Pen not always going the whole way down

My Line-us seems to be occasionally getting stuck when trying to put the pen down. It would appear that the cam has rotated to the correct position but the body of the robot doesn’t always seem to follow along. From what I can gather, either:

  • The springs are starting to lose their force
  • It needs some lubrication inside of the shafts

Please help! I love this lil guy.

Looks like your Line-us needs a bit of lubrication as you say - I’m guessing you’ve been using your Line-us a lot, which is great!

I’ve just put together a quick post in the FAQ on how to do it and it should get you back in action.

Let us know if you have any questions or if there’s anything that’s not clear in the post.

Thanks Rob! A quick test with my Line-us after applying some silicone lubricant and that seems to have done the trick. I’m using my Line-us programatically with JS so I’m definitely putting it through its paces compared to the average user. :slight_smile:

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Nice! Not sure whether you’re aware but we now have Websockets support (firmware 2.0.4, which is now the released version). Just update firmware from the app or send M997 if you’re interested. Only thing to be aware of is not to power off Line-us during the update.

Ah great! I’ll have to give it a go at some point. Is there any documentation?

Not yet - same commands as the socket interface and this should get you started…

<!DOCTYPE html>
<html lang="en">
<p id="output"></p>

    var lineUsName = prompt("Please enter the name of your Line-us.\n\nIf you're not sure just click OK to accept the default name.", "line-us.local");
    const socket = new WebSocket('ws://' + lineUsName);
    socket.addEventListener('open', function (event) {
    socket.addEventListener('message', messageHandler)

    function messageHandler(event) {
        document.getElementById("output").innerHTML += ( + "<br>");
        if(, 2) == "ok") {

Hi, my Line-us is stuck the pen down, i can´t lift up. I don´t know, but it seems to me the servomotor, if so, how can i replace it?

Sorry to hear that. I’ll send you a new servo, and we also have a Nylon shim that may reduce the cam friction a bit that you can try. It’s not too difficult to replace - I’ll put together some instructions in time for when the servo arrives. Should I send to the same address as your original order?

HI, thank you very much for the support. But I think the problem is due to the intensive use of the line-us, two weeks ago I put for people experience it here in a bookstore, working everyday :blush: … so I assume this responsibility and I pay the servomotor …

Thank you very much. Yes, the address is the same.! Just some images :wink:

Nice drawing! Pen looks like it’s a bit low but very nice. Would love to hear more about the reaction to Line-us in the bookstore. I’ve sent you a replacement servo - as you say it’s probably because of heavy use but we’ll replace it for no charge as you haven’t had the machine for very long. I’ve also included some silicone grease and the Nylon piece - it should take 3-5 days to get to you so let me know when it arrives.

I am also facing this problem.It looks like that you are using the lineme frequently.That’s good.
I am posting the same problem then lets see if anyone gives us the right answer.
Thanks Regards TheWing.Pk