Fei Bao MiG-21 Fishbed Instruction Manual - Introduction
Fei Bao MiG-21 Fishbed Instruction Manual (Draft Rev 0)
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A.
Introduction
You have chosen a model that represents the pinnacle of ARF technology. While there is not a
lot of building to do, there is enough to keep you busy for a few evenings. Even if you have
assembled maybe other ARF jets, we highly recommend following our assembly sequence and
procedures anyway. Chances are it will save you a lot of time, prevent you from running down
dead ends, and perhaps remind you of a few small things that might end up saving your aircraft.
We have tried to arrange a construction sequence that will allow you to keep moving forward,
rather than standing around waiting for glue to dry before you can proceed to the next step.
Just because the model is almost completely built does not mean you can rush through the final
assembly.
You need to employ fine craftsmanship every step of the way, turbine models are critical. Keep
this in mind with everything you do, every part you install, look at the work you just did, evaluate
it critically, and ask yourself "is this going to potentially crash my airplane?" If there is any doubt
about the work you have done, back up, and re-do it properly.
B.
Adhesives
The correct adhesive to use for all procedures is Loctite Hysol 9462. This is a very strong white
epoxy that is thixotropic. "Thixotropic" means it does not run at all, but stays only where you put
it. It is infinitely superior to regular epoxy, even slow-setting epoxy, for our purposes, because
of this characteristic. Regular epoxy will run downhill with gravity as it dries, taking it away from
where it is supposed to be. A good example is in the hinges ... using regular epoxy, a good
portion of the glue will migrate down away from the hinge into the inside of the wing as it dries,
and you won't even know it is happening. Hysol stays where you put it. The downside of Hysol
is it takes overnight to dry properly, but we have tried to arrange things to keep you busy while
waiting for glue to dry. We also highly recommend that you only use a proper Hysol dispensing
gun, and only the long-type mixing nozzles. The short nozzles do not sufficiently mix this glue,
and only a thin nozzle and gun will let you fill the hinge and control horn holes properly with
glue; you can't do it mixing your Hysol on a flat surface and trying to get the glue in the proper
place by a brush or stick. You can buy a complete Hysol setup with a gun, nozzles, and two
cartridges of glue from your dealer for approximately $60. Consider it a great investment, the
glue is the best you will use. One cartridge is plenty to assemble your MiG-21 Fishbed.
C.
Using Pneumatic Systems
The Fei Bao MiG-21 Fishbed uses pneumatic brakes and retracts. If you follow a few tips, you
should have very reliable, leak-free operation. Neatness counts. All airlines should be secured
to the airframe to keep them from flopping around or getting kinked. Use tie wraps for this. The
other very important thing is to cut off the end of each airline dead square before installing it on
the nipple. This is VITAL. You can either purchase a professional tubing cutter from your
dealer (they are approximately $10), or you can make up a little jig to hold the airline and keep
a sharp, new razor blade perfectly upright as you cut. Either one works, just ensure that all
ends of all airlines are cut off dead square. Make sure all airlines are pushed ALL THE WAY
onto their nipples. They should not need to be secured otherwise, but you can add fine wire
safety wraps if you like. Make sure all left and right matching airlines are the same length,
particularly the brake lines, or you will get uneven retraction or braking action. It's worth taking