear failures   

    For my gear pictured below, the strut force will be given by:
    (Strut tension) = (Upward load at wheel) * 19.66/13.51. Assuming a tooth jarring 3g load @ 1200 gross that is 1200 * 3 / 2 = 1800 pounds upward at the wheel, so the strut tension will be 1800 *19.66/13.51 = 2619 pounds tension in the strut
     If I do like I guessed and use 5 pucks each 1.5" long for a total of 7.5" of polyurethane length.
    F = E * A * (delta L) / L0 = 4400 * 2.356 * (-1) / 7.5 = 1382 pounds at 1 inch deflection
    looking at the equation it will be linear, so 1382 pounds per inch deflection with a 7.5 inch starting length, so 2619 / 1382  = 1.9 inches of deflection
    Looking at an additional puck for 9" total yields 1152 pounds per inch equating to 2.27 inches of deflection
    The second picture shows what my gear would do at 1.9" extension of the strut, which would be an upward travel of about 3.2 inches of the wheel, not counting any tire deflection.
    Thinking I may switch to 9" of pucks so I can preload them a little. I'm thinking no sag at empty weight would be good and then once loaded will sag a little. My old Kitfox sagged a tiny bit when empty with the stock gear and stock bungees but they were old I'm sure. I would think new bungees would not sag. So at 9" of polyurethane I would give it about 0.26" preload which would support 300 pounds per side without sag, and that would give me 2 additional inches of extension before 3 g @1200.


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  5. 109jb added a post in a topic Bush gear failures   

    I do have a lathe but not with a 2" spindle bore. I will likely cut them a bit long and then put them in the lathe to clean them up.
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  6. 109jb added a post in a topic Bush gear failures   

    I bought the 2" OD, 1" ID, x 36" long, 90a durometer black tube from Mcmaster Carr that I had linked earlier in the thread.
     
    edit: how did youyou cut yours? I'm debating on whether to use my bandsaw or was thinking my miter saw might work better
     
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  7. 109jb added a post in a topic Bush gear failures   

    Nice. My polyurethane tube arrived today from McMaster Carr, and the 4130 tubing for the new struts is on the way from Wicks Aircraft. This weekend I plan to knock the new struts out. Maenwhile, here is what the project is looking like right now.

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  8. 109jb added a post in a topic Bush gear failures   

    Dusty, One more question for you. You said that you drilled the pucks like a revolver cylinder. Do you recall how many holes and what diameter you used?
    Thank you so much for your help and inspiration.
     
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  9. 109jb added a post in a topic Another Kitfox IV rebuild project   

    Got the final coat if blue on and got it unmasked.  Came out nice. Has good gloss but a little orange peel that was expected. Latex is a win so far for ne. 


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  10. 109jb added a post in a topic Bush gear failures   

    Dusty: So I have a 36 inch long (914 mm) piece of the McMaster Carr polyurethane tube on its way.  So I gather from your posts that the 4 pucks that are pictured are 50 mm OD (about 2 inches), 25 mm ID (about 1 inch), and 38 mm long (about 1.5 inches long. That would be 152 mm total length ~6 inches).  My thought is to make struts that allow up to 200 mm total length, start with 4 50mm long pucks and see how it goes. This way, if too soft or too much travel I could insert a solid spacer to replace one of the pucks. What do you think of this plan, being the resident expert?  Also, a question. Does your setup sag at all with the airplane empty.
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  11. 109jb added a post in a topic Another Kitfox IV rebuild project   

    Getting the color on her. The gloss of the latex is definitely better than polytone. The white is really hard to tell but the blue has a little orange peel which was not unexpected. It is about what I was expecting and is in the perfectly acceptable realm for my tastes. If I ever decide to I could color sand and buff it but I doubt I ever will. Overall I would call it a success but in doing the fuselage I have learned a few things and will be modifying the process a little. The results that Malcolm at wienerdogaero.com gets can't be argued with, but at least for me a few changes to his process make it much easier for me. For my rudder and landing gear legs I made the following modifications which work very well for me.
    I am starting to thin the first coat of primer a bit more than he recommends in order to make it easier to get more complete wetting of the fabric.
    On the primer coats on the fuselage I used the wienerdoaero method and brushed each coat on sanding between each coat with 320 grit dry sandpaper. I still brush that first coat on, and on the landing gear I also brushed several coats, putting the primer on in one direction and tipping it at 90 degrees. Ultimately I went to spraying the primer on. The primer is still thinned and sprays nicely, leaving a slightly orange peeled surface. The orange peel is much easier to sand smooth than the brush marks from brushing/tipping. On my rudder I am spraying all but the first primer coat and it is going very well. You can get a smooth finish brushing and sanding, but it is a lot more work in my opinion. Spraying i was also able to reduce the sanding interval to 1/2 by applying 2 coats (one cross coat) at a time, waiting until the first coat tacks up and applying the crossing coat. I have also gone to wet-sanding with 400 grit which again is much easier for me.
    Anyway, here is crappy picture of the airplane after the first cross coat of blue was applied and had dried about an hour.
     

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  12. 109jb added a post in a topic Brakes For Tundra Tires   

    MC-1 and MC-3 are already 1/2" bore. 
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  13. 109jb added a post in a topic Brakes For Tundra Tires   

    If you have older matco masters they probably already are 1/2". Newer matco masters can have the intensifiers installed. What part number are yours?
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  14. 109jb added a post in a topic Brakes For Tundra Tires   

    FYI, cylinder intensifiers simply reduce the bore of the newer matco master cylinder from 5/8" to 1/2". If the bore on the master cylinders you have are already 1/2" then you don't need the intensifiers, nor will they work
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  15. 109jb added a post in a topic Brakes For Tundra Tires   

    On the 582 powered Kitfox 4 I sold last year, I had single puck Matco brakes with 1/2" bore Matco master cylinders. I ran the Nanco 21" tires. The brakes would not hold for a full throttle run-up, but almost. I never felt they were lacking on landing though. On my rebuild I am using the same master cylinders but putting on 2 calipers per wheel.
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