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3D-objects - where to find or store?
Re: Parallel-kinematics versus string-pod - 17 years ago
Hi Zach, ... access would be fine, then i can post some images and videos of progress and some experiments in the blog Viktorby VDX - Mechanics
Re: Easy to build linear stages - 17 years ago
... i'm nearly ready with the mechanics of my vertically aligned Tripod: (from here: ) Viktorby VDX - Mechanics
Re: Parallel-kinematics versus string-pod - 17 years ago
... here is an image of my vertically aligned Tripod-repstrap-demonstrator - i only have to mill the fittings for the ball-magnets, so next week the mechanic is ready, and i can search my driver-boards ... The height is 21 cm, footprint nearly 17x17cm and the working area is a cylinder of 6cm diameter and nearly 8 cm height with an estimated accuracy of 10 microns or better (not in every zone thby VDX - Mechanics
Re: Live CD - 17 years ago
Hi Zach, ... look at LinuxCNC or EMC2 ( ) - it's for free ... They have Ubuntu as Live-basis, some CNC-programs and tools for controlling different setups and you can install the whole on your harddrive, if it's ok ... Viktorby VDX - RepRap Host
Hi german reprappers, where are you? - 17 years ago
Hi all, ... i'm located in Grosskrotzenburg, near Frankfut/M, Germany. Wo's reprapping nearby too? Viktorby VDX - Schwarzes Brett
Re: Reprapping Engines - 17 years ago
Hi Ian, ... the spinner is a pump, you need a motor to activate it ... Here is a sketch of the previous mentioned MRF-Engine: If you activate the solenoids in the sequence 1,2,3,4,1,2,3... then the MRF (brown) in the elastic hose (yellow) would travel slow from right to left ... Viktorby VDX - General
Re: Reprapping Engines - 17 years ago
... here i have a sketch of a spinning magnet-ferrofluid air-pump ... Viktorby VDX - General
Re: Reprapping Engines - 17 years ago
Hi Ian, ... i tested some MRF-pumping methods with moving and spinning magnets (see the image for two rotating setups), but for best pumping of MRF i had the sequencial switching solenoids - it seems, that the traveling effect in the elastic hose needs sharper activating and releasing edges, than the moving magnets can perform ... The spinning magnets works good with ferrofluid - when you closeby VDX - General
Re: Building Low Pressure Solenoid Valves - 17 years ago
Hi Sean, ... the magnets arent so expensive (maybe 10 cents or so) so that's not the problem - with my oszillating-pressure-setup there would be the real chance, that the ball drifts away from the holes, so the magnets on both sides are essential for switching the solenoids off after changing position ... Viktorby VDX - Mechanics
Re: Reprapping Engines - 17 years ago
Hi Sean, ... there are many possibilities and methods, for working with potential-differences, when you can switch and direct forces to the right 'muscles' ... My simplest approach is an oszillating piston, which changes the pressure in the main-tube periodically between max and min (~vacuum?). Through phase-right switching valves i can selectively output pressure (valve open short before andby VDX - General
Re: New plastic is strong as steel, transparent - 17 years ago
... actually most nano-work is spin-coating, film-drying or even dipping, as in this article ... Some months ago i found some clever guys aligning nanowires through solving them in soap-liquid, blow soap-bubbles and wet with one side of the bubble a silizium-plate, so the solved nanowires in the liquid-film could be separated, aligned and transferred to the surface of a SI-sensor For 'real' nby VDX - Polymer Working Group
Re: Reprapping Engines - 17 years ago
Hi Ian, ... ok, boiling water can be used too Another point - i can build a pure current/magnetic-driven MRF-engine without heating and steaming, when i dont need much displacement. I described it already in another thread, but here is a short scetch: When i surround a MRF-filled elastic silicone-hose with three or more solenoids and switch the solenoids in a sequence, then the MRF acts as bby VDX - General
Re: New plastic is strong as steel, transparent - 17 years ago
... it's mostly a composite from very hard and strong nano-particles (or ceramic-flakes) embedded in a polymer ... It's nearly the same principle, as in glass-filled epoxy-sheets (GFK) or 'virtual stone', where you fill an epoxy with sand - only the particles are much smaller and have a rough surface or some molecular structures on the surface, where the polymer-molecules can dock, so the structby VDX - Polymer Working Group
Re: Reprapping Engines - 17 years ago
Hi Ian, ... obviously right I'm maybe half'n step ahead - when there's an reprapped 'engine', then there can be reprapped 'muscles' too ... Back to reprapping 'hardcore engines'. With MRF-hose-valves and reprapped bellows- or membrane-chambers i have all together, what makes a low-temp stirling-motor. I need a low-temp boiling fluid in the chamber (maybe aether - but what's with dissolvingby VDX - General
Re: Reprapping Engines - 17 years ago
Hi Ian, ... what i describe, is a hydraulic machine, powered by a moving magnetic 'virtual piston', which articulates varying pressure, that is phase-senitive switched to the appropriate hydraulic 'muscles', and then bend or move the corresponding mechanical structures ... It's the same principle, as in an hydraulic motivated excavator, powered by a combustion-engine ... Or better a bionic-sampby VDX - General
Re: Artifical Muscles - 17 years ago
... i found a new basis for my pastes: 'Lanolineum'or 'Cera Lanae' - it's pure wool-wax and smells strongly like sheeps, but it's soluble with water/glycerine or oil too and is only quarter the cost of dexpanthenol. For big amounts it would be much cheaper then dexpanthenol (e.g. 8 Euros per 100 gramm, instead of nearly 30 Euros!) and it seems to do the job as well as the other mixtures, so i'llby VDX - General
Re: Reprapping Engines - 17 years ago
... i mustn't have heat or air-pressure to move pistons - as in the 'Artificial Muscles'-thread mentioned, i can build solid-state pumps and valves only from hoses and solenoids, if i have MRF or ferrofluid as active and transporting medium ... With MRF i already designed peristaltic pumps, which move the fluid only through serial switching of solenoids, without any moving parts ... With a diffby VDX - General
Re: Artifical Muscles - 17 years ago
Hi Samuel, ... this is a mixture from carbonyl-iron-spheres (grade CC, that means nearly 50 microns diameter), vaseline and some vegetable-oil (from the kitchen) to reduce viscosity - no surfactant, because it's a MRF, not a ferrofluid ... It stays stable over months (i have some fluid mixtures which are 5 years old and working), when i have to much oil and/or there would be sedimentation, i caby VDX - General
Re: Artifical Muscles - 17 years ago
... here's my first experience with uploading a video to youtube: As you can see, i pour some MRF (Magneto-Rheological-Fluid) in the field of a neodymium-magnet, where it stiffens. With removing the magnets it went fluid again, and with applying the magnets it got stiff again, and so on, and so on ... Viktorby VDX - General
Re: Furfuryl Alcohol and blocked catalyzers (formerly delivery woes...) - 17 years ago
Hi Fernando, ... sounds really good! Actually i'm bound with other tasks, but that's a way, i want to go - keep us informed and be carefull, not to rocket your house in the sky To the diode-lasers: you should salvage lasers only from newer Drives, so 40x or faster - in older drives the diodes haven't enough power, in pointers it's the same - with a 5mW-Diode there isn't a sensable heat in theby VDX - Paste Extrusion Working Group
Re: delivery woes and general relaxation - 17 years ago
Hi Fernando, ... glass and ceramic melts much better then metall, but they have a higher thermal contraction, so i must mix materials with different TK-values for better stability, or it would brake apart, when cooling down ... Another point: - i have to dry the paste with lower energy completely, befor i can melt the powder to solid, or the evaporating solvant would blast the powder away ...by VDX - Paste Extrusion Working Group
Re: delivery woes and general relaxation - 17 years ago
Hi Fernando, ... you can make tests with stark instead of cellulose, should work similar ... My tests with laser-melting gold-dexpanthenol-paste went fine, the heavier part is now to adjust the output-power of the diode-laser, to liquidize the gold-powder, but stop melting, before the gold-pad under the paste is melted completely too ... Tomorrow i'll try sintering or melt the iron-paste, whicby VDX - Paste Extrusion Working Group
Re: Artifical Muscles - 17 years ago
... here i have a static image-sequence of a MRF-mixture (Mangneto-Rheological-Fluid) of carbonyl-iron-microspheres, dexpanthenol and some glycerine for lower viscosity ... As you cn see, in a magnetic field (here from some NdFeB-magnets beneath the glassplate) the fluid stiffens, so it can hold the inserted stick -- without the magnets it went fluid again, and so on, and so on ... So this mixtby VDX - General
Re: Support material slump - 17 years ago
... maybe low-temp-melting wax (parafine/stearine?) is usable as easy to remove support? When i once had to optimise/debug a heatcuring glue-dispenser-system, the problems were drastically reduced, when i wound a heating wire around the dispenser body and the outtake/needle and put some aluminium-foil and a foam-hull around the complete dispenser-head. With this i could set and hold temperatureby VDX - General
Re: Artifical Muscles - 17 years ago
Hi Samuel, ... an dc-motor with an excenter ist the simplest way for an oszillating pump with variable sinusoidal output and precise pressure-curves over the period. Maybe two separate (normal) pumps for static pressure and vacuum with tanks for charging and damping would be a try too for pneumatics, then you need two valves per muscle, but can act every muscle in asynchronous mode ... For a hby VDX - General
Re: Reprapable linear drives ... - 17 years ago
... i had some tsting with powders from VAC in germany - they fabricate high-quality but expensive magnets. Maybe the guys at www.supermagnete.de have some - i'll ask them ... Viktorby VDX - General
Re: Reprapable linear drives ... - 17 years ago
Hi Samuel, ... 'China'-magnets can be cheap bought in big amounts for some cents each, so in bulks bought in Asia it's not so expensive ... The coils can be wound manually with a drill, so it's best homemade ... And the accuracy is dependant of the relation: step-width of the magnets against the amount and displacement of the coil-series - with aligned series of 8 coils in 4 rows i can make 32by VDX - General
Re: Building Low Pressure Solenoid Valves - 17 years ago
Hi Samuel, ... look on the image above - i changed it and inserted the holding magnets, so the solenoids acts only in short pulses, to pull the ball between the two possible end-positions ... With oszillating pressure-pulses the ball moves in the 'closed'-position slightly between the two holes - until it's properly pressed at the opposition hole and blocks the flow, a small amount of fluid canby VDX - Mechanics
Reprapable linear drives ... - 17 years ago
Hi all, ... on sunday i was with my youngest son in the basement at my parents house, where we 'revisited' some of my old projects from scool-time, nearly thirty years ago ... One of them was a workaround, where i converted a Brother-HR1-typewheelprinter in a pen-plotter for my oldstyled Commodore C64-homecomputer. It was really working after the long time - a condensator in the powersupply fuby VDX - General
Re: Artifical Muscles - 17 years ago
Hi Samuel, ... for me it's after 10:00 PM on Saturday night, it isn't much to work and i'm a sort of on the way in my bed It seems, we're on a side-way from the normal talk, so it's not so much folks involved - and the 'core-team' isn't at home now, to moderate or place comments ... Bye and good night, Viktorby VDX - General