Parachute drop box

In this article, I will show how I made a parachute drop box out of scrap foam board. 

I live in the beautiful state of Colorado, the problem is that in the middle of winter the weekends are usually cold and windy.  Now, during the week, while I'm at work, it is beautiful outside. So, what do you do on a cold/windy day??  Why not build a parachute drop box.  So on to the build:

What you will need:

• 5” x 6” piece of foam board.
• 8” x 2” piece of poster board
• one 9g servo
• Control horn (I used a dental floss handle)
• ~2” pushrod
• 2 BBQ skewers 
• Parachute men (My wife got me mine from the grocery store)

 The Build

Start off cutting out the foam board based on the image below. The resulting box will be the same width and height as the power-pod design, so if you want you can print it out and use it as a template.  Just note that you will want a flush top, and you will cut it straight across 5 3/4in from the back.

 The center “cut out” will make the bay door for the drop box.  ***When the box is folded, make sure there is not a lip inside the box that would cause the parachute to not easily drop out. 

After cutting 3 sides and score cutting the 4^th side (on the back side), use your razor blade to bevel cut all of the sides so the door opens and closes easily.

Now that the door is cut out, you need to cut a hole for your servo to fit in.  I cut my servo hole off-center a bit so the servo arm will mount in the center.

Once you have everything cut, glue the two sides up (not the servo wall) using A folds to form a U. 

From there, glue the servo into the servo hole and attach on the servo control arm (do not put the screw in yet).  With the servo in, you need to fold the servo wall in place.  Use the servo arm as a guide to align the servo arm slightly over the door.  Keep in mind that if you are using an easy push rod connector it will extend a little bit past the control arm.

Once all of the sides are glued up, cut out some scrap and glue it in place to make the box sturdier.

Installation of the control horn and push rod:

I used a modified dental floss handle as my control horn, but you can use whatever you have handy.  I wish I could give you a simple mark for how to put this in correctly, but I had to re-glue mine a few time to get the door to open and close well.  What I have learned is that you want your servo to open the door all the way.  The picture below shows the door opening 1 inch.  After testing this a bit, it is NOT enough.  The parachute will come out, but you have to pack it so tightly that the parachute will not open on its way down.  Play with the push rod length, and the control arm until you are able to get the door to fully open.  Note:  it is more important that the door opens fully than closes fully.

After you are happy with the way your door opens and closes it’s time to finish this project up.

Cut out a piece of scrap that can be glued between your servo arm and the main portion of the box.  This will keep your parachute from hanging up on the servo.

Cut a hole in one side of the foam board to pass your servo wire through.

Wrap the exterior of the box with a piece of poster board either by gluing or taping it on.

Measure out and put holes through the box so you can mount it to your plane. 

Mount the box and then give it a try. 

I’ve been using mine on my FT Old Speedster. 

 And finally, some video of parachute drops.

Safety notes:

I do my best to fly as safe as reasonably possible.  I fly at a local park that isn’t very busy, but on occasion there are kids around that are interested in the plane. The falling parachute will attract kids, so please be mindful of that.  It’s better to turn your plane into a scrap pile than risk the safety of others.  Also, if they do come up to you, use the opportunity to talk about the hobby and try to spread the fun.  You never know, you could inspire the next generation of scientists.

Something to consider:  If you fly upwind and release the parachute as your plane is starting to fly away from you the parachute will usually land well behind you.