I bought myself a TAZ 6 a couple of months ago - but do to house repairs taking my attention, I haven’t been able to get it completely set up until last weekend. It is a very impressive piece of equipment, but I think I need to do a bit of tweaking out of the box to get it to work a bit better.
I have printed 4 Roctopuses with the included nGen filament. Only one of them was successful. The first three all had the same exact problem. They were so stuck to the bed, that I thought that the glass would break before I pulled them off. I was able to get all of them off the bed, but they all lost their arms in the process and one of them almost felt like it welded itself to the glass. It took a lot of convincing to remove them. So, I figured something was wrong and it wasn’t just me. I looked at the roctopus that was included with the TAZ. It too had a broken arm, but more importantly, I noticed that the bottom of my print had a hard shell (no lines) and the sample that came with the unit looked very different (lines diagonally across). I did a Google search and found some posts about the Z-axis not being set correctly from the factory. I looked at the skirt and noticed that it was super flat. Looked in the adv. configuration and found that the Z-axis was around -1.400’ish.
I turned it down to -0.300. The next print’s skirt didn’t stick so well. In fact, the skirt pulled up and was interfering with the actual print. So, I turned it to -0.749 and it seemed to be just right. It adhered well. Finished printing and popped right off with only a few taps of the removal tool. So, my guess is that the Roctopus sample was not printed by the printer that I have or whomever printed the sample, over road the machine configuration with Cura. Either way, I think my machine has some more adjustments that may need to be done.
Which brings me to my new issue. All 4 roctopuses (and the included sample) all appear to have a fine webbing between the tentacles and the bull horns of the hand. It is most noticeable on the hand. It appears to be so much so that it has a peach fuzz hair quality to it. Unfortunately, the sample that came with the printer had that particular arm broken and missing. However, looking at the sample’s tentacles - I am sure that the sample had the same issue. I did some Google searches on this and I found that it may have something to do with retraction settings (sucking it back into the extruder?). I saw an Eiffel tower piece with the same issue but much more excessive than my own test prints.
At the moment, I am using OctoPrint on a Raspberry Pi. I have the ability to hook a laptop to the TAZ directly and use Cura, but I would like to stick to OctoPrint as the webcam, remote control capabilities are a necessity long term.
Does anyone have any suggestions on the webbing issue?
The 1.4mm value in advanced configuration is the distance from the top of the corner washer to the bed. If you change that back to the original value and just add a little positive z offset in your slicer, it will loosen up the bond to the build surface. Also, make sure your nozzle is good and clean and that it isn’t pressing the corner washers down during the bed level measurement. That will also cause an over squished first layer.
I hate to jump right in with a contradiction to @nopick’s suggestion but I would not change the z-offset back to -1.4 in your advanced settings. I had the exact same issue with my TAZ 6’s first print. My z-offset was -1.350. Inter some testing I have now set it to -1.250 and my initial layer heights are about spot on. I can only imagine the difference in temperature/humidity is what made the 0.1mm difference in the factory offset setting to what works best in my house (we are talking Florida vs. Colorado). Changing it in the firmware and writing it back to the printer is th enter option than changing it only in the software. That way the change follows the printer, not just that version of the program.
Not sure if I need to tweak the Z-Axis too much further as it appears “just right” for the moment. If I have any issues of the filament not adhering - I’ll bump it back to -1.1ish. The nozzle is very clean (only has been used on my 4 roctopuses so far).
My current problem is the webbing. Not sure what to do about that. Especially since the sample that came in the box had the same issue.
The disassembly. shipping, then re-assembly of the printer usually causes some shifting of the bed/nozzle amount. So I would recommend a check on setup of a new printer anyway. As for the slight oozing(AKA -hair) you can adjust retraction and temp to reduce such things, the default print settings tend to be close but not perfect.
I have seen several people comment about an overly squished first layer on the Taz 6. I wonder if there is some variance in the corner washers and standoffs. I also wonder why they don’t notice the problem when they run the test print at the factory.
Not sure… I was actually really disappointed with my initial print on the TAZ 6. I actually found a calibration Rocktopus on the Lulzbot website that prints a really looooong skirt relatively slowly and is meant to be used at the factory for setting the machines z-offset. You can go into the Advanced settings and change it while the printer is active so as the skirt was printing I’m slowly rotating the knob to bring the number closer to zero then wait a little bit for the layer height to take effect. After a few adjustments turn the printer off then measure with calipers and go back to the offset that seemed the best. Another test print of a regular model, etc. After a few tries I got it to consistently be pretty darn close to the slicer’s specified initial layer height.
I got the Mini first, the first print was incredible and I was hooked right away. The build volume as well as the inability to print more than one thing at a time were the two main excuses I kept nagging my wife with to get the 6. My first print experience on the 6 was actually a bit of a letdown and I actually wonder had it come first and the same initial print experience would I have been as excited right from the start. Probably so, but just as I tweeted not long ago the Mini was just an awesome choice for a first printer.
I think the nGen might be some of the problem with the hairy prints. I did notice a lot more stringiness on my first 6 Rocktopus using the nGen than I did on the Mini using the supplied HIPS. Even subsequent prints on the 6 using other filaments than nGen. A lot of folks rave about nGen and I know Colorfabb makes great stuff, just haven’t had the chance to really use any yet. I have about a $1K of filament screaming to be used…
Well, I’m wondering if someone took a shortcut during the QC process. Unless things got jostled during transport/re-assembly - the sample print seemed to have a MUCH different Z-axis offset of nearly an entire 1mm compared to my first few tests. In addition, it would have been nice if I received a sample that was completely intact. The sample was boxed at the factory missing one arm and it wasn’t anywhere in the box or in the sealed bag along with the rest of the sample.
I guess I could go through a complete calibration, but for now - I want to start using it. Last night was my first successful print - even have OctoPrint recording the entire print via webcam. I was happy - except for the stringy-ness. But - when looking at the sample print - it also had the same amount of stringy-ness around the tentacles. I guess the reason why I didn’t see it before was do to the missing arm with bull horned hand, which had the most stringing with an almost peach fuzz appearance.
I’ll have to play around with the retraction and see if I can minimize it. I did notice that if I send a 10mm extrude command to the printer - after loading the filament - it seems to keep coming out on it’s own for about 10 seconds. Small little drips, that fall about 80mm before it cools and hardens. I remove the strand with tweezers and then wait another few seconds only to see a new smaller and finer strand come out on it’s own. I remove that one as well and that usually takes care of it.
I guess that is what is somewhat frustrating for me. This is my first 3D printer even though I have been following the reprap community for a long time. I chose it due to the bed size and the reviews of the TAZ 5 and TAZ mini. However, out of the box - it doesn’t “just work”. BUT - I am okay with that as long as I am able to find a solution.
I should try the spool of HIPs that I have. Since I have made multiple tests on the nGen, I don’t have much left anyway (maybe 1-2 more roctopuses worth). I also have some PLA and ABS arriving on Saturday. I’m wondering if nGen would do better at 3-5c cooler than what is specified in the gcode.
Also, thanks again to everyone. I’ll let you know if I was able to take care of my stringy situation and how I fixed it this weekend.
You should definitely notice a difference with the HIPS. I actually liked it the most in the beginning. Had a nice matte finish to it, very little strings. I only started to get frustrated with it (and ABS) when printing large, flat items or large, tall items, because of the warping. There are ways to counteract it and the first while of 3D printing is just a learning process.
Best advice for HIPS, if you have a large flat piece on the bed, is to use a brim or you’ll get the corners start to curl up on you. Not sure what brand HIPS you have but if it is eSUN then set the filament diameter to 3.00mm and flow to 100%.
So, Sunday - I screwed up. I did another test with playing around with the retraction and it was a little better, but not much using nGen.
Then, I loaded up the HIPS spool and found the HIPS profile on the LulzBot website. What I didn’t realize is that the profile was for the TAZ1-4 models and Cura using the new profile seemed to remove the auto-leveling and cleaning portion of the GCode when I exported the GCode for the Roctopus to uploaded it into OctoPrint. In fact, it didn’t even set the bed temp correctly (at all actually) - it stayed at 60c which was what I had it set to before I started the print.
Anyway, this resulted in me having to clean up a mess and figure out how to get my old profile back in Cura. Figured it out and last night had time to do a Roctopus print using HIPS. Oh my … what a difference. Hands down, nGen appears to be a more viscous plastic than HIPS. I also noticed that in the nGen prints, there appeared to be a little Z wobble in the rocker hand. However, with the HIPS, using the default settings - it was spot on with very little stringing at all.
I also found out that a heat gun took care of any of the stringing on the nGen after the fact. But - it still doesn’t solve the wobble that I didn’t even realize I had until I compared it to the HIPS print. Could it be that nGen should be using 220 instead of 230c for the hot end? Or is it just the property of the plastic itself to be more fluid?
Anyway, it’s nice to see how the different plastics react. I’m going to try out PLA when I get home tonight and ABS next. Also, I’m using Gizmo HIPS and Hatchbox for the PLA and ABS.
Thanks for the tips everyone. Does anyone know of a video tutorial series for advanced 3D printing concepts? I understand the basics, but there seems to be a lot of tweaking that can be done in Cura and the information for those settings (and why you use those settings) are spread out all over the place.
