Idea about Quallity and dualextrusion compined Construction blueprint, design (UMO+).

[ABurkandt8519 0]

Hi all,

I've an idea about the thopic in the title:

If while dualprint one hot end is tied up and the other is down, the hot ends should not damage the layer, the other one has printed.

Warn me if I'm wrong, please.

Now to my idea:

I thought on two lever plates, which are seperate to the other. I drawed a rough draft, which I post at the end of this post. Short to explain it:

I used a color scheme to describe which parts then are fixed on the print-head and which aren not fixed.

Green: These parts are fixed on the print-head.

Yellow: Hot end down.

Blue: lever plate if lever plate position is up ( hot end not drawn in )

Orange: reed relay, Fixing would have to be clarified.

Black and Red: Power lines to the coil.

Of course, the sketch were speaking only for one Hotend.

So far about the hot ends, if there is also a problem with the power Supply, I came to the idea to use a second one for the hot ends and use a couple of voltage divider and power transistors for controlling the heater Voltage from the second power Supply.

Now I'm interested what you mean. Specially if you are one of the >>Team Ultimaker<< members.

I know, my rough draft is not exactly proportional or in the right size nor it is drawn clean. It should show the principe, only.

Regards Arne.

[3dcase 37]

Hi Arne,

Good to see some thoughts about the dual extruder again, or I do not look into the forum deep enough..

After a few months of trying and modifying, I honestly admit I abandoned the second hotend to spareparts.

Looking at your idea, my first thought is, your looking into a problem I am not aware of.

There is no (with the right adjusting, or a alternative printhead design) problem with hotends hitting a printed layer.

The problem is in oozing, leaking of the nozzle, lifting the nozzle or printhead would only delay the problem, because it keeps leaking.

For the design, the downside is it adds a lot of extra weight which will reduce your speed.

Speed might not be a problem, if the print quality is a huge improvement.

Speed could be solved with a better Drive, wider belts, heavier motor, sturdier guide rods etc.

My guess is you first have to look at the nozzle leaking :(.

regards Kees

Edited December 31, 2015 by Guest

[ABurkandt8519 0]

Funny, in this thopic was told from problems, which was a reason to don't do further deloppments on dualextrusion: https://ultimaker.com/en/community/10344-company-update?page=1&amp%3Bsort=

It was a big part of the thopic. So I thought it was a serious problem.

Now the information contradict what I have. Because this I don't know what is facts.

[3dcase 37]

Funny, in this thopic was told from problems, which was a reason to don't do further deloppments on dualextrusion: https://ultimaker.com/en/community/10344-company-update?page=1&amp%3Bsort=

It was a big part of the thopic. So I thought it was a serious problem.

Now the information contradict what I have. Because this I don't know what is facts.

 

Well, It was indeed a serious problem, the printhead modifications that came with the kit, were insufficient, hard to adjust the height. not sturdy enough to keep the height setting during the print. Even retraction and feeder pressure, made a difference in height because it was to flexible.

After some experimenting I made/printed myself a new printhead, easier to set the levels and hold them during the print. As said in your quoted topic the 'knocking and hitting previous layers' was solved. dual-printhead.

Stil leaving the bigger problem (in my opinion). of oozing/leaking.

At first people added extra parts to their design to wipe the nozzles before printing the other colour. Later Daid come up with a more professional ooze shield in Cura, a extra wall around the print.

It all helped, but prints were still dirty from the different colours/materials.

Took a lot of extra time in retractions and movements.

So not to many people are using it anymore I guess :(.

Regards Kees, keep up your good ideas!!!

all hoping the problem is solved one day.....

Edited January 1, 2016 by Guest

[jhertzberg 19]

I don't know if you read the printhead changer thread. Would it suit your needs?: https://ultimaker.com/en/community/10657-a-different-multi-extrusion-approach-um-tool-printhead-changer

[ABurkandt8519 0]

Hi,

after a week I was away, I reponses again.

I had thake a look at the thopic jhertberg had postet shortly. It don't seems like that what I need. I need dual extrusion in a way, where the not used hot end is lifted till it will be used.

It took a week till  I had modelled my mind with blender, but now I need to let some parts produce "as prototypes" made of metal. With the meaning of Opensource, I post a zip-file with some stl-files, the latest blender-file and some datasheets (which I have downloaded by Conrad, where I want to order these parts) and an explosion-sketch included.

The URL to the file is as follows:https://drive.google.com/file/d/0B9fr43SFS-59YzZCQTU2TWpTRUU/view?usp=sharing

Attention: Some of these parts are said to have threads, not all but some and I forgot that the elctromagnets and the compression springs are not shown in the files.

I hope simply, that you understand what I mean. Elsewhere it would be difficult to explain.

Best regards, Arne.

Edited January 10, 2016 by Guest

[macua85 52]

It does seem here that you are trying to reinvent the wheel. The dual head changer system removes the second nozzle as a concern, and even takes care of any oozing issues as it oozes in the corner rather than on the print. Not sure why you would go through with this complex design, unless its just for the challenge,then go for it! We all like seeing new ideas here.

[3dcase 37]

Another thought....

In my humble opinion, we (me, you, the community, R&D @ Ultimaker) should concentrate on stopping the leaking. A dual head change system will not solve that, perhaps if you could tackle the leaking problem, but then you would not need the change system anymore.

Once upon a time the dual extrusion was new and Hot. Cura (@daid) come up with the idea of wipe towers, ooze shields and such. Super ideas, but nobody (user or software) could figure out how much priming was needed to compensate the for leaked filament.

In the new cura I saw a setting for extra a prime amount, have not tried it with a dual extruder though :(. But I'm pretty sure it is a 'one' time setting, so will not calculate how much the leaking extruder will need.

[neotko 1,417]

Maybe the dual printing should be just done with the printer upside down. Or with a hydraulic retraction system...

[ABurkandt8519 0]

Hi,

after a few stressfull weeks, I could find time to response again.

In the time between, I thounght about some of the told problems:

I think (perhaps I'm wrong) the leaking or oozing could be possible to solve with a wide retraction, may be via feeder. That's an idea, only. So correct me if I'm wrong, please.

With the calibration of the second print head an the nozzle, I came to the conceptional idea, to use screws and adjusting nuts to adjust the height of the second lever. Of course then I need two axes and seperate, splitted of leverholders.

As I said, actually I have the concepts in my mind, only, no drafts or modell datas.

One of the problems I see on the changer system is, that it seems to need more time to change the print head. Which can lead to the problem that the previous layer is too cold, to allow the new layer does connect it.

Kind regards,

Arne.

Edited January 31, 2016 by Guest
I did forgot some words.

[Labern 774]

Hi,

after a few stressfull weeks, I could find time to response again.

In the time between, I thounght about some of the told problems:

I think (perhaps I'm wrong) the leaking or oozing could be possible to solve with a wide retraction, may be via feeder. That's an idea, only. So correct me if I'm wrong, please.

Kind regards,

Arne.

 

Retractions don't remove all the plastic from the nozzle. they just release the pressure in the hot end. The left over plastic sits in the hotend and gets hotter and hotter as its not moving. as it gets hotter it expands and oozes out of the nozzle.

Reducing the heat zone reduces the amount of plastic left over and reduces oozing, But this means you then cant print as fast.

[neotko 1,417]

Check this video, it's for e3d hotends but they illustrate very well how the hotend actually works.

 

[aelric23 2]

Hi all. I'm also thinking about going to dual extruders on my UMO+ as well. If the problem is leaking at the nozzle, wouldn't it be simple to just hack the printer firmware to retract the filament out of the nozzle (feed rate to reverse) and wait until the filament is needed again? That is if the filament is leaking directly at the nozzle. If the leak is elsewhere, please say because for dual extruder printers, I have seen quite a bit of overlap between the two filaments (whether it be PLA and ABS and etc.). It's never perfect, but I would take a look at other 3D printers like the Taz 5 with the dual extruder and see how their community is tackling this same problem or if they don't, see what the design entails to prevent this. Like neotko said, "you do not have to reinvent the wheel" unless all other options have been exhausted.