I’m waiting for some ColorFabb VarioShore TPU. It has a foaming action at higher temperatures which can lower the Shore-A hardness down into the mid-sixties. The range of hardness is 92-A to 65-A depending on nozzle temperature. As such, the flow rate goes up too. So, it looks like this filament will have to have multiple definitions to fully take advantage of the variable hardness.
I have found a quality issue with TPU HF (it could be all TPU though) when printed using a hardened steel hot-end.
As this might be related to high-speed filament in general, you may wish to take a look.
Just to confirm: you do have a viable silicone sock on the hot ends, and both silicone socks are in good condition?
Yes and yes.
I’ve added my test regimen to the new post I made to keep it all in one place and on topic if you wish to use the link above.
Honestly the only thing you can do is trial and error. I will say with the exception of 1 specific type of high speed ABS my bambu lab printers do really well with about everything ive ever put in it. If i notice some weirdness in the print ill run a flow calibration since I already service my machines weekly including belt tension. but mostly I run the same filaments. Sunlu is mentioned and i use it quite a bit, but i will say that voxel lab filament prints really nice. Id use more bambu filament but what i want is either always sold out or i can get a comparable filament cheaper.
Agreed. That said, it is so far holding true even with the cheapest filaments I’ve tried. I’m presently testing black Juno HS PLA, and although I did dial it in to get the best results I could from it, its maximum extrusion rate was 25mm3/sec, and with a 0.4mm nozzle it’s printing adequately without needing to help it by lowering speed or acceleration. Juno is among the cheapest of the cheap filaments that I’ve run across.
Come to think of it, I should probably print some kind of calibration object, like a benchy, for every new filament that I try, and then sometime down range I’d be in a better position to compare overall print quality. I hadn’t been doing that, but I think I’ll start now. Aurora Tech Channel does this using an Alpaca as the test model for the purpose of making comparisons among different printers.
https://www.printables.com/model/436470-robo-alpaka/files
It’s a fairly large print, but I’ll give it a try using lightning infill to reduce the amount of filament consumed.
However, even doing that it’s still more than a 3 hour print. 
Maybe benchy is, yet again, the better choice?
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Im Glad that i could help you! 
Personally other than the flow calibration models already built into the system I find it a waste of time to print “calibration” prints unless they directly correspond to what you’re actually printing. What I do instead is make a small run of a part of something I already make. If it’s a failure or has print issues I know I need to make adjustments, if it’s acceptable it goes in the part bin for that project.
I do this for a couple of reasons, first being the benchy doesn’t represent what I generally print, so I’m not getting the acceleration or long runs most of my parts typically get. Next is it’s a good benchmark to actually print something you may say put multiples of on the build plate but only print a single part. Then it’s typically a good part and not a waste. I can only think of a very few times I’ve had a failure. Usually it’s a clogged nozzle which may have happened anyways.
I actually have more issues with the a1 than I do with the x or p series printers and most of those issues are due to parts getting knocked off the build plate. I think that is more to do with the nature of the bed moving and the nozzle knocking it off. I had a part knocked off last night that was near the end of the print that was otherwise perfect. Had maybe a half an hour left out of a 13 hour print. I actually heard the part make contact with the hot end and pop off the plate. Honestly I regret the A1 purchase but admit it’s the best bedslinger I’ve ever had.
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I also have a similar approach. I try to catch critical regions of the print and do minor tests of them on a smaller scale. Only if I feel that is an ambitious print.
I never liked painting the boat, as it doesn’t float. Still, I understood the advantage, especially in non-BL printers, as it was possible to quickly identify causes for printing issues or lower quality, as the model is well known and documented over the community.
Do you feel it necessary? Have you noticed the belt tension decreasing over a week? Fast prints? I personally do the opposite: don’t touch it if there isn’t an issue, except for the regular maintenance.
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Honestly, yea I can tell at the end of 6 days printers start having minor artifacts. Do I NEED to adjust them every week? Probably not, but since I’m cleaning the bottom of the printer, the carbon and steel rods and lubricating the machine anyways and I already like to move the axis by hand each week to identify if there my be a problem it just takes a second to loosen the adjustment screws and retighten them.
If I primarily printed pla I doubt I’d do even the cleaning weekly but since ABS has a lot of airborne contamination and the glass does haze over pretty quick so I clean them weekly and just perform general PM. I have to also say that the longevity of Bambus hardened steel nozzles has generally been quite good. I did have a silicone sock I needed to replace last week but that sock was the original sock that came on that particular printer.
A lot of that goes back to my plastics days. Back then we PMed on 3 schedules, daily visual inspection and lubrication, weekly service and inspection, and timed PM for oil and hydraulics and any part that had “timed out” time out maintenance was usually performed during a tooling change or on fridays which is why I adopted the Friday maintainance schedule. Since there is very little data really on components failures on Bambu machines I don’t change any parts based on time in service.
I typically optimize my printing schedule to minimize downtimes. So my machines typically run as close to non stop as I can make it. One may sit a few hours at most before a new print is started. I think I have 2 that finished printing just a little bit ago, and when I get home I’ll re strat them with the next batch of components on the run list.
Ultimately it’s habit from many years in plastics production. It certainly doesn’t hurt the machines any. I have yet to identify a problem with a machine but keeping them clean and well oiled can’t be a bad thing.
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That would be an interesting debate to have, but at the moment my motivation is a bit different: I’m in the midst of trying a number of different PLA filaments from different manufacturers in an effort to identify which are the few that will be my best “go to” filaments for most of my printing, where best is a function of cost and quality in print results and speed. So, I need some way to compare results, and so I need a test model that covers enough ground that it’s not a trivial comparison. When I finish for PLA, I’ll likely do the same for PETG, then for ABS, and maybe others after that.
In a comparison of filament attributes I’d agree that you have to have some model to use as a reference. But I have to caution you that cheaper filaments print quality can vary roll to roll since it’s unlikely you’re going to get multiple rolls from the same batch. However the same can be said on some more expensive brands too.
The issue comes down to quality control in the amount of pellets are in the blend, and consistent resin bead supplier. Most of the name brand filament makers use the same supplier for everything and have a pretty dialed in metering system to ensure accuracy. The cheaper guys tend to buy the resin beads in bulk from whoever is offering the best price at the time and use crude mixing techniques. Bear in mind this is a very basic explanation and I’m painting with a wide brush.
I will say for pla specifically one of the best filaments I’ve used hands down is voxelab. But there are cheaper filaments to be had. Most of what I do is sanded and painted anyway so I do t give 2 flips about color consistency, only print quality. And I mostly don’t use pla and when I do the majority of it is grey, black or white.
But it sounds like perhaps most of what you will be doing will be finished products off the build plate so it really does matter to have a baseline as you describe.
Reporting back: it may be that ASA provides the best dividing line yet between high speed and non-high speed filament.
I’ll explain. I’m in the midst of printing a pretty big ASA object. It seems that none of the ASA filament on amazon is rated for high speed. In fact, most of it is rated for around 30-50mm/sec, which is much, much slower than speeds in the presets for Bambu Lab’s official ASA filament, where inner walls have a speed limit of 300mm/sec and outer walls at 250mm/sec. So, I bought two rolls of Elegoo ASA from amazon (because I could get it delivered overnight), and I 1. ran the Orca Slicer calibrations on it, but 2. I copy/pasted the speed limits from the official BBL presets for BBL ASA filament (the 300 and 200 numbers I refer to immediately above). Well, the print did complete in about 14 hours, but the print quality was very poor (for instance, lots of zits). And that was after drying it for a couple days at 80C in a blast oven. Now, it did lose more than 11 grams of moisture during the drying process, but I weighed it muliple times during the drying process, and I could see that further drying would have no meaningful additional effect.
So, I’m reprinting it now using the other Elegoo ASA spool which I had purchased at the same time as the first one, but with the speeds cut in half. So, 150mm/sec inner walls and 100mm/sec outer walls as the speed limits. Yes, this is still much higher than the 50mm/sec limit that Elegoo recommends, but 1. even with just this 50% reduction, now the print time is already 46.5 hours, and 2. the print quality is clearly a whole lot better (so far, anyway) than on my earlier attempt. Here’s a picture of its current state that I screen scraped just now:
You can see a small amount of stringing on it and possibly one small zit, but that’s maybe 1% of the hair and zits that were on the first print at BBL’s recommended speed limits. I’m pretty sure it would do better if I dropped the speed to Elegoo’s top recommended 50mm/sec, but the incremental improvement wouldn’t be worth the week of printing that would take.
I have not yet tried BBL’s ASA filament, but I’m assuming it probably does print well at the speeds it had prescribed in the presets.
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I tested the Creality Hyper PLA and the Sunlu HS and for me the SUNLU was superior. Yes that much better. I wanted to buy the safe choice original BL filemants, but SUNLU convinced me. Even on SPORT mode if I am in a hurry (lets say almost never) still solid prints and amazing surfaces.