This one's beyond me at the moment engineering wise, but might be worth thinking about...

When I was a kid my microscope allowed me to rotate a lense carousel which clicked into place allowing each lense in turn to be aligned under the eye piece & allowed it to be out of the way when not in use. The carousel was cone shaped so that the unused lenses would always be above the one in use. I was thinking how this might work for delta type robot effectors where the filament tubes would travel as a bundle. I was thinking that the heads could be stepped into place with two solenoids rotating the carousel in the two required directions so that it could unwind. The benefit being that each head would sit in the same position when selected & be above the print area when not. A common fan could cool the assembly & heat to the individual heads could be maintained throughout or switched on or off by aligning selection contacts.

Has this idea already done the rounds? If so, my apologies I can't have read far enough.

Edited 2 time(s). Last edit at 06/09/2014 10:56PM by Harleym.
I looked at this. It sounds good on paper, Probably doable if you have a SLS available, but you'd have operational issues.
It would probably work better with just 1 filament tube. Then retract until the filament clears the hotend. Rotate to the new hotend. Extrude. Wipe. Keep printing.


I have been looking at the same thing for a dual or tripple colour system.. The main idea is that if doen correctly you should be able to pause as a specific layer, change the nozzle, then start printing again in the new colour without affecting the nozzle position. The only code changes required are the pause print, an output signal for the head change and possibly an input to say the head is in position. I have some ideas floating around on how it can be done but haven't commited the design to cad yet.

My delta build blogspot [d3delta3d.blogspot.com.au]

Custom Delta printer
300x500 build volume
magnetic effector
Smoothieboard controlled
i just had the same idea and found this thread
did you guys see this? [www.3ders.org]

i'm very interested in this since it (and maybe some other configurations for multi-hotend) would allow for a single calibration point, which from my experience is the only way multiextrussion can be properly done in a delta

What I got in mind for this to attach a motor on the mount to rotate those hot ends, but the hotends would be limited to bowden only. The motor shaft facing downwards as the hotends orbitting around the shaft
And to stop blobs dripping out, you can cap the hotend as it moves away from the printing position.
But I agree, I think the best thing for this idea is for it to be bowden driven and 1 strand of filement per hot end.

Different nozzle diameters? A lot of work for a switch in accuracy.Is it really worth all the work?
Quick render of how it could be done.
First image is an overview.

Second image is a detail show of the ooze plug.
open | download - Hotend Turret.jpg (46.7 KB)
open | download - Hotend Turret anti ooze.jpg (34.9 KB)
Mine not really like your picture, it is like you see them on top, from z axis to x y plane, rather than a 45 degree axis rotation, I would suggest at 90' axis, all nozzle would point downwards thus having much smaller and compact design, like a planet orbiting sun seen from above =)

Using stepper motor are good for accuracy but the body are too big to make it compact, I guess a servo much better so the bowden tube won't get tangled since servo has rotation limits and its center too

Try imagine most dual extruder/hot end mount design in bowden, switching places each other, no compromise on print volume (but watch out on bulldog clip or something =)
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