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General discussions. For specific printers / electronics / fabrication methods / softwares, please see other sections.
Re: A madman with a blowtorch (problem soldering wire) - 16 years ago
How about a conical screw, mounted offset to the axis of the feedstock? Tip against the heater, wide end on top. The screw would have to change in pitch from "base" to "tip". By doing this, you'd be able to mount the motor at an angle other than in line with the feedstock, without relying on a flexible shaft. I can see making one by wrapping a cone in a string, and making a sandcasting of it.by Roach_S - Reprappers
Re: Printing working 3D Body Parts already being done. - 16 years ago
That's great. Personally, I figure the real medical test will be to make a kidney or a lung with a rapid prototyper. Beyond that, imagine an eye replacement, or even an aftermarket improvement. (Think squid eye, with the optic nerve BEHIND the retina, or that reflective layer in the back of a cats eye...or both.) Darn it, I want a few new organs now, and they all work. The future of doping sby Roach_S - Tissue Engineering
Re: Beads Instead of Teeth? - 16 years ago
Which also stretches. Actually, when I get around to starting, I'm considering motorcycle chain. I live on a farm. My access to junk is excellent.by Roach_S - General
Re: What about the use of UV glues and UV light - 16 years ago
On that note, how about replacing your plexiglass, that you opt to keep, with window glass?by Roach_S - Polymer Working Group
Re: Extruder Rate (request for crackpot ideas) - 16 years ago
Only in part. The ultimate overhang issue, in my mind, is a bell with fabbed-in clapper. The bell, sitting upright, has a clapper that hangs free underneath. Even if you don't require the clapper be hinged relative to the bell, you have the issue of how do you start fabbing the clapper out in the middle of nowhere.by Roach_S - General
Re: Servo motor VS Stepper motor - 16 years ago
I suggested running to the limit switches as that hardware is already part of the design, so no more hardware to solve the problem. Otherwise, I'm with you, put a sensor on the head, and let it watch markings on the guiderail rather than using the endstops. You COULD get away with one sensor, if you were willing to mark the ends, middle, and reference points along the length, with three differeby Roach_S - Mechanics
Re: RepRap forum organization - 16 years ago
Write once, and run forever? You better hope you're still alive when year 10000 rolls around. Heck, I figure a lot of calendar dependent apps will fail in the year 2100. Sometime between February 28 and March 2, I think. Edit. I originally wrote 2400. They should work fine in 2400. Edit 2, spelling error.by Roach_S - General
Re: Consolidated Directions - 16 years ago
Oh. I had nothing to say about PowerPoint. On that subject, however. I downloaded two different PowerPoint viewers, both different year versions of MicroSofts, in an attempt to view a powerpoint file that came with some church graphics. Both failed, in the same manner. I don't hold to PowerPoint being reliable. Something else, though. How about scripting it to update a certain number of theby Roach_S - General
Re: Consolidated Directions - 16 years ago
Only one problem with scripting the thing to post a .pdf of the current page at 2:00am. All the spammers who'd learn to hit the 'site at 1:59am. If there was decent automated anti-spam methods in place, along with, perhaps, a trusted last-known-good page, then this would be great. Doing this, however, means that the .pdf would generally lag behind the wiki by about a day. Enough time for anyby Roach_S - General
Re: Extruder Rate (request for crackpot ideas) - 16 years ago
TheGuy, Your idea sounds great. Perhaps that will be our Crick&Watson model.by Roach_S - General
Re: Servo motor VS Stepper motor - 16 years ago
For the given hardware design, how about running the stepper into the wall every so often? At full speed, find (one of) the limit sensor(s), and use that to recalibrate on the fly. If you attached two per axis, find the one that is supposedly closest. If you only have one, find it every so often.by Roach_S - Mechanics
Re: First RepRapped RepRap? - 16 years ago
It's like what qualifies as a computer? The first computers were less capable than the all-solar scientific calculator in my pocket, but I'd not call that calculator a computer. The calculator can't be reprogrammed, but until EDVAC, or rather the duplicate of the concept built by its inventors student, the first computers had to be manually rewired to "reprogram" them anyway. As for wire, andby Roach_S - General
Re: First RepRapped RepRap? - 16 years ago
Except give a practically free repsrap parts kit to your friend. Once YOU make a repstrap, there's no reason for you to use it to make a reprap, for yourself, until the next design iteration. But, you can make a reprap to give to your friend, or you can decide the repstap is too slow, you want to make that art-project lightswitch cover AND the doorstop you promised your mother-in-law in less tiby Roach_S - General
Re: Scaling Down - 16 years ago
I didn't say something that shrunk as it cooled. That's exactly the problem I referenced. I was thinking of something that could be extruded in a viscous solution, then boil off the solvent. If the material shrunk by a large factor as the solvent was boiled off, and if you could boil off the solvent in such a way that the object was dried evenly, you might get something that could be "printed"by Roach_S - General
Re: Scaling Down - 16 years ago
How about something that shrinks, and hardens, as it dries? Not cools. Of course, drying a largish object evenly would become as much a challenge as figuring out the future shape of an object that's shrinking as you lay another layer on top of it.by Roach_S - General
Re: RepRap forum organization - 16 years ago
I'd hold out for a tatto gun head made on a reprap machine, myself, and I'm not getting a tattoo.by Roach_S - General
Re: RepRap can help end slave labor! - 16 years ago
I've read Probability Broach, fist as the webcomic, then in the dead tree, and am currently reading American Zone. I like them, and casually daydream about finding a blue tinged hole in space in my bedroom. Actually, I'm not ignoring the cost of capitol. That's also rarity. Organizing labor is labor. What I'm saying is the cost of anything eventually boils down to how many people had to spenby Roach_S - General
Re: Dot printing rather than Extruding? - 16 years ago
Oh. Sorry. I'd known that about the dustbed, but managed to forget. Sounds like a dustbed would work wonderfully. I still see problems with "just in time" sintering, as you couldn't form components that were suspended from an overhang not yet made.by Roach_S - Reprappers
Re: Re RepRap forum Organization - 16 years ago
Personally, I like the way things ramble. From the digressions, interesting ideas develop.by Roach_S - General
Re: Scaling Down - 16 years ago
How about printing the part on stretched latex then?by Roach_S - General
Re: RepRap can help end slave labor! - 16 years ago
My theory is all cost can be summed up in two things. Rarity and labor. If it takes ten manhours to make a useful item out of something that is free, where competition is allowed to flourish, the price of that item will closely approximate the value of ten hours labor. Then you factor in education. A combination of rarity, (those willing to delay being productive, (and thus getting paid,)) andby Roach_S - General
Re: First RepRapped RepRap? - 16 years ago
And then we raise the bar and demand that the first reprap print an improved version.by Roach_S - General
Re: Extruder Rate (request for crackpot ideas) - 16 years ago
Steve. I'm with you. I think the best way to work in One material is four heads. One to rough, one to carve, one to add fine detail, and one to fill voids to allow for arbitrary overhangs. Additionally, I'd modify the two working material extruder heads so they could work with five threads, not one. One thick, (relatively speaking,) head for the material, and four thin ones so loaded with pigmby Roach_S - General
Re: Darwin Costs So Far... - 16 years ago
Yeah. I think Bernanke is finding out just why Greenspan wasn't open about his decisions. That and the Euro is doing for European currency exactly what I think its creators were hoping for.by Roach_S - Reprappers
Re: Dot printing rather than Extruding? - 16 years ago
One thing I suspect you forgot to consider with SLS. When you lay down the first layer, you're fine, but you immediately lose any overhangs starting with the second layer as your metal dust falls through to the layer below before you get a chance to irradiate it. Personally, I'm wondering how much candlepower you'd need to use a video projector, and sinter a frameshot at a time, but it still leby Roach_S - Reprappers
Re: PCB Production - 16 years ago
How about the nozzles used to inflate sports balls? They have a side port, so they'd have to be cut short, and I don't have one handy, so I don't know the internal, or for that matter, external, dimensions.by Roach_S - Mechanics
Re: interchangeable pressure nozzles - 16 years ago
Just a thought on how to get that ribbon extruder. If you make it along the lines of a wood plane, you could probably machine it easier. Make a shallow "U" shaped "shoe", and a blade that fits tightly against it. Against it, so you can tap the sides of the shoe for screws to hold the blade. Preferably at least two screws per side. The shoe would be wedge shaped, basically a wedge with a wedgeby Roach_S - General
Re: Furfuryl Alcohol and blocked catalyzers (formerly delivery woes...) - 16 years ago
I've heard of someone repairing an engine block with waterglass. I don't know if he was successful, but that was his stated goal when he purchased it from my mom.by Roach_S - Paste Extrusion Working Group
Re: Fibre powder - 16 years ago
Be careful. You're the chemist, so you probably already know this, but I can think of another potential use for cellulose that would make a lot of people nervous.by Roach_S - Polymer Working Group
Re: First (basic) attempt at a repstrap - 16 years ago
The idea is to make as much of it from scratch as possible. Screws and such, if I remember the argument, are so ubiquitous that it's cheaper to buy them than to machine them special. The same goes for most of the other structure. The electronics are something a lot of us would like to see made from scratch, but the technology isn't there yet. A lego fabricator that makes things out of legosby Roach_S - General