Hangprinter version 2

This thread is for discussing Hangprinter version 2, presented here:
[salt.bountysource.com]

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torbjornludvigsen.com

I have printed the parts for the hangprinter version 2 but the bottom plate is not congruent with the Version one bottom plate. I seem to have been caught between your iterations. Anyhow I am interested to see how this works out. is there any way that you could produce a video of your setting a hangprinter up? specifically I am not clear about how and where to set the distances for the ABC and connections for the firmware. Is it possible that this interface is something that could be added to slicer of perhaps an excel based interface? Also how refined is the drawbot printer firmware? I think that this configuration lends itself very well to multimodal output drawing, laser CNC and 3d printing. I also am partial to the idea of gearing down the axis a harmonic drive seems to be an idea deployment to keep the number of loops to a minimum.

Ye gods, the idea of that thing swinging around the kitchen with a laser attached is terrifying

Quote
JamesK
Ye gods, the idea of that thing swinging around the kitchen with a laser attached is terrifying

But the pets will enjoy it.

I was wondering about wobble as it just didn't look secure enough to be accurate, but the prints show a different story.

... read through this old threads - some related info too ...

[forums.reprap.org]

[forums.reprap.org]

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Hi NOVAprint, I'm excited to hear you're building one.

Sorry to have caught you between versions. Did you compile the stls yourself or did you use the pre-compiled ones found here:
[github.com]
?

Here's the relevant code line where you start setting the ABC and D distances:
[github.com]

You need to re-upload Marlin after you've set the values in Configuration.h. It is also possible to temporarily set new distances with M665, see
[github.com]

These interfaces are clearly not easy or optimal, but I'm not prioritizing to improve them myself right now.

I'm not sure I know what you mean with drawbot printer firmware.

Harmonic drive is a good idea that I've just haven't had the time to test =)

Ask more questions and please, send pictures

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torbjornludvigsen.com

Yeah it's bad enough half the room taken up with 3D printers,
Was there a reason you never went with the motors on the walls?
Esoteric Levitation...I'm wondering if a 3D printer could be developed utilizing the old magic trick Chinese Sticks

Yup several reasons, of course. One of them is that I have to tidy up after me each time I've used the printer. I wind in the lower anchor point lines and park the printer in the ceiling like a lamp:

[vimeo.com]

If we're expecting guests, I also unplug and tuck away the power cable and hide away the print bed.

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torbjornludvigsen.com

But surely you could also do that with motors on the walls.

Quite possible, of course. I'd love to see such a solution.

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torbjornludvigsen.com

I would have thought you where in a better position to mentally picture what it would look like, due to your experience with this.

Oh yes, you would have to choose between synchronizing steppers wirelessly, drive them from a stationary PCB or to find a smart way to wind stepper cables.

Last alternative first: You could carry the stepper drivers and the microcontroller on the moving part. Signal noise because of the stepper cable lengths would be no (or a very small) problem, but they will of course have weight. You could wind in the motors when not in use and park everything in the ceiling. Nice.

Wireless motor control is probably the best solution for very big high-performance machines. You must do more programming, need more PCBs and more power supplies. The PCBs could be placed almost anywhere and you don't need to hide a lot of ugly cables. Semi nice.

With one stationary PCB and long cables to stationary motors, it will be a lot of work to make it look tidy. You will have to transform your entire room into a RepRap frame. If quick and dirty solutions, like cables taped to the floor/ceiling, works for you, and if you never need your room for something else, then this solution gives you the most print performance for your time and your buck. Or at least, that's my guess.

I want to reduce weight by using lighter BLDC servos instead of the steppers. See this thread for BLDC discussion: [forums.reprap.org]

Edited 1 time(s). Last edit at 02/09/2017 04:48PM by tobben.

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torbjornludvigsen.com

See I never thought of the cable length issue, but these guys obviously sorted that issue out
[www.youtube.com]
[www.youtube.com]

A mains powered drone that can be plugged into a light socket, that would cool, but so would print.

Tobben,

I am having a hackathon at my college in about a month and I would like to know if you would be interested in doing a Google hangout to issue the challenge for the hangprinter? What are the issues that you are encountering, what can we do to improve the design? I think that I will print two units and present them to the group. I hope that I can get it up and running by then. One issue that I see very integrally is the need to move the firmware to a 32 bit system. I say this because I think that the smoothie board is a good platform for executing the hangprintyer well, with all of it's possibilities for materials and build volume. multiple tools etc. I suggest the smoothie board as well because there are more voltage and thermal protections afforded those units too. Any feedback would be appreciated.

Thanks!

Hi NOVAprint, sure suggest a time for the Hangout.

The main challenge is calibration. That is, measuring the distances between action points and fish rings along the x, y and z axes. The calibration process just takes too much time.

Other important challenges are the extruder and the weight. They both limit print speeds right now.

My own next technical development sprint will try to integrate BLDC motors, hopefully using the ODrive board:
[hackaday.io]

A Smoothieboard increases the $-cost with about 50 - 60 % but I can definitely see why you would want to do it. Go for it. I have a Smoothieboard lying around, so I have the option to join in on your development.

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torbjornludvigsen.com

Awesome, sorry I did not check this blog earlier to continue our convo. I am trying to mount the Ramps bracket. It has two sets of legs and I cannnot figure out the orientation between the three motors, could you post a picture of the mount orientation?

A hangount would work for me anytime this Saturday or sunday. I

I was looking at the drive and it seems very interesting, and then again not, only tow motor drivers when in reality at least four are needed, I like the closed loop feedback solution as an option, I was also thinking about the concept of an H bot cube printer, the ones that have one belt that connects the x and y axis. Isn't it possible to have one piece of filament that connects all three axis and the vectors would be calculated as a combination of the three motors moving in concert rather than independently, that way three motors would be stabilizing the unit. Extra length would be provided as through one large spool, and the diameter of the spools would stay the same. Just an idea.

Have you thought about the use of a laser pointer or rangefinder aimed at the corner that would give a digital distance to the computer? More expense that way. I have seen IR sensors that can determine distance for about 20 dollars.

Hi I think you found a bug in the Ramps bracket. It's supposed to be used like this:


The new stl is here:
[github.com]

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torbjornludvigsen.com

If you find a solution that uses one line for three or four of Hangprinter's axes, similar to H-bot or CoreXY, then I'm very interested to hear about it

The last time I thought about it I didn't manage to come up with a working one-line solution. Right now I don't have the time to dive into it again.

I've thought about multiple different distance measurement solutions. My pet idea right now is using draw-wire displacement sensors like this:
[www.micro-epsilon.com]

... in combination with accelerometer/gyro like described here:
[www.appropedia.org]

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torbjornludvigsen.com

If you find further bugs, you're welcome to dive into the .scad files in the repo (https://github.com/tobbelobb/hangprinter). There will always be bugs in the stl-files that are already fixed in the .scad files =)

The repo should have a Makefile to automatically update stl-files, similar to nophead's solution in the Mendel90-repo...

I afraid my schedule has been squeezed. I'm happy to answer questions here, but i must cancel the Hangout.

Edited 1 time(s). Last edit at 03/11/2017 04:59AM by tobben.

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torbjornludvigsen.com

Hi Torbjørn,
You mentioned you had some ideas for development yourself. What are you working? Is there a wishlist yet?


All the best,
Martin

Hi Martin,
I want to make the printer faster and more automatic. A few wishes include

• Pellet extrusion, since filament is expensive
• Cheaper, faster and stronger motors. The oDrive project is moving forwards: [hackaday.io] I'm hoping to be among the beta testers to get BLDC motors on the Hangprinter ASAP
• Electronics with an SD card reader and maybe Wifi would be nice
• Automated procedures for pausing over night and changing filament spool
• Sensors that allow an automatic calibration and/or homing procedure. Many sensor setups could achieve this:
  1. Metal tubes on each line that can close a circuit
  2. Accelerometer+gyro (IMU) units
  3. Sound sensing (maybe 1 mic + 5 speakers)
  4. Draw-wire displacement sensors in each direction
  5. Optical sensing from salvaged computer mice
  6. Small touchpad area on the build plate. For example calibrating and homing with a tablet or smart phone below print head.

I won't have the time to add all of this myself unless the Bountysource campaign would _really_ take off
[salt.bountysource.com]

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torbjornludvigsen.com

Quote
tobben
...
* Electronics with an SD card reader and maybe Wifi would be nice

Sounds like a job for the Duet WiFi to me. What kinematics does Hangprinter use?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

It uses the Hangprinter kinematics

How hard would it be to design a circuit board in the shape of the Hangprinter's bottom plate?
(see [github.com])

Such a PCB is on my wish list, especially if we can design BLDC servos right into it.

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torbjornludvigsen.com

Hello!

I think the easiest (and the cheapest) way to get wi-fi would be to connect a raspberry pi 3. And to get a sd card reader would be to mount a lcd screen (LCD 2004 )


Sorry for my bad english

... or a RaspBerry Pi Zero W - [www.raspberrypi.org]

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

What a nice little thing =)

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torbjornludvigsen.com

tobben,

I seem to notice that you only have one side of the ramps powered. is that correct? I would suspect that only one side of the mofset would be necessary, would you please send a picture of the line voltage going into your ramps?

Edited 1 time(s). Last edit at 03/13/2017 10:46PM by NOVAprint.