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jpolenek

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About jpolenek

  • Rank
    Member

Personal Information

  • Real Name (Public)
    Joe Polenek
  • Location (Public)
    Guelph, Ontario

Flying Information

  • Flying Status
    Katana DA20

Project/Build Information

  • Plane
    Cozy Mark IV
  • Plans Number
    1550
  • Chapter
    14

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  1. How are some plastic planes (e.g. Lancair) able to get away with such dark color schemes? Sure, they're made of carbon, but isn't it the epoxy that softens in the sun? Joe Polenek Cozy Mk IV #1550
  2. I'm noticing that the top spar cap templates for B.L.52 and B.L.67.5 are slightly curved in addition to being tapered. Is the purpose of this curvature to make the top of the completed spar follow the shape of the airfoil more closely in that area? What's confusing me is that the plans don't mention the curvature, and sections C-C and D-D do not show it either. Joe Cozy Mk IV #1550
  3. I don't have LongEZ plans as I am building a Cozy, but thanks for the info. It confirms that if I go ahead with a modification that would make a part of the fuselage sides flat, it will still look ok. Joe Polenek
  4. Purely out of curiosity, is there a portion of the LongEZ fuselage side that is straight (flat) or is there curvature throughout the entire length like the Cozy? Joe Polenek
  5. ...and the scale can still be useful later on for periodic verification/calibration of the pump. Joe Polenek
  6. In the canard video that I bought from Aircraft Spruce, the LongEZ guy says that his project didn't really take away from family time because his kids were involved. When I work on my Cozy, I find that A LOT of time is spent working with epoxy, making dust, or operating power tools, none of which are good environments for small children. At this point, my kids are too small to participate in my project, but it would be nice to have them with me, even if they putter around doing something else. Could I get some suggestions on how to involve the kids? When are they old enough? How can I make it safe and fun for them, and still be able to work on the plane? Joe Polenek
  7. Back to the Cory Bird method... If you're using MGS335 fast epoxy and let a coat cure to the point where it has lost most of its tackiness (e.g. 1 hour), is there enough potential crosslinking left in the epoxy to provide good adhesion with the next layer? In other words, does it have to be wet-on-wet, or can it be wet-on-semi-tacky? Joe Polenek
  8. While working on the bottom surface of my canard, I've discovered that the trailing edge is about 1/16" too short, according to the Canard Bottom Contour Checking Template. Should I... (1) Repair the canard TE to extend it. (2) Leave the canard TE short but install the elevators forward by 1/16" so their position relative to the canard TE is correct. (3) Don't worry about it. Proceed per plans. Joe Polenek
  9. I'm planning to use this technique on a surface which I have filled & sanded to the shape I want, and it is quite smooth (maybe 120 grit or better). If I try to rough it up with coarse grit at this point, the sandpaper will take more out of the filled areas than the glass areas, and that would change the shape. Is the 36 grit finish intended to avoid unnecessary fine sanding since the epoxy will fill the grooves anyway, or is it required in order to provide more surface area for improved adhesion? Joe Polenek
  10. A while ago, I downloaded the attached photo but can't remember who posted it. Can somebody tell me if they were successful at getting the plane out without damaging it or the house. I'm looking at moving to a new house and would like to determine if I NEED a double garage door, or if two singles will also work. Joe Polenek
  11. Apparently, Wick's still sells it. It's called "Building The Rutan Composites". Probably still only available in VHS, though. Joe Polenek
  12. True. And the process of removing the cross stitch further distorts the fibers, even if you hold down the UND to stabilize it as the plans state. When I did my spar cap, I let the UND hang several inches over the edge on both ends. This allowed me to give each bundle of UND a little tug, first from one end, then the other. Looking at the spar cap while doing this, it was evident how much this tension was straightening the fibers. I did this a few times throughout the squeegeeing process for each layer of UND. For the pieces that were shorter than the full span, the technique had to be modified a little, but is was still possible to pull on the strands to straighten them. Joe Polenek
  13. Depending on where you live, you should be able to find it locally. I got my microballoons and flocked cotton from the local fiberglass supplier. They, in turn, needed to order the flocked cotton from another local supplier that specializes in boat-building. Joe Polenek
  14. The way the plans are written, you do the right wing first to the end of Ch19, and then start the chapter all over again for the left wing. As Lynn Erickson points out, doing both wings simultaneously would require two tables, two sets of jigs, etc. Another option is to flip-flop between right and left wing as you work through the chapter, which is what I did. This means that you do one wing to a certain point (preferably the right one since the plans are written for the right), put it aside and do the next wing to the same point. Then continue with the right again, etc. My initial reason for doing this was to reduce the cost of mandatory inspections (Canada) by having the shear webs for both wings and the canard complete at the same time. An advantage of this method, which I did not anticipate, was that it enabled me to achieve more consistent jigging, methodology, etc. between right and left because the techniques and tricks were fresh in my mind. Some parts that did not require extensive jigging could still be done at the same time for both wings. (e.g. wire cutting, wing attachment depressions, etc.). This is probably not as big a deal if you can complete a wing in its entirety within a short period of time so you can remember it all for the other side, but if you're on the 10- to 15-year plan like me, a lot of time could go by between one wing and the next. Joe Polenek
  15. As it turned out, I over-filled the canard bottom spar cap a bit - overall about 1/32", and a few 1/16" bumps. I guess I was afraid of underfilling it and compromising strength because of insufficient UND, but went too far the other way. For some reason, using the template to control the layup height, as suggested by others, didn't work that well for me. After trying to hand sand it with a block and messing around with all the clogged sandpaper, I realized how much effort it took to make miniscule progress. Bumps come out pretty fast, but it really slows down when trying to reduce an entire surface by hand. So I went out on a limb and picked up a small belt sander... and it worked GREAT! I started off with a 50 grit belt, and then 80 grit. Finally, I switched to hand sanding with a 80 grit block followed by a 120. The method I used was to check the profile against the template every inch or so along the entire length of the spar cap, and mark the high spots with a Sharpie. The markings were then sanded away, and the whole process of checking and marking started over again. This was repeated until there were no more high spots to mark. (Also, lots of vacuuming between sanding passes was needed to prevent blockage of sandpaper/belt.) I have to say that I couldn't have asked for better results. For future spar cap lay-ups, I will try to use the template more effectively to control the spar cap height and avoid so much sanding, but it's nice to know there's a backup plan that seems to work. Joe Polenek
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