Kraken thread

[Polygonhell]

Finally got around to at least getting one head of the kraken printing, are you supporting the silicone tubing for the water cooler in any way?

[mhackney]

Yes, I used cable wrap and wrapped both silicone tubes to one of the Bowden tubes that goes to a sidearm. From there, the silicone tubes split off to my water reservoir. This is the only photo I could find:

[img]http://mhackney.zenfolio.com/img/s7/v15 ... 0773-3.jpg[/img]

[enggmaug]

I personally used velcro straps to keep all wires, bowden and hoses together. I don't have pics, though.

I just printed an extruder, I hope I'll have time to set up my machine for dual extruding before my company sends me away from home for 1 month and a half... I will indeed be frustrated.

I had some issues with the first hot end, as the plastic managed to leak between the nozzle and the heat break. I thought it was tight enough, but I don't know, apparently it was not. Anyway, yesterday, I cleaned it all, and it seems to be fine now.

One thing I noticed is that I need to set up my temps really hot compared to with the SeeMeCnc hot end... I did not check the temp accuracy on the kraken with the thermocouple yet, but it was fine on the SeeMeCNC HE.

[mhackney]

Sounds like you may have a nozzle bore length problem engmaug. Check the E3D Hotend thread on the Rostock Max topic. I am now printing at normal PLA temps of 185°C on the Kraken and E3D V5 hot ends after modifying my nozzles.

[mhackney]

Here you go, this shows the Bowden with the silicone tubes wrapped together.

[Eaglezsoar]

That red wrapping you used looks good, it matches the color of the effector.

[enggmaug]

Sounds like you may have a nozzle bore length problem engmaug. Check the E3D Hotend thread on the Rostock Max topic. I am now printing at normal PLA temps of 185°C on the Kraken and E3D V5 hot ends after modifying my nozzles.

I did some research on the forum, and the terms "bore length" point me to hundreds messages in the E3D V4 HE.

Kraken is simillar to E3D V5 if I'm correct. I'm not sure to understand the problem or the solution. I printed few parts without any issue after cleaning it all... so... I'm not not I want to spend too much time researching for something I'm not quite sure I really need...

Do you have a specific link to point me to right at your hand ? if not, don't bother, I'll do more research if I realize I do have a problem. Thank you anyway.

[Polygonhell]

One thing I noticed is that I need to set up my temps really hot compared to with the SeeMeCnc hot end... I did not check the temp accuracy on the kraken with the thermocouple yet, but it was fine on the SeeMeCNC HE.

FWIW my Kraken was the same as the last E3D I got and the supplied Semitec thermistor is MILES off with the "correct" setting in the firmware. I ended up making significant changes to the Beta values to get accurate temperatures at 250C.

Mine was off by 30C (reading high), so you'll want to check it with a thermocouple.

[Eaglezsoar]

Sounds like you may have a nozzle bore length problem engmaug. Check the E3D Hotend thread on the Rostock Max topic. I am now printing at normal PLA temps of 185°C on the Kraken and E3D V5 hot ends after modifying my nozzles.

I did some research on the forum, and the terms "bore length" point me to hundreds messages in the E3D V4 HE.

Kraken is simillar to E3D V5 if I'm correct. I'm not sure to understand the problem or the solution. I printed few parts without any issue after cleaning it all... so... I'm not not I want to spend too much time researching for something I'm not quite sure I really need...

Do you have a specific link to point me to right at your hand ? if not, don't bother, I'll do more research if I realize I do have a problem. Thank you anyway.

http://forum.seemecnc.com/viewtopic.php ... &start=640 This is the start of where Michael talks about shortening the inside bore length.

[mhackney]

The E3D V5 and Kraken nozzles and hot zone are the exact same and the overall design of the SS heat break is very similar. Both are subject to the issue I found with the bore being too long. If what you have is working, go with it. But when it starts jamming up again, go back and look at the link Eagle mentioned above. This, in my now educated and well tested opinion, is the root of the PLA printing problem with these hot ends. Get the nozzle right and you will have the best hot end on the market for printing PLA.

[enggmaug]

Eagle, Thanks for the link.

MHackney, I read your method for shortenning the bore on page 60 of the E3D V4 HE thread. You are right on that the symptoms look similar to mine.

I will check with a thermocouple as Polygonhell suggests, and if it gives a correct reading, I may try to modify one of my nozzles.

What is the bore diameter on the nozzle you tweaked ? If I need to modify a different diameter, is there a rule for the length to aim to ?

After you modify it, how well can you print a different plastic with it ? I mean, I usually use different nozzles for PLA ans ABS, so it would not be an issue, but should I also lenghtn the bore on my ABS nozzles, and what if I want to try Nylon (I just bought a roll) ? Is it something you do whith all your nozzles, or just the PLA ones ?

Anyway, I would never have thought that E3D could overlook the length of the bore on their nozzles... and did they make the mistake on V4, I don't understand why it's still an issue on V5, knowing their reputation, their ease of communication with their customers, and overall quality of their products.

[mhackney]

My nozzle was a .4mm bore but I've done the .25 mm also. I think a good ratio for nozzles below .4mm in diameter is 1:1 to 1:1.5 (diameter to bore length). For larger nozzles, 1:2 is probably better to minimize oozing.

PLA is one of the more difficult materials to print in my opinion. After modification, these nozzles work great for ABS, Taulman Nylon (all varieties they make - I have them all), poly carbonate, LayWood, NinjaFlex.

Consider - every other hot end that I've either measured or found data for has a bore to length ratio of about 1:1 in the .4 to .5mm diameter.

I don't think it's fair to say E3D overlooked or made a mistake. We don't know what the actual spec is. It really seems like a manufacturing issue given the variability we've seen with some being very long. I've been in close contact with Josh and they are very interested in this thread and results and are working on a new V6 that should address the issues. And I should say, many people have been using the stock V5 with PLA with no issues. It could be that they are not printing as much as some of us, their parts are not as "complicated" or they got a hot end within spec.

[enggmaug]

Ok, so yesterday evening, I checked my temp with a thermocouple. Temp was off by 7°C.

It is not enough to justify for my temperature raise. That is why I decided to shorten one of my nozzle's bore.

The result is very convincing, I could lower my temp down to 190°C without an issue, I printed an extruder's cold end perfectly. 190°C minus the temp offset, and it is roughly 185°C.

That is much better than before.

Thank you guys for the tip. I just hope the shorten bore will not let the nozzles to ooze when I print more than one filament.

Anyway, I have my second extruder ready, Probably I'll be able to print with 2 heads soon.

[mhackney]

No oozing on mine. Think about it, oozing can be compounded by back pressure. Eliminate the back pressure and one big contributor to oozing is gone.

[Polygonhell]

IMO it reduces ooze, because you can drop the temperature and this is pretty much true of all plastics, I don't think there is a downside to the shorter nozzle length.

[pyrophreek]

I am about to start Kraken on my Rostock, and I had a couple of questions.

I am planning to use the Azteeg X3 pro, and I was wondering if you had any elegant solutions for mounting? also, can you hook the LCD that comes with the Max to the Azteeg board? or do you need a different LCD panel if you want one with it?

Finally, any progress on an elegant solution for mounting all 4 EZstruders? I currently have two on the top of mine, and was thinking of mounting two more on the sides, but I am having trouble finding the source files for the old side mount lasercut holders to make myself some.

[mhackney]

I ended up with a Viki display - it's a nice unit! No elegant solutions, I haven't buttoned mine down yet. I actually have a mount I made for the RAMBo in my base, I plan to do something similar.

2 ezStruders up top, 2 on sidearms (no longer made). Otherwise 2 or 3 on top and one on some sort of stand off to the side. It's the filament rolls that are the PIA!

[pyrophreek]

I imagine. I will contact seemecnc to see if I can get a copy of the dxf files for the old sidearms, maybe put two of those on mine as well.. I like the idea of having it balanced with two on top two on sides. Will have to make some spool holders for the spools to sit on my desk for the sidearms. Maybe build a rack at some point....hmmmmm so many choices lol.

[mhackney]

Here you go:

SHEET1.DXF

(3.08 MiB) Downloaded 470 times

SHEET2.DXF

(1.29 MiB) Downloaded 432 times

SHEET3.DXF

(6.39 MiB) Downloaded 381 times

SHEET4.DXF

(973.19 KiB) Downloaded 342 times

[pyrophreek]

Are you using the adapter from the github repository to use the ezstruder or do you have the geared extruders. Trying to figure out how it all fits together.
https://github.com/seemecnc/EZStruder/t ... 20adapters

[pyrophreek]

nm, found your previous post:
http://forum.seemecnc.com/viewtopic.php?t=1106&p=12426

[pyrophreek]

So I have installed my kraken and I have completed some first prints, but I am having a bit of a problem with leveling the nozzles. I bring it to center, level two, then move it to the side, and the first is good, but the second is now higher than the first. Moving it the other way results in the opposite: the first is slightly high, but the second is now good. Anyone encounter something similar? What is the best way to go about debugging this? Obviously this is a result of the geometry of the Rostock design, and most likely something in my build is slightly off (not enough to notice with a single nozzle, but multi nozzles becomes an issue).

[mhackney]

Mine are dead level. It sounds like you might have a delta radius calibration problem. Focus on 1 nozzle. When you move to X=Y=Z=0 and then move to the edge of the build plate at Z=0, what happens? Does the nozzle loft or start to dig into the plate? If so, you need to calibrate as per the manual.

I level mine at the same time - no moving the head around to bring the nozzle to center. You should not need to do that.

[pyrophreek]

From what I understand of the delta configuration, if the towers are properly aligned and the arms are all uniform etc (in otherwords the build is perfect) then the print head platform should be perfectly parallel to the bed at all positions, in other words I should not see this. Printer radius problems would result in all nozzles lifting up/gouging slightly not the shifting I am seeing. What I need is to debug the physical linkages/configuration.

[mhackney]

Not true. In addition to having a properly aligned mechanical build, the math needs to know the exact values for two things: the delta arm length and the delta radius. Even with a perfect build, if the delta radius is off, the nozzle will not travel in a plane for a fixed Z.

I may have misunderstood what you mean by shifting. Perhaps a drawing or photo would help us. The nozzle should stay perfectly aligned along the Z axis as it travels about.