... 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
... i know ... this was a (catastrophic) test how ordering/shipping from USA works, but then it seems the involved banks frauded me and the colleague - finally we payed 3 times the bank-transfer-fee Next time i'll mail my sister (she lives near NewYork) what i'm interested in, so she could bring it with her next time visiting Viktorby VDX - General
... i'm in Germany, so ordering at Amazon USA is a pain - finally i payed nearly 120 USD for Gillilands book (instead of 30 USD at Amazon) after shipping, VAT- and transfer-fees Viktorby VDX - General
... ahh, OK - i couldn't see the videos in your first post, but solved this now, so i finally realized, you worked with Gillilands book too. Until now i didn't have the HP-51604A-inkhead and tried with some others salvaged from old Lexmark and other HP-printers. Have you already tried with other fluids than the original ink? Viktorby VDX - General
... i have the book "Inkjet Applications" by Matt Gilliland ( ) with some circuitry and software for a HP-BW-inkjet. I think some basics and combination wit other brands souldn't be a big problem ... Viktorby VDX - General
... i had some trouble getting high rpms with the nanotec SMC11-microstepping driver ( ) and a standard nema-23 stepper with 1.8°/200 spr. With 12 Volts i only managed to run the stepper with max 6kHz at 1/8 microstep, what's something like 3.75 rpm. With 30 Volts and the same parameters it was running smooth until 20kHz or 12.5 rpm. It's highly dependant of the maximum voltage and the acceleby VDX - Mechanics
... or instead of a single price for the finished concept, maybe funding interesting evolution lines from start works better Viktorby VDX - Kartik M. Gada Humanitarian Innovation Prize
... there should be a regarding clause, so the winning system will be auotmatically published as open source. But you're right - people or groups hoping to win the price will start to develop in secrecy as opponents, not in cooperation with others ... Viktorby VDX - Kartik M. Gada Humanitarian Innovation Prize
... i've had some thoughts abot the 'optimal' design of a real reprap - for me this could be a single but complex part out from an elastic resin resembling a tower-like structure with some dozens canales and cavities within the body. This part is fixed to an array of valves, which could open and close the canales for pressure, so the elastic body deforms and moves the tip with the toolhead arounby VDX - Kartik M. Gada Humanitarian Innovation Prize
Hi sid, ... did you receive my email regarding milling the 8mm-holes? Viktorby VDX - General
Hi Korn, ... sorry, i didn't manage to find the time - but good to hear you found the problem Viktorby VDX - RepRap Host
... maybe we should take a closer look on the parts the common reprap can't print: motors/bearings, electronics/wiring and all other parts actually made from solid metal. Sometimes it's more effective use cheap and/orcommon parts e.g. bamboo-sticks instead of steel-rods or such. We had some talk in the past about replacements for the motors (reprappable linear drives) or major changes in the seby VDX - Kartik M. Gada Humanitarian Innovation Prize