5 ms·

Cartesio – Low-cost Cartesian plotter robot

93 points by satchet 7y ago

WrtCdEvrydy 7y ago
I wonder if we might see a resurgence of these plotters ala 3d printers. A tronxy x1 is $85 right now for a full small form factor 3d printer.
- homarp 7y ago
  a review of the tronxy x1 https://www.techradar.com/reviews/tronxy-x1/2 https://www.techradar.com/reviews/tronxy-x1/2 check aliexpress or similar for the $89 self upgrade to make it better: https://www.reddit.com/r/3Dprinting/comments/81xkut/tronxy_x1_before_and_after_selfprinted_upgrades/ https://www.reddit.com/r/3Dprinting/comments/81xkut/tronxy_x...
errantspark 7y ago
I don't understand the decision not to use CoreXY. I have a very very similar plotter that also cost me next to nothing using essentially the same BoM as this. It's directly descended from this one [0]. It can absolutely fly, I've spent some time tweaking it but I can reliably and accurately drive it at something like 20cm/s. That's largely a factor of the low inertia of the CoreXY design, which keeps both the main steppers stationary during operation. Anyway, plotters are dope and to anyone thinking of building one of these, I highly recommend a CoreXY based design. [0] https://www.thingiverse.com/thing:1514145 https://www.thingiverse.com/thing:1514145
- edge17 7y ago
  Not sure if this is a dumb question, but what is CoreXY?
  - grzm 7y ago
    https://corexy.com https://corexy.com
- microcolonel 7y ago
  CoreXY is interesting, and seems especially well suited to plotters, where you don't need to worry generally about the speed of the tool. I've seen CoreXY machines doing circles at two or three linear meters per second (!) with print heads on them, I can only imagine how fast a light pen plotting head could go. Is there a reason why people aren't using thin cables or wires instead of belts at this point? If you used wires you could have a simpler crossover, I think (wouldn't need the extra pulleys); this could also reduce belt inertia, if that's of any importance.
mrfusion 7y ago
Is there a practical use for this? I’m thinking if my 3d printer does I could repurpose it for this.
- hugs 7y ago
  I've spent the last several years working with this scale of robot at my start-up. The practical use is mobile phone, tablet, and general touchscreen testing. In some products, such as automotive head unit displays or any medical device with a touchscreen, there are legal and company policy rules requiring that functional testing of a device must match human actions as closely as possible. Which means you can't only test the device through USB or some other back-end developer interface. In other cases, performance/latency testing teams want to test a touchscreen device as a black box, meaning with no extra instrumentation running on the device-under-test, to get good real world performance data. In all these cases that means a capacitive tablet stylus, instead of a pen, is attached to the end of a robot like Cartesio.
  - vosper 7y ago
    Huh, that's really interesting to learn. I'll file it in my big file of "Never thought about it, but makes sense" (sorry, nothing otherwise constructive in this comment)
- StavrosK 7y ago
  I just spent a day upgrading my printer and playing with Gcode, but it wasn't until your comment that I realized just how easily I can write a program that outputs gcode itself and add a pen so I can have the printer draw on paper. I'm going to have to test this right now.
salgernon 7y ago
Plotters are addictive and lovely - look for #plottertwitter on twitter. I've always loved this spray painting printer (poor quality video, unfortunately): < https://youtu.be/V4aXw0Zotzw https://youtu.be/V4aXw0Zotzw > The people that made AxiDraw also helped put together a kid's kickstarter plotter "Sylvia's Watercolor Bot" which is fun. They also have a plotter that draws on eggs... I don't have an AxiDraw, but I'd be willing to bet the differentiator from homebuilt is the rigidity of the platform and being able to get very consistent results. (Personally, I'm a fan of 80s pen plotters from HP and Rolond.)
romwell 7y ago
FYI, if you already have a 3D printer, you can totally use it as a 2D plotter (if that's not obvious). And you can totally use a fountain pen if you feel like it. In action: https://www.instagram.com/p/BlQHk43gwra/ https://www.instagram.com/p/BlQHk43gwra/ Final result: https://www.instagram.com/p/BlJHawZgFi1/ https://www.instagram.com/p/BlJHawZgFi1/ Same, with a ballpoint: https://www.instagram.com/p/BlJ8dgmAaTA/ https://www.instagram.com/p/BlJ8dgmAaTA/
- StavrosK 7y ago
  How do I do this? Installing the pen and adding some initial gcode to raise the Z axis above the bed so the nozzle doesn't touch isn't a problem, but what generates the drawing gcode?
  - romwell 7y ago
    I wrote code that generated this particular G-code for the Dragon curve. In general, there's software to convert PostScript or DXF to G-code (used with e. g. engraving machines). The G code to move in XY is simple enough (G0 x y) that you could write a converter yourself.
    - StavrosK 7y ago
      G code is simple, I'm just not sure how simple reading the curves would be. I worked around this by exporting as a png and having Cura slice that, then writing a script to extract a single layer. It works beautifully, now I want to see if I can make PCBs with it, it would be a revolution.
bmordue 7y ago
This looks like the logical next step after building a brachiograph! https://brachiograph.readthedocs.io/en/latest/ https://brachiograph.readthedocs.io/en/latest/ https://news.ycombinator.com/item?id=21281525 https://news.ycombinator.com/item?id=21281525

93 points by satchet 7y ago

I wonder if we might see a resurgence of these plotters ala 3d printers. A tronxy x1 is $85 right now for a full small form factor 3d printer.

homarp 7y ago
a review of the tronxy x1 https://www.techradar.com/reviews/tronxy-x1/2 https://www.techradar.com/reviews/tronxy-x1/2 check aliexpress or similar for the $89 self upgrade to make it better: https://www.reddit.com/r/3Dprinting/comments/81xkut/tronxy_x1_before_and_after_selfprinted_upgrades/ https://www.reddit.com/r/3Dprinting/comments/81xkut/tronxy_x...

errantspark 7y ago

I don't understand the decision not to use CoreXY. I have a very very similar plotter that also cost me next to nothing using essentially the same BoM as this. It's directly descended from this one [0]. It can absolutely fly, I've spent some time tweaking it but I can reliably and accurately drive it at something like 20cm/s. That's largely a factor of the low inertia of the CoreXY design, which keeps both the main steppers stationary during operation. Anyway, plotters are dope and to anyone thinking of building one of these, I highly recommend a CoreXY based design. [0] https://www.thingiverse.com/thing:1514145 https://www.thingiverse.com/thing:1514145

edge17 7y ago
Not sure if this is a dumb question, but what is CoreXY?
- grzm 7y ago
  https://corexy.com https://corexy.com
microcolonel 7y ago
CoreXY is interesting, and seems especially well suited to plotters, where you don't need to worry generally about the speed of the tool. I've seen CoreXY machines doing circles at two or three linear meters per second (!) with print heads on them, I can only imagine how fast a light pen plotting head could go. Is there a reason why people aren't using thin cables or wires instead of belts at this point? If you used wires you could have a simpler crossover, I think (wouldn't need the extra pulleys); this could also reduce belt inertia, if that's of any importance.

mrfusion 7y ago

Is there a practical use for this? I’m thinking if my 3d printer does I could repurpose it for this.

hugs 7y ago
I've spent the last several years working with this scale of robot at my start-up. The practical use is mobile phone, tablet, and general touchscreen testing. In some products, such as automotive head unit displays or any medical device with a touchscreen, there are legal and company policy rules requiring that functional testing of a device must match human actions as closely as possible. Which means you can't only test the device through USB or some other back-end developer interface. In other cases, performance/latency testing teams want to test a touchscreen device as a black box, meaning with no extra instrumentation running on the device-under-test, to get good real world performance data. In all these cases that means a capacitive tablet stylus, instead of a pen, is attached to the end of a robot like Cartesio.
- vosper 7y ago
  Huh, that's really interesting to learn. I'll file it in my big file of "Never thought about it, but makes sense" (sorry, nothing otherwise constructive in this comment)
StavrosK 7y ago
I just spent a day upgrading my printer and playing with Gcode, but it wasn't until your comment that I realized just how easily I can write a program that outputs gcode itself and add a pen so I can have the printer draw on paper. I'm going to have to test this right now.

salgernon 7y ago

Plotters are addictive and lovely - look for #plottertwitter on twitter. I've always loved this spray painting printer (poor quality video, unfortunately): < https://youtu.be/V4aXw0Zotzw https://youtu.be/V4aXw0Zotzw > The people that made AxiDraw also helped put together a kid's kickstarter plotter "Sylvia's Watercolor Bot" which is fun. They also have a plotter that draws on eggs... I don't have an AxiDraw, but I'd be willing to bet the differentiator from homebuilt is the rigidity of the platform and being able to get very consistent results. (Personally, I'm a fan of 80s pen plotters from HP and Rolond.)

romwell 7y ago

FYI, if you already have a 3D printer, you can totally use it as a 2D plotter (if that's not obvious). And you can totally use a fountain pen if you feel like it. In action: https://www.instagram.com/p/BlQHk43gwra/ https://www.instagram.com/p/BlQHk43gwra/ Final result: https://www.instagram.com/p/BlJHawZgFi1/ https://www.instagram.com/p/BlJHawZgFi1/ Same, with a ballpoint: https://www.instagram.com/p/BlJ8dgmAaTA/ https://www.instagram.com/p/BlJ8dgmAaTA/

StavrosK 7y ago
How do I do this? Installing the pen and adding some initial gcode to raise the Z axis above the bed so the nozzle doesn't touch isn't a problem, but what generates the drawing gcode?
- romwell 7y ago
  I wrote code that generated this particular G-code for the Dragon curve. In general, there's software to convert PostScript or DXF to G-code (used with e. g. engraving machines). The G code to move in XY is simple enough (G0 x y) that you could write a converter yourself.
  - StavrosK 7y ago
    G code is simple, I'm just not sure how simple reading the curves would be. I worked around this by exporting as a png and having Cura slice that, then writing a script to extract a single layer. It works beautifully, now I want to see if I can make PCBs with it, it would be a revolution.

bmordue 7y ago

This looks like the logical next step after building a brachiograph! https://brachiograph.readthedocs.io/en/latest/ https://brachiograph.readthedocs.io/en/latest/ https://news.ycombinator.com/item?id=21281525 https://news.ycombinator.com/item?id=21281525