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danilius

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Posts posted by danilius

  1. Yup, I have had quite a few CAD file exports going wrong from various programs, which I was forced to correct by hand in Blender.

    I would agree with Nallath that Sketchup is really not suited for 3D printing, because it really does not care about issues that affect 3D printing, since it does its job quite nicely without it.

    In Blender, OTOH, most of the issues that affect a good print can cause problems with things like boolean operations, correct material rendering etc; so it kind of gets 3D printing made easy for free.

  2. Thing is, the Ultimaker website for the UK does not seem to sell the PTFE coupler. Anyone know where I get it from? How much it costs?

    Also, I don't recall anything in the literature saying that this was effectively a consumable. I don't want to sound like I'm moaning, but I felt pretty disappointed when the dual-head printing I bought the UM2 for did not pan out, and now this seems to be a consumable they forgot to tell me about that I will have to spend precious time fitting myself because I cannot afford the downtime and probably not the courier either.

    Sigh. I think it's a matter of getting used to the way they do business. I was just hoping that with all the open-source and yada Ultimaker would not be in the habit of shafting their customers, but clearly that's the only way to do business today. Never mind. Rant off.

  3. You need to check a few things. First of all, that the bottom layer is pressed tightly on to the bed, which the bed levelling is all about. This is crucial, but you do not have to do it very often. You want to see the lines being printed so that they are flat, not rounded. Of course if your bed is too near the nozzle, the printer will be trying to force out a load of plastic for which there is no space, and you will that knocking sound from the extruder.

    So basically, you need to balance the need for a squashed down bottom versus a too tight gap.

    Bear in mind that you cannot print most PLA at 200C, 60mm/sec and 0.2mm layer height. That's just too much plastic being forced through the nozzle and the extruder motor will kick back and "tock". So, start off with PLA at 210C, 0.1mm layer height and 15mm/sec for your first layer, 30mm/sec for the rest.

    With the bed height adjustment and these speeds, you should be able to dial things in quite nicely.

    • Like 1
  4. Weird problem that has only started recently. After printing, the filament is left with a little shoulder (by the green arrows) that prevents the filament from feeding through for the next print. Sometimes that little shoulder will jam in the bowden if I try to remove the material.

    What I do at the moment is simply to remove the bowden from the head, extrude some filament, trim off the end and pop the bowden back. Not exactly something I want to have to do ten times a day.

    Any idea why this might be happening? The printer has done at least 1400 hours.

    5a330e847dd4d_filamentwithshoulder2.thumb.png.deefda41d1658d80cf7c1e2b6335e1b3.png

    5a330e847dd4d_filamentwithshoulder2.thumb.png.deefda41d1658d80cf7c1e2b6335e1b3.png

  5. There is a good chance that the filament you have is poor quality. I have bought a variety of filament, both ABS and PLA. It's a hit-and-miss affair.

    Some PLA turned out to be OK for printing, i.e. 210C - 220C, 0.1mm layer height at 50mm/sec, but quite brittle. Also, at 0.2mm I had to drop the speed to around 25mm/sec.

    Some simply was useless, and I use it for pinning, head-cleaning and little else.

    My current favourite (despite it's awful smell) is some cheap ABS I bought of ebay, followed by the black PLA from 3dfilaprint.com which can be pushed quite hard. The ABS manages 60mm/sec at 0.25 at 260C with no hassle, and the black PLA can manage 40mm/sec at 0.25 at 220C. By far the best results I have had so far are with ABS.

    So, I suggest you try a different supplier and see what they offer.

    • Like 1
  6. Print it with the holes facing down on the bed. You will still need supports for the inside, though. You can cut it into more pieces to avoid supports altogether, such as making the tube on piece, and print that vertically.

    It's a tricky part, though. You might want to design it differently to make it easier to print.

    • Like 1
  7. That's just how one would expect it to look like, since that area is where the supports were.

    If you need all the surfaces to look clean, the number one rule is do not use supports. Split your model into two or more parts to avoid using supports, add locating holes on all mating surfaces, print separately and assemble, popping some filament into the locating holes. Use superglue as an adhesive.

    If you upload your model I will show you what I mean.

  8. I have also noticed that filaments from the same manufacturer will vary by colour. Having played around with dozens of different filaments, it appears that there is little guarantee that if you pay GBP34.5 per kilo for something like colorfabb that you will get twice the performance/quality of something costing half the price. I have had really cheap Chinese stuff that was pretty good. Some of it was quite horrible as well, so YMMV.

  9. I think you will find that most Ultimaker users print overnight, since printing a bed full of small parts can take more than 8 hours quite easily.

    It's a matter of hoping your supervisor can see sense and balance the risks as opposed to proving that the Ultimaker is safe, for whatever given value of "safe".

    For example, electrical sockets are not absolutely safe. I have seen one bursting into flames. Would you leave an electrical socket switched on overnight?

  10. This will probably come as a surprise to most CAD users - but I use Blender for a lot of CAD work, simply because it's the tool I use the most for my day-to-day work, and whatever package you use, the files end up as polygons anyway. Also, I can show the client a photo-real render or animation before I print out whatever it is I have designed for them, all in the same program.

    Here is a warning though: Blender has an insane learning curve. Yes, it does organic shapes brilliantly, can sculpt, and even does CAD in a strange way, but it is very, very difficult to get up to speed with it quickly.

    Why mention it then? Because I produce useable and printable designs with it very quickly, since it lends itself to be used as a CAD sketchbook, so to speak. A basic idea takes very little time to create. With experience, you will be able to refine the initial "sketch" and improve it until it is done.

    So, Blender is not your obvious choice for CAD, but you might want to consider it for the above reasons.

    Oh, and it's open-source and has a great community.

     

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