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codemaven

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  1. Impossible... I doubt it.... Extreamly difficult and frustrating - certainly. Cheers, Troy.
  2. I'm not overly familliar with the Cura code myself, but in essense I don't think there's any need to sort the list of path segments based on any solid ordering criteria... You have is a 'travelling salesman' problem, which is notoriously difficult to solve optimally. But as far as TSM problems go, this one isn't the most challanging and Cura already does a good job at it and I doubt it really accounts for more than a few milliseconds worth of the overall slicing time. You basically just have a list of unordered discreet line segments, What you are looking to do is link the lines together in s
  3. For the ultimate in adhesion and warp-free printing I often print with blue painters tape on the heated bed @ 60-70 degrees, It works great. I used to have a custom heated bed but I switched to the kit and so far it has been perfect for me. I'm mostly just printing right on the glass with just a tiny bit of glue stick and I have not yet had any adhesion problems with that. Cheers, Troy.
  4. Actually, I see you are using ClipperLib in the cura code for clipping... I believe clipperlib is basically using something similar to a BSP tree to do the clipping. For my tree building, I build the tree from a stream as I read the stl file.. I found it to be in the range of a couple hundred miliseconds max for the largest models I could find on Thingiverse. I only need to build the tree once for the process. I tested on quite a few models including very large ones and very high resolution ones and none of them exceeded ~500ms for the building of the tree. Holes in the mesh were an issue fo
  5. The BSP tree allows for very fast intersection testing. By testing the BSP tree against a plane I get back a sub list of all crossing points on that plane - i.e. the verticies / line segments of all of the triangles that intersect that plane and where they meet. This was my insperation: http://evanw.github.io/csg.js/ I originally started by building an implementation of something similar to OpenSCAD in Java... and while playing with that I realized that the same code for building 3d meshes by intersection of two BSP trees could also be used to return 2d 'slices' of a model very quickly. Al
  6. Cura is already the fastest slicer out there. Compared to the older generation it's really quite impressive. I wrote a slicer myself a while back... It was around the time that Daid first started on the slicing engine for Cura (before he was hired by UM). My slicer was written in Java and was of comperable speed to Cura. I did have a threaded pipeline in it, but only in a couple of spots. Some areas that I had hoped to multthread turned out to not be possible - for example, I wanted to read the file in triangle by triangle and pass each triangle to the slicer immediatly running in another thre
  7. There are bits that can be multithreaded... But multithreading is not the solution to every problem. It can seriously reduce performance in many cases. Some tasks are inherently threadable and others are not. You could slice different models on the build plate in parallel... The easiset way to do this is just to spawn a new instance of the slicer engine thread... But within the slicer it's a poor focus of effort in my opinion. Better to work on making the process more efficient than just throwing around threads at it and hoping that it will go faster. You will run into contention without seri
  8. John, Most of slicing is an inherintly linear task. Some small parts can be broken out... but for the most part you can really only process one polygon / line segment at a time because each segment is dependant on the last... You need to do one layer before you can do the next one because you need to determine overhangs, etc. Not all tasks lend themselves to multi-threading... If Step A requires Step B to be complete before it can begin then by multithreading it you are just locking resources and introducing overhead. I've looked at slicing algorithms. There are some places where it can be
  9. Great to see some practical tests being done. I've always been skeptical of the carbon fibre filament myself because by the way it's described I just can't see how it could possibly be stronger than regular PLA. It's just PLA filled with short chopped carbon fibres... That is really no different than Bronzefill or anything like that. What gives carbon fibre products their strength is that the fibres are long and interwoven or intertangled with eachother, which just isn't the case in the PLA. I actually wouldn't be surprised if they weakened it overall because I don't think the PLA will bond 10
  10. Hi Drayson, The temp sensor ports on the Ultimaker are all designed to work with thermocouples, which require a thermocouple amplifier to work. That's the little board with the blue light on it on the top of the print head (on the UM1 at least...). I just used a thermistor for the temperture sensor instead, but I took advantage of the +5v power supply for the TC amp on the connector to charge a small 1F SuperCapacitor on a little board under my heated bed. I ran this through a resistor and a 35 degree bimetal thermal switch to an LED. Thus when the bed is above 35 degrees the switch closes, c
  11. Hmm.. 5 mins isn't too bad for a heat up time I suppose. My current home-built solution is 300watts so it heats up to 70 degrees in just ove a minute... However I've bought the upgrade kit (and have it sitting under my desk awaiting install on the weekend) mostly for the 3-point levelling and improved z-stage. There are some features of my solution that I'm going to miss like the redundant over-heat cut-off sensors and the led light that indicates when the bed is hot (even with power off)... but I'm looking forward to trying the 'official' implementation. My current heated bed is aluminium wit
  12. Yes!!! Now... if only I could send back my Fab colours to get them spooled up... I already have between 20 and 100 meters of every single colour that they sell...
  13. Criminals have been doing this for years. This is the first I've heard of 3d printed facades, but a few years ago criminals were doing the same thing in the US and Canada with elaborate injection moulded pieces. Cheers, Troy.
  14. Cool! I assume that is planned for release with PinkUnicorn too?
  15. Nice to hear that Cura is continuing to progress. The feature mentioned in this thread is one of the few big Netfabb features that I miss which are missing in Cura... In fact, now that you have seperate speeds for outer shell vs inner shells I think the different layer heights for infill vs shells is the only significant feature that I find missing in Cura compared to NetFabb... Although the ability to do contour type top/bottom skins would be nice too. Cheers, Troy.
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