Rubber bands pinless attachment for taking loops Pro Preview

Rubber bands in the LEGO Mindstorms sets are very handy when it comes to collecting objects, especially loops. The mechanism most of the time could work like this - an axle is pushed, a rubber band is released and a lever collects the loop. 

  • #95
  • 08 Jul 2015
  • 4:03

In this video tutorial we are building an attachment for an EV3 competition robot construction. This attachment uses a rubber band to collect a single loop without the use of a motor. The attachment is also pinless, which means it could quickly be attached to the robot without any pins being involved.

Previous videos on rubber bands:

  1. Rubber bands - Solving the FIRST LEGO League World Class COMMUNITY TREE
  2. Rubber bands - LEGO robot attachment that triggers with a motor
  3. Rubber bands - LEGO robot attachment triggered with a motor - part 2 removing the motor
  4. Rubber bands - one more way to remove the LEGO attachment dependency on the motor for triggering

Other pinless attachments:

  1. Quick Pinless Attachments for LEGO EV3 Competition Robots (Part 1)
  2. Quick Pinless Attachments for LEGO EV3 Competition Robots (Part 2)

Instructions for building the robot:

Pinless Rubber Band Attachment

Building instructions for the Pinless Rubber Band Attachment:


In this video, we continue our series on using Lego Mindstorms rubber bands for solving different challenges from the first Lego League competition. In this video, we're working on the Senior Solutions Challenge where you should reach the mission model, take the loop and return it back to base. And in the video, we'll also use a pin-less attachment. This is an attachment you can attach to your robot without any pins which is quite fast for a competition.

Again we're using the EV3 competition robot. You can find instructions for building this robot in episode 58. And the challenge is to take the loop from the mission model and to return this loop back to base. Of course you can do this in many different ways, both with passive and active attachments. This is, here, the attachment that we built for this mission. You'll reach-- somehow you'll reach the mission model with the robot and this here is the lever. Like this and when we reach the mission model, we lift the lever and we take the loop. For this we will use the rubber band. We add the rubber band right here. Like this and now you can see that whenever we push this axel here, the lever is released. And the rubber band returns the lever back up and we can take the loop. Now we load it again. We program the robot. It moves. It reaches the competition model. We push. And we take the loop and we return back to base. An interesting solution is how do you attach this attachment to the robot. And you can do this with the pin-less attachment. What does it mean? Attachment without any pins. So you attach the attachment without pins to the robot. Just look at how do we attach it. We just add-, we just place the robot above the attachment. And this is it. And now we move. And now we can reach the competition element. Again this is an attachment that we just place the robot on the attachment or we place the attachment below the robot. And that's the whole process of attaching the attachment. Just place it. It's very, very easy. Again and now we program the robot. It moves. It reaches the competition element. We've loaded it. We program, take the loop and return back to base. It's a very interesting idea. Again the attachment is not dependent on the motor. So you can use the motor for other missions as you can see it's free. And there's plenty of space here for adding different attachments that are dependent on the motor. But this attachment here it's only a rubber band and it's triggered by pushing the robot. Again, works every time.