Evezor Robotic Arm Engraves 400 Coasters

When you’re running a Kickstarter for a robotic arm, you had better be ready to prove how repeatable and accurate it is. [Andrew] has done just that by laser engraving 400 wooden coasters with Evezor, his SCARA arm that runs on a Raspberry Pi computer with stepper control handled by a Smoothieboard.

Evezor is quite an amazing project: a general purpose arm which can do everything from routing circuit boards to welding given the right end-effectors. If this sounds familiar, that’s because [Andrew] gave a talk about Evezor at Hackaday’s Unconference in Chicago,

One of the rewards for the Evezor Kickstarter is a simple wooden coaster. [Anderw] cut each of the wooden squares out using a table saw. He then made stacks and set to programming Evezor. The 400 coasters were each picked up and dropped into a fixture. Evezor then used a small diode laser to engrave its own logo along with an individual number. The engraved coasters were then stacked in a neat output pile.

After the programming and setup were complete, [Andrew] hit go and left the building. He did keep an eye on Evezor though. A baby monitor captured the action in low resolution. Two DSLR cameras also snapped photos of each coaster being engraved. The resulting time-lapse video can be found after the break.

15 thoughts on “Evezor Robotic Arm Engraves 400 Coasters

      1. While I did leave during the run, I was present for a majority of the time. The baby monitor was to watch the job while I was there, so I didn’t have to go near it often because of the lack of other safety precautions (for filming purposes).

  1. Ok, looks nice, but $3,162 is a bit pricey. Take a look at this robot arm:
    I don’t know the company, but it costs only $1,399. Ok, it can lift only 1.5 kg, compared to 3 kg, but the repeatability is specified (0.02 mm) and probably better than what evezor can do, and it looks a lot more professional. And the company already produced successfully another robot arm.

      1. Right, that’s strange, website says “pre-sale is available”, but I can’t find it on the webpage. But it is the same with the Evezor, $3,162 is the Kickstart price, so it will be higher later, too. But probably not twice as much as with the Dobot, didn’t know this.

    1. [Andrew founder of evezor here] Why would you assume the repeatability would be better on a machine that has not yet made a demonstration?
      The increased weight capacity has more value in these types of machines than just payload. As you increase the weight it deforms the machine (throwing that .02mm claim out of the water.) That’s why I have opted for a welded steel frame and steel skeleton.
      These choices have lead to a machine that may look a little less professional (the pictures above are from an earlier prototype), but as an engineer I’m more worried about making a machine that’s repeatable and dependable and have sourced components that will provide that kind of reliability.
      Another plus is that we’re open source (links to source files can already be found on our kickstarter page.) A machine like this, you want to be open source. You want to be able to use whatever tools you have on hand and get the job done.
      I’m going to respond to your last point and your following comment here. It’s true, I’m an unknown quantity, I can’t argue with that. As far as our price it comes down like this. We also have a touchscreen, cameras, offer extra toolheads, are open source and more. Also, this isn’t my first rodeo. I’ve brought products to market before and know where the numbers are such that I know I can make what I promise. Admittedly, we’re not giving as deep a discount as some of our competitors, but this was a choice we made for risk management and have future plans to further reward backers that we are unable to say on the kickstarter page.
      Finally we’re a group that hopes to provide a lot of good and pledge to donate 10% to various open source, open net initiatives and to our own community towards the exploration of community ownership of a company. I would love any input on how you think something like that should be implemented and sustained.

      1. At least their video looks nice, with the micrometer measurement device to show the repeatability, and the laser engraving examples. But maybe you are right, I don’t know much about mechanics, but if the payload is higher, then it will be more difficult.
        BTW, why do you use stepper motors? In the video of the Dobot arm they say they are using linear DC motors. And when I read about the big robots from Kuka etc., they are using DC motors, too. What are the advantages / disadvantages? Maybe the Dobot is faster, but less accurate?

        1. Yeah, their video is better produced than ours but the video above isn’t even our main video, it’s just a project video. I never thought the micrometer examples showed very much, in the example above I have hundreds of frames showing the process over and over showing repeatability.
          We’re using stepper motors because we’re utilizing a lot of the toolchains from the 3d printing community, they’re readily available and easy to program. I’m not aware of any open source driver and controller packages that are available and reliable right now, if so please let me know.

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