How to insert the marker

Now let’s move to the marker itself. After a few test runs with the Print3r bot, we realized that the marker was inserted too far into its assembly. I took two pics to show how it should not and should look from the side when in the marker assembly.

This is too far.
This is about where you want the marker tip to be.

Test Printing

After a lot of troubleshooting with the paper roll and figuring out how far the pen should be inserted, we were able to get the Print3r bot to print “LEGO EV3.”

The kids thought this was neat, but after a few times of printing out “LEGO EV3,” they wanted to be able to print more than that. So we came to the difficult part: building the remaining letters of the alphabet from mostly scratch. At this point, we decided to call our bot “SharpieBot.”

One other thing with the marker assembly, sometimes the motor wouldn’t be reset properly or the marker would catch on the edge of the paper, and the whole marker assembly would go flying off. Our fix for this was to make sure the arm and the assembly were positioned as in the following picture.

Make sure your marker assembly starts off in the right position.

Some of our flying marker assembly videos!

This Post Has 13 Comments

    1. Anonymous

      I agree

  1. Tiffanie Bialis

    Hello!! You said that you came up with all the letters, exported here, but I can’t find them. Can you direct me as to where to find them to help my son?

    1. Lynn-Marie

      Hi, Tiffanie! Thanks for stopping by! The way we set up the letters for download is kind of confusing. My son and I will work on it right now to get it more accessible.

      Update: I have rewritten the post to make it more clear where to download the letters and have also put up a few pictures to show what they will look like in the Lego Mindstorms programming environment. I hope this helps!

  2. jihane

    Hello I loved what you made, it is awesome continue like this and if you have any other projects send it to me

  3. Anonymous

    Nice robot but it isn’t really working for me and i don’t have any paper rolls

  4. Anonymous


  5. Judah

    What type of marker are you using?

    1. Lynn-Marie

      We used a Sharpie for the banner printer bot. I think that is what we saw other people using in their banner printer bot builds. We did end up with permanent marker marks on some of our LEGO pieces though.

  6. Vadim

    My son and I put together the printer. But we cannot write a program. Please share the program.

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