109jb

Members
  • Content count

    217
  • Joined

  • Last visited


Everything posted by 109jb

  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.


    • 3 replies
    • 102 views
  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.
    • 0
  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,
    • 2 replies
    • 85 views
  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.


    • 1
  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.
    • 1
  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
     
    • 0
  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.

    • 3
  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.
     
    • 0
  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. 


    • 0
  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.
    • 0
  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.
     

    • 1
  12. 109jb added a post in a topic Brakes For Tundra Tires   

    MC-1 and MC-3 are already 1/2" bore. 
    • 0
  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?
    • 0
  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
    • 0
  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.
    • 0
  16. 109jb added a post in a topic Avid MK4 For Sale.   

    He doesn't fit in it well and decided to sell, but after reading threads on here is having second thoughts about it and considering modding it to fit him better.
    • 0
  17. 109jb added a post in a topic Avid MK4 For Sale.   

    I disagree to an extent. With a flying airplane you know what you have. You have everything to make it fly with the exception of what you need for the mods. With an unfinished project, is something missing? Is everything there for the engine install, instruments, etc.  I am currently rebuilding a Kitfox 4 that was a flying airplane that was involved in a nose over and except for my changes everything is there and I know it was working. From the sound of it, you are looking to do a stretch type mod involving recovering the fuselage. I don't see what difference it makes if it was flying first or not. The fuselage can be uncovered in an hour with a pocket knife. You would also have the benefit of wings and tail surfaces already covered and set to go if you don't decide to mod them. I think if it were me, and I decided to do the mods I'd just do it. Heck on mine, I could have just  done the repairs and had a big patch on the fuselage covering and it would have flown, but I decided to make more changes. Just my 2 cents.
    • 0
  18. 109jb added a post in a topic Bush gear failures   

    Holy Cow are those expensive.  Why not just use the McMaster Carr urethane tubes I posted above? 50mm is close to 2" and 25mm is close to 1"
    • 0
  19. 109jb added a post in a topic Bush gear failures   

    I've been thinking about making new struts for my gear and using snowmobile springs and then saw this. My setup currently would use bungees. Here in the USA, Mcmaster Carr has the 90A durometer tubes for sale, here are some links:
    https://www.mcmaster.com/87235K58 6" long tube 2" OD, 1" ID 90A durometer
    https://www.mcmaster.com/87235K32 Same thing but 36" long and much better price per inch.
    I may have to give this a go.
     
    • 1
  20. 109jb added a post in a topic Cabane Gear for the Avid+   

    If you don't mind me asking, how much did the acme aero shocks cost?
    • 0
  21. 109jb added a post in a topic Another Kitfox IV rebuild project   

    Had about 1-1/2 hours this morning and got the side fabric stuck back down and the new top fabric on. Heat shrunk everything and longerons still straight. Then tonight I got all of the tapes on and put the first 2 cross coats of primer. 2 more cross coats and I'll be back to where I was. Looks good and the only way you can tell anything was done is because the corner tapes aren't continuous from tail to turtledeck. Hardly noticable even if you know what you are looking for. Lost 3 evenings of work on the airplane but glad I fixed this instead of having to look at it for years and years.  

    • 0
  22. 109jb added a post in a topic Another Kitfox IV rebuild project   

    Took a step backward today. While painting I noticed that the longerons had pulled in at one location from fabric tension. An Internet search revealed that at least on the model 4 and earlier the final shrink temp should be 300 deg. F, whereas I used the 350 stated in all of the fabric covering manuals. I have the build manual for the airplane but it did not have the fabric covering section otherwise I may have caught it in there. Anyway, I checked the rest of the airplane and only the one bay on top pulled in like this. All others were fine. So I had to pull the top fabric and peel the side fabric from the bay in question. Once I did that the tubes were once again straight. No damage, just a setback and a little fabric and tape to re-do. Worst part was cleaning all the glue to prep for re-attaching.



    These tubes are also the same location that incurred the trailering damage on my previous Kitfox, and I have seen many examples of damage in this area on various sites and forums. Most I've seen were trailering damage, but I remember at least a couple that were landing damage. It all adds up to this location being a weak link in the fuselage truss. I had thought about reinforcing this bay before covering and now wish I had welded in some tubes. Since there is still fabric everywhere except that last top panel, I couldn't weld now, or at least it would be problematic, so I decided to fabricate some diagonal reinforcements and install them with structural epoxy. Each end of the 3/8 x 0.035 cross tubes have a half section of 9/16 x 0.035 tube welded on to form a saddle over the longerons. As noted they were then installed with structural epoxy.



    Hopefully tomorrow I'll get the side pieces re-attached and a new piece of fabric on top with the tapes and hopefully at least one coat of the primer.
    • 0
  23. 109jb added a post in a topic Another Kitfox IV rebuild project   

    Well I'm committed now. Here is a picture with the first cross-coat of latex primer on. I now have the second one on and it is going well. Hope to be painting color on it this weekend.
     
     

    • 1
  24. 109jb added a post in a topic Avid MK4 For Sale.   

    Nice looking airplane.
    • 0
  25. 109jb added a post in a topic Learning How to Cover a Plane   

    https://www.youtube.com/c/StewartSystems/videos
    The above link is for Stewart Systems youtube channel. They are one of the most popular covering systems out there right now.
    https://www.youtube.com/c/ConsolidatedAircraftCoatings/videos
    This one is the consolidated coating youtube channel. They are probably the most popular aircraft covering, previously known as Stits, now polyfiber. 
    I have used polyfiber a couple times in the past and am using the Stewart method for attaching the fabric and tapes on my Kitfox project. I much prefer the Stewart System method for this.  I am deviating from their system from the tape attachment step and using latex paint for the final finish. The method for that can be found here:
    http://wienerdogaero.com/Latex.php
     
    • 1