Scratch Push Me Pull You Original Design / Scratch Built

Scratch - Push Me Pull You {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
(Contributed - by Dick Stafford - 11/01/02)

Brief:
This is two-motor, two-winged helicopter model that employs MicroMaxx motors. Thus, it's a bi-copter as opposed to monocopter. The Push Me Pull You uses cardstock construction and is based on a design concept developed by Art Applewhite for his Mark 4 monocopter. You can see his Mark 4 in the files section of the MicroMaxRockets Yahoo group, or on his site.

Construction:
You will need enough card stock to cut out the components shown below, and a piece of an ink tube from a BiC pen (or equivalent). To construct it, you'll need a ruler, Exacto knife, and white glue.

The component measurements and step-by-step instructions are included in the attached diagram. You should also refer to the two photographs during construction. I have to apologize but I built the bi-copter 'on the fly' and backed into the plans - just like software design, eh ;-)? As noted in Step 3, there is one possible issue with those plans. But don't fret, if you refer to the figures, this should become clear while you are constructing the model.


Rocket Pic
Rocket Pic

Flight:
Since the two motors are so far apart, I made an igniter by removing the plastic shell from two MicroMaxx igniters and soldering on wire pigtails. For my first igniter pair, I used stiff wire, which was hard to deal with. For the second set, I used flexible 30 gauge wire-wrap wire.

For a launcher, I clamped a piece of wire from a thick paper clip into a low power pad that I made from a drill chuck. I used a second piece of ink tube as a standoff to keep the monocopter elevated. You must make sure that nothing will obstruct the wings, which hang below the plane formed by the beams. To supply the juice, I used my Pratt GO Box.

I removed the ejection charge from the motors and used some tape to hold them in. The bi-copter flew great to an altitude of about 20-25 feet

Summary:
This is a unique-looking rocket and flies great. You should give it a try, and while you're at it, build one of Art's Mark 4's also.

Rocket Pic

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