This sounds like a problem with the anchor position calibration. I'm guessing that you don't do auto anchor calibration of any sort? If not, then you'll have to measure anchor positions manually. It's a bit involved, but not impossible. Here's a nice discussion: Sorry for this answer being so late. Since the Discord server became more active, I've tended to check this forum less often.by tobben - Hangprinter
Hello Sebastian! Welcome to the community! I'm hoping your build is going well. We've already connected a bit on the Discord server. For some reason, I guess the notification visibility, the talk on Discord tends to become more synchronous and engaging than on this forum, so over time I've tended to check this forum less and less often. It's a bit of a shame since this forum is easier to searchby tobben - Hangprinter
Hi pvsfa! I honestly don't know how people manage to get the Hangprinters working given the state of the documentation. You must have searched for and found little pieces of information in very many different places. Like it says in the repo, this project does not yet have any stable branch. So no easy entry point for newcomers. Right now there has been a long pause in HP development for myselfby tobben - Hangprinter
My point too was that cable driven 3d printing is an older and wider concept than just HP. No worries, you're not dismissing my work, rather the oppositeby tobben - Hangprinter
QuoteAtmark ... the Hangprinter concept ... I think Seil-Tripod is more similar to Tetra (than to Hangprinter). They both constrain xy-rotations with vertical parallelograms spanned up by lines, tool-head and anchors. They both also have three high anchors and no low anchors. Hangprinter constrain xy-rotations by having three low anchors, and constrains z-rotations with non-vertical parallelogramby tobben - Hangprinter
I've had great results with using ceramic eyelets (like these, or search for "ceramic eyelet" on ebay or similar) instead of fishing line guide rings on HP v4. Since you're up to buy a lot I thought you wanted to know Would it work to wind the line around the spool two times, in that track between your GT2 belt?by tobben - Hangprinter
Interesting! Is the length of each color segment ca 4 mm long? If each impulse measures a color change, then the readout will be 4 mm * 150 impulses/sec = 600 mm/sec Do I understand correctly how the sensor works? With a faster processor, we'll get plenty of impulse reads per second, I'm sure, so maxing out on sensor speed should not be a problem for this sensor. 4 mm is a bit coarse, but we cby tobben - Hangprinter
Very nice test rig! I love that spring loaded spool. I see that you've got Duet<->ODrive UART plugged in. I've done some work on that in the last few days (blog post coming I guess). GPIO 5 on the ODrive is a tad noisy because of the circuit board design. I used that pin for motor A/C direction signal, and started to notice a slight random-walk pattern on my prints. Experiments showed thatby tobben - Hangprinter
Cool! Interesting to see how it behaves. Both the max load and the min load will be challenges I guess. A lot of the time, motors will have to wind in line with very very little counter weight. Brand new FireLine behaves almost like steel wire, and then it becomes soft like silk after only a little usage. I hope the pinch system will work with even the softest of line. However, since we won't hby tobben - Hangprinter
Yes, the firmware should be straight forward to install. Just use the Duet2CombinedFirmware.bin you find in the repo (https://gitlab.com/tobben/hangprinter/tree/version_4_dev/firmware/RepRapFirmware), and follow standard Duet installation procedure. Gcode should to the magic, yes Be aware that your ODrive configuration will affect the movements. Max acceleration, max speed, step size etc needs tby tobben - Hangprinter
Yes, you could build anchor units with motors that shift the anchor position on a given command. For the Babel Tower print, this unit would have to be extremely slim, and mountable along the wall, since space was scarce, but it's sure possible. More weight on the effector does not give the same effect as a spring pole. Weight can only ever give accelerations limited by the gravitational constantby tobben - Hangprinter
Woah, that's even more friction than I imagined. Impressive! CF enforced plastics have a quite rough surface. Where did the line snap? Was it the CF that wore down the line? Since I would be aiming for HP usage, I'd test numbers relevant to the application first. I'd use ca 50% more weight, speed and acceleration than my HP4 prototype is experiencing. So ca 5 kg of weight, accelerate 15 m/s² ,by tobben - Hangprinter
Cool! Independent spool units are nice. If you can place them at the anchors (instead of having all several spools at one anchor), you will get less line flex, since there will be less suspended line in the air. Good idea to pinch the line under the belt. That might actually work very well =D You could pinch it for several rounds (along a helix groove), or just increase the spool radius, if oneby tobben - Hangprinter
It might be easier and cheaper to build three tall Tensegrity structures than to build one tall tetrahedron. I don't know. I find tetrahedrons very simple, sturdy, easy to transport and to set up. I guess I would need to see it hands-on, or see a very detailed construction video, to be convinced that a tensegrity structure can be either simpler, sturdier, easier to transport or easier to set up.by tobben - Hangprinter
Cool! @tswallen 1. If I had to print a house with Hangprinter, my first approach would be to just scale everything up. I'd have to put all motors, spools and electronics somewhere near the ground, so not up in the D-anchor though. If I had to increase the build volume, I would pause and move the ABC anchors up mid print, like I did when printing the Babel Tower. 2. The "three wires suspended" dby tobben - Hangprinter
Hello! This thread and the facebook group contains most of the info. Tom's videos use closed loop. And all the blog posts I wrote before going closed-loop. Good luck with your builds!by tobben - Hangprinter
Interesting! Haven't seen this issue before, at least not this much. It would be interesting to know if the effector travelled in different directions on outer versus non-outer walls. Could it be that the plastic trace will look different when going clock-wise versus counter-clock-wise? Other than that, I would experiment with trying to make the nozzle mounting more rigid.by tobben - Hangprinter
Hello pvsfa! 1) The HP3 should work with any electronics that with 5 stepper drivers or more. If you plan to use Mechaduinos/Smart Steppers, then you must also have access to i2c pins and step/dir pins. Not all electronics provide that. Very few have tried anything other than RAMPS, so you might bump into something, but most probably not much. I've used some RAMBO boards myself, and it was quiteby tobben - Hangprinter
Oh crap If the line jumps off the bearing, it wears down very quickly. It's not possible to use motor torques to recognize such an event, since a slightly mis-calibrated machine will also have close to zero torque in many positions. But we need to think harder about a anchor design where lines are guaranteed to always stay on the bearing, within a wide range of 3d angles. The planned Cartesianby tobben - Hangprinter
Awesome! Congrats on successful debugging =) Looks like you downloaded those corner clamps before June 7, 2018 More recent versions are a bit stiffer (see ) I stiffened them up before I actually had any practical problems, so yours might just work problem-free anyways. I'm interested to hear if your ABC lines bend your corner clamps over time or notby tobben - Hangprinter
Yes, if you use corner clamps from HP4, then 2, 2, 2, 2 is correct. D-line adjustment for HP4 doesn't have a good solution yet. If you have any progress with it, please track it here: The autocalibration script acts like that if it can't find any optima at all. I have never used Marlin with 2 ,2, 2, 2 mechanical advantage, so I'm not entirely sure why your data is not good. Do some sanity cheby tobben - Hangprinter
Nice. Only error is that Az, Bz, and Cz should be measured from where line enters mover to where line enters anchor. Not sure if that error is enough to explain the behavior you're observing, but at least fixing it is a good startby tobben - Hangprinter
Great! Was the nozzle was at the origin when the measurements were taken? Have you also measured the Z-values (not depicted in the diagram)?by tobben - Hangprinter
Hi, steps/mm settings are not used by the Hangprinter. The behavior you describe sounds like something is up with the anchor position calibration values. Are you measuring manually? If yes, then the most common mistake is to not measure between the right pivot points. Are you measuring from the point where the line enters the effector, to the point where the line hits the anchor?by tobben - Hangprinter
Yes, definitely use gitlab Openscad_Version_3 versions of the firmwares. Otherwise you'll bump into problems I don't recognize and can't fix.by tobben - Hangprinter
Hm. Then it sounds like those pins were not initialized properly by the firmware. Do you have MECHADUINO_I2C_COMMANDS defined in your Configuration.h?by tobben - Hangprinter
Not that I know of. I think Trampas might be working on including HP support upstream, but you have to ask him to get the exact status.by tobben - Hangprinter
@LordThingol There's a lot of hours of HP wisdom in that post. Greatly appreciated! @jaxshah Awesome work!by tobben - Hangprinter