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danzen

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  1. I did a quick test, printing 16 cylindrical pillars (4x4) each with a diameter of 5mm and a height of 10mm. The pillars have a spacing of 5mm and are placed on top of a 2mm thick base. The pillars were printed in the following order: 10 13 15 166 8 11 143 4 7 121 2 5 9 So the head definitely moves trough other towers while moving from one to the next, but no collision like what you said. One thing I forgot to mention in my first post, because the platform repeatedly moves up and down while printing a tower/island (other than the first one), there is significant blobbing since Z motion is not nearly as fast as X-Y motion. So while there is significantly less stringing, there is also significantly more blobbing. As it is now, stringing is replaced with blobbing, which is why I'm wondering the purpose (if there is indeed one) of the repeated up and down motion?
  2. Hi all, I've recently decided to try out the tower plugin in SF45 in an effort to reduce stringing. I am very very happy with the results. I was printing at 0.1mm layer height and I set the maximum tower height to 10 layers. The reduction in stringing was very significant, though I think it would also vary depending on the model. However, the tower plugin seems to be doing something rather unintelligent. Upon finishing the first tower/island, the head moves to the next and the platform rises 1mm (or the head drops 1mm depending on your perspective). So far so good. Then a layer is printed but instead of dropping the platform by 0.1mm and printing the next layer, it drops to the height of the previous tower/island (downwards 1mm in this iteration) and rises back to the next layer where it's suppose to print (upwards 0.9mm). This pattern continues, i.e., drop 0.9mm, rise 0.8mm, print layer, drop 0.8mm, rise 0.7mm, print layer, drop 0.7mm, rise 0.6mm, print layer, and so on... Not sure if I'm getting the point across here but this seems very inefficient and sometimes causes stringing within the tower/island itself which normally shouldn't happen. Anybody else have the same issue?
  3. So I did a quick experiment using transparency sheets as a printing surface. This is kind of off-topic but I'm not sure starting a new thread would be a good idea. At first I applied blue tape to the transparency sheet and tape that to the acrylic bed. When I started my test print I realized I didn't apply enough tape and some of the PLA was printed on areas of the transparency sheet without any blue tape. I stopped the print after a while and was expecting that the PLA would not separate from the sheet but I was pleasantly surprised. So on my second try I printed directly on the transparency sheet without any blue tape. The sheet was simply taped down at the edges to the acrylic bed. The test print was a disk 120 mm in diameter and 20 mm in height. As one might expect the sheet isn't completely flat on the bed but the first layer printed pretty nicely. One thing to note is that using the transparency sheet I can clearly see that the PLA was thinner at certain areas and thicker at others, in particular it exaggerated the unevenness of the blue tape that's on the acrylic bed. That's partly my fault as it's pretty difficult to apply the blue tape without any gap or overlap. The adhesion of PLA to the transparency was very good. I say this because normally after a few layers, the part would curl and slightly lift off he printing surface. Printing on the sheet however, the part still curled but pulled and distorted the sheet with it to the point that it looks as if the tape used to secure the edges to the bed would come loose at any moment. I didn't finish the print as the curling was pretty bad. Anyways, I removed the tape securing the sheet and proceeded to peel the sheet of the part. You wouldn't believe how effortless it was to remove the part. A very big plus was that the bottom surface of the part was as smooth as the sheet itself, something I think is only achievable if printing on glass. I conclude that the transparency sheet is a pretty decent surface to print on from my initial experiments. The problem with actually using it is the need to secure it firmly and evenly on the bed, requiring something along the lines of a vacuum table. Taping it down at the edges just doesn't work at all.
  4. Hi Matt, Interesting idea. I'm not sure if it would work well though. The problem I had with a large print was that the part was significantly thick that it could not flex. Normally with a part that has a large surface area but relatively thin, a small a mount of flex lets you "peel" the part of the bed from a corner or side. I think your idea would work for prints with small surface area and/or thin profile but then again you would have to make sure to print on top of the set screws. Plus, it would require that you reapply the tape after every print. My tape can survive quite a large number of prints as I use a spudger instead of blades/scrappers to pry the print off the bed. For those who don't know, a spudger is a nylon tool useful for prying open gadgets and whatnot. Yes, the spudger needs to be replace periodically but at least I don't damage the part or the tape/bed as much. You have given me idea though. If the part can't flex, why not make the print surface flex? Maybe secure a transparency sheet or a mylar sheet on top of the acrylic, apply tape on it, and print. When done printing, the transparency/mylar sheet with the blue tape can be peeled off from the part. The only question is how to secure the transparency/mylar sheet on the acrylic bed so that it is flat and stationary. Right now the only thing that comes to mind is vacuum but it's too complex and expensive.
  5. Hi guys, it's been a long time since my last post. I was so hooked to 3D printing after receiving my UM that I simply did not have much time for anything else. I've just finish my first reel of PLA and just got past the stage of just sitting there for hours watching the UM print (anyone else find it hypnotic?). Anyways, I'm very happy with the UM, but I think its far from ideal. Basically I'm looking to improve the build platform. Not the printing surface itself or the z-drive but the cantilevered stage. What I like about the current design: - The idea of a cantilevered stage in general. - The acrylic bed is supported with springs. I occasionally crash my print head into the bed during my very 1st week or so. That doesn't happen anymore but I like the redundancy. What I don't like: - The structure of the platform in general is not as stiff as I would like it to be. - The drive nut assembly is way too flimsy. Is this intentional? - 4 adjustment screws. I think having the acrylic bed supported by 3 points, 2 of which adjustable, is better. - How the acrylic bed is latched onto the platform. It's simple enough to attach and remove but the leveling is affected every time I do so. It would be preferable to keep the build simple as well. Laser cut parts are fine, as well as basic sawing/cutting/drilling. I'm thinking of using MDF and/or aluminium beams instead of plywood. The plywood used in the UM seems to work decent enough but I'm not fond of it for various reasons. I'm also trying to think of a method to attach the build surface to the platform in a way that would make it easier to transition to a heated printing surface (or any other type of printing surface for that matter). I won't be upgrading to a heated surface yet but will definitely do so in the future. Recently I printed a large part (wide and thick) and it got stuck to the bed because I printed the first layer at high temp and squashed it slightly to prevent warping. Took me hours to remove it and in the end the initial solid layers tore off from the sparse layers (was printing at 20% fill). Epic fail. Any ideas would be greatly appreciated. Thanks guys.
  6. Hi guys, I still have a long wait before my UM arrives but a few details of the mechanical assembly is bugging me. To begin with, why the lack of washers? They are dirt cheap and helps to distribute the load of the bolts. I think washers are especially important here since the frames are made of wood and tend to give quite a bit. Secondly, I'm thinking of replacing the majority of the regular nuts used with locknuts. I understand that locknuts are not provided in the kit to keep the cost down. The movements and vibrations would eventually loosen regular nuts and I'd imagine that it would affect the quality of the prints. It doesn't seem very fun to regularly check and tighten each of the 120(?) nuts on the UM. You could say that the give of the wood could serve as some sort of preload but I'd hate to rely on that. I'm probably just really picky. It doesn't look like locknuts can fit in the T-slots though, can someone confirm this? Not really a mod, but maybe small changes that would result in noticeable improvements?
  7. There seems to be quite a difference here. So basically 2.3 kg could last at best more than a year and at worst less than 3 months? Ooooh....maybe ice trays in naughty shapes...that would be fun and hilarious to serve to guests. Imagining their reactions got me giggling a bit. I wonder how flexible PLA fairs in the freezer.
  8. Yeah, that's exactly what I'm aiming for in my very first material purchase. Wow, there are some really nice colors at Faberdashery (I think the naming helps, being fancy and all). It's making me drool... Also great that I get to choose exactly how much I want. Damn, if only they had flexible PLA. I wouldn't think twice if they did. Btw, the PLA that comes with the UM kit, how much do I get and is it a random color?
  9. I've just placed my order! Now all I need is patience... lot's of it... Anyways, I'm looking to get some materials and the "flexible" PLA from the UM shop seems really interesting but unfortunately it's out of stock. RepRapWiki lists two other suppliers with "soft" PLA which I assume is the same thing. The problem is, both sources are from Germany and the shipping to Australia is way too expensive. Does anyone know a reliable source of "flexible" or "soft" PLA that doesn't cost a fortune to ship to Australia? p.s. Anyone else find it extremely annoying that you can't find all the colors you want/need in stock from a single supplier?
  10. Hi Somerwil, Thanks for the input. I think the word 'fluffy' works pretty well. Guess I'll be able find out personally what works when I get my kit.
  11. Hi Daid, Wow, thanks for the tips, it will surely come in handy. I'm curious though, what's the logic/physics behind thinner layers having stronger bonds? Hmmm... that means PLA is better for some applications while ABS is better for others, not exactly a drop in replacement. I hope someone comes up with a mod to improve ABS printing on the Ultimaker. I would definitely like to be able to print in both PLA and ABS. Hi Somerwil, Sorry to disappoint but I'm no hardcore RC geek. Not at all competitive, just very light recreational entertainment. Probably giving the example of RC gears isn't quite appropriate as some, such as yourself, immediately think of high performance gears. I will most probably be using the Ultimaker to print parts for robots, and that includes custom gears that one simply cannot find anywhere. So high performance and reliability aren't exactly necessary. The examples you gave of what PLA works fine for is definitely encouraging. But I noticed you did not mention motor mounts or brackets. Would that mean PLA simply cannot handle the heat? I do understand that the motors you're using probably heats up quite a bit, but what about something less intense? As for precision, I think from all the pics that I have seen, it doesn't seem to much of a problem for the Ultimaker provided that it is tuned and calibrated well. It certainly has much higher resolution than the commercial printers I've used before. Thanks for the replies guys.
  12. I'm aware that bonds between layers aren't as strong, which is where careful design and print orientation comes into play. So it all comes down to the fill? I haven't looked into Netfabb, but I assume it can do solid fill so long as I have the time and materials? Thanks for mentioning heat. Can't believe I forgot to consider that. Guess I'll have to be more careful when printing things like motor mounts or brackets. Thanks for the insight. I can't wait to get my kit.
  13. Hi Owen, thanks for replying. I'm aware of the initial accuracy and adapting the model to suit, which is why I'm not concerned with accuracy at all. You make a good point about not changing things when printing. It's starting to sound very promising. Yeah, I had the impression that PLA is more brittle, which is a cause for concern since practical prints would typically need to support loads in one way or another. I'm just curious as to how brittle it really is. Will PLA shatter when dropped on a hard surface? Maybe similar to acrylic? I've seen some of those pics before. But seeing pictures doesn't really tell me how well they work, which is why I was hoping someone with personal experience can share their opinions on this. Going off topic for a bit, has anyone tried polishing PLA prints before? I'm thinking that if all goes well for me, I may want to DIY a vibrating tumbler to polish parts. Probably will need some experimenting with slightly over-sized prints to account for material loss if I need accuracy.
  14. Hi all, I've decided to purchase the entire kit (needed to "persuade" significant other). But before I do, I just wanted to clear a few things up. I've seen plenty of beautiful prints (thanks to the collection at Durant's blog). But, aside from looks, is the Ultimaker good for printing practical stuff? Things that actually work reasonably well? Like for example, properly meshing gears or Lego blocks that assemble together nicely. I'm concerned about the repeatability as well as the printing material. Of course, I'm not expecting the quality of a proper commercially manufactured product, that would be unreasonable. I have some experience with a commercial ABS printer, and even though the best layer thickness I can get out of the machine was about 0.2 mm, I was very happy with the usability of the prints. Given the resolution of the Ultimaker, I'm guessing accuracy shouldn't be much of an issue, but how repeatable is it? Using Lego as an example, if the prints are not reasonably repeatable some blocks are going to fit too tight while others too loose. I love how strong ABS is, especially when the the model is designed carefully and printed in the optimal orientation. Correct me if I'm wrong but Ultimaker prints best using PLA. I don't have anything against this material but I'm not really familiar with its mechanical properties. Using gears as an example, will PLA gears disintegrate under load? Reasonable load that is, I'm not going to print myself a gearbox for the car I drive to work but maybe one for an RC car. I'm not expecting the gears to work forever (there will be wear and tear) but at the very least work well for a few months under frequent use. So can anyone share their experience with practical prints and how PLA compares to ABS? Some pics or even videos would be nice. Am I expecting too much from a DIY 3D printer? I would still be happy with merely "good looking" prints though, but "working" prints would be so much better. Thanks guys.
  15. Your are absolutely right. But I was thinking of getting some sort of kit with all the electronics, motors, bearings, etc, and then I'll cut the frame myself. Probably do a bit of customizing while I'm at it. Though having said that, as of now I'm not entirely sure how much the cost saving is. This partial kit is currently non-existent hence I have no way of estimating the total cost. I'm in no hurry but I have a feeling I'll probably just get the full kit in a few weeks time anyways. Thanks for your input, appreciate it.
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