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Discuss any sort of mechanical stuff here: positioning systems, gears, extruding methods, etc.
Re: mcwire cartbot....drilling holes - 15 years ago
Thanks for all your help. I was able to get my rails mounted. Documentation is here:by robacarp - Reprappers
Re: mcwire cartbot....drilling holes - 15 years ago
yea, I have a center punch...the problem is not the drill bit walking, it is my inability to locate the same center twice. I tried using the printout sticker that is on the mcwire howto page, but I couldn't even get close with that thing. I drew up my own full-page sized paper sticker and that got me a lot closer. I think that my screws are setting at about 2by robacarp - Reprappers
mcwire cartbot....drilling holes - 15 years ago
I am working towards building a mcwire cartbot and I am having a terrible time drilling the holes in the iron pipe. The physical drilling goes well, but my holes are off center. I can't for the life of me seem to figure out a way to get two holes in the center of the pipe. Anybody have any ideas?by robacarp - Reprappers
Re: SNAP library question - 16 years ago
...the same code snippet exists in void SNAP::receiveByte, under case SNAP_readingDataPassby robacarp - RepRap Host
SNAP library question - 16 years ago
I have been reading through the SNAP library that is included in the reprap arduino firmware package and I found these two identical methods: void SNAP::receiveError() { //init our rx values this->rxState = SNAP_idle; this->rxFlags = 0; this->rxHDB1 = 0; this->rxHDB2 = 0; this->rxLength = 0; this->rxDestAddress = 0; this->rxSourceAddress = 0; this->rxCRC = 0; thby robacarp - RepRap Host
Re: I've made some scrappy looking hollow squares! - 16 years ago
QuoteForrest You set a powerful example, Nop! It is true...both of you do. I wanted to jump in headfirst into a darwin but I am repstrapping now. First because I want my repstrap to be able to hold and use a dremel for milling too. And second because at the time I was expecting to be able to come by a set of darwin parts from a member with a working darwin. C'est la vie. Now I'll be ableby robacarp - Reprappers
Re: an idea: another extruder barrel heater - 16 years ago
Do you think that a 50-60Hz would inductively heat a piece of steel tubing to the 250Degree melting range of our plastics? From what I can tell, it needs to be down around 8-10Volts, which can be done easy enough, and that would also step up the Amperage quite a bit. I can't reason how to calculate how much that would pull the Amperage up though...I guess you'd need the resistance of the coilby robacarp - Mechanics
Re: OSX 10.5 Software startup issues - 16 years ago
QuoteJohn Gilmore[...]without all the JVM headaches So as to avoid defacing the public forums, my rant on the subject of Java is posted here: Edit: I am using the Gen 2 electronics...a Sanguino to be specific.by robacarp - RepRap Host
Re: Accuracy of the cartesian bot - 16 years ago
QuoteForrest HiggsGiven that extruded filament currently has a 0.5 mm^2 cross-section (0.5 mm diameter orifice) Does that not translate to the width of the extrusion being 0.5mm?by robacarp - Mechanics
Re: Accuracy of the cartesian bot - 16 years ago
So, removing the steppers from the equation, what steps have you taken to maximize your accuracy? I'd think backlash is a concern which, from what I can tell, is not addressed by the McWire cartbot. Is it something addressed by others repstraps? Does darwin address it on the X-Y plane? What about precision threads? Ball screws are ridiculously overpriced: I am not entirely sure but I get theby robacarp - Mechanics
Re: OSX 10.5 Software startup issues - 16 years ago
peteredworthy- Thanks for the script. I'd just about given up on this thread, and besides that I have been busy with the stepper motors I just got in the mail. It does seem to change the way the program runs. Marius- Sweet...thanks. Unfortunately Apple is not doing a 32-bit JVM 1.6...ever. I am now, thanks to peteredworthy's pointer, getting some rxtx errors. I'll look at the mailing listby robacarp - RepRap Host
Re: I got steppers...I need help adjusting the current on the SMC board - 16 years ago
Okay. I am sorry but now I am totally lost. Some questions: 1) Why are R1 and R2 the sense resistors? I see that they are hooked up to the sense circuits, and if that is what make it then so be it. 2) If R1 and R2 are the sense resistors, how does the test circuit (labeled 'stepper adjust') measure the current or voltage across those? Is it being faked by the rest of the 'stepper adjust' cirby robacarp - Controllers
Re: I got steppers...I need help adjusting the current on the SMC board - 16 years ago
Hey thanks nophead! I was just sitting down to calculate that target voltage value and I realized the error in my math above: QuoteThe coil resistance is measured @ 3.0Ohms. The packaging says they are made for 4V. I=E/R=1.3Amps which makes sense because they are labeled 1.4Amps. Now I figure I want to back these off about 30% to keep them from running so hot. .3 * 1.3A is 0.4Amps. That bold sby robacarp - Controllers
I got steppers...I need help adjusting the current on the SMC board - 16 years ago
I got my stepper motors super cheap on ebay. They work just fine as far as I can tell. I wired them up to the Stepper Motor Controller board and they all spin. I pull the Full step jumper off and they spin slower...cool! I didn't leave the controller on any one motor for long because I haven't adjusted the trimpot to cap to the correct Amperage. I only know *basic* electronics theory butby robacarp - Controllers
Re: an idea: another extruder barrel heater - 16 years ago
Quotekorndogas far as i know, induction heating needs AC power. Yes it does. From what I can tell, we would need to be able to control a ~100Hz, maybe 12v, but high current (any ideas?) waveform. I have no idea how to go about controlling AC power...but I bet that if some EE took apart my soldering iron they could tell me. My electronics experience and knowledge is...lacking. It does temperaby robacarp - Mechanics
Re: Sanguino build notes - 16 years ago
Bill- I am no Arduino expert, but I suspect that you are getting errors because your arduino ide is to generations old. I'd try updating the IDE to the newest version, arduino0012.by robacarp - Controllers
Re: an idea: another extruder barrel heater - 16 years ago
QuoteViktorwith an accuracy of some 1/100by robacarp - Mechanics
an idea: another extruder barrel heater - 16 years ago
While soldering a motor controller for my reprap I had a thought about the extruder/nichrome problems that I have read about some people having. My iron has exchangeable tips and heats them with an inductive heater. It does so really fast and to very high temperatures. Can we replace the nichrome wire with an inductive heater? This would, as far as I can tell, not require as much current as mby robacarp - Mechanics
Re: Accuracy of the cartesian bot - 16 years ago
Forrest Higgs Wrote: ------------------------------------------------------- > [...] I don't think I'm too far off the > 0.1 mm resolution of my coarsest resolution > stepper (Y-axis). Do you find that 0.1mm resolution is enough? I ask because nophead's commercial table has, iirc, 0.001mm resolution. I'll be honest though, I've not really read any other builder's blogs.by robacarp - Mechanics
Accuracy of the cartesian bot - 16 years ago
In reading through some of the builders blogs I have been curious how to maximize the positioning accuracy of my to be built cartesian bot. The reason I have been thinking about accuracy is due to reading through Nophead's blog: his pieces look amazing, but he started with a commercial table and microstepping positioning system (not that he cheated, just that I am really hoping to build my tableby robacarp - Mechanics
OSX 10.5: Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: javax/swing/GroupLayout$Group - 16 years ago
Hi, I am attempting to run the reprap 20080523 software on my intel mac and am still having some errors. My original problem was one of not having the correct serial port indicated by the configuration file and is posted here: I have done some investigating around the forum and find that others are having similar problems, but their solutions did not remedy my particular issue. I am now gettby robacarp - RepRap Host
Re: My first Arduino powered drawing - 16 years ago
The good news is that your math is correct. The bad news is that the sin() function is where the non-linearity exists. More good news: After watching your second video again, I find myself wondering if the non-linear nature of the design is a moot point due to the short arc that your arm swings. Without doing some experiments of my own, I couldn't even say. The non-linearity that I was speakiby robacarp - Reprappers
rrrf.org store out of stepper motors - 16 years ago
I see that the rrrf.org store is backordered on stepper motors. Is this really the case? Is there a reason for the backorder? Should I go somewhere else or just place my order for steppers with rrrf.org store? So many questions, so little time...by robacarp - Reprappers
Re: My first Arduino powered drawing - 16 years ago
Dan- I like it. I was wondering what that swinging arm was doing on top (your positioning system). I thought that I would throw out there that you could improve your resolution on your positioning system with a set of gears and a multi-turn pot. If you have your lever spin a gear which would double or triple the amount of rotation before spinning your potentiometer you should be able to get gby robacarp - Reprappers
Re: My reprap begins! - 16 years ago
> let the electrical utility people get their hands on your pocketbook True...but they have smaller hands, and, if need be, I can easier generate (eg. solar, wind, water) my own electricity than my own gas. Robertby robacarp - Reprappers
Re: OSX 10.5 Software startup issues - 16 years ago
That is the package that was installed yesterday over software update and again later by me. Thanks...good try thoughby robacarp - RepRap Host
Re: OSX 10.5 Software startup issues - 16 years ago
Okay! making progress .... some anyways. fool: Thanks for your reply and the link...and I now see the "search within last 30 days" dropdown -- an odd restriction to be the default. Some poking around and the OS X "reprap.properties" file is located at ~/.reprap/reprap.properties . In order to find the correct port name I plugged in my Arduino board and ran `ls /dev | grep tty.u`, removed theby robacarp - RepRap Host
Re: My reprap begins! - 16 years ago
Kitep- My EV conversion project is on hold: I'm saving money, doing research, and building tools (hence reprap...). The idea of converting a car to be electric is not (primarily) a method of saving money...its an act of establishing independence. Thanks for reading!by robacarp - Reprappers
OSX 10.5 Software startup issues - 16 years ago
Hi! I am trying to install the reprap host software on my Intel mac and am apparently having some difficulty. I followed the directions and I am getting the following error message in a popup window. If I start the program from a terminal it also comes out there, along with a stack dump. I can post the stack dump if you want. ---------- Could not connect at /dev/ttyS0. Check to make sureby robacarp - RepRap Host
My reprap begins! - 16 years ago
Hello all reprapers! My name is Robert and I am a hopeful reprap hacker. I thought I would post a thread in this here fancy forum to indicate the start of my project. Just today I received a stack of static shielding zip-lock bags filled with parts for my reprap: the whole electronics kit in one tiny express mailer. I'll be keeping my updates mainly on website:by robacarp - Reprappers