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danilius

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Posts posted by danilius

  1. Well, I got my new bearings from Ultimaker (worked out cheaper than buying them from Ebay, interesting) and swapped them out on the left hand side. I think the noise had gone for good, but remains to be seen.

    So, how painful was the experience? Actually, not so bad. The bearings slide off quite easily, and they were the least of the problems. I did not have to retention the motor belt either since I left the motor attached to the wall.

    What I did discover was interesting. Some of the screws had their heads stripped and were difficult to remove, so they had been over-tightened in the factory. Um. Fortunately I had some spare screws which I was able to shorten to fit.

    Also, from the day I bought the machine it never stood perfectly flat. One side always wobbled by a millimeter or so. No biggie, but now it stands absolutely flat. Yay!

    Other than that, not much to report.

    • Like 1
  2. I think one of the shaft bearings is going, because I'm getting weird problems when printing. If printing a square, on the front and left side the walls don't touch properly, and the infill in the rear left hand side is noticeably thinner than the front right hand side. Circles have walls that do not touch properly.

    Now, you might think the temps or e-steps are incorrect (I swapped out the standard hobbed nut for a grooved one) but I checked both of those elements exhaustively.

    So, how does one change the bearings? Has anyone got a video or some tips? Is it a complex operation? Where can I buy them from?

  3. I use Singer sewing machine oil, and periodically oil the shafts. Having listened to the bearings closely, I think it is one of the rear left-hand bearings that sounds like it has an issue, the ones mounted in the walls. Has anyone replaced those? Is it difficult to do?

  4. I moved the head by hand, and it seemed fine and did not make that noise either. It's possible the bearings are going there, or maybe one of the ball bearings on the drive shafts. Problem is that I can't seem to track it down, and don't fancy replacing the shaft bearings if I don't really need to.

    Oh well, it looks like I have some fun ahead of me :(

  5. For a while I've been getting this noise from the y-axis of the printer, but I have no idea where it's actually coming from or what the problem is. I have recorded some of this here, and you can see that the noise only appears on longer moves on the y-axis. Short moves and x-axis moves do not make the same noise.

    Anyone have a clue what the problem is?

  6. I have been using ABS juice exclusively for a while now, and figured now is a good time to share my experience with it, since there are so many posts regarding bed adhesion.

    I use juice for PLA, ABS and Nylon (Taulmann Bridge) on borosilicate glass and regular float glass (way cheaper, and works just as well).

    My recipe is quite simple, I stuff some white ABS filament into a bottle (a thin solution of white ABS makes for an almost entirely transparent film), fill it with acetone and then let it stand for a while. Every now and then I shake the bottle. I have tried thicker and thinner versions, and prefer a very thin solution. This is determined by eye, no fancy calculations.

    For printing PLA the bed is set to 50C, for ABS 110C. Once the bed has cooled to ambient temp, PLA usually peels off leaving the film behind, which is re-usable for another few more prints, not sure how many, I usually re-coat once a week, or once there is no more usable film left on the glass.

    The two biggest issues with ABS juice for me is applying it in the first place, and then removing it before recoating.

    For coating I use an 8mm steel rod and simply dribble some juice across the glass and roll it out. It only takes a few seconds, and dries within 20 seconds or so. If the rod is clean and the juice is thin, it leaves a transparent film on the glass that is almost invisible (if you use white ABS), really thin and gives an almost glass-smooth bottom layer.

    After a disastrous encounter with a stanley blade and my left thumb, I took up @Cloakfield's advice and used hot water and a sponge to wash it off. One day I placed the glass bed in a bowl of hot water and promptly forgot about it; when I came back the film had separated and was floating on the surface! So now I  simply do that, put the glass into a bowl of hot water and leave it there for ten minutes or so, and it cleans itself.

    There are three techniques I use for removing prints: the instant, the chilled and the cool.

    The instant method involves removing the glass bed and tapping the part with a sideways hammer blow. Even if the glass is hot, a well-placed blow will snap the print off. Of course your part may not stand up to that kind of abuse, so it's not universally applicable. Another disadvantage is that it will inevitably remove some film in the process, even with PLA.

    The chilled method is simply to pop it into the freezer. This takes perhaps five minutes. The disadvantage here is that the glass condensates rapidly, so the plate has to be dried one way or another. I don't bother with this method anymore because of that.

    The cool method is to allow the glass to cool to ambient. This can be expedited by removing the glass bed from the printer. After around ten minutes you can hear the print crackling as it contracts and disengages from the film. At this point the print can be removed by careful tugging at one corner. If using PLA, you can wait a little longer and then the print will have detached itself fully and can simply be lifted off. Either way, PLA usually does not remove the film, leaving it reusable, whereas ABS always pulls the film off with it, but just in the printed area.

    All in all, this is a rapid and easily employed method that so far has yielded really great results for me.

    A tip: have some float glass plates made up for you at your local glass shop. That way you can always have a ready-to-print bed in your printer, and they are so much cheaper than a borosilicate one you can afford to have two and still save over half the price of a UM glass bed. I paid £4.50 each which included having the edges bevelled and polished.

  7. Im not giving up, its just im hoping my current print will not fail, my attempt before fan shroud calibration and block height did fail and produced weaker layers.

     

    I rarely use the fans, even when printing PLA, since they only seem to benefit when printing really small areas. For most prints I simply keep them off entirely.

     

    You only get blocked nozzles when the roll jams or the temps are too high when it gets stuck or....

     

    ...a host of other reasons. I print from a roll that sits on a custom holder I made with ball bearings. The only problem I encounter with that is a tangle, something more likely to occur when using loose filament.

  8. @cloakfiend, I went through a horrible hour or two trying to free the thermal doohicky from the old, standard UM2 block, and failed miserably. However, having learned a great deal from previous life experience, I only undertook the change having spare parts at hand, which I of course eventually needed.

    But it was worth it for several reasons. First of all, now I am no longer afraid of doing a head rebuild. It makes me around 20 minutes to strip everything down and put it back together again. Secondly, the Olsson block has made life much easier. Blocked nozzle? Take it out, put in an unblocked nozzle, clean out the old one over the gas cooker.

    The thing is that when it comes to the unknown, you have to throw yourself into and convince yourself that it's easy if you know how. That's the hardest part. So don't just throw your hands up and say voila! I'm done! You didn't do that when it came to paint, did you? You bought a shedload of paint and spent hours experimenting and sniffing fumes. OK, the latter was a fringe benefit. Anyway, don't give up now!

  9. I encountered the same problem in Fusion 360 and created a work-around which I haven't tested until now:

    - create nut and bolt like you described (for example M12x1,5)

    - the inner diameter of the nut for M12x1,5 is ~10,5mm ( I know it's actually 10,5xy :p)

    - go to sketch a circle on the center of your nut with a diameter of 10,8 (or may be larger)

    - extrude this circle "through" your nut, so that the cylinder cuts away the inner 0,3mm of the thread.

    - now you should have a nut that fits "your bolt" ;):p

    And yes, this is not very elegant nor high quality design, but it will work for sure.

    hth,

    Joerg

     

    I don't think this will work, because the it makes no difference how much of the "tip" of the thread you remove, you still need clearance above and below the mating thread profile. I "hand-make" my threads because of this, by making a spiral extrusion. In Blender this is a doddle, there a screw modifier that does all the hard work in a matter of a few clicks. In FreeCAD this is a bit more painful, but still eminently doable using a helical extrusion path.

  10. I usually leave a 0.1mm or slightly less, depending on how tightly the nut and bolt have to fit. It also depends on how accurately your machine extrudes the width of each line, which of course will affect the tolerances as well. So, experiment away, until you change rolls and discover that every colour even from the same manufacturer behaves differently, and there go your measurements :-)

    • Like 1
  11. I tend to avoid supports as well, but if I have no choice I plan the model very carefully to minimize the amount of support needed.

    To remove supports, I use jewellery pliers, a craft knife and my fingers! Lately I have been using slic3r exclusively, and it offers really great control over supports, and some impressive results if tweaked carefully. It has many options for support than Cura does.

    Bit of a pain to setup, mind you, and it is far less stable than Cura, and takes aaaaaaggggeees on high poly models compared to Cura.

  12. here's my new acetoned and copperplated shroud designed by mr labern to cover me till the new one comes out, been meaning to print this for a while, but didn't want to leave it in plastic due to warping over time, this copper plate is like a reinforcement. no idea if it will, work, but we'll soon see.....

    IMG_8966.thumb.JPG.2a3ac757cc2ae26242496c851a8caf16.JPG

     

    Love your latest work, especially all this gorgeous copper plating. I doubt the copper plating will add even a gram of structural support to your shroud since the metal is so thin, so much thinner than silver foil.

  13. This topic has been covered extensively all over the forum, but essentially I use UHU stic (that's how they misspell it), heat the bed to 60C and draw lines across the glass. The heat helps to melt the glue a little. After that, it works for about a week, even after being overprinted and being cooled in the freezer (makes for easy removal). The stick that came with the Ultimaker 2 simply does not compare.

    If I'm not too lazy, I use acetone juice even for PLA, and spread it by dribbling a line of juice across one edge of the bed and then using an 8mm steel rod like a rolling pin to create an even coat across the glass. The only drawback with this method is that the models will pull off the acetone film underneath them, so it's not re-usable, unlike glue stick.

  14. When I first got my Ultimaker, I used the glue stick that came with it for PLA. Results were so-so on big pieces. After a while I tried UHU stic and that was superb, with the disadvantage that parts were difficult to remove. That was solved by either allowing the bed to cool to room temp or sticking it in the freezer.

    For ABS I use ABS juice only. I have printed some seriously large parts with this (30 hours + prints) and had no warping issues. I used to close up the Ultimaker with paper everywhere, concertina-folded paper on top. I simply don't bother anymore, because my room does not have breezes running through it, so that might be a factor. ABS juice works for PLA as well.

    The advantage of glue stick over ABS juice for PLA is that a coat of glue stick can last a week or two of printing. You can re-use any spot on the bed several times. ABS juice, on the other hand, comes off as a fine film with every print, so you have to recoat the used spot. Also, gluestick is far easier to apply than ABS juice which is messy and sticky.

    For parts the size you are printing I do not use a brim. There is no reason not to, but your biggest concern is ensuring your parts has good adhesion to the print surface. Half of that is the adhesive, and the equally important half is getting an optimum first layer. They both take some experimenting. There is a wealth of information covering both these aspects on the forum. YMMV with most techniques (including mine of course) so be prepared to try several until you find something that works for you.

  15. The way I see it, there are two issues here:

    1) Are you going to get a decent printer?

    2) Just how ethical is it, since these guys are using all the research Ultimaker did to build their clone without passing anything back to Ultimaker

    On the first note, it's impossible to tell, because even if you get 100 good prints off it, it might deteriorate irreparably from that point forward, for a number of reasons. Or you might just get lucky and it's as good as the UM2.

    On the second point, even the the Ultimakers are open source, it does not necessarily follow that commercialising their source without their permission is in the spirit of open source. So, difficult choice there.

    Ultimately, it's a case of greed versus being sensible. If you are greedy, take the gamble and go for the cheap product. If you are ethical and sensible, buy the UMO+ and get a known quantity, and support the company that brought this research to you.

  16. Well, having registered this bug and gotten no response, it was time to go hunting. I finally tried putting this: "from OpenGL import GL" at the start of the cura_app.py so it looks like this:

     

    #!/usr/bin/env python3# Copyright © 2015 Ultimaker B.V.# Cura is released under the terms of the AGPLv3 or higher.import sysfrom OpenGL import GL

     

    and hey presto, it works!

  17. You need to tackle this through a process of elimination.

    So, if ABS is fine and PLA is not, there is clearly no issue here other than the nozzle. Feed 20cm or so of PLA through at 240C and that should help clear out any ABS up quite nicely. Make sure you run the PLA through really quickly, otherwise you will get a bigger mess on your hands than you want. You could always print some random object at 60 mms/s and 0.2mm layer height, which will be shoving plastic through at a fast clip, and although 240C is a little high for PLA even at that speed, it should not burn.

    For the record, I switch between PLA, ABS and nylon regularly so it's quite a normal thing to do.

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