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element7721

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  1. I've seen just as many people who clogged their nozzles by just preheating the machine and leaving it idle for too long. For example, they heat it up to change the filament and then forget about it for 30 minutes while they are doing someone else on the computer. I've also seen people who changed their ending script to prevent the machine from cooling down at the end, which would allow them to print back-to-back parts quicker. So regardless of what software you are using, there's lots of ways you can create problems when working with PVA. So that's why I tried to write some extra info above - I think it's much more important for a new user to understand why they have to be careful with PVA and what things to watch out for. They will still need to remember those things even when working with Cura to do machine maintenance or when performing manual operations on the LCD panel. Back to the simplify3d profile, personally, I really hate waiting for the temperatures to constantly change in the extruders. I would rather just set them to a constant temperature for as long as I need them, and they turn them off when I'm done (or when they are no longer needed for that section of the print). It's also quite rare that I print a part that has 1000's of layers that aren't using the PVA, so this is far easier for me. But of course, other people may prefer something else. Maybe it makes sense to have one version of the profile that automatically cools down the PVA extruder every time it changes tools and another where it just stays at a constant temperature. Then people can choose which ever one they prefer.
  2. I'll add a few more observations to this thread. I've been using S3D with my Ultimaker 3 since the day I got it. Both of the above profiles work well, and I also got a profile directly from the simplify3d support people that worked very well. I've already printed close to 50 parts and I've got simplify3d dialed in really nicely now. There seems to be some concern above about how long you can leave an extruder heated, so I'll go ahead and add my findings. I've tested this quite extensively on a few different printers, so I'll try to give some facts from my tests. I have quite a few different printers and have been printing in PLA for years. PLA usually has a melting temperature of around 175C, so if you're using 190-195C on your 3D printer, you're just slightly above that value. I've never had any issues with PLA burning unless I tried to take it above 230-250C for long periods of time. There's many other studies out there that also confirm this - you really have to be above 230C for a long period of time to see any burning with PLA, and you shouldn't be printing anywhere near that temperature under normal circumstances. So I wouldn't be concerned at all about leaving your PLA heated to 190C for a few hours. I've never had any issues doing that with the many other printers I own, so unless the UM3 has some terrible temperature distribution or has some other design flaw that I am not aware of, there really shouldn't be any concerns about PLA in the nozzle. PVA on the other hand has always been a tricky material. Personally, I far prefer using ABS/HIPS or PLA/PETG, but I've also been using PVA a lot for the last 2 years. I can't even count how many spools of PVA filament I've gone through.. There are a lot of things that you have to watch out for with PVA. It soaks up moisture from the air like crazy, so take care to store it in a sealed bag with a desiccant when you aren't using it. I've found I get the best extrusion at around 215-220C for most of the PVA spools I've used, which is just above the melting point for the material. But PVA also has one big disadvantage compared to all the other materials mentioned above - it can start to undergo pyrolysis anytime it is above around 200-210C. Pyrolysis is a reaction where the material essentially burns and becomes a solid charred substance with some gas and liquid byproducts. And yes, you read that right - the normal extrusion temperature is above the pyrolysis temperature, hence the problem. Now this reaction doesn't happen immediately. From my tests, it usually takes around 20-40 minutes at 220C before you start to form the charred solid byproducts that can clog the nozzle. So if you are just preheating your extruder for a few minutes minutes before you start a print, no need to worry. If you're printing a part that is going to be constantly switching between PLA and PVA supports, there is also no need to worry. The only time you could get into trouble is if you are heating up the PVA nozzle, but not extruding any material for a long time. The example given above was if you have a part that needs support for the first 15 layers, but then it doesn't need any other support for the next 1000 layers. Personally, it's pretty rare that I print parts like this, but if I do, it's really easy to deal with it in simplify3d. The simplest option is to just edit your process settings to turn off the PVA extruder after layer 15. Takes 2 clicks and you can even pick when and where this happens. Sometimes if I'm doing dual color printing, I use the same technique - if I have a region where I'm only printing with one color, you can just reduce the temperature of the unused extruder for that section. Another thing that I have done in the past is used a prime pillar or a full-height skirt that is always printed with the PVA material. This way you always make sure that you are extruding a small amount of PVA plastic on each layer which keep the nozzle flowing cleanly. Both of these things are really easy to setup, and as I said, I've been using S3D with PVA for about 2 years now. As long as you know a bit about the problems with PVA, it's easy to plan around them. If anyone needs help with setting these things up in S3D, let me know and I can explain it more. Anyways, if you're new to 3D printing, I really wouldn't recommend printing with PVA at all. It has far too many issues compared to the other filaments mentioned above. But if you do choose to use it, just make sure you understand the things to look out for.
  3. I've used hair spray in the past. In most of my prints, it actually did too good of a job holding the prints down, and it ended up being really hard to get them off the bed! So if you want more stick in the future, that can be a good option. As you would expect, it is flammable though, so make sure you take care when applying it
  4. Nice tip! I've tried using hairspray before, but had similar problems with it being a bit too difficult to remove. I usually worked around it by just tweaking my first layer position to get just the right amount of grip, but this could also be a good trick to know
  5. I wonder if installing the new USB somehow installed some new drivers that are getting in the way. Maybe you can try finding the USB hub in the device manager and uninstalling it. Then you can see if the remaining USB ports start working again
  6. I've been using S3D with my UM3 from the first day I got it Really nice results so far. There's several profiles posted on this forum that work, and also some on the simplify3d forum.
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