Hi Grogyan, there are some methods and materials for building really stiff and big frames - e.g. big and high precise CNC-mills are built from stone, not from steel or aluminium. Similar DIY-frames are made from hollow structures out of steel or aluminium and filled with sand-epoxy-mixtures, what's a really rigid compound sometimes even better than real stone and much cheaper and easier in handby VDX - General
... for 'really big' repstraps you'll use much sturdier/stiffer materials (there are big cartesian 'bots' for handling ship-containers with some ten meters dimensions) or you'll try with parallel kinematics and lightweight rods made from carbon. I made a tripod setup with hinges made from magnetic orbs ( ), that could easily be scaled up or down (here i scaled down ), but the controlling softwaby VDX - General
Hi all, here: you can find a 'Propeller'-shield for the arduino with the capabilities of video- and audio-interfacing and some more capacity - maybe it's interesting for the Arduino-RepRap too? Viktorby VDX - Controllers
... my 1.8°-steppers with 2Amps (@60V-f/h, @30V-microstepping) can drive safe until 2kHz with fullstep, 5kHz with halfstep and until 10kHz with microstepping (max. steprate of my controller/drivers ). So with direct driving and a 5mm/rev-spindle i have 50mm/s @full-, 62.5mm/s @half- and the same speed at 1/4- and every slower (but more accurate) at higher microstepping-ratio ... Viktorby VDX - General
... i've found small chainwheels and chains in different sizes and lengths (smaller formfactor than bike-chains) in old copiers - there are many other usefull parts for repstrapping too ... Viktorby VDX - Mechanics
Hi Walter, ... i use hollow glass-spheres (=eccospheres from Trelleborg) around 50 microns in size until 400 centigrades, solid glass-spheres around 100 microns (until 1000 centigrades) or molten rock-spheres around 200 microns (until 1500 centigrades) from Sil-trade mixed with waterglass. There are some comercial mixtures based on waterglass with talkum and different additives for temperature-by VDX - Paste Extrusion Working Group
... the hard and abrasive particles in most ceramic slips would damage the pump, so you need another design (e.g. a peristaltic one) or you mix with microspheres which are round and smaller in diameter than the gaps. Viktorby VDX - Paste Extrusion Working Group
Hi Kerstin, Kerba Wrote: ------------------------------------------------------- > up to now I have exactly one response for RepRap > ;-) > But I only started contacting RepRap folks today, > so I assume you found my survey somewhere else. ... ooopps, this one should be mine - i stumbled in your call at fab@home ... I hope there will be some more activity here Viktorby VDX - General
Hi Kerstin, i've run through the survey some days ago - have you already collect some representative data? Viktorby VDX - General
... it's my aim too to cocreate a "technological environment" where everyone is able to produce all he need either on his own or he can find it in the local sphere - from food over clothes to sophisticated hardware. But in this world most of the common markets and commercial structures aren't stable or needed any more, so it could be a very hard/dangerous way there ... Viktorby VDX - General
... a good reprappable redesign of the extruder ... Viktorby VDX - General
... we had last year some talk about measuring the extruding-speed. One possibility is marking the filament with colour-dots for visual sensing, another is embedding some magnetic microparticles and magnetize single segments and measuring with a highres Hall-sensor. AFAIK sensing without marking was not possible as the extruded filament is very homogene in colour and occasional air-bubbles wereby VDX - Mechanics
... the lower border is dependant of the accuracy/resolution of the positioning system and smallest diameter of the extruded tray or dispensed droplets. Actually i'll guess the best achievable accuracy is around 10 microns (RepRap is designed/specified for 100 microns accuracy) - i have mechanics, electronics and reference-switches that are capable of 0.1 microns accuracy, but the mechanical setby VDX - General
Hi Sven, Willkommen Ich bin im Rhein-Main-/Main-Kinzig-Gebiet Daheim - wie's aussieht, sind die RepRapper in D noch ein recht selten anzutreffendes und ziemlich verstreutes Völkchen, so daß nur selten lokale Gruppen zusammenfinden Ich hoffe doch, daß sich das in der näheren Zeit ändert! Ciao, Viktorby VDX - Schwarzes Brett
... first comercial 3D-LOM-printers around 1994 used 'endless' paper-sheets from a roll, were laminated with a heater and contour-cutting was made with a CO2-laser. The fabbed parts had a look and were nearly stiff/rigid like wood. A 'modern' LOM-printer i found some years ago used endless PVC-sheets, laminating/fusing was made with some sort of solvent and cutting with a knife - the price was aby VDX - Reprappers
Hi Max, ... was mir als mögliche kostenlose Quelle auch noch eingefallen ist: - bei uns auf dem Bauhof im Altgerätecontainer findet sich ab und an auch mal ein alter Haar-Fön oder Toaster - beide haben brauchbare Heizdrähte drin Viktorby VDX - Altes Forum
Hi Max, anbei erstmal eine Skizze mit 2 parallelgeschalteten LM317 á 1A, also für genau 2A Stromausgang. Für mehr Strom kannst du entsprechend viele der Stromregler parallel schalten. Ich betreibe damit Lasedioden mit. z.B. 6 parallelen LM317 á 0.7 A für 4.2A Maximalstrom. Den Eingang kannst du mit einem Halbleiterrelais oder Powermosfet per PWM beschalten, dann mußt du den Puffferkondensatorby VDX - Altes Forum
Hi Max, wenn du in etwa weißt, wieviel Strom du benötigs, um den Draht 'dunkelrot' aufzuheizen (ab Hellorange/Gelb geht er langsam kaputt), kannst du einen simplen Stromkonstanter mit einem (bei <1.2A) oder mehreren LM317 aufbauen und den Draht damit per PWM von 0 bis max. Leistung durchsteuern, ohne ihn zu gefährden. Such dir im Internet eine LM317-SChaltung als Stromkonstanter (besteht nurby VDX - Altes Forum
Hi Fabian, ... es gibt hier schon einige Basteleien mit Steppern - du mußt dann 'nur' in der Software statt PWM die passenden Schrittpulse für den Motor ausgeben ... Viktorby VDX - Altes Forum
... schau mal im Bauhaus nach dem Ersatzdraht für die Proxon-Styroporschneider - das ist eine Rolle mit 30m (ich glaube) 0.2mm-Draht drauf und kostet auch nicht die Welt. Zur Not kann ich dir auch mal einen Meter zuschicken ... Viktorby VDX - Altes Forum
... you can search someone with a CNC who can mill-route PCB's. I'm doing this sometimes, but located in Germany Viktorby VDX - United Kingdom RepRap User Group
... AFAIK some development in 'cooperative robots' was done with measuring the exact position and orientation of the specific bots by triangulation with coloured lights in the corners of the working area or simpler with ultrasonic beacons placed around. For robot-soccer the bots are colour-tagged on top and the position/orientation is measured and calculated with cameras above the arena. Anotheby VDX - Mechanics
Hi sid, ... some years ago i had to redesign a manually operated SMD-placer from Finetech into a camera-controlled microassembly system. That was a really nice mechanical setup with two freerunning linear bars in X and Y where the toolhead with a (manually) controlled rotating vacuum-gripper (essential a syringe-tip with a small rubber-cone) is atached on the Y-axis. With iron-strips atached tby VDX - Pick-and-Place Electronic Assembly (and robots!)
... the simplest solution will be a webcam visualizing a spot on a pan- and XY-stage - e.g. a simple manually XY-stage with a rotating plate on it. Then you put a part (or a hopper with more parts) in the focus, move and rotate the stage until the part is in the right position and orientation (maybe a crosshair on the screen) and start your pick'n'placer ... Viktorby VDX - Pick-and-Place Electronic Assembly (and robots!)
... a method for recycling ABS 'without colorchanging' is grinding and solving in Acetone. For 3mm-filament it's not working, but maybe thinner filament can be extruded horizontally on a heated surface (e.g. big rotating cylinder) so it dries with nearly circular shape. I tried this for my dispenser where i manually drawed some trays, what's working, but waits until i finish all the other tasks.by VDX - General
... i'm working on the delta-robot- and tripod-kinematics since two years now and all the single components ready - beside my tripod-demonstrator with 1/8-microstepping i have three 1/256-microstepping drivers (resolution of 51200 steps on a 1.8°/200-fullstep motor) and some different types of old Nema23 and a set of bigger and stronger steppers too for a really 'strong' delta. For my tripod witby VDX - Delta Machines
Hi Phil, look at the images in this post: - This are sketches of a laserplotter where i moved the X-arm with a wire-loop and the laser-head (Y-axis) with a 2:1-pulley, so i had to double the diameter of the disk for the Y-wire. This setup allows to fix both motors to the base and the moving parts are much lighter than the standard setup with the Y-motor sitting on the moving X-arm ... Viktorby VDX - Mechanics
... i used different highly elastic steel-wires with diametres from 0.3mm to 0.8mm in my XY-Pen- and Laser-plotters. For best traction i used aluminium-discs with 16 resp. 32mm diameter and 3 or 4 windings of the wire around. The ends of the wires were fixed to the moving head or sidepart and a spinning nut-tube for adjusting the tension. Atached is a photo of two old gearheads i used for theby VDX - Mechanics
... i'm trying with LOM-fabbing or laminating thin rectangular sheets of material and cutting only the contours and some additional lines in the outer area for dismantling the object from the surrounding material. For this i made an 'inverse' STL, where i constructed a cuboid embedding the object and skeinforge 'filled' only the outer areal with honeycomb lines. As result you would receive a blby VDX - Plastic Extruder Working Group