I've also considered using pottery techniques to create the heater barrel, using nichrome as the heating element (as well as using glasswork techniques on glass tubing). I haven't started looking at using either technique yet though, so I'm very much looking forward to your results on this! Microwave technique sounds interesting -- my own thoughts were to just put the work into small can, insulby BeagleFury - Plastic Extruder Working Group
Metal mesh seems good on weight and maybe cost -- how do you prevent risk for electrical shorts though? Maybe instead of metal, plastic mesh would be better, and thinking about that -- it's printable too.by BeagleFury - General Mendel Topics
nophead Wrote: > The faster the zigzag, the more it > shakes and things start to fall of the desk. I > haven't seen a faster one that shakes less or a > slow one that hits a resonance. I believe that if you limit jerk, you won't be able to create the vibrations -- the tighter and 'faster' the zig-zag, jerk limits won't allow acceration to even approach the maximum --- overall forceby BeagleFury - Polar Machines, SCARA, Robot Arms
nophead Wrote: ------------------------------------------------------- > The thing that makes big differences is hitting > the resonant frequency of the structure. With say > a zigzag motion on a Cartesian machine the > excitation force would be a square wave. Would you agree that, given a square wave, and a number of 'zigzag' frequences, that the chance of hitting a resonant frequenby BeagleFury - Polar Machines, SCARA, Robot Arms
nophead Wrote: ------------------------------------------------------- > I am not sure jerk has any meaning on a CNC > machine. You can change acceleration as fast as > you want as long as you don't exceed the > acceleration limits. I sort of hoped this would be the case. Does this mean that the RepRap type structures are mostly immune to the high frequency noise and vibration inducby BeagleFury - Polar Machines, SCARA, Robot Arms
The latest bits of code I've worked on include a GCode compiler, to compile cartesian oriented GCode into motions the RepolaRap configuration would be able to use. I'm still working on porting the acceleration limited motions to this code -- jerk limits still elude me -- but I thought the velocity limited curves look interesting for the simple GCode test I've been using -- it simulates a few layby BeagleFury - Polar Machines, SCARA, Robot Arms
I'm personally not quite ready to start evaluating heated beds, but is the point of discussion avoidance of purchasing heating elements (power resistors, nichrome wire, etc?) On that subject, graphite is generally an electrical conductor. It seems if you mounted a thin enough sheet onto an tough insulator (both electrical and thermal), it would be interesting to see if plastic would stick to itby BeagleFury - General
Lots of very interesting stuff there. Thanks.by BeagleFury - Polar Machines, SCARA, Robot Arms
It will be interesting to see if you're able to overcome the challenges I think you'll encounter. I look forward to reading about your progress.by BeagleFury - Polar Machines, SCARA, Robot Arms
jgilmore Wrote: ------------------------------------------------------- > If it WAS specified in volume, gcode still > wouldn't be portable between machines with a > different filament size because the filaments > would have to be closer together/farther apart. I understand the basis for choosing distance. I disagree the abstraction works as well as volume though. From a firmware /by BeagleFury - General
galaxyman7 Wrote: > About the gear on the base, how will I get a gear > that size accurately made? I thought you said that > if I made a gear, it would create inaccuracy. > Also, I still want to do away with stepper motors, > so that's why I want to change to threaded rod, > which creates much more accuracy. If you come up > with a design for the base that is cheap and can &by BeagleFury - Polar Machines, SCARA, Robot Arms
Thanks, Wade. Seems a bit counter intuitive to tie the E code to a distance, since tying it to volume would allow some gcode written for a 0.5mm machine to work on a machine of 0.6mm or 0.4mm, but I guess that's how things lay. I tried to find a page on the wiki for general filament information, couldn't find one, so created a page specific to discussion about filament. I also included in tablby BeagleFury - General
For X,Y, and Z, the units are metric (mm) or imperial (inch) based on G20/G21. What are the units for the number following E? I would expect this to be volume based? Is it square mm? or length of .5mm round extrudate, or length of 3mm feedstock, or something else? Anyone know? I couldn't tell for sure from the code I looked at.by BeagleFury - General
lond Wrote: ------------------------------------------------------- > Hi! > > I have upgraded my mill with a reprap controller > board. > When I test it with a simple job, I get strange > results, instead of a square I just get a simple > line divided in three parts. The result is > attached below. > > M3 > G21 (All units in mm) > G00 Z5.0000 > G00 X0.00by BeagleFury - General
galaxyman7 Wrote: ------------------------------------------------------- > Hey, I have thought about the gear design, and I > have decided it is too much trouble both to make > it work and to maintain accuracy. Therefore I have > changed the design to something much simpler, a > threaded rod driven arm. The way it works is > this: > There is a pivoting holder for the nut onby BeagleFury - Polar Machines, SCARA, Robot Arms
I took the "build-benchmark-v1-0.stl" file found in the distribution of RepRap I had on my machine (reprap-mendel-20100105), ran the java RepRap console, loaded it using the "Load STL" file, selected to send the GCodes to file, and clicked print (I did not change any preferences from the default.) It got thru the first 53 layers, and appears to have hung at layer 2 (2/55) It took ~5 minutes toby BeagleFury - General
LOL. I'm not sure why I'm still in this conversation, having said and raised the points I thought needed raising. But -- you're right -- broken stuff is more fun than boring unbroken stuff.. ..anyway, since you ask... > For small values of "works". You want us to "educate them and give them the information needed". How do we do so? 1. Clarify the legal 'licensing preference' position anby BeagleFury - Administration, Announcements, Policy
SebastienBailard Wrote: ------------------------------------------------------- > That's a really inelegant hack - a technological > solution to a social problem. I think we really > need to have a word with the FSF. Convincing them > they need to upgrade the GPL will be easier than > convincing our fellow users to start using another > license as well as the GPL? Hack? It wby BeagleFury - Administration, Announcements, Policy
SebastienBailard Wrote: ------------------------------------------------------- > Also, (and I still need to do my reading), are the > OHL and GPL compatible? Or are there self > contradictions when you run both? Yes for compatible... Actually, I think a bit the opposite for contridictions -- TAPR OHL in the introduction states it seeks only to cover those areas not covered by copyrighby BeagleFury - Administration, Announcements, Policy
jbayless Wrote: ------------------------------------------------------- > Really, the latest RepRap Host does circles? > That's good news for SpoolHead, because it would > save us a fair amount of effort if we can do > circular movements for wire printing. Actually, I believe it was the reprap 5D firmware I was looking at. I don't know about the host software supporting circles...by BeagleFury - General
nophead Wrote: ------------------------------------------------------- > Isn't the reason the GPL does not cover hardware > simple because the law does not allow it to? I.e. > the GPL is based on copyright law. The equivalent > for hardware is patents. So you can't simply dream > up a new licence unless the law is changed? Yes. GPL restrictions and licensing is based on copyrightby BeagleFury - Administration, Announcements, Policy
SebastienBailard Wrote: ------------------------------------------------------- > cost = price of materials + price of shipping + > delta, Right now, that "price of materials" includes about $200-$300 in parts that must be purchased (motors, rods, screws). This is the part that a company could sweep away with very innovating (and patentable) ideas. If it costs the company $60 to producby BeagleFury - Administration, Announcements, Policy
Triffid_Hunter Wrote: ------------------------------------------------------- > the thing with gcode is that it changes depending > on your machine and settings, eg layer thickness > and a lot of the other settings relating to > perimeters and things. > > For testing the gcode interpreter in my firmware, > I've been generating gcode with skeinforge > on-demand, and makingby BeagleFury - General
Well, you asked for a hypothetical situation; I'm not sure. I did raised this thread in response to an actual incident. In that particular case, it seems everyone is happy again, after a few initial angry words and hurt feelings... it seems an innocent mistake (And still, I do not believe the person selling the boards had any *legal* obligation to provide the design modifications as a conditionby BeagleFury - Administration, Announcements, Policy
SebastienBailard Wrote: ------------------------------------------------------- > ... Describe a hypothetical scenario wherein a big > corporation tries to "steal from us" (my words) > and the RepRap community's likely reaction? > > Remembering that each RepRap user-developer owns a > personal factory. Sure... Hypothetical situation: Big company collects and organizes alby BeagleFury - Administration, Announcements, Policy
galaxyman7 Wrote: > An accuracy of .1 mm can be attained using > multiple sensors that are offset from eachother > (quadrature encoders), but this would require many > pins on the microcontroller. The only other way is > to convert this parallel data to serial, giving > you binary output to the microcontroller. This > method basically divides the amount of lines per > incby BeagleFury - Polar Machines, SCARA, Robot Arms
I'm looking for something that could be considered a 'pass/fail' test for the GCODE compiler I'm working on for my polarbot configuration. Is there any "we use this model" or "we use this gcode file" to test an pass/fail test for executing GCODE to produce a specific model? It seems that setting up something like this, I.E, a set of STL files (to test STL -> GCode modules), a set of GCode fiby BeagleFury - General
galaxyman7 Wrote: > Anyways, I was also thinking that a simple > potentiometer could be used for the arm joint > motors, since they only rotate about 90 degrees > maximum. An RC time circuit or something better > could read the resistance and get the angle from > that. For the base motor, the gear is 12.7 cm, so > an optical encoder will work fine. I wonder whether you wouby BeagleFury - Polar Machines, SCARA, Robot Arms
Very cool. Some of the images are a tad blurry. I like how compact the whole thing is. galaxyman7 Wrote: > However, if > the optical encoder is placed on the large gear > that is attached to the arm, the gear tooth > accuracy will not matter, since the > microcontroller just moves the motor until it sees > another black line. What happens in between > doesn't matter veryby BeagleFury - Polar Machines, SCARA, Robot Arms
SebastienBailard Wrote: ------------------------------------------------------- > BeagleFury, your personal context is that of a > mathematician and RepRap fan, and you want to make > sure that our definitions and codes work and are > self-consistent. Also, you don't want to see a > "bad guy" behave unfairly by releasing a > closed-source RepRap knockoff. Yep. That pretty mucby BeagleFury - Administration, Announcements, Policy