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Science Rocks!

Door Opener


your results

Sent in by:
Becky of Valparaiso, IN

Simply open the door...from across the room!

Materials Needed

  • a door
  • rope
  • string
  • straws
  • bamboo skewers
  • tape
  • rulers
  • wire clothes hangers
  • rubber bands
  • spool of thread
  • paper and pencil



  1. Design a contraption that will help you open a door, even when you're across the room.
  2. You can use rope, string, straws, bamboo skewers, tape, rulers, wire clothes hangers, rubber bands and a spool of thread.
  3. The ZOOMers drew their designs on paper before they began building. This made it easier for them to see how their designs solved the problem of turning the doorknob and opening the door.
  4. You may want to ask a few friends to help you come up with ideas. Then, try them out!

How are you using the ruler? Does the spool of thread make it easier to open the door? What other problems could you solve using the same materials? Could you find a way to turn your light switch on and off? How about opening a cabinet to get a snack while you're on the couch? If you come up with any problems along with some great designs to solve them, be sure to send them to ZOOM!

Some of your Results

Madisen, age 11 of Gresham, OR wrote:
Some stuff I didn't have. Plus, I didn't want to have duct tape across my floor. My parents wouldn't like that. So, I decided to run it along the ceiling. What I did was tie strong string to the part of my door that you push down (or up) to open the door. Then I screwed in (which took a long time cuz u have to screw it by hand!!!) a thing u run the string through to the wooden thing that goes around your door (because u can only screw those things into wood). Then I ran the string through that, then screwed in another one of those things to my window frame (which is wood). Cause' my window is right next to my bed, I ran the string through that. Then I pulled it down and... the handle went up! But the door did not open... yet! Next I tied string around door knob, and ran it through another one of those screws which was screwed into my board behind my door. Next I strung the string through the window frame screw again. But then when I let the string hang, my parents would get stuck by the string! So, I tied weights to the string so it would be tight at all times. Now to test it. First I pulled on the string that pulls up the door knob. Next, I pulled the other string to open the door... and tada! It worked! I was really proud of my self. It was really helpful and fun to make too!

Esmeralda of San Antonio, TX wrote:
When I was trying to turn the doorknob with the rope the other month, the door almost open, but it didn't.

Jared of Orlando, FL wrote:
It was Halloween and I wanted to scare some kids with a self opening door. so a few hours early I installed my contraption and it worked like a charm. I just had to keep tape on the latch.

Brook, age 11 of Caro, MI wrote:
The first time it fell off. But then I got it!!!

Nadia, age 11 of Pontiac, MI wrote:
it slipped straight open

Usman, age 10 of Cambridge, ON wrote:
Frist I tied one end of the string to the door knob. Then on the wall I put a paper towel roll to act as a pulley. When I tried the door opener the paper towel roll went flying like an airplane that's out of control. Even if it did not work I had lots of fun trying to make a door opener.

Daisy, age 10 of TX wrote:
o used a mashin and my door opened by its self

Verquell, age 10 of Milwaukee, WI wrote:
Me and my sister keep doing it over and over and over agine it was cooooool.

Damaris, age 8 of Lynn, MA wrote:
When I did it really opened.

Alex, age 10 of Brampton, ON wrote:
I had a string tied and then wrapped around the knob. when I pulled the string the knob twisted and the door opened!

Brian & Preston of ID wrote:
Since My bed and my brothers bed are not directly in front of our door, I used a spool to redirect the direction of the string like so.

Mark, age 10 of Tonopah, AZ wrote:
I tied it around the door knob and taped the end so it wont come off then I put tape around a spool of thread and around to the back thenput the string through the spool. Next just do the same thing below to keep the top spool in place then just pull and it open'd.

Hannah, age 6 of Columbus, OH wrote:
I made a contraption with string to open the cabinet door. I put a rubberband around the door knob and taped the rubberband to the string and opened the cabinet by pulling the string.

Sara, age 8 of Ajax, ON wrote:
The firs time I tried it it didn't work because insted of using duct tape I had to use masking tape. And another posibility could be that my bed is infront of the door. I was going to use duct tape but I couldn't find it so I willtry agian onse I find the tape.

Corin, age 11 of Austin, TX wrote:
Remember when you did the door opener? Well instead I used string and tied it outside the door and it worked!

Irene, age 8 of Baton Rouge, LA wrote:
I used green tape, clear tape and rubber bands. I pulled the rope and it opened

Lindsey, Allison, Lauren of LA wrote:
I did this with my friends, Allison and Lauren. It worked!! We also figured out how to turn off and on your lightswitch without getting out of bed!!

Tyesha, age 12 of Toccoa, GA wrote:
The first time I did It the tape broked because, when I put the string on my door handle I did not wrap it. So the second time I did it, I taped it on the end and then wraped it and taped it again and it worked.

Jaskeline, age 8 of Chula Vista, CA wrote:
It woorked it out and now when ever Im sleeping and mi mom knoks I could just open it without standing up.

Olivia, age 12 of San Francisco, CA wrote:
I tried using a coat hanger and taped it to the door. Then I attached two strings to the hanger. Then I sat on the bed and tried it. It worked.

Emily, age 11 of Fergus Falls, MN wrote:
My little brother always trys to make "traps" but usually they don't work. When I saw on TV that you made a contraption that would open and close doors by just pulling a string I just had to try it. All I used was tape, rubber bands and string and it works! My brother went crazy when all he had to do is pull a string and the door would all by itself open and close!

Kelly, age 14 of Pickering wrote:
I tried using paperclips. First I put them all together. Then I tied a string on the end and taped it to the door. Then I tied another string and taped it on my bed. Guess what... It worked.

Deblina, age 9 of Monmouth Jct, NJ wrote:
I did it with two pieces of string. I used 1 string for twisting and 1 for pulling. It worked very good!

Ian, age 8 of Sunnyvale, CA wrote:
I used a lot of tape on this project for the first try, but it diddn't work. On the last try,(I made it that time) I used my bed as a structure becauseit was a bunkbed. I also used a type of string that was really strong. P. S. I loved it!

Bibek, age 8 of Sunnyvale, CA wrote:
Well, my bed is next to my wall, so my door is right in front of my bed. I only used duct tape and yarn and it worked! I tied the string to my door knob and then I taped the other end next to my bed and when I need to pull I just lift the yarn and pull as far as possible then swung the yarn back and forth to open and close my door!

Ciana, age 12 of Eugene, OR wrote:
I tryed closing my door instead of opening and it worked. I tied a thread roll on the back of the door, (I used string). I taped hangers to the door and ran the string threw them and pulled the string to my bed. With the sring roll I measured how much I would need to open the door and then put the string in the slit (on the string roll ).

Rachel, age 11 of Cumming, GA wrote:
When I tried it the first time it worked great! All I used was rope and tape.

Erin, age 13 of North Andover, MA wrote:
I saw this experiment while flipping through the channels. I like science so I tried it. I used two spools, a hanger, for support, and some rope. It worked really well and now I don't have to bother opening the door, I can just pull a string.

Nishiki, age 9 of Austin, TX wrote:
What I did was I took 2 jump ropes and tied them on a knob. Then I put one rope out side and one inside. I sat on my bed and pulled the rope. It opened! This happens because when I put the rope out side it did not close all the way.

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