The BlueJay Build -- Part 3

 The Thrifty Rocketeer blog continues with part 3 of the BlueJay Build...

Make a mark 1/4" from the end of the spent motor casing. This will be your limit mark. In the coming step, when inserting the motor block and glue, DO NOT push the spent motor casing in farther than this mark. This assures that you can grip the motor to pull it out quickly, AND that it will not be glued inside the body tube.

Tie the motor block ring to the spent motor casing using an overhand knot or slip knot or two half hitches....whatever you like, as the next step will be to secure the knot with a drop of glue. Trim the loose stub of the Kevlar string off, and then remove the spent motor from  the loop. This assures that the motor block ring is lassoed by the Kevlar, but is free to move about, trapped on the loop.

The next step is to spread a band of glue 2 1/4" down inside the REAR END of the body tube. This band of glue will seize the motor block in the next motion when shoved into place by the spent motor.  Make certain you have ahold of the REAR end of the body tube, where you have recently glued the sky hook unit and the launch lug. DO NOT APPLY GLUE TO THE TOP END OF THE BODY TUBE by mistake.

Once the band of glue is inside the rear of the body tube, rotate the body tube so that the glue encircles the inside of the tube, and then begin to insert the motor block ring, trailing the Kevlar string. Using one swift motion, insert the spent motor by shoving the motor block ring ahead of it into the tube. STOP AT THE MARK 1/4" FROM THE END OF THE MOTOR CASING, and QUICKLY WITHDRAW THE MOTOR WITH A TWISTING MOTION.  Do not pull the string or motor block back out. It is in place at the correct location to block new motors and apply their force at the correct point of the booster rocket, underneath the sky hook pod unit and the launch lug.   Set the body tube aside for the motor block to dry in the glue.

When the glue has dried, feed the remainder of the Kevlar string through the body tube and secure it to the nosecone at the screw eye. Use a drop of glue to secure the knot you tied to the nosecone.  Attach the streamer to the Kevlar string with the adhesive tape and roll the streamer tightly enough to fit into the body tube. You will add dog barf or recovery wadding BEFORE the streamer when preparing to launch.

Note: The adhesive sticker that was included in my kit appears to have been a pegboard hanger, with a hole punched in either end of the plastic strip. Only the center portion, near the fold, had adhesive.  I struggled with different orientations of how do position it, and determined  that it should not be used.

Instead, cut a piece of sealing tape the same length as the streamer is wide. (That is, 2" long if your crepe paper streamer is 2" wide.)  Lay the tape on the table sticky side up.  Position the end of the streamer halfway up the tape and press down onto the adhesive, aligning the edges.  Fold the top half of the tape down over the streamer and seal the end in a "sandwich" of tape.  Use a hand-held hole punch to pierce the center of your plastic and thread the shock cord through the hole.

                                       

I like this last option the best, as it utilizes the holes, and sandwiches the streamer. However, the tying of the Kevlar string could be difficult since we have already tied the end to the nosecone and glued the knot.  An alternative might be to make a loop in the Kevlar, feed it through the holes and tie it back upon itself.  This would rely on the strength of the holes to keep the streamer attached. 

The Final Step, if you have not already completed it, is to glue the tail wing up against the end of the spine (keel) of the glider.  This will hold the tail at a constant upturned angle, and make any wind-flow over the tail give the gilder lift.  To accomplish this, spread a little glue on the exposed notch of the spine without any excess spilling over to add weight. Use a clothes pin to compress the spine and the fin together and hold while drying. (Make certain no glue squeezes out and adheres the clothes pin to the glider. This is a temporary clamp that works well.)  Let this dry well before releasing and removing the clothes pin clamp.

This completes the construction of the BlueJay.  The next step is to trim the flight and balance the bird with a bit of modeling clay from the kit.

On a mild day, not too humid with a gentle wind, take only the   glider outside and face into the wind. Grasping the glider by the spinel , under the pod hook unit, toss the glider lightly forward like you were pitching a ball.  Watch the flight.   If the glider bobs up and stalls multiple times, (like a fish feeding at the surface of a lake) you need to add a bit of clay into the eyelet hole at the nose end of the keel.  Relaunch into the wind again and observe the flight..

If the glider continues to bob, add more clay.   If the BlueJay glider nose dives, you have added a little too much and must subtract some clay.

Also, once the glider has been balanced, you need to observe the flight for curving left or right.  If the glider sharply curves to one side or the other, add a bit of clay to the leading edge of the wing opposite the curve.  In other words, if it curves to the right, add clay to leading edge of the left wing about two inches away from the fuselage.  

Continue tuning and balancing the glider until you have a smoothing gliding aircraft. HOWEVER, you WANT some curve to your flight, so that the glider will circle back to your launch point.  Failure to have SOME curve will result in a long, straight glide and require a LONG WALK to retrieve the glider.  BEWARE:  While it is possible to tune and balance the glider to perfect balance, you do not want to achieve this goal.

You should be ready for your maiden launch.
But wait, you say, shouldn't this be painted?

A word about paint color choices:   I traditionally paint my nosecone's red, and in this unit, I sealed the nosecone in prep for a light coat of red paint.  However, you have a brightly colored streamer, that as long as it remains attached, should help you spot the unit during recovery much better than a small red nosecone.  You could paint the whole body tube orange or red to aid in visibility, but that would clash with the color scheme of the BLUEjay.

Likewise, any color other than blue might not make sense, but it's up to you. Remember the trade off between weight and appearance.

Yes, you could spray a LIGHT coat of paint over your glider and launch pod (masking off the lip of the nosecone, and the teeth of the hook).  However, paint adds weight, and gliders perform better with lighter weight.

Store your BlueJay in a low humidity environment, as moisture and time will warp the wings and the tail section.  The glider relies upon the tail section's cant to achieve lift.  For this reason, you MIGHT want to paint the glider, but you sacrifice lift for life span. 

If you decide to paint your glider, I would like to see your color choices.

Send your digital photo to The Thrifty Rocketeer, or attach in the comments below.

***EDIT: After the first launch with this orange crepe paper streamer, the paper began to tear below the plastic hanger.  I found when rolling the streamer, the plastic was too stiff to bend. It tended to spring open, pinning the paper roll inside the body tube.

A much better option is to skip that stiff hanger completely.  Get a roll of sealing tape and cut off a square that is exactly as long as the crepe paper streamer is wide.  If that's a 2" streamer, cut off a 2" length of the sealing tape.  Apply this over one end of your streamer.  You've just created a sandwich over the end of your streamer.  Use a HAND PUNCH to pierce a nice clean hole in the middle of the tape.  This should last you awhile, until the crepe paper begins to tear after several launches.  Then, you can cut off the shredding top and repeat this process for another re-enforced tape leader with hole punch.