Friday, August 02, 2013
New open source slicer: CuraEngine!
"Cura is the name of a divine figure whose name means "Care" or "Concern""Source: Wikipedia
Ever heard of Cura? Besides a divine figure, it's a 3D printing solution that is meant to be useful and usable to both beginning and advanced 3D printer users. David Braam is full-time developer of Cura, at Ultimaker. We recently released version 13.06, which was a major update. Compared to the previous version it looked... well ...exactly the same. But on the back-end, the engine that generates the toolpath from the mesh-surface model (e.g. the STL or AMF) was replaced by a new engine, written entirely from scratch.
The short summary is for this initial release:
- Faster slicing
What took hours now takes seconds. Also, this enabled us to create the following two features. - On-the-fly model preparation
There is no slicing button anymore because it starts processing right-away. - Live tweaking of slicing parameters
Because you see toolpaths re-appear whenever you change a setting, you can quicky find the optimal settings for your print job. - Model fixing
The engine can fix major problem in a model. - Multiple materials
The engine was built from the start with multi-head printing in mind. - Cross-platform
The Engine is written in C++ and released for Linux, Windows & Mac. Compilation on these and other platform should be trivial. - Open source
The license is Affero GPLv3.
A nice side effect of the new slicer is that it turns out to be fast, really fast. We decided to do something unconventional: removing the "Prepare for printing" button from Cura's interface entirely. It will just start slice the model in the background (with a low-priority). If you change the layer height or any other setting, it will just restart. If you don't change settings, it may already have finished before you're thinking to save the resulting G-Code to an SD card or print directly through USB. An extra, pretty useful, side-effect is that you can inspect the generated toolpath, change the settings and see the new toolpath preview appear automatically and quickly, without pushing a button.
Because Cura is developed to work with the Ultimaker and most other RepRap-based designs, we'd like to ask you what you think of the new engine. Also, because, like Cura (source), the Engine is released under the Affero GPL version 3, we'd love to see anyone benefit from this new solution and possibly help us improve it further.
Below is a 45-minute presentation on the Cura release, focusing mostly on the new Cura Engine.
Below is the interview with David by Andrew of 3DHacker.com:
Labels: announcements, G Codes, g-code file, host, host software, improvements, Mac, mesh, multiple materials, simulation window, stl
Saturday, July 17, 2010
Mendel & multiple materials
It has always been the intention to fit a head changer to Mendel, I've had a go myself on several occasions but always ran into the same problem i.e. I haven't been able to do so without substantial modifications to the core frame of the machine unless there is a substantial loss of build volume (...I once had a design that ended up having a maximum build height of 2cm.very practical:D). Moreover, it’s more difficult to have a head changer for extruders whose designs are still in the early stages (such as the paste extruder). The main problem I suffered with is that regular designs of extruders are just too bulky without increasing the overall size of the machine, which incidentally I think is the perfect size as it is. Any bigger, and I would find it too big to find houseroom for!
Thankfully, eD had the idea of bowden extruders some time ago, which quite a few people seem have gotten work. Thus I think way forward for the time being is to implement a carriage for multiple bowden style extruders. Although this is almost certainly going to reduce build quality slightly. Some have already designed multiple bowden extruder carriages; here is my take on it:
The main differences are:
1. Support for three extruders, either bowden or paste. (limited syringe size of 10cc).
2. All the multiple head machines I've seen rely on the extruders being exactly the same height in order to get the bed clearance just right to produce good builds. I've always found getting adjusting bed clearance is tricky enough just for one extruder, and I think it's likely that there will always be a build up of tolerances that extruder heights will always change by significant magnitudes. Even still, with warping and so on in the carriage, it may still be difficult even if the extruders were identical. Thus, the carriage treats each extruder clearance like pretty much everything else on Mendel, by allowing for adjustment. All extruders are attached to a mounting plate, of which on the underside are of series three captive nuts for each extruder arranged in an equilateral triangle. Three compression springs are then placed between the plate and the extruders, and cap screws are used to adjust the compression of each spring independently. (In the picture above I’ve only used the springs on the left hand extruder, it makes sense to fix the main extruder and adjust the other two to match it)
3. In the same style as the mini carriage, the bearings are all located within the carriage itself. Having the bearings located on the outside surfaces of the carriage( like the standard Mendel design) ensures that the walls of the carriage must lie between the bearings and any extruders, eating into the working volume. However this does result in quite a wide carriage.
4. I needed to make some compromises, neither of which I'm particularly happy with, so that I don’t have to redesign the whole x-axis. Firstly the belt travels through the carriage itself on the 360 side, and secondly the belt is clamped from the inside out.
5. Finally its NOT makerbotable (its about 115 x 95mm), but it should be a fairly easy redesign to allow for only two extruders. . Even still, if you have a RepRap I'd recommend printing in PLA or using a heated bed or you'll probably run into trouble
Anyway, I’ve heavily modified the Paste Extruder, and used it in parallel with a bowden extruder I designed that based on Erik’s design but using a worm gear to do the driving (Designs to be on the SVN/thingiverse shortly). Gerrit Wyen (an intern at the RepRap Lab @ Bath Uni) created a simple script to take account of the offsets between the extruders and modify the GCode accordingly. Also Adrian has done so much I’ve forgotten exactly what he’s done, but its a lot:D. Here is a video one of the first prints; it’s a cube using PLA for the outline and top and bottom layers, and silicone sealant for the interior infill:
Whilst I did reverse the extruder to prevent ooze, and this is sufficient during a "normal build", its sat there for such a long time doing nothing whilst the paste extruder is working it still oozes horribly. For this reason I built little barrier to collect the ooze from hitting the part, but I think we may need to lower the extruder temperature a little when not in use. Anyway, here is the final part, which came out surprisingly well:
There are some more photos of the test setup and some other less successful prints here.
Labels: Bowden Extruder, extruder, multiple materials, paste extruder, x carriage
Thursday, October 30, 2008
Puddle to the Metal
I don't normally blog mere links, but with progress being so rapid recently we'll revivify the metal-inlay extruder very soon so we can do electricity. So here are some materials that we could use for that:
http://www.princeaugust.ie/alloys/
Note that one would also be able to cast just about all of these in a silicone mould.
Labels: multiple materials
Monday, July 16, 2007
Mendel Preview
The idea is to have a row of extruders along one (or more) sides of the machine, and have it pick each up and use it in turn so that many different materials can be incorporated in a single built object.
I had originally thought that each extruder would have its own RepRap controller attached to it. Docking and undocking an extruder would momentarily break, and then re-route, the token ring that allows all the controllers to communicate. But now I think that that would be unreliable. Better to have one controller on the moving carriage, and to connect the drives for the motors and heaters from that to each extruder when it is picked up. The extruder machinery doesn't need clean data during the moment of connection, and so this would be far more robust. Any extruder that needs a controller when it is parked (to keep it at temperature, for example) can have its own controller attached to its docking station that makes contacts in the same way.
Another change will be that the X, Y, and Z flags for the opto endstops will be on each extruder (rather than having just one set on the carriage), so the machine can always zero with precision and get the registration between materials exactly right. The picker-upper grip on the extruder in the carriage is firm, and it doesn't move. But this zeroing scheme would also mean that the grip wouldn't have to grab an extruder in exactly the same place each time.
Labels: extruder changer, multiple materials
