Should I use Dobots?

So which robots should I use in my classroom? Dobots? Lynxmotion? Rotrics? Fanuc? Great question! Jim and I use Dobot’s exclusively in our classrooms for many reasons. One of which is because we wrote the curriculum for them: Teach and Playback and Blockly. Below we have come up with some justification for their use in our classroom, as we get asked “why?” a lot!

The Lynxmotion arms have their place.  Their scale is very proportional when adding them to a VEX project.  Programming is decently easy to pickup if given enough time to practice (which students rarely get), Cost is low, there’s the PLTW technical support, and they match the curriculum.

Full Disclosure: when you order Dobots from InPosition Technologies Tell them Chris and Jim sent you, and they will help pay for this website.

Just call (303)-579-9634 and ask for Ben Sawyer, and he will take care of you for sure. You can email him as well: bens@iptech1.com. Tell him that Chris and Jim sent you!

Lynxmotion Concerns/Limitations/Issues

  • Communication is one of the biggest issues
  • Can not run offline (must be connected to a computer)
  • Repeatability is extremely low
  • Built from hobby servos which often burn out and can be time consuming and frustrating to fix (depending on which ones)
  • Positions are rarely repeatable from day to day
  • Comparison to an industrial robot arm is limited
  • Electronics are exposed and can easily be damaged.
  • The Robot is light and must be mounted to something more rigid to keep the robot from damaging itself.
  • Friction plates are used to help the robot maintain position and take load off of the servos, which in turn also make the servos work harder?

Dobot:


In education, there is no doubt that we would love to get high quality, industry standard equipment and software in the hands of our students to give them a glimpse into their future and to better prepare them for industry.  But as everyone knows, the biggest drawback to finding these products is often costA small industrial robotic arm will typically cost $18,000 and up (about 12 Dobots).  The robotics industry seems to be changing on a daily basis.  What will it look like by the time our students actually enter the workforce?  How quickly will our financial investment become obsolete?  Are we trying to certify students and get them directly into industry upon graduation? Or is it our job to get students excited about robotics and expose them to its possibilities and let post secondary education take over from there?  

Industrial Robots?


The game then becomes trying to find higher quality equipment that is as close to what we are trying to expose students to at a realistic price point.  We also want to find a way to get as many hands on the equipment as possible in a short period of time. Ideally we would love to have an arm per student but could live with two students per arm.  A third student is often left out or is willing to sit back and watch… or, worst case scenario, not watch or do anything at all.
The Dobot robot, so far, is the best robot we have been able to find that takes care of the concerns/limitations/issues that we have with the Lynxmotion robots but for a price that will allow us to get more hands on with the equipment.
Trying to explain the benefits vs cost of the Dobot over the Lynx can often be difficult if you have little to no experience with the Lynxmotion robots.

Dobot Advantages

  • The Dobot robot can be programmed in three different ways:
    • Teach and playback (Robot programming by demonstration PbD). You can manually grab the arm, move it to various positions and ask the robot to repeat the process.  This is the way many industrial robots are going. Teach and Playback Curriculum
    • Blockly, a scratch style programming that is fairly intuitive for students to pick up. Blockly Curriculum
    • Python, for more advanced programming (also the style of programming VEX is shifting to)
  • We rarely have had any connection or communication issues.
  • Students pick up the programming and learn how to run the arm quickly.
  • Repeatability is extremely high.
  • Program can be uploaded to the robot and run without a computer.
  • The Dobot has more than 15 inputs & outputs, many more than any robot we have ever used in our classroom. The Dobots I/O’s are varied and can deal with 3.3, 5 and 12V, as well as servo motors.
  • One computer can actually communicate with multiple robots at one time.
  • The Dobot’s electronics are all enclosed and protected.
  • The Dobot has many industrial grade accessories like a slidebase, vision system and conveyor.
  • End of arm tooling (EoT) can easily be changed.  Comes with a gripper, 2D printer from Printron Company, pen and a suction cup (we use the suction cup most often).  A laser engraver can also be added.
  • Arm uses stepper motors rather than servos. (a big portion of the cost increase)
  • Robot base is heavy and robot arms do not need to be mounted to the project.

Our Lynxmotion arms have all been packed up.  The students’ and teachers’ level of frustration with the arms was one of the biggest reasons to make this shift.  We did some really cool things with the Lynxmotion robots and they were a great addition to our curriculum for the price, but there is little comparison to what students can do with the new arms. It took us a few years to get enough Dobots to replace them all but so far we have no regrets. 

Have more questions about Dobots? call us or just call (303)-579-9634 and ask for Ben Sawyer, and he will take care of you for sure. You can email him as well: bens@iptech1.com.

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The Lynxmotion AL5D V2: Putting it all together

So you have new Lynxmotion robots for your classroom, so now you have to build and wire them. I’ve put together 4 videos to help you assemble and wire them. This is not meant to replace the manual, but rather to supplement it. You can find the manual here: PLTW-AL5D-Guide-11.  Lots of new stuff in the manual too, especially about how servos work.

Here’s a few short videos to get you going!

Tips & Tricks on Assembly

Wiring the Power Supply

Wiring the Servos

Centering the Servos

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Centering Servos

Question:

How do you center the servos when you build your lynxmotion AL5D?

Answer:

Best way is to NOT turn the servos; like that’ll happen! There is a whole section in the new manual that can help you teach how servos work, so check the manual too! You can find it here: PLTW-AL5D-Guide-11. One way is to do it with a special tool called a servo driver. You can buy these on line, or at your local hobby shop. RobotShop used to carry it, but I do not see it there any more.  See the video below on how to use one.

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Wiring the Power for Lynx AL5D

Question:

How do you wire the AL5D Lynxmotion robot arm for power?

Answer:

You really have to make sure that you do this right, or you will damage the SSC-32U and/or the power supply, and it will not work. So, start by reading the manual; you can find it Here: PLTW-AL5D-Guide-11. Also, see the video below.

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How do you wire the Lynxmotion AL5D?

Question:

How do you wire the AL5D Lynxmotion robot arm? That’s a lot of wires!

Answer:

Well, start by reading the manual; you can find it Here: PLTW-AL5D-Guide-11. Also, see the video below.

Gaylord box of Assorted Wires

 

 

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Tips & Tricks for Building a Lynxmotion AL5D Robot Arm

Question:

I heard building the AL5D was really hard. Do you have any tips or tricks for building it?

Answer:

Of course we have tips and tricks! Best one yet? Read the new manual; you can find it Here: PLTW-AL5D-Guide-11.  They just spent a lot of time rewriting the manual, and added a lot of our suggestions to it, so please start there. Next just watch the video below!

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What else do we need to teach CIM?

Question:

What else do we need to really teach CIM? Are there any “extras” that you recommend?

Answer:

We get this question weekly. So here’s what we are going to do. Give you a preview to a Google doc that is live so we can update it on the fly. You will see it right below this paragraph. Be sure to scroll left and right and up and down to see all of the content! Links are live too!

 

 

 

 

 

 

 

 

 

 

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NEW! Lynxmotion AL5D PLTW Guide

Question:

The guide for building the Lynxmotion AL5D robot is not easy to follow. Do you have any suggestions for building the robot?

Answer:

Of course we do!  #1: Robotshop & Lynxmotion put out a brand new guide that can be found HERE. The new guide is very easy to follow with great step by step directions as well as great instructions and diagrams. They even added a whole bunch of information on servos and how they work. Please download this immediately!

I also made a short video on “Tips & Tricks” for building it. Watch it below.

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CalPoly Pomona: Factory Smackdown!

The new CIM (Computer Integrated Manufacturing) teachers at CalPoly Pomona’s CTI successfully completed another “Factory Smackdown”.  See the videos below!

Concierge Factory:

In our factory cell an AGV stops at each of four stations, where a signal is sent to a robotic arm. The arm picks up a product, places it into the package, then sends a signal to the AGV to rotate the pack and move to the next station. Once the package is full, the AGV offloads it onto the shipping dock.

In our factory cell an AGV stops at each of four stations, where a signal is sent to a robotic arm. The arm picks up a product, places it into the package, then sends a signal to the AGV to rotate the pack and move to the next station. Once the package is full, the AGV offloads it onto the shipping dock.

Fruit Sorter:

By using VEX and Lynxmotion we created a fruit sorting factory. The Lynxmotion robots grabbed the fruit from the funnel line, placed the fruit at the color sensor(aka line sensor) then placed the fruit into the correct bin. The AGV then took the fruit away, and the system started all over again.

Special Thanks to~ Our Master Teachers Chris Hurd and Moises Gonzalez and our group members: Khris Kading, Martin Velasio, Donnie Whitworth, Rich Mayfield, Candy Drabek, and Gary Potter.

Toxic Waste

Cal Poly Pomona CIM Core Training, 2016. Team Toxic Hurd takes on the challenge of packaging, containing, sealing and transporting toxic waste, practice golf balls. This factory cell uses two Lynx Robotic Arms and two VEX Cortex. The Lynx arms and the Cortex communicated with each other to signal the ‘handshake’ required to keep all the operations ruining on time.   The Lynx arms are controlled with Flowarm, and the Cortex was programmed with  RobotC.

 

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