QuoteWith one of these along some guideline material strips Making a robust, precise guideline is in itself a difficult precision operation Making something that can reliably and accurately to sub-millimetre precision with a high degree of repeatability isn't simple. The magnetic strip approach is nice, because it doesn't require fancy manufacturing capabilities or super high precision machininby Ru - Mechanics
QuoteI'm new here, but have a few ideas: Hi! I'm going to be a bit mean and shoot some of them down, I'm afraid. QuoteThe ability for the next version of RepRap to have, say, three slots off to the side with different write heads to be slotted into Multiple toolheads are intended for v2 of the reprap, I believe. Work has been done on them, see here: I think the current goal is to make the bby Ru - Mechanics
QuoteI also believe that the support structures should be IN the stl file rather than calculated by the software I think this is bad for a few reasons: 1) Hassle. The designer is going to have to sit down and add in each and every bit of scaffold himself, which may be very tiresome for more complex parts. The more difficult it is to design and print your own parts, the less people will be keenby Ru - Plastic Extruder Working Group
QuoteI played around with some sugar tonight to test it as a possible support material and it seems to have some potential That would cerainly show that sugar has potential as a bed material. Using caramelised sugar as a support material is slightly inconvenient, as it implies a 3-toolhead system... part material, sugar (presumably in the form of water icing, or similar paste) dispenser and a sby Ru - Mechanics
QuoteSay what? What about PVOH What about it? It may, possibly, be useful. Only No-one knows if it sets fast enough to be a useful support material, nor if filament will stick to it. So it is a wild guess, that might be slightly better than the other few dozen wild guesses we've had, QuoteIn any case, the statement that "absoluetly no-one has any idea what on earth it could possibly be" is quiby Ru - Plastic Extruder Working Group
...because changing names and copypasting the same general electronics question in a non-general electronics forum will encourage people to answer you Also... you've been searching for solutions to this problem for a whole year? I suspect you may have other issues here.by Ru - Controllers
Ahh, I assumed as much. Good to know, anyway.by Ru - Mechanics
I'm trying to remember if anyone has tried using CAPA as a raft? Presumably you could heat some up and then roll it out to an even thickness on a suitable underlay. Apply hot water to unstick, or whatever. CAPA sticks to all sorts of things quite readily, and would play nicely with a heat-to-detach peltier in the build bed. Reusable to boot. I've got vague niggling memories of something like thby Ru - Mechanics
I'm not sure I follow. You don't like them being optical, or you don't like them being there at all? Something needs to provide a notion of a 'home' point, and be able to inform the controller when the toolhead is home. Stops at the non-home end of each axis would just be failsafes though, and are already considered optional as things like the extruder valve solenoid are driven from pins formerlby Ru - Controllers
Quoteanalyze the overhanging slice with reference to material properties like bridging strength Given that we make single material prints, things like 'max bridging span' can be yet another build parameter, and should be calculable without too much hassle. One experimental print would do. Quoteand shrinkage We make no allowance for this anywhere else, nor is it a trivial parameter to calculateby Ru - Plastic Extruder Working Group
Interesting scaffold idea... I hadn't thought of that. But it doesn't have any significant advantages over plain old vertical scaffolding poles aside from saving material... the previous problems of scaffold density and detaching scaffold from the part after printing still arise. Of course, if you have a nice, brittle, easily removed material everything is fine. BUt in the absense of such a thinby Ru - Plastic Extruder Working Group
\..... x\.... \... #\.. # \. # \ Here's a demonstration of what I meant. As you pointed out, for flat surfaces parallel to the bed, scaffolding is fine. But for angled surfaces, like the example above, it is not. The ... is the part. the # is some scaffolding, \ is of course the outer surface. Look at point x. If the surface between the top of the scaffolding and point x slopes outwaby Ru - Plastic Extruder Working Group
QuoteI think I can wrap the wire around the nichrome, put a blob of solder to form an electrical connection Just crimp the condutor with the heater. Twist em up a bit and squish with some pliers. You could always use a fold of some suitable metal crushed on top if you were worried about it coming apart. QuoteI think with my method it could be cheaper than cerastil and more efficient than any ofby Ru - Mechanics
QuoteBut that's just it. A repstrap can also build replacement/spare parts for itself. And a reprap also uses parts it cannot build itself. I must be missing something, because I still don't see the difference. Can it? Many repstrap designs will not be capable of that. They are constructed to be cheap and easy, not to be universally capable. What you seem to be saying is 'if I make a really goby Ru - General
Blargh, I've just realised this wasn't a support material question after all. Apologies. I'll go sit in the corner for a bit. I get the vague impression that tempering chocolate is a complex process, and therefore not something you'd be able to do to a freestanding chocolate sculpture. Not that you have to temper it of course, but it does make the end result a little nicer It would perhaps beby Ru - Plastic Extruder Working Group
Quotewhy can't we (I! I mean I, really!) just anodize it? Sounds like a reasonable ida. I think you should try it. Let us know how it goes Quoteand then heat the nichrome up to, say... 300by Ru - Mechanics
Quotewhat can a reprap do that a repstrap can't? From what I've read, they seem to be pretty much the same thing. The reprap design can, and will, evolve. This makes it possible to print out a next gen reprap when teh designs are available. Sure, you can improve your repstrap design to your heart's content, but when someone else has already made the designs for a better extruder or a toolhead swby Ru - General
QuoteSo... why use a thermal insulator between the nichrome and the barrel? Probably due to the difficulty of finding a good thermal conductor which is also an electrical insulator which can withstand that much heat. Something has to keep the heating element in contact with the barrel, after all, and I don't believe that the nichrome is electrically insulated?by Ru - Mechanics
QuoteThe L293DNE is only rated to 600 ma according to ! So it's about 6 times to small for my gearmotor. That's a monstrous gearmotor you've got there... probably waaaaay more power than is needed for pushing filament It is probably easiest to grab a little commercial DC motor driver... there will be loads about for pushing robots and RC cars around and the like. Cheaper and easier than tryinby Ru - Controllers
QuoteDo you mean the nichrome will get hotter than that when heating the barrel to 240by Ru - Mechanics
Google knows allby Ru - Plastic Extruder Working Group
QuoteIt doesn't make sense to me to have 40mm (two 20mm lengths on each side) of the heater wire heating the air instead of the barrel Does it matter that much? I guess it isn't very neat, but I don't imagine it has any negative impact aside from the small amount of power it wastes. Quotethe solder might melt Will melt, I reckon. But that wouldn't stop you crimping the two bits together and thby Ru - Mechanics
Will an extruded filament stick to it? I'm going to guess not. The hot filament seems likely to melt a thin layer of chocolate underneath it, which would lubricate it some what allowing it to be dragged out of position when the toolhead turns a corner. It would be a very simple experiment to try though. The second problem is how quickly the chocolate will set once extruded. If this is too slowby Ru - Plastic Extruder Working Group
Now I think about it, scaffold would be most efficient in the case where the surface it supports is parallel to the printer bed, given that we know that bridging between supports can work quite well. Angled surfaces, unless they're reasonably self supporting, would need more dense scaffolding to hold them up as they're being built. Perhaps it would be easier if the bridges between scaffold pointby Ru - Plastic Extruder Working Group
QuoteNow that I look back on my answer to your question, the answer is that time is what is stopping people from building cheap RepStraps. Motivation is also another factor, but it is partially dependent upon time. Even things like the McWire, intended to be a cheap and simpl way to build a cartesian bot are not entirely cheap or simple. If a kit were to appear that was half the cost of, say, thby Ru - General
With some tricks you might be able to increase the angle a bit, but this method isn't going to allow you to print at extreme angles approaching 90 degrees as eventually gravity is going to bend the edge downwards when the iverhang extends far enough from the main body of the part. Maybe being able to build at, say, 60 degrees is useful enough? A suitably organic-looking part with curved/angled sby Ru - Plastic Extruder Working Group
Quotefor reprap the best use of an FPGA would be to offload any processor intensive algorithms that would overload the main microcontroller, ie a co-processor I think I can safely say that processing power is cheap and easily available if we ever needed it. Hell, as a last resort, you could get the host PC to do the hard work I don't believe that reprap is limited by the power of our various cby Ru - Controllers
QuoteIf that's true, and hundreds of Repraps have been sold, why can't people buy the parts for $20+shipping instead of $360??? Especially if people are following the recommeneded each Reprap builds 2 for friends... I assume it could happen, it's just not organized. If people buy repraps, get them working and never tell anyone or offer to help (or sell their services), that isn't the fault of tby Ru - General
Quote(complex machine vision circuit board disassembly plan) If you're dismantling a board which you can already fabricate, this is easy. If you're dismantling a board which you have not fabricated, but migt need to build or dismantle more in the future, it might be worth trying to automate the process. For one off boards? Have a jog controller, and mark the corners of each IC and each discreteby Ru - Controllers
QuoteAnybody done anything with the Atmel devices ??? What is their software like? Xilinx and altera offer pretty reasonable packages, and I rather hope that they'd make less awful tools given that programmable logic is what they do best. QuoteFPGA v CPLD. FPGA's are bigger so you can get more into them. Either more peripherals or cleverer peripherals. CPLD's are smaller so you get less intoby Ru - Controllers