Maly Modelarz Bz-4

Discussion in 'Aircraft & Aviation' started by Darwin, Dec 8, 2005.

  1. Darwin

    Darwin Member

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    The problem with helicopters is you can't stop with just one. Doing the Airwolf gave me the incentive to start a project that has been at least a year on the back burner. At least a year ago I did a redraw of the Maly Modelarz Bz-4, and got as far as printing out a set of parts when distracted by a couple of ship projects. There have been a few minor little problems so far....the parts were printed out using an Epson 740, which has since had the drive gears give up the ghost and was replaced by an Epson photo 820. During the build so far, the house ate a couple of parts. When they were reprinted, there was a very obvious color difference....same files, printed with the same image processing program, but the new parts have a color shift into the green range. Printers do have a definite effect on color fidelity. (If any one is interested, the older 740 printer gave colors much closer to that of the image file than does the 820.) And, an initial dryfit of the fuselage skin gives warning of some fit problems (fortunately, too large rather than too small, so some judicious trimming may salvage the build without going back to the drawing board.) I hesitate to say the problem lies with the original design....any build made from an extensive redraw casts a big question on whether the problem lies in the original design or the scan/redraw/print process. Here are a few pics of progress to date.

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  2. josve

    josve Active Member

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    Nice! Seems to be a great project.

    What do you mean when you do a "redraw" ?
    (maybe a stupid question)
  3. Darwin

    Darwin Member

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    As you may have gathered from some of the discussion strings, Maly Modelarz kits prior to about 1995 had horrible print and paper quality. However, they have some great subjects and, although the kits were more simplistic than current designs, they were ususally quite buildable. The redrawing process I refer to is to scan the model kit, then import the files into a 2D graphics program and literally redraw and recolor the parts (after manipulating the image size if I also want to change the scale of the model). If there are known fit problems, I try to make corrections during the redrawing process, and sometimes redesign portions of the kit to bring it into line with current building techniques (like eliminating tabs and replacing with joining strips, making an eggcrate framework for JSC ship kits, replacing graphically-depicted details with three-dimensional parts) and to refine poorly depicted parts in the original (such as replacing rectangular doors with oval (or rounded corner) water-tight doors). Since my paper supply is in American dimensions rather than European, I also use this as an opportunity to rekit the parts onto letter (or legal) size pages for printing. In cases where the part really needs coloring on both sides (like ship railings), I also create a page file for the back side of such pages. I then print the redrawn pages out onto appropriate thickness (and quality and texture) cardstock or bond paper. Admittedly, it would be a whole lot easier just to buy a modern kit, but I find the challenge of making a silk purse out of a sow's ear is as much, if not more, fun than the actual build. I've also found that, in the process of doing the redraw, I have pretty well figured out how to do the build before the first paper scraps fly.
  4. Darwin

    Darwin Member

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    Finished the fuselage. When I dry fit the fuselage skin segment containing the doors, it was too long. I figured I could correct that by cutting the piece into three segments ( roof and the two sides), and make length adjustments on the roof part. Well, fit problems cropped up everywhere in the canopy. Turns out that the instructions did not show the correct side view of the canopy former. The instructions showed a break in the former where the middle canopy bow attached, and the top of the former had the same slope completely to the top of the canopy (see photos of the frame in the first posting). To make things fit, the canopy former also has a break where the upper canopy bow attaches, and the side view of the top portion of the canopy former is vertical, not slanted. When I made that correction, it effectively increased the circumferance of the cabin cross section....turns out the length of the cabin skin piece was right to begin with, and I didn't need to cut it into sections. No more fit/alignment problems....the only problem with the fit is due to inadequate builder skills.

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  5. Darwin

    Darwin Member

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    I really hope some of the older hands give some feedback on the redraw, and whether or not they think the effort was worth it.

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  6. mOONwOKA

    mOONwOKA Member

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    Nice build, Darwin. I agree, redrawing a kit adds more fun to our hobby. In plastic modeling it's much easier to get diversity - just to paint different colors and use different decals (well, in most cases) :)

    In card modeling you usually get one subject for all and it involves more creativity to make something different, that is printed. I did this with my submarine "United" and found it to be great fun. Keep up good work
  7. Darwin

    Darwin Member

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    Closing in on the end of the build. The wheels still need to be chucked up on the Dremel tool and sanded down, plus the blades and a few other small details.

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  8. cygielski

    cygielski Member

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    How solid is the tail boom? Did you impregnate it with anything? Very interesting build of a rare design - I may have to get out there and try out a helicopter build myself.
  9. Bowdenja

    Bowdenja Active Member

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    Darwin,

    It looks amazing. I do not know this copter, but I'm interested now!

    For a pre-2000 Maly, you HAVE done a lot of re-work! Beautiful job!

    john
  10. Darwin

    Darwin Member

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    Simon, the tail boom is a lot stronger than it looks. I superglued florist's wire down the inside of the two upper folds of the boom. The lower beam, being where the join is made, came out fairly stiff after the glue dried, and the wires in the upper portion of the boom privide plenty of load-bearing strength, even without the rotor drive shaft wire. The strengthening wires extend clear to the back cabin former, passing through one bulkhead and the skin, so there is plenty of resistance to the bending moment of the tail structure. I also painted the backs of the boom cross-beams with superglue to stiffen them up. I was initially thinking of building the boom from 1/20-inch square basswood strips (and drew up the patterns for building, just like for my old gum-band freeflight models), but decided at the last minute just to do the build as originally designed.

    Since this was one of my older redraws, it was done on my old "idiot" computer, which was lucky to have enough memory to figure out how to boot, and I limited the image resolution for the redraw to 100 dpi. Very noticeable jaggies in the curves. I think this project does illustrate that the deficiencies of the older Maly models lies in print and paper quality, and not parts fit. Speaking of which, I have encountered another minor problem with the original design. The wire used as a stiffener in the main rotor blade should be about an inch longer in order to use it to plug the blade into the rotor hub. I think I can get around it by using some small diameter tubing to splice some more wire onto the blades built "by the book" and thus salvage them.

    John, you should try a heliochopper or two....but I warn you, they are addictive. With the four wheeled LG of this one, I'm reminded of some of the old aerocar designs, only with rotary rather than fixed wings.