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Hangprinter version 3

Posted by tobben 
Re: Hangprinter version 3
October 21, 2018 04:08PM
Made a pull request to get this fix merged upstream in stock Marlin as well: link.

Thanks for reporting.

Re: Hangprinter version 3
October 21, 2018 05:32PM
Thanks, I’ll try that out!
Re: Hangprinter version 3
October 22, 2018 04:40AM
Great, I hope it works now smiling smiley

On your second question:
Is there a configuration change in the stepper_nano_zero FW (aka Smart Stepper FW) to tell it to use D0 and D1 pins for STEP/DIR?

I took a look in the Smart Stepper Firmware to find more details on how we might make it run on Mechaduinos. Looking at boards.h, try these settings:
linke to line on Gitlab

Comment out
#define NEMA17_SMART_STEPPER_3_21_2017
Link to line on Gitlab

Comment out
Link to line on Gitlab

And also, as you suspected. Dir/step pinout has changed. Actually, it looks like Trampas has just swapped them, see
#define PIN_STEP_INPUT  (0)
#define PIN_DIR_INPUT   (1)
Link to lines on Gitlab

Then, I noticed another difference. Mechaduino firmware sets step/dir, and enable pins in INPUT mode (source). Smart Stepper firmware sets them in INPUT_PULLUP mode (source). If your experiencing problems with the step/dir signal on your SmartStepperFirmware powered Mechaduino board, try changing the step/dir/enable pin modes.

I know it sounds quite optimistic to say this after all these details, but I think running SmartStepperFirmware on the Mechaduino hw should actually work smiling smiley

Re: Hangprinter version 3
October 23, 2018 03:12PM
Hello again guys. Finished building my hangprinter v3 without mechaduinos and i've spent the last week or so just fine tunning it. The major issue i'm struggling with is the calibration and precision of the extruder movements.

The best i've achieved is a 5% error on the X axis and 12.5% error on the Y axis. So i'm looking for tips into improving this, especially the y axis offset.

I've been testing it using a simple 40 mm square and making some minor and not so minor updates on BX, BY and CX, CY in the firmware. But it seems like i've hit a wall.

I've even manually remeasured at least 3 times all the required distances and started from scratch the fine tuning in firmware, but to no avail.

So guys any tips?
Re: Hangprinter version 3
October 23, 2018 04:30PM
Have you looked through Configuration.h and set all the relevant values?

Re: Hangprinter version 3
October 24, 2018 04:10AM
Yep. I did the measurements as recommended in the Chris Riley build videos (part 2 and 3): [www.youtube.com]

My anchors are nailed to a wooden floor and the AY,BX,BY,CX and CY were measured against the mover on the floor level, then i set up the build plate (small wooden board) and zero'ed the extruder to the board. From there i did the ABC-Z measurements from the top of the mover to the floor (,not the board). And from the top of the mover to the ceiling anchor.

Honestly the X axis error doesn't bother me, because i can compensate for that, but the fact that diference between the X and Y axis is so great leads to the print being a bit skewed on smaller prints. The strange thing is i've done the calibration about 3 times from scratch and the errors remain the same. Well they start worse off, about 15% on X and 20% error on Y. But with tweaking they all go to about 5% and 12,5% respectively.

Maybe the filament is catching a little on one of the anchors? Since i couldn't find cheap ball bearings i had to 3d print both the spool ball bearing and the anchor ball bearings. The spool bearing work great, kinda quiet actually. The anchor ones are a bit smaller but seem to work. Probably gonna go use some WD40 on them and see if it changes anything.

I've also used 0.5 mm 18.8 kg nylon monofilament, the strongest they had available in a local store, nothing like the 50kg fireline you guys use. But i can get it pretty tight , almost like a guitar string and the mover is only able to move about a 1mm in every direction if i push or pull it, before returning to the original position.
Re: Hangprinter version 3
October 24, 2018 04:55AM
Hm.. When you measure by hand, it's important that you measure from the start point to the end point of one single line.

For example, when you've measured Bx, By, and Bz, take a fourth measurement Lb from the point where the line exits the anchor roller to the point where it enters the mover.
If you get sqrt(Bx^2 + By^2 + Bz^2) = Lb, then you've probably done all four measurements right.

Given the size of your errors, we can be quite sure that either something is wrong with the measurements, or you put a lot of line (> ca 15m) on your spools, so that it builds up a lot more than the default config allows.

I didn't watch through Chris' videos, but can you confirm that Mounted line is measured and configured right?

We use FireLines (or any brand of as straight UHMWPE fibres as possble) for stiffness, not for breaking strength. Nylon lines are springy and will allow your mover to vibrate a lot.

To really make the buildup compensation work well, you need to configure the fine decimals of Spool buildup factor and Spool radii as well, but save that for later.

I made the auto calibration mostly because the manual calibration procedure is so hard to explain. A complementary source on how to hand-calibrate is here. At some point I will have to stop trying to explain this hand measuring procedure. It's so hard.

Re: Hangprinter version 3
October 24, 2018 11:46AM
Ok tks. I'll sanity check the line lengths and mounted lines. Maybe thats the issue.

Edited 1 time(s). Last edit at 10/24/2018 12:29PM by LordThingol.
Re: Hangprinter version 3
October 28, 2018 07:25AM
I generate my 3D models via Rhino/Grasshopper. This software is not available for Linux and it is very time consuming to switch between the Linux and Win installation. I am using the HAW usb stick right now. I have no interest in running Rhino/Grasshopper and/or the hangprinter on a virtual system.

Does anyone run the hangprinter on Win10? If I would use Prontrface on Win10, what do I have to change in the standard software to use it with the hangprinter?
Does anyone run the hangprinter with Cura or Simplify 3D and is willing to share the settings?

Edited 2 time(s). Last edit at 10/29/2018 03:26PM by Dahah.
Re: Hangprinter version 3
October 28, 2018 07:33AM
You don't need to change anything to host from Windows, you can run Hangprinter from any 3d printer host software on any operating system winking smiley

If you find a slicer config meant for a big delta printer with a big nozzle, then that config will work for Hangprinter as well.

Re: Hangprinter version 3
October 28, 2018 09:42AM
spinning smiley sticking its tongue out Merci!

I'll try to generate g-code directly from my grasshopper patches and feed it to the hangprinter.

By the way....Is there an UI for OpenSCAD like the grasshopper UI (https://www.grasshopper3d.com/)

Edited 7 time(s). Last edit at 10/28/2018 04:29PM by Dahah.
Re: Hangprinter version 3
October 28, 2018 10:26AM
@Tobben Just reading the blog. Everything looks so promising! smiling smiley

Edited 1 time(s). Last edit at 10/28/2018 11:30AM by Dahah.
Re: Hangprinter version 3
October 28, 2018 12:13PM
=) I currently have two ODrives up and running with G95, G96, and M114 all working properly. A couple more work days, and we'd be ready to have HP4 in the ceiling for the first time.

I will have less dev time going forwards though, see Bountysource update for more details.

Re: Hangprinter version 3
October 28, 2018 04:28PM
=) Next Level!
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