Hi Fernando, ... thanks! Sounds to be a very interesting material, when dispensed and tracted with the laser With a heating spot of 50 microns i think the activation-zone should be around 80 microns, if the reaction doesn't expand on self? If you find a mixture, which will stay stable and fluid at room-temp and harden in seconds when lasercured, then there should be some testing with partialvon VDX - Paste Extrusion Working Group
Hi Demented, ... my approach is a low-viscose paste, which i can dispense in diametres under 100 microns or single droplets down to 10 microns, which i heat-cure with the laser to harden directly after releasing ... A second setup is to output a complete layer and bake the layer completely - then a big IR-heater, which activates the complete surface is better and faster, then a laser-spot ...von VDX - Paste Extrusion Working Group
Hi Samuel, ... it's only theoretical In practical issues the one-motor-per-axis-approach ist the best start. It's not so essential, if the setup is cartesic, polar, polypod or other - in the cartesic systems is the software easier to create, some others (like my tripods) are very easy to assemble, but the controling is a mess ... When i'll have a fabber capable of making elastic resins, thenvon VDX - Mechanics
Hi Fernando, ... can you give me the formula and tech-specs of your polymers please? I'm playing around with a 1Watt-Diodelaser with 60micron-fiber at home and in my job i today finished the drivers and optics of a 9-Watts-Diodelaser with 100micron-fiber, so i can make a focus down to 50 microns and tests with sintering or heat-curing of different material. Some years ago i had 3Watt- and 5Watvon VDX - Paste Extrusion Working Group
Hi Steve, ... in the past (2002 or so) i had good experiences with and with a company called '4D-concepts', which i didn't find online anymore ... I send STL-data per email and received the finished epoxy-parts 3 days later. My last try this year was with , here i received FDM-test-parts for free, so i didn't know, what's cheaper, epoxy or FDM ... Viktorvon VDX - Reprappers
Hi zzorn, ... you're right, but this would extend the building time per slice (in a 2D-Peano-curve with rounded edges) from minutes to days or weeks, if you want an usable accuracy I had some ideas for reducing the amount of motors too - if i use two rotating axes, where an arm moves horizontally (like the arm of a phono) and the other turns a threaded rod, where i can change with clamps the mvon VDX - Mechanics
Hi Samuel, ... i'm working now at - a small company with 4 employees, where i have to develop and realize all kinds of micro-stuff (sometimes nano- too) ... From 2000 to 2006 i made the same thing for GERWAH - here i invented and built some micropositioning systems ( ), microgrippres and special video-microscopes (with the tenfold field-of-view then normal), to realize stereo-vision in the mivon VDX - Mechanics
Hi Samuel, ... in this sample-setup i have only linear bearings with 40mm free run, so the maximal displacement in XY would be at 30 millimeters with a 'safe' heighth-zone of 10 millimeters over the whole working area (in the centre then more, so at 30 millimetres too). I designed this 'micro-fabber' for a special problem, where we have to fab mikrosensors from a ceramic-paste with gold-inlaysvon VDX - Mechanics
... most liquid-curing RP-systems activate the surface of the liquid epoxy through an UV-laser or LCD-beamer-focus, so you build slices on slices as normal - but you have to build supports too, or your hardening parts would crumble, if you move the basis-platform in the bath and move the washer to make the surface plain after overfilling ... I had similar thoughts - when the curing area would bevon VDX - General
... it's not so hard to make a hydraulic reprap - for my tripod-setup i can replace the three linear stages through three big syringes and activate them through three thinner but much longer sysringes, which i'll push with weak linear motors (here: TylerM tried a similar approach for a Stewart-platform or hexapod in Nov. 2006 ) ... If, for example, the inner size of the small syringes is a tentvon VDX - General
Hi zzorn, ... hydraulic structures are much better for reprapping, because fluids are not compressible, and you can activate expanding silicone-tubes with a simple syringe full of water ... Try to twist some elastic tubes to a kind of helix and fix them with radial orineted strings - if you arrange it feasible and expand the right tubes, the structure can rotate, expand and bend. With thinningvon VDX - General
Hi zzorn, ... i'm playing around with different concepts - look at the 'bionicle'-robots at my c't-bot-gallery: In the past i experimented with many other active structures and methods too, as pzt-actors and -resonance-drives, shape-memory-alloys (e.g. nitinol-bug-bot 'boris'), magnetorheological- and ferrofluids, magnetic-shape-memory-alloys (active NiMnGa-crystals) and other stuff like thatvon VDX - General
Hi Sean and nophead, ... i knew, that elastic tubes will shorten a bit, when twisted. For this reason i searched a bit, until i found the perfect material: It's a merely stiff pneumatic tube - you can have them in different shore-values, my type is so stiff, that i can't sense any distortion, when twisting the rod against the motor-shaft (i had to apply a lot of force to screw the rod into thevon VDX - Mechanics
Hi zzorn, ... i would prefer a single oszillating pump and fast switching micro-valves for the capillaries. When the pump is oszillating, then you have a sinusoidal pressure-curve between max, zero and min. For rising the pressure in a single capillare the corresponding valve should only open, when the pressure is on max, then it adds pressure in every half period, until max -- for reducing thvon VDX - General
Hi Demented, look on the linked images and files in - here i described the tripod-system and linked some infos in my answer to Zach, where you have some background ... In my concept the three linear stages aren't in a plane as usual, but parallel, so i have a more cylindrical defined working area - here i can perform a straight Z-movement with moving all three axis synchrone. The thin rods bvon VDX - Mechanics
Hi zzorn, ... the simplest moving structure, which can be build by 3D-fabbing, is a pneumatic or hydraulic setup from a highly elastic resin. Image a 'finger' from elastic silicone with some capilaries in the outer area: - if i apply pressure to a capilary on one side (and mabe vacuum to the corresponding one on the other side), then the finger would bend away from the pressurized side. Combinvon VDX - General
... here is my idea for a tripod-setup with the 'Easy to build linear stages' and the self-assembling magnetic joints from . The green parts could be entirely made from plastics (reprapped, molded or milled) or from aluminium, the spheres are my joint-magnets and the linear stages from the previous post ... The transparent insert is a displacement-sample of the toolhead, to demonstarte the plavon VDX - Mechanics
Hi mimarob, ... you must have a plain and stiff table under your object, so the most weigt is in the surrounding hardware, not the objects himself ... I'm on prototyping different approaches with a diode-laser-fiber in the head, here the moving mass is so small, that a normal plotter wouldn't sense the difference to a pen ... Viktorvon VDX - General
Hi all, ... i tried an idea for simply assemble of small motorized linear stages for a noncartesic micro-reprap and found a good intro - this should be working with bigger and longer linear drives too. As the threaded rod has the same diameter, as the motor-shaft, i could use short pieces of pneumatic tubes (elastic and stiff in the same time) as couplings. The rods i found in our 'Bauhaus'-tovon VDX - Mechanics
Hi SOI, ... ther is the fair possibility, that the extruded strings and droplets would stick to the knife and hang around, so they could kontaminate the building area, so a cleaner beside is safer. I thought about a kind of revolver or endless ribbon, but it's the same, loose particles can fall down and stick to the actual slice ... Viktorvon VDX - Mechanics
Hi Forrest, ... yes, some companies use paper-LOM until now for lost-casting-forms or large-scaling prototypes of combustion-engines, very big hardware or so ... In 1993-94 i designed and build two 2D-CO2-Laserplotters (with a 5-Watt-RF-CO2-laser) for marking and cutting of plastic-sheets -- for the possibility of 3D-processing or marking of very high parts i made it so, that the base-plate couvon VDX - Mechanics
Hi Samuel, ... if you want a high accuracy, e.g. 0,1 mm per slice, then you have to process 10 slices per millimeter or 100 slices per centimeter. With an even as big accuracy and activating/melting every pixel of the body it can last many minutes per slice, so a 'normal' part like a gear with some centimeters in square can consume hours for building, dependant of the 'pixel-processing' speed .von VDX - Mechanics
... i looked in a local toolstore for fast hardening pastes and found some 1K- and 2K-types from 'Fischer' for fixing bolts in walls, which harden temperature-forced in some minutes to a extreme durable solid ... So it could be interesting testing with outputting a single sheet, pause the reprap, then heat the sheet with a thermo-radiator until hardening (or bake the cookie sheet-wise ) and thevon VDX - Reprappers
Hi moonspud, ... i think it's needed only for the Z-axis to adjusting the extruder and manually turn the axis, until the extruder-tip is in the right plane ... With the motor parallel by the rod you can make the same thing with a knob on the end of the rod too (if the motor isn't to strong). Or you insert a freerun(?) ... Viktorvon VDX - Reprappers
... best workaround to avoid a dual-shaft-motor would be to set the motor beside the (then longer) rod and drive the rod over a tooth-belt. Then the motor can be smaller, coarser and weaker - with the right ratio of the gears i can make the wished power-translation ... Viktorvon VDX - Reprappers
Hi Sean, ... it seems, i misinterpreted a second time Then a bit more explaining: - The white big 'buckles' at the very left is a 'normal' child-seat-design, but made from stark with cyanacrylate for elasticity-tests. - The red 'buckles' (or clamp?) beside is a generic sample/giveaway from DimensionPrinting made in red ABS, i received as test for accuracy and stability, it was made on an Alpvon VDX - General
Hi all, ... on sunday i played around with my children and made a second try for a pantograph-sample (see the images) Here you can see an original scaleable oldstyle-2D-pantograph and my 3-dimensional analogon - if i lever the outer pin, the inner pin would go up in the same manner, but scaled down (here nearly 4:1) too! You may notice, that my sample is overdefined, as it has two arms, but wvon VDX - General
Hi SOI, ... thanks! It's the same idea and some other hacks and hints - i'l read through the infos and make a try, maybe with other inkjet-vendors too ... Viktorvon VDX - General
Hi Sean, ... sorry, i had to look in my dictionary, to sort it out ... The 'buckles' are my designs and prototypes of micro-grippers and tool-tips for microassembly, but you can find similar designs from some german universities too - it's a generic 'parallel-kinematic'-structure and i was in cooperation with some groups, but the basics are much older, so it's not my personal invention The clvon VDX - General
Hi Sean, ... call me Viktor, it's more comfortable for me If you meant my avatar-image, then yes, i created some 3D-objects and scenes for fair-presentations and articles. It's no real problem for me, only some time-consumption, to create virtual scenes with available or selfmade 3D-objects and output them in photorealistic iamges or animate them and make small clips - there are some open-souvon VDX - General