Zatsit printer
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@fma
Pardon Frédéric, c'était juste pour faire une blague en introduction ! Merci de votre soutien ! -
J'avais bien compris
I have a question about the PTFE tube between the heater and the silicone tube: does it limit the maximum temperature? AFAIK, PTFE can't handle more than 240°C (and releases toxic fumes)... Could it be replaced by something else? Does it have to be an insulator? PEEK could be an alternative, but expensive.
Frédéric
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@fma
The joint between the stainless steel tube and the flexible hose is reliable and stable, and can be forgotten indefinitely.Its only weakness concerns the possible strong mechanical stresses while it is hot.
The flexible hose is cooled by the water flowing through it, but there is a thermal gradient in its thickness, and some of the material is softened. If you pull it hard while it is hot, you can create a leak. I realized this because I keep fiddling with my prototypes, but there's no reason for a normal user not to force the water tube while the machine is running!
And in any case, repair, if necessary, would be child's play!
Creator of Zatsit, the delta printer with none assembly
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@fma
PTFE does not decompose in a toxic way until 400°C. From 250°C, its mechanical characteristics deteriorate. It flows, in particular.In our case, this small tube does not support any mechanical effort, it is simply there as a stop during installation, and therefore, PTFE does the job very well.
Creator of Zatsit, the delta printer with none assembly
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@zatsit I have a couple of questions but don't answer them if you don't want to.
Firstly, I assume that the stainless steel tube with the M6 nut is made of two parts. The tube being one part and the hollow not being the other? If that is the case, how is the tube fixed to the nut? Is it glued, braised or simply a press fit?
Secondly, what do you use to cut that thin wall stainless tube? I'm assuming that you buy it in longer lengths then cut it to the required length, or do you buy it already cut to length?
Thanks
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@zatsit said in Zatsit printer:
@fma
PTFE does not decompose in a toxic way until 400°C. From 250°C, its mechanical characteristics deteriorate. It flows, in particular.Mmm, that's not what Wikipedia says: https://fr.wikipedia.org/wiki/Polytétrafluoroéthylène#Toxicité
Frédéric
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@deckingman
It's a very relevant question, and I spent a lot of time on it!I first soldered the two parts with silver, but this inevitably leads to a change in the internal surface condition of the tube which loses its polished finish even in the transition zone, and in fact, I noticed a less regular operation with the PLA, for the Hot-Ends so made. I use a medical tube, which is very finely electro-polished inside, probably for aseptic reasons. I think that the spectacular resistance to jamming, which I have seen, even with PLA, is largely due to this excellent surface condition in the transition zone.
So I understood that I had to preserve this polishing, and use a cold assembly, with a press-fit.
Pressing too hard necessarily reduces the diameter of the stainless steel tube, which is not in the right direction. I came to a compromise, with a tube tightened just enough to ensure that there would be no leakage in any circumstance, and a needle punch on the tube's face to prevent it from being driven away by extreme pressures.
These details are very important, and that is why, in my production plan, this part will be the only one I will personally produce, with my lathe adapted for this purpose, at a rate of 20 parts/hour...
Creator of Zatsit, the delta printer with none assembly
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@fma
You're right : 350°C, not 400°C. It doesn't change my conclusion. -
Toxic products start to be emitted at 230°C; no deadly, but toxic.
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@zatsit Thanks for that. As I thought, it's not a simple process. Would you open to the idea of just supplying this part? I don't have a delta so the complete kit is of no interest to me. I would be needing batches of at least 6 and possible 12 at a time.
Also, you didn't answer my second question which was how you cut the tube to length. If you don't want to answer that, I fully understand but if that is the case, could you supply shorted lengths of this tube?
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@deckingman
Yes, all accessories, including this adapter for Hot-end watercooling, are available independently of the Zatsit kit, during the campaign on Kickstarter, and then on the online shop that will follow.Take a look at the Kickstarter page, it says it all!
To manufacture this adapter, I use a specially modified small lathe with a special saw to cut the tube straight, and without blurr.
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@deckingman said in Zatsit printer:
could you supply shorted lengths of this tube
Probably.... What do you have in mind?
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@zatsit said in Zatsit printer:
@deckingman said in Zatsit printer:
could you supply shorted lengths of this tube
Probably.... What do you have in mind?
I'd rather not say at this time. As this is getting way off topic, is it OK if I PM you?
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@deckingman
Yes, of course. -
Now I am imagining very interesting uses for the tube... hmmm...
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@rcarlyle
Yes, this small stainless steel tube, thus cooled, opens up a whole bunch of possibilities, which I am currently developing, and which I hope to be able to offer after Kickstarter.1 - The volume of the Hot End can be divided by 5, and the weight reduced by 3, by directly integrating a miniature nozzle at the bottom of the tube. It is the tube+nozzle assembly that would become interchangeable, rather than the nozzle only.
2 - These miniaturized hot-ends make it possible to have a very light extrusion head, of the Direct/remote type, with two or four independent extrusion channels, but with a single drive motor, in the Flystruder position. I have already made a single-track version, which works extremely well.
Delta printers have great qualities, but they were generally limited by their single-channel Bowden tube. With 4 printable materials, you can imagine the possibilities!
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Congratulation for the successful campaign!
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@Zatsit it would be cool if you could get an example config for the Duet out when you start shipping, so it can be added to https://configurator.reprapfirmware.org
Would make it a lot faster for us to get up and running with a known good config!
I just need to sell my CNC laser now so my wife isn't so mad when she hears I've got to pay for yet another successful Kickstarter
3/3 Kickstarters backed and delivered so far, got my hopes up that this makes 4/4!
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@keyz182
Just after the end of the KS campaign, two new pages will appear on my website www.zatsit.fr : STORE and DOWNLOADS.You will be able to download the configurations for the different systems I was able to try, including of course Duet WiFi.
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@t3p3tony
Many thanks to all my backers, who allowed Zatsit to be born!
