NOTE I have created a new post detailing how to configure the sand bot once you have it running. So after reading this, if you have questions, please see my new post.
I have also created a forum for Sand Table Questions and Answers here: http:///forums/forum/diy-sand-table/ – I figure this will be easier to read than the condensed comments section under the post.
I forget exactly how, but one day browsing the internet I came across the kickstarter for the sisyphus table, and was blown away. This is the first time I had seen something so captivating that I immediately wanted one. Checking their page, I was disheartened by the prices of the full wooden coffee tables, but I still considered it. I decided to try and see if anyone had built a DIY version of this table that I could perhaps take on myself before dropping thousands of dollars.
Sisyphus Industries Breaks Down Their Kinetic Art Tables
Eventually I stumbled upon a UK Engineer named Rob Dobson’s personal blog page. He had created a smaller version of with a similar mechanism. This looked promising. I saw he re-designed his whole bot and the mechanism to a new SCARA type robot. He had the 3D model and all the stl files ready for 3D printing, so I decided to start my journey of creating my own table from these plans.
As a side note – during my research I learned about all the CoreXY tables that have been doing similar things for years. I stumbled across the very nifty Sandify tool as well, which generates pattern gcode. I entertained the idea of a CoreXY table, but I had my mind set on a round coffee table after seeing the beautiful sisyphus tables, so the XY machines just wouldn’t fit my needs.
Rob’s blog gives a good idea of how to go about assembling everything, so I will just go over my differences here.
Sisyphus: The Kinetic Art Table
I think the easiest think to do here is link my build album, because it shows the progress of the build. I wanted to build an actual piece of furniture for this table, to sit in our sitting room, so it had to look nice.
Building a round table is hard! I used 2.5mm underlayment plywood cut into strips to build the round structure around my table frame. Using ratchet straps, I was able to clamp the wood good enough to make a decent structure. I then decided to glue maple veneer on the outside of the table for finishing. This was a nightmare. Trying to use ratchet straps on the veneer just created a whole new set of problems with bubbling because the veneer is so thin. It’s not really noticeable, but in my final table, there are noticeable bubbles in the veneer. Oh well.
I tried many different types of material for the “sand”. After researching for a while I couldn’t find any specific link to anything that I could actually buy. Some people recommended shuffleboard wax.. Some people said baking powder.. I tried them all. I finally settled on the hamster bathing sand. This is the finest sand I could find, while still able to maintain the peaks needed for nice shadows
Diy Sand Art Terrarium
With some coaxing, I was able to get Rob to add support for .thr files (Theta Rho), which are the native files for the sisyphus table, so now we can take advantage of the sisyphus pattern designer’s hard work and use these patterns on this custom table. There are still some kinks with thr support, but the majority of the files work correctly and look great! The sisyphus subreddit is a great place to find custom files.
Rob and I worked hard on this, and in the end the only thing we could get to actually work was the Adalogger feather wing with SD Card in it. We tried external card readers (My PCB is wired for one), but couldn’t get anything to work reliably. Even with the feather wing, I had serious problems getting it to recognize a micro sd card. I had to try about 5 before I could finally get a 1GB micro SD card to be recognized. I used the official SD card formatter app in windows and various filesystems before this was successful. I think working SD card support is vital for having an interesting table. Without it you can only store a few smaller thr files, however you can fit many parametric patterns.
In my original post I forgot a few things to make the SD card work with my PCB and robot configuration. By default, the adalogger wing has the chip select (SDCS) pin hard wired to pin 33. In my configuration, the little jumper needs to be scraped away, and a wire jumper soldered to pin 21.
Sisyphus Kinetic Sand Art Tables
When I said I could only get one SD card to work, this is the card I got working. It is a kingston 1GB microSD card formatted in FAT with the official SD card formatter.
While Rob’s PCB does work – I found it very confusing at first. It is designed for more than one application, so I figured I would create a single purpose PCB for the sole reason of powering a sand table. The project can be found at Easy EDA, and the PCBs can be ordered through JLCPCB. My version 1.5 has everything needed for a functioning sand table and allows either RGB (Signal/+/-) LED control or White LED dimming control (- PWM). I have only used (And the firmware only supports) White dimming LEDs. The board also has a socket for a light sensor, which at some point will auto dim the LEDs. I wasn’t happy with my implementation of the dimming algorithm, so auto dimming is currently not supported in the firmware either.
Here is my custom PCB outfitted with everything but the drivers and processor. I’ve also included vias for probing and debugging if necessary.
Easy Diy Sand Art Candles
Since my PCB has a different pinout than Rob’s, the robot configuration will be different. This is the robot configuration I use for my setup.
I’ve fielded a LOT of questions on how to get the software onto the robot for the first time. I’ve compiled a screen recording of all the steps necessary to load the firmware onto the Huzzah32 (I can’t be sure this would work with other micro processors)
While it is still under construction (Probably forever…) I have created an android application that can interface with the sand bot to control the robot and preview existing files on the robot. You can not create or upload patterns yet, and sequence creation/editing is not implemented yet. Feel free to improve/create pull requests! https://github.com/grammesm/SandBot-Android
Pcs Diy Simulated Cherry Tree Decorations Desktop Sand Table Cherry Tree
After running my completely 3D printed robot for over a year, I could tell that it was getting really sloppy. Homing wasn’t consistent, and patterns weren’t ending where they should. Graciously, Rob had sent me some laser cut acrylic top and bottom plates a while back, so I got the making a second robot that would hold tighter tolerances. These were the major improvements I thought I needed.
I’ve uploaded all my 3D models for printing on my github. The SandTableScara model is a direct import of Rob’s original model, so that I could extend the arms.
While the tensioning system Rob devised does work, I wasn’t happy with the tension I was getting on any of my belts. I don’t think the motors were secured strong enough to put enough tension on the drive belts. I believe this was due to my 3D printed plates, and the plastic just deforming over time. I devised a system of 3D printed tubes to help me ensure the new plates would be perfectly parallel to each other. These are secured with nylock nuts, so they aren’t going to be loosening up
Easily Build A Machine That Destroys What It Creates
The long arm belt was just floppy after a year of running. I think this is due to trying to tension a belt that wasn’t the correct size. After some trial and error I decided to print arms the exact length I needed in order to put the perfect amount of tension on a new belt of 488mm. I found that for my 3ft table and a bit less of drawing area, I needed new arm lengths of 184.5mm exactly to give me the perfect tension on the 488mm belt. I printed the bottom arm of near solid PLA, and the top arm of PETG to give me flex.
I believe my sloppy homing was due to the inconsistency of the magnets and hall effect sensors when dealing with different amounts of friction due to how much sand the ball is dragging around during homing. I decided to migrate to optical end stops, and designed and printed out a new concentric gear lock and elbow gear lock that allowed me to mount optical end stop sensors to track the rotational movement.
I originally started with a plywood sand surface, with the bottom coated with urethane and polished as smooth as I could get it. After I saw how uneven this surface was, I migrated to a piece of hardboard, with the smooth
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