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Re: heater barrel turns on with the reprap - 16 years ago
This is probably not your issue, but i had something similar happen. turns out i had my pinout from my sanguino incorrect. the pin wasn't an output for anything, so it was just floating and told my PWM board to turn it on. however, if your thermistor is still detecting 17C when the temp is obviously higher, then that probably isn't your issue. try setting the temp to something under 17, if theby Andres - Controllers
Re: New Chicago RepRap group!!! - 17 years ago
Why wait until the summer? i think people are getting together to build some mechanicals this coming sunday. (i won't be attending due to imminent vacation, but i'm sure they would welcome you.) check out the google group for information: Andresby Andres - Illinois, Chicago RepRap User Group
Re: Dual Action extruder - 17 years ago
i don't think the main pressure is coming from the plunger at all. but that's where fine adjustments can be made. (including creating back pressure to halt flow from the nozzle.) andresby Andres - Mechanics
Re: General granule extruder design concepts - 17 years ago
yeah, a full production environment and materials will certainly be much different than an at home fabrication setup. the trouble for me in a quality job for a medium size manufacturer is that our suppliers would love to use whatever they can get cheaply, and they aren't about to submit an in depth report of the material's entire history. one thing i do plan on doing is leveraging my experienby Andres - Mechanics
Re: General granule extruder design concepts - 17 years ago
What i can say about regrind is from my professional life (corporate quality engineer) we tend to limit the regrind allowed for our suppliers (chinese and otherwise) to about 20%. it lets us ignore the heating cycle questions for older material since most of it is guaranteed new. as the regrind goes up on a material like ABS the part becomes more and more brittle, which as you can imagine tendsby Andres - Mechanics
Re: Recycling / reusing old machinery? - 17 years ago
There are a bunch of people in chicago putting together a "hacker space" where tools like this might be useful. they are a non-profit so maybe a donation like this could be tax-deductible. They are called Pumping station one. they don't have a location yet, but they are getting everything lined up pretty quickly. and there is also a google group. i'd say get in touch with one of the mainby Andres - Mechanics
Re: The RepRap*R* - 17 years ago
i have several, don't you? in all seriousness though, with a gravity fed hopper, and with pieces of a decent size (what i mentioned above was a quick example) it should be possible to isolate and feed one stick at a time, and like i mentioned above, if you keep the moving parts out of the heated zone, you should be able to avoid some of the issues with a granule extruder. andresby Andres - Plastic Extruder Working Group
Re: The RepRap*R* - 17 years ago
on thought about recycling plastic, it seems that getting it long and uniform like our 3mm filament is way tough and perhaps more work than it's worth. granual extruders are complicated and are difficult to keep from jamming what about melting plastic into bolts. (either recycled plastic,straight pellets, or more realistically for recycling, a mix. ) say 3 inches long and 5mm =/- .5mm. shoulby Andres - Plastic Extruder Working Group
Re: I'm looking to buy a RepRap near Chicago - 17 years ago
oh and of course a moderator could move this thread to the chicago forum if they care to. dresby Andres - For Sale
Re: I'm looking to buy a RepRap near Chicago - 17 years ago
There are actually quite a few of us in the area who have gotten together recently to pool our resources and build one (and then two and then three. but we are not there yet). if you wanted to finance one (meaning a bitsfrombytes or ponoko laser cut repstrap), we would all group together to assemble and trouble-shoot it. and in return we'd just ask to keep it long enough to make one or two setsby Andres - For Sale
Re: Sanguino blinky light build note - 17 years ago
bruce, don't sweat it, the board looks great, and i can't wait to see what a fully furnished reprap motherboard looks/works like with an SD card and lcd screen and buttons. Andresby Andres - Controllers
Re: Sanguino blinky light build note - 17 years ago
hey bruce, didn't know the specifics of your display, just thought i'd mention the similar display board. i can definitly see the benefits of that many buttons on top of the display while only interfacing on the i2c required pins. you dont happen to have a link to a blog post or some such on it, right now i can only think to search the forum for "bruce's LCD thing". thanks! andresby Andres - Controllers
Re: Electronics Course Suggestions - 17 years ago
you can also apply the mechanical analogy. voltage is like potential energy (perhaps stored in a spring or simply a hanging mass), resistance as friction (also dissipates energy as heat) and current as velocity. transformers as levers or gear ratios, etc. all the parallels are pretty interesting. andresby Andres - Controllers
Re: Sanguino pinout, red LED - 17 years ago
all, not sure if yall have seen this before, but it's from the guy who makes my favorite "flavor" of arduino clone, the "Really Bare Bones Board" or RBBB for short. It is basically a serial interface to most generic LCDs. only needs 3 lines (+5v, gnd, and 1 output) plus it has some great built in features such as custom characters and even a "big number" mode that automatically converts charaby Andres - Controllers
Re: Heating barrel length - 17 years ago
wow, i wasn't expecting to get such a dismissive response. feel free to ignore me if i bring this idea up again. and yes, i fully intend to look into if it will actually improve anything though isolated experimentation as well as normal reprap use once i have a baseline system. I'll present the data and people can discuss if the design adjustment has any merit. if it turns out to have no benefiby Andres - General
Re: Heating barrel length - 17 years ago
Forrest, I definitely agree that much of your documentation is absolutely great. i've certainly spent plenty of time going over any information i could find on your Tommelise. and it's all been wonderfully helpful. unfortunately some of the other instructions i've found skim over the heating element specifically. naturally aiming for something that works rather than works well. i just think thatby Andres - General
Re: Heating barrel length - 17 years ago
Jeremy, part of what i want to look into is "preheat", but it will really vary between materials. any given material to be used in the extruder would have a specific melting profile. basically at X temperature the material is at Y viscosity/deformable. at the nozzle, where most of your deformation occurs, you want the plastic as liquid as possible, in order to limit your pressure build up. of coby Andres - General
Re: Heating barrel length - 17 years ago
actually the reverse is true. the heating barrel may be any length, as long as the heated portion (at least the portion heated beyond the "yeilding" temp) only needs to be localized to where the plastic deforms, i.e. the nozzle. the longer heating barrel (note, not necessarily the element portion) may make it easier to isolate the heated part of the system. I've been thinking a bunch about the wby Andres - General
Re: Any word on the electronic kits comming back instock at RRRF? - 17 years ago
wait a minute though, why is the full kit $150, when by my maths, the kit would only cost $135.25 when each of the individual kits are bought separately. does it also come with cables or some other item that isn't listed? note: i'm not trying to be a conspiracy theorist or anything. i just don't need the arduino breakout shield (already bought the sanguino and sanguino breakout kits from RRRF.by Andres - Controllers
Re: Sanguino failing to run sketches - 17 years ago
haha. i had the same thing when i built up my sanguino yesterday. the sanguino page was even down for about 20 minutes (the exact 20 minutes when i was trying to look it up). of course i also had the issue at first that i forgot about the USB/EXT power switch was switched to EXT. though the green LED lit (at least dimly) when i hooked up my FTDI cable, it wouldn't transfer the sketch. ho hum.by Andres - Controllers
Re: Will the new Arduino work? - 17 years ago
I'm also waiting on the full electronics kit to come back into stock. i'll be using it with a sanguino, but i am certain it will work with the new Arduino Duemilanove. as i understand it, there are only slight differences with automatic power select (between usb and wall power) and a 500 mA fuse. functionally it would work as expected.by Andres - Controllers
Re: Chicago, IL - 17 years ago
hey all, i'm definitely interested in helping out with anything i can. i'd also like a reprap of my very own one day, so anything leading towards that end would be awesome. i've got a bunch of electro/mechanical/coding experience, and an ME degree from NU which i'm not using nearly enough. (in terms of modeling and fabbing stuff at least.) andres (at) healthytiger (.com)by Andres - Illinois, Chicago RepRap User Group