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Idea: A RepRap Hanging From the Ceiling

Posted by tobben 
Re: Idea: A RepRap Hanging From the Ceiling
March 08, 2015 12:36PM
It makes cirkles now. Kinda...
Vimeo


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Re: Idea: A RepRap Hanging From the Ceiling
May 11, 2015 10:43AM
I did some openscadding (see attached).

I'm wondering about the roller-fairleads, if I would be better to just use fishing rod leads since I want to aim for cheap and simple. The roller leads adds a lot of complexity to the build...


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Attachments:
open | download - Hangprinter0.png (43.4 KB)
open | download - Hangprinter1.png (42.7 KB)
open | download - Hangprinter2.png (33.6 KB)
open | download - Hangprinter3.png (45.3 KB)
Re: Idea: A RepRap Hanging From the Ceiling
May 15, 2015 09:40AM
check this out, this was my diploma project form a couple of years ago, now i am taking on the project again. but it was a similar concept.

[galomoncayo.net]
Re: Idea: A RepRap Hanging From the Ceiling
May 29, 2015 06:35AM
Wow, cool. Does it do precise movements?


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VDX
Re: Idea: A RepRap Hanging From the Ceiling
May 29, 2015 08:05AM
... instead of three motors you can use only two and a spring-loaded rewinder or a weight at the free end of the wire.


Viktor
Re: Idea: A RepRap Hanging From the Ceiling
May 29, 2015 04:56PM
Definitely, swapping one motor with a spring would be possible. Saving a motor is a huge win but there are drawbacks.

The main one (I think) is that the printer wouldn't be able to accelerate quickly along the action line of the spring. The printer will be heavy because of all the motors onboard, so it will carry more momentum than for example the Sky Delta.

A smaller issue with a spring is that it would make imprecise firmware harder to detect (lines would never go slack if accelerations are always low). Another smaller issue is that tension would be different depending on position. To get closer to constant-force springs, we would probably use a very long rubber band and wind it many times around a pulley-system, like on the Sky Delta. Not a big issue, but maybe eating up some og the complexity gain from dropping a motor.

With all that said, I don't really know since I haven't tried. I will have to sit down and calculate how large force the spring must have to enable reasonable accelerations along its action line...


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Re: Idea: A RepRap Hanging From the Ceiling
June 21, 2015 01:07PM
Sorry, I read answered as if you had written just "spring", and not "spring loaded rewinder". A spring loaded rewinder would of course be much smarter than just a spring,
since we could use spiral torsion (constant force) springs for winding. Let's limit discussion to springs are made for one full rotation (360 degrees) or less (don't know about realism in this assumption, not my area of expertise). Since the spools on the hangprinter are limited to a ca 80 mm diameter, and we want the lines to be at least 2 m long, we need 8 full rotations. That is, we need to gear up the spring by a factor of 8.

The constant force we need can be approximated like this: If we want acceleration of 500 mm/s^2 when spring is at a 45 degree angle, and the printer weighs 2 kg, we get

F = sqrt(2)*2*0.5

Say F = 1.5 N for simplicity. The spring will need to exert a minimum torque of 8*1.5*0.04=0.48 Nm. Even doubling that to take reality into account sounds totally possible to me. Avoiding the assumptions about the springs and gearings, I imagine retractable dog leash strong enough to lift a mass of ca 300 g in a 2 m span to be entirely realistic.

Avoiding springs all together, weighs at the end of lines would be dead simple, dirt cheap and easy for experimenting with different weights...

To be honest, I'm surprised by these numbers and I'm a litte unsure what to do with it. I'm quite close to actually testing the first prototype now, with 5 motors. If the spring-solution still looks promising when I see the 5-motor protoype move (and test needed forces empirically), I might just try to build the 4-motor 1-spring version! Computational and economical gain seems quite obvious. If you want to try buliding the 4-motor 1-spring before I get the time, and want to fork/branch the repo, please do =) [github.com]

All the best!

Edited 1 time(s). Last edit at 06/21/2015 01:11PM by tobben.

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Re: Idea: A RepRap Hanging From the Ceiling
June 21, 2015 01:19PM
Still collecting my thoughts about the weight-at-end-of-line solution, I just wanted to mention a couple of developments in the project:

I'm doing my masters thesis about Hangprinter! smiling smiley So we're rich in potential work hours =D

E3D have kindly sponsored the project by sending me a free Volcano power pack, a hobbed bolt and 2 kg of filament =D Big thank you to E3D!

I have put up some pics an comments over at [vitana.se]


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VDX
Re: Idea: A RepRap Hanging From the Ceiling
June 21, 2015 01:39PM
... looks really interesting, but too a bit complex for me ... if I'll start with a hangprinter, then it would be a plane 2motor+rewinder stringy at the ceiling (hold magnetically) and three rollos/blinds releasing the printbed winking smiley


Viktor
Re: Idea: A RepRap Hanging From the Ceiling
September 11, 2015 07:29AM
Hello again. The printer is ready to be mounted in somebodys ceiling... Video

Looking forward to seeing what the prints are going to look like tongue sticking out smiley


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Re: Idea: A RepRap Hanging From the Ceiling
September 11, 2015 09:27AM
Has anyone done a design where a gyroscope is placed in the effector?

That would reduce or maybe eliminate the need to maintain perfect tension.
Re: Idea: A RepRap Hanging From the Ceiling
September 16, 2015 03:51PM
@Ezrec: I don't know anyone who have made a hanging RepRap, even without a gyroscope, but it's definitely a good idea!

It moves now. Lines tight and all (for a little while before it crashes into the floor). Check it out: Vimeo.


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Re: Idea: A RepRap Hanging From the Ceiling
September 18, 2015 07:38AM
Did a calibration 2d-print today:


smiling smileythumbs up


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Re: Idea: A RepRap Hanging From the Ceiling
November 22, 2015 12:59PM
Hey guys, it works! smiling smiley

video of print on vimeo
See blog for more explanations and stuff.

Does anyone have recommendations regarding driver chips?

I'm soldering on the drv8825s to put them in fast decay mode, like Quentin Harley does here. I would like to get rid of the soldering routine, but keep the smooth running and high current. Would this be achievable with for example SilentStepsticks?


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VDX
Re: Idea: A RepRap Hanging From the Ceiling
November 22, 2015 03:15PM
... I'm using a RADDS board with RASP128 drivers (1/128 microstepping), which are good for 1.7A continuous or 2.2A with aggressive cooling ...


Viktor
Re: Idea: A RepRap Hanging From the Ceiling
November 22, 2015 03:23PM
Thanks, hadn't heard about them before. RAPS 128 looks very interesting. I'll order some of them and check it out smiling smiley


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Re: Idea: A RepRap Hanging From the Ceiling
November 23, 2015 02:45AM
Congrats! Are you planning on doing scaling tests next?
Re: Idea: A RepRap Hanging From the Ceiling
November 23, 2015 03:05AM
Yes, I'm thinking about something that's hard to build with other methods, like a really tall auger. smiling smiley


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Re: Idea: A RepRap Hanging From the Ceiling
November 23, 2015 02:06PM
Wow! That's excellent, @tobben!
While some people are working at getting printers small enough for their desktop, you're pioneering in the other direction!

Maybe someday we'll have folks building Clercks in smaller frames on their desks. For those who can't dedicate a whole room to a 3D printer smiling smiley
Re: Idea: A RepRap Hanging From the Ceiling
November 24, 2015 05:03AM
Thanks @maso! smiling smiley

I've done some rough calculations on resulting forces and momentum if lighter Nema14 motors were used. My qualified guess from this is that hanging RepRaps with smaller motors are feasible, so I will try to go for smaller, cheaper more easily frameable in my next design.

I have a really patient wife who lets Clerck take over the kitchen for now, but in a months time I've got to dismount it.


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Re: Idea: A RepRap Hanging From the Ceiling
December 07, 2015 09:21AM
Clerck is printing reliably and prints come out good enough for self replication (even with 1.2 mm nozzle). Check out Vimeo and blog.

I see this concept as proven now, maybe I'll put on a smaller nozzle just to be able to comparable level of detail directly to other RepRaps. Final exams are getting close, so development will slow down again.


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Re: Idea: A RepRap Hanging From the Ceiling
December 16, 2015 02:45AM
That's excellent, very impressed.
Re: Idea: A RepRap Hanging From the Ceiling
December 16, 2015 04:08AM
Thanks!


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Re: Idea: A RepRap Hanging From the Ceiling
January 03, 2016 07:42AM
Splendid work!
There is much potential in this. thumbs up
Re: Idea: A RepRap Hanging From the Ceiling
February 01, 2016 08:44AM
Awesome work !
Re: Idea: A RepRap Hanging From the Ceiling
February 01, 2016 02:45PM
Thx =)


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Re: Idea: A RepRap Hanging From the Ceiling
February 02, 2016 01:31AM
Quote
tobben
Thx =)

By the way, if you ever want to implement an arm solution for this machine-type into Smoothieware, I can send you a broken board ( with like a mosfet or ethernet not functional ) for free.
Re: Idea: A RepRap Hanging From the Ceiling
February 02, 2016 03:31AM
smiling smiley I have no ARM plans myself right now. If you would like to develop it with me I'd be happy to co-develop using your fixable Smoothieboard =)


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Re: Idea: A RepRap Hanging From the Ceiling
February 02, 2016 03:32AM
If you want the board, I can definitely help you with the coding. If you've already done the coding for Marlin, it should be trivial to add to Smoothie. Just tell me.
Re: Idea: A RepRap Hanging From the Ceiling
February 02, 2016 04:42AM
Hm... I think the Smoothieboard version of Clerck would be best developed by someone "scratching his own itch" (someone who really wants a Clerck with Smoothie and understands the Smoothie benefits well). That's not me, so I won't do a physical build with Smoothie myself.

The moment you decide to do a Clerck+Smoothie build, send be the board, and I'll help you as much as I can. Since you have the coding skills, chances of success are high smiling smiley


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