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Praise, questions, complaints, etc. go here. Want to change our policy? This is where we calmly and thoughtfully discuss these matters at length.
Re: wooden reprap parts - 15 years ago
Hi nophead, ... pigtailed means, that a fiber comes out of the laser-housing. A laser-diode is mostly a bar of active material (sometimes many aligned bars) with a very poor optical output-quality - the laser-diode emits a conical 'plane' of light, instead of a sharp laser-beam, as in a gas- or solid-lasers with the much longer and better resonators. With a special cylindrical lens there is aby VDX - Laser Cutter Working Group
Re: wooden reprap parts - 15 years ago
Hi Zach, today i've got a 1,1W-pigtail-diode-laser (see image) with a 50 micron-focus-tube for testing and playing around and i made first tests with gold- and glass-pastes (solved with dexpanthenol) and some burning/cutting ... First infos: the gold-paste (as mayby every other metall too) would dry very fast, but didn't sinter or melt to a solid because of heat-dissipating in the mass ... Theby VDX - Laser Cutter Working Group
Re: wooden reprap parts - 15 years ago
Hi nik, ... sounds very good for testing with the design - what's the price for all needed parts? On the other side, if it should be a straightforward reprap, then it should be able to do this work too! Maybe with a LOM-(Laminated-Object-Modelling)-building approach, where i stack sheets of self-adhesive (or glued together) paper or other material, and with a 'high-power'-cutting-laserdiode fby VDX - Laser Cutter Working Group
Re: Powder support - 15 years ago
... acetone is very low viscose and is drying very quickly, so plastics solved in acetone could go (maybe with an extra drying idle time per slice). Maybe sand as body-powder and ABS-acetone-solvent would be a good try ... Another idea: maybe it's possible to 'print' droplets with a dispenser instead of an ink-jet-head, when the dispensed fluid is outputted above the powder-surface in discreteby VDX - Mechanics
Re: Dot printing rather than Extruding? - 15 years ago
... for ink-jet-printing you need viscosities equal or lower then water! There are very expensive hot-wax-ink-jets, which print 3D, but the actual powder-3D-printers use normal ink-jet-heads with a glue-liquid, which is thinner then water for koagulating the powder. I think the 'objet'-printers use a very low-viscose epoxyde wit UV-curing to hardening the wet droplets on the surface ... Old thby VDX - Reprappers
Re: stepper motor bulk purchase - 15 years ago
... testing the needed torque of the motors can be easy made with a string wound around the axis (or a bigger roll on it for easier calculating), straightened horizontally and feed over a fixed roll and then append a weight on the string (maybe a small bag or cup for stepwise increase mass with heavy parts). So the motor can turn freely around and you can calculate the torque from radius of theby VDX - Mechanics
Re: Arduino as simplified comm/controller board - 15 years ago
... what's the trouble with direct driving all motors from one controller without hanging on syncing different driver-boards? When i first build a pen-plotter with steppers, i used a 6502-EMUF (german short for Single-micro-processor-board with universal-fixed-programming ) and a lot of discrete transistors, so the main advantage was to have many I/O-pins ... The next run was then with a PIC-cby VDX - Controllers
Re: Gluestick-gun as extruder ... - 15 years ago
Hi nophead, ... i disassembled the head a bit more (see the image) - there aren't wire-windings, as i meant, but two aluminium-blades separated by a kind of metallic-ceramic-blade as heater I think, the hint with the gluestick-gun is aimed to experiments with higher extruding-speeds (for example a lathe-style extruding on a roll or so). The small 7-mm-guns have much lower power, so this typeby VDX - Mechanics
Re: Gluestick-gun as extruder ... - 15 years ago
... OK, i read the comments ... Is some particularly wrong with them? In the local tool-store i have seen 5 or 6 different vendors with varying techspecs (and prices). My disassembled Glue-gun is from PowerTec, has 78 Watts and i used to disassemble it because of the weak housing and transport ... An "esco powertronic" with 500/40 Watts (heatup and constant?) and a much better transport runsby VDX - Mechanics
Gluestick-gun as extruder ... - 15 years ago
... i don't know, if someone already tried to use a gluestick-gun for melting plastic. In the appended picture there is a extracted heater of a gluestick-gun, which runs with 240V AC. With adapting of the inlet to 3- or 4-mm-sticks (my thicker Gluesticks have 11mm, the thinner ones 7mm diameter) and changeable nozzles (more expensive Pattex-guns have changeable heads, but others sometimes too .by VDX - Mechanics
Re: Parallel-kinematics versus string-pod - 15 years ago
... it's not so hard to make ONE straight edge - in all motors runs parallel, so for example say motor M1 and M2 are the both aligned motors in the back and motor M3 is the longer one in front ... Then it should run in a similar mode: X = M1 = M2 = M3 - if all tree motors run synchrone, X is straight X ... Y = (M2 - M3)xAlpha1 + M3xBeta1, where Alpha and Beta are trigonometric calculated valueby VDX - Mechanics
Re: nichrome alternatives - 15 years ago
... some soldering-tools have a tube-heater with a hole of 6 to 8 millimetres throug them. There are lowcost 12-volt-solders in use too, maybe it's worth to look, if the heating-heads are hollow, and then try them as extruder-heating? Viktorby VDX - Controllers
Re: New to Fab, resolution question - 15 years ago
... if someone has a thermo-transfer-printer or -FAX, then he already has an 3D-capable setup! In the thermotransfer-process a transfer-foil coated with a thin sheet of coloured thermoplastic is aligned with the paper and a moving printer-head with heatin resistor-pins melts the outputted pixels through the transfer-foil, so the melted thermoplastic can stick to the paper ... If i repeat this pby VDX - Tissue Engineering
Parallel-kinematics versus string-pod - 15 years ago
... as with the tripod-structure from the thread "Magnetic joints and self-assembly..:" there could be constructed several 3-axis-systems with different approaches, here for example with wire-feeding over fixed rolls. In the appending image i have a concept of a 'stringy tripod', which has only 3 gliders as moveable parts, which can be moved throug beltdrives or linear motors. The toolhead canby VDX - Mechanics
Re: Digitizer-tablet for XY-measurement ... - 15 years ago
... at home i checked the tecspecs of my old 'Summasketch III Professional'-tablet: - active area = 12 x 18" or 305 x 457 mm - resolution = 2540 lines per inch or 100 lines per millimeter (=10 micron) - accuracy = 0,010 In or 0,254 mm ??? The tablet has a stylus and a 4-button-mouse, which would do better. (I found an Aiptec-HyperPen-tablet too, but the active area is only 10 x 12,5 mm and the sby VDX - Mechanics
Re: Article on Home Rapid Prototyping - 15 years ago
... as appendix to the discussion with my 9-years old son, what to do with a reprapper, we found some very expressive samples. One is building separable slices of a human body with coloured inner parts from gelatine (slices separable with sheets of wax-paper). The other project would be a birthday-cake in form of a castle with interieur and some action-figures, made from chokolade, melted shugaby VDX - General
Digitizer-tablet for XY-measurement ... - 15 years ago
Hi folks, ... an idea for easy reading the absolute coordinates of the XY-motors or of the tool-head absolute position in general ... If someone has an old digitizer-tablet (best an inductive with crosshair-mouse) laying around or can buy it cheap at ebay or so, then it's worth trying, if it could be fixed under the reprap and the digitizer-mouse mechanically syncronized to the moving reprap-heby VDX - Mechanics
Re: Article on Home Rapid Prototyping - 15 years ago
... for building fitting lego-bricks you need an accuracy near to 10 microns, but the problem is more the material and the smooth surfaces, you need ... My prototypes and giveaways from commercial high-end 3D-printers have accuracies from 0,2 to 0,01 mm (STL-epoxy), but none of them is capable of building 'real' lego-bricks, because of the surface-finishing or the durability of the material. Onby VDX - General
Re: Complex LOM-Objects made from laminated steel - 15 years ago
Hi mimarob, ... for bigger objects i can cut thicker sheets, so the amount of stacking is variable. Maybe in coarser regions without overlapping i use 1 millimeter and in finer segments 10 micron thick laminates ... The slices are cut out from the sheet and laminated/stacked one after the other. For high accuracy in the slices are fitting-holes, in which i insert small sticks - e.q. 0,3 mm thiby VDX - Mechanics
Re: Beaded belts - 15 years ago
... yes, it's limited of free length, but why not fixing the z-bed directly to 4 vertical steel-strings, which comes from two closed loops, that runs over a single motorized roll, instead of 4 screws which are synchronized with a (bit more elastic) belt? In the plotter i drived with 2 stepper-motors (which sat on the same plate) two wire-loops, which moved the rail (in X) and the toolhead (in Y)by VDX - Mechanics
Re: Beaded belts - 15 years ago
Hi mimarob, ... you can make a slip-free system without gears or beads. I build my first penplotters with 0,5 mm thick steel-strings over rolls, i made from plastic-coated ball-bearings, in which i lathed a v-grove. Two steppers drived bigger rolls, over which i had 2 to 4 rounds of the string and at one end i had screw-spanners (?), which apply some amount of stiffnes in the loop ... There wby VDX - Mechanics
Repository of mechanics and technical samples - 15 years ago
... here the link to databases with mechanical stuff, which is interesting for some mechanical ideas: There are downloadable STL-files for the parts , so people would be able to reprap examples and play around with technical questions ... Maybe we should start with a similar CAD- and STL-database too? Viktorby VDX - General
Re: Article on Home Rapid Prototyping - 15 years ago
Hi reece, ... yesterday i had a short discussion with my 9 years old son, what he would do, if we would have a capable reprapper. He grumbled a bit, then said, he would build lego-bricks for his actual favorite sites, or maybe a cool shaped pencil-sharpener ... Then i self thought around, what sort of needs i have. It sorted out, that my home-reprapper must be able to build with thermoplastiby VDX - General
Re: Arduino as simplified comm/controller board - 15 years ago
... here are the data-sheets of the IC's with connection diagrammes ms3479p: IMT901: [1].pdf Viktorby VDX - Controllers
Re: ALTERNATIVE SOURCE FOR MAGNETIC SHAFT ENCODERS - 15 years ago
Hi Jono, ... i played around with web-cams and encoding positions with open-source image-recognition. The normally used optics allows absolute resolutions down to 5 microns, if you revert the objective. For another approach i tried 3D-measuring with a single camera-chip without lenses, a LED and two metallic sieve-sheets - with interpreting the moirby VDX - Controllers
Re: Article on Home Rapid Prototyping - 15 years ago
... thank you very much, a very interesting discussion! On the other side i wondered too, why reprap and [email protected] wasn't more cooperative ... I found [email protected] first, then some weeks later reprap - now i'm focused on reprap, because of the a bit more active comunity and distributed ideas, i can test or dispute with others (and because it's not so US-centered ) For me the basic-concept and hardby VDX - General
Re: Complex LOM-Objects made from laminated steel - 15 years ago
Hi Zach, ... i was playing with rapid prototyping since nearly 30 years, but then the CAD- and encoding-software wasn't really capable and i had to sell my 3D-mill in exchange for other ressources ... With first attempts in CO2-laser-cutting with a 'cheap' gaslaser for 1.500 DM i invented the LOM-technique for me in 1989 or so, but it wasn't so easy to earn enough money with the selfmade systemby VDX - Mechanics
Re: Arduino as simplified comm/controller board - 15 years ago
Hi Zach, ... i had to design stepperdriver-boards with discrete transistors, the MC3479, L297/L298 and the IMT901. The IMT 901 was much better, because of the simple layouting and connecting, high possible currents and frequencies and microstepping ... Actually there are better driver-chips, some with up to 1/128 microsteps, but i agree, that the design should avoid SMT and higher complexitiesby VDX - Controllers
Complex LOM-Objects made from laminated steel - 15 years ago
... in the appended image is a sample of a LOM(Laminated-Object-Modelling)-housing, i stacked with lasercutted 0,1mm steel-sheets. The housing is 3x2 millimeters big, has 6 slices and two troughputs for glass-fibres. I made this as a prototype for a ultraprecise fiber-sensor/switch because of the high-temp form-stability of tempered steel (the milled PEEK-housing, which was used before, was to iby VDX - Mechanics
Re: Arduino as simplified comm/controller board - 15 years ago
... some years ago i developed on my own microstepper-drivers with the IMT901 for driving a laser-cut-plotter and have some prototypes of single-chip- and two-chip-boards with latches for my part ... But as i mentioned in the posting above, for others the ready-to-use module SMC11 ( ) from nanotec could be the easier alternative. A single one costs 29by VDX - Controllers