Hi clint, ... i made some tests with laser-sintering different pastes and powders with a diode-laser outputting until 5Watt and a small focus of maybe 100 microns. At home i have a 1-Watt-diode-laser with a focus-spot of 60 microns, so it's nearly the half energy-density, but is enough to cut 0,5mm thick sheets of plastic or sinter 0,4mm thick layers of plastic-powder. With most materials it'sby VDX - Plastic Extruder Working Group
... you can use pure oil as coolant too - so it wouldn't rust and it's no problem, when intruded somewhere ... For releasing blocked/rusted metal parts you can apply frost-spray - maybe you can find it at the tool-store as nut-releaser or in medical as aid against strain ... Viktorby VDX - Reprappers
... if you want to make lost-cast moulding-forms from wax then it would be easier to mill them with a dremel atached to the Z-axis. As wax is an extremely easy to mill material you can do this even with the Darwin-mechanics ... Viktorby VDX - Plastic Extruder Working Group
... for someone with a CNC-router or a Dremel on a repstrap it shouldn't be a problem to mill some adapters from single-sided boards. If you're interested, i could draw and output the isolation-contours and cutting-outlines as DXF, G-Code or any other relevant format. With my CNC-mill i sometimes made doublesided PCB's until 160x100mm size and have some boards and engraving-bits lying around.by VDX - Let's design something! (I've got an idea ...)
Hi sid, ... ich habe hier im Ort eine Firma, die Kunststoff umschmilzt (in lange dby VDX - Altes Forum
... solange wir bei Orbi-tech Einzelbestellung tby VDX - Altes Forum
Hi Reece, ... glad to help you If you find or make something like 3D-scanning with a set of two stereo-images or a live-stereo-videostream, it would be great for 3D-micro-scanning! I've developed simple microscope-optics for web-cams that can capture 3D-stereo-images (e.g. red-cyan-anyglyphs or shutter-3D-sequences), so it would be great to calculate a 3D-representation from a microscopic imaby VDX - 3D Scanners, Book Scanners, and Optics
Hi Reece, are you in contact with David laserscaner ( )? The combination of this freeware-tool, meshlab ( ) and some more informations about 3D-scanning (e.g. ) should be a good starting point for optimizing the tool-path ... Viktorby VDX - 3D Scanners, Book Scanners, and Optics
... no, not really ... the exact amount of current depends mainly on the feeding-rate and changes in environment-temperature and -pressure, so you would have to measure much more variables with high accuracy and an immense overhead. Because of this nested problems i'm searching a solution for room-temp-fabbing with low viscouse pastes for very small and precise parts - mostly ceramic bodies and/by VDX - Reprappers
Hi Jon, the rotary encoder measures "threads per turn" or with an estimated 1:1 transmission "millimeters filament per turn". If the filament-diameter varies, then the transported millimeters are the same, but the extruded volume varies with the diameter of the filament ... Viktorby VDX - Reprappers
... my idea was to squeeze the round filament with some pressure and heated rolls, so it would temporarily or permanent change the shape to a square with rounded edges. So you have a defined shape for measuring and when the traction of the rolls should be enough to press the filament through the heated tube, this could possibly replace the screw-drive too. ... again - some more crazy ideas Vby VDX - Reprappers
Hi Chris, ... i think the error in circular/ellipsoid shape isn't so big that you can't estimte the correct metrics. Picture an ellipsoid with two orthogonal viewing angles and calculate the diameter by { D=(d1+d2)/2 } - the error is biggest, when the a-axis of the ellipsoid is aligned to the camera-direction or 90 deg away. But it's a very small error, as the filament should be only slight disby VDX - Reprappers
Hi Chris, ... AFAIK the web-cam/ICE-solution actually should be the simplest and cheapest solution, as you can use any web-cam/video-grabber you have at hand. My cheapest web-cam was 20 Euros and an USB-videograbber around 40 Euros - some PC's have built-in grabbers. With a line-cam (e.g. salvaged from a scanner) you need the right software or videograbber to work with ... With rough feeding tby VDX - Reprappers
... it's no problem to measure both diameters with one web-cam, when you arrange two mirrors behind the filament - so you have two perpendcular sides of the filament in one image and have only to measure the distances of the border-lines ... here a sketch of the setup: Viktorby VDX - Reprappers
... i've found the sources (and some aditional too): - ICE - free C-library and tools for IR: - DIAS - maybe now for free too?: - VIGRA: - IR-package from University of Hamburg: - and the CImg-library: Viktorby VDX - Reprappers
Hi sid, some years ago i did some tests with a low-cost (DIAS, 650by VDX - Reprappers
... my first experiences with 'geological times' (e.g. >10hrs rendering for a 3D-scene with 800x600 resolution) were on a 12MHz-V20 with 1MB Ram and a PC-XT-Clone (with math. coprocessor and 4MB Ram) and Autocad 9 and/or POV-Ray2 ... Now we're in the ranges of some giga-Hz and giga-Bytes, but 'actual' software consumes this resources in the same exponential rate - so your hardware is five orby VDX - RepRap Host
Hi Fim, ... bis Ende des Jahres werde ich kaum noch Zeit fby VDX - Schwarzes Brett
Hi sid, ... look at if you're searching magnets (or ask me, maybe i'll have some dozends of your desired size ) I had to design and to build some magentic components as motors, magnetic gears, hysteresis-couplings an such, so there's some experience and residues around ... Viktorby VDX - Reprappers
Hi Fim, ... willkommen in der Runde! Dann sind wir ja direkte Nachbarn - ich pendle Wochentags tby VDX - Schwarzes Brett
... then it's the same again (remember some old discussions) with a homebrewed CNC-mill: - this definition classifies this CNC-mill as RepRap, because i can make most mechanical parts for a new one and the PCB's (what's more, then Darwin is capable to do!) and need only the mill-head, the stepper-motors, some linear bearings and the electronic components ... Viktorby VDX - Reprappers
Hi sid, for fast (>1kHz) PWM-switching a 8Watt-diodelaser i used this part: (HALBLEITERRELAIS 1A 25A 250VAC AQN411VL) from Conrad. It's simply triggered by 4 to 32Volts DC (i run it at 5Volt) and is able to drive until 25Amps ... But it's a bit pricey with 32 Euros Viktorby VDX - Mechanics
... you have to calculate with the current through the coils - this is 3.0 Ohms, so you would have a measured voltage over the coils of 3 Volts ... Viktorby VDX - Controllers
Hi Forrest, i have a PT100-resistor empedded in a 2mm thick ceramic-tube and had the idea to place it inside the heater, so it would have contact to the molten plastic or paste. I tried with a digitally controlled soldering station, but the power wasn't enough, so when the plastic flows by it changes the temp-readout in the range of someby VDX - Mechanics
... i'm actually using and optimizing high-precision-heaters for our WLD-sensors - here i have three diferent designs with heater-transistors or -resistors, where a NTC-resistor or a PT100 acts as sensor and an OP-cascade controls the end-temperature with an accuracy of some 1/100by VDX - Mechanics
... then make overlapping puzzle-fittings. Think in 'lego'-metrics - build any size you want from smaller interlocking pieces and slices ... Viktorby VDX - General