Victor, Is there any particular reason why you're using servos and not steppers?by Igor Lobanov - Powder Printing and Selective Laser Sintering
Azhar, I wasn't sure I knew exactly was quasi continuous wave laser is, so I looked it up here: QuoteQuasi-continuous-wave Operation Quasi-continuous-wave (quasi-cw) operation of a laser means that its pump source is switched on only for certain time intervals, which are short enough to reduce thermal effects significantly, but still long enough that the laser process is close to its steady statby Igor Lobanov - Powder Printing and Selective Laser Sintering
Azhar, I am by no means an expert in practicalities of the sintering process, so the following is merely a speculation based on my understanding of the principles. The model does assume full absorption of the beam energy by the powder, which is close to what one could expect with black powder and laser in a visible or near-IR wavelengths range. If you've got white powder it is going to reflectby Igor Lobanov - Powder Printing and Selective Laser Sintering
tleneel, I did realise that. The model "assumes zero laser beam dissipation/reflection" like with "black powder and visible light laser". If you've got a powder which is transparent or highly reflective at the wavelength of the laser, it wouldn't barely pick any power from the beam. Pragmatically, it means either CO2 laser as clear plastics are opaque at 10um, or near IR/visible light diode lasby Igor Lobanov - Powder Printing and Selective Laser Sintering
Thanks Me, glad you found it useful. I'm still adding some content to it, so please come back from time to timeby Igor Lobanov - Powder Printing and Selective Laser Sintering
Since no one has given me a feedback, I'm assuming there's no obvious mistakes So I'm adding the information to the DIY SLS FAQ.by Igor Lobanov - Powder Printing and Selective Laser Sintering
bobc Wrote: > I thought I already answered that, did you find my > answer lacking? I read your answer as mostly addressing cost side of my question, but I see what you meanby Igor Lobanov - Controllers
Fascinating thread, especially since MatchboxARM folks have joined us Just want to repeat earlier question, is there a benefit of using micro faster than 16/20 MHz when controlling a RepRap?by Igor Lobanov - Controllers
Thanks guys, interesting perspective on the limitations, but what about benefits? Can ARM bring anything to the table in terms of cheaper/better electronics for RepRap? Or it's just for variety sake?by Igor Lobanov - Controllers
Guys, There's an interesting kickstarter called MatchboxARM: In essence, it's ARM Cortex-M3 chip running 72MHz with 64Kb flash on a small board cheap enough not only for prototyping, but also for embedding it into the final project. The board would have USB port and would run on its own without any extra components. One needs to pledge 15 GBP (it's UK-based) to get a single unit, which is cheaby Igor Lobanov - Controllers
Guys, I had been doing some modelling to find out how much laser power is required to do selective sintering of nylon powder, and, to be honest, I'm a bit surprised with the results. It turns out that to sinter nylon powder heated to the temperature of 8 degrees below melting point with a beam focused down to 0.2 mm spot and using layer height of 0.2 mm with feed rate of 300 mm/s one needs onlyby Igor Lobanov - Powder Printing and Selective Laser Sintering
I've stumbled upon this amazing study published by taulman on instructables.com regarding safety of common 3d printing materials, namely ABS and nylon (and trimmer line!) as far as releasing outright toxic CO and HCN gases. The testing setup seems watertight to me, so I'd say the results are credible. Long story short: Quote Based on our measurements using the world Safety Authorities (OSHA NIOSby Igor Lobanov - General
I'd like to do some experiments with SLS and I'm looking for a source of fine PLA powder, ideally black or some dark color. Will buy several kg. Preferrably from the UK- or Europe-based supplier. Many thanks!by Igor Lobanov - Wanted
Guys, Some time ago I started research on feasibility of building a DIY Selective Laser Sintering rapid prototyping machine to work with thermoplastics. It quickly turned out that a there are quite a few enthusiasts who are already doing something in this area, as well as wealth of helpful information. However, what I found, it is very time consuming to gather enough background information to acby Igor Lobanov - Powder Printing and Selective Laser Sintering
Wow, great article, many thanks! Adding some black coal powder looks more attractive then messing with water cooling and 20 kV electronics for a CO2 laser. At least to start withby Igor Lobanov - Powder Printing and Selective Laser Sintering
I've been thinking about DIY SLS machine and doing some research, but couldn't find an answer to a seemingly simple question. Are wavelengths of ~800 nm of an infrared diode laser enough to heat clear/white thermoplastic powder such as PLA or ABS and, hence, can be used for sintering, or it needs to be considerably higher, like 10um of a CO2 laser? More generically, is there any easily accessiblby Igor Lobanov - Powder Printing and Selective Laser Sintering
Thank you Traumflug, works perfectly. The only thing is that I need to use M140 instead of M104 as I drive spindle using bed MOSFET.by Igor Lobanov - Firmware - mainstream and related support
Peter, I'm not an Arduino programming expert, but in general the error you're getting is triggered programmatically using C/C++ #error compilation directive. It is normally used as a safeguard against compilation with nonsensical combination of settings. Hence, by looking at the source (pins.h, line 647) might give you an idea of what exactly it considers to be nonsensical. Regards, Igorby Igor Lobanov - Firmware - mainstream and related support
Dear All, I'm looking into building drilling and milling head for my Prusa and need to control a DC motor. I'm using Gen7 electronics and Teacup firmware for printing and my initial prototype of the head is driving the motor using heater2 (bed). I'm just setting bed temperature to anything non-zero and off it goes with 12V raw power. The problem is that I can't control the speed of the motor. Tby Igor Lobanov - Firmware - mainstream and related support
I've created an issue report at the back of this discussion:by Igor Lobanov - Slic3r
Thanks for your comments guys. Nudel, I've tried your model and slic3r has generated layer with bridges correctly. Apparently, there's a combination of slicing parameters and a wall thickness that causes slicing problems. I've done some experiments and it turned out that slic3r doesn't generate bridges correctly if walls are thinner than 3 lines of perimeter. For 0.5mm nozzle and 3 perimeters iby Igor Lobanov - Slic3r
Dear All, I've just finished building my reprap and now I'm doing very first prints. Today I was doing tests with overhangs. I've built a very simple object in OpenSCAD using the following script: difference() { cube([10, 30, 10]); translate([-1, 1.5, 1.5]) cube([12, 27, 7]); } As you can see, it's just a hollow box 10x30x10 without two side faces, i.e. only bottom, front, top, and back. Eaby Igor Lobanov - Slic3r
Alright. I've already tried that, actually, i.e. downloaded teacup master and put old gen7 config over that. Can confirm that it prints correctly.by Igor Lobanov - Next Wave Electronics Working Group
Traumflug, Having the same problem. Will try with master branch. Could you advice what are things to worry about when switching back to master branch for Gen7?by Igor Lobanov - Next Wave Electronics Working Group
You definitely can do that without a computer, though you almost certainly need a microcontroller, say, Arduino-based. That aside, this is rather strange choice of motors. You clearly should be looking for servo motors, which are much simplier to control from an MCU.by Igor Lobanov - Stepper Motors, Servo Motors, DC Motors
Dear All, I'm building a brand new Prusa Mendel based on Gen7 electronics, and I've installed A4984-based stepper motor drivers I'd bought on eBay from a member of the community. Once I started testing, I've got strange issue with my motors. Seemingly there isn't enough torque being produced. The holding torque feels okay, but movements is rather jerky, if any at all. Worst is that Z-axis is unaby Igor Lobanov - Stepper Motors, Servo Motors, DC Motors
@nb99, Thanks for pointing that out. I've updated the wiki page on stepper motors. @JoeDaStudd, That's what I've done. I missed them when I had first look.by Igor Lobanov - Reprappers
nb99 Wrote: > and for those of us metricificated - for (e.g.) a > Prusa-Mendell, typical holding torque recommended > is "at least 40 Newton*cm", NEMA 17 steppers. Hm, interesting. Wiki page on stepper motors recommends using motors with approximately 13.7 N*cm. Where did you get 40 N*cm figure? I'm particularly interested, because I'm currently selecting steppers for my first Prusaby Igor Lobanov - Reprappers
Hi guys, Have you considered using ceramic material? Definitely not an expert in vacuum ceramics, but accoding to NASA there are quite a few epoxies and ceramics exhibiting low outgassing in vacuum. It seems that vacuum chamber of arbitrary size could be relatively easily casted and then cured with home-achievable temperatures.by Igor Lobanov - MetalicaRap
@Victor, Alright, having done some searching I conclude that the idea with printed nozzles is recurring with periodicity of 1 year It seems you've done lots of experiments with ceramic slurry indeed, and waterglass-based ceramic compounds definitely look promising. Although, I've got an impression that you weren't satisfied with the result. BTW, have you tried adding metal powder to get thermaby Igor Lobanov - Polymer Working Group