You're using the h-bridges on the extruder controller to drive your extruder stepper? That was always a nasy hack. Worked fine for some people, not so well for others. The only advantage is that you didn't have to buy additional hardware, the stuff you already had (designed to control a DC motor) would work. It will never work as well has a genuine current-chopping stepper controller, like the poby jgilmore - Controllers
brnrd Wrote: ------------------------------------------------------- > jgilmore Wrote: > -------------------------------------------------- > ----- > > Concern about the current-carrying capacity of > the > > #18 wires is important. Let's not catch things > on > > fire! > > > > But that wasn't what I was talking about. I > meant > > that a 20by jgilmore - Sanguino(lolu)
All the specs you've listed look good, and should work fine. There are two vital numbers missing though. What size are these steppers? 1.7" between bolts (indicating a nema 17 size) or 2.3" (indicating a nema 23 size) or what? How much torque are they rated at? They're almost certain to be strong enough for the axises. The extruder requires a little stronger motor, and a randomly selected nemaby jgilmore - Reprappers
I think that's a very standard thing to do. The prusa design has two Z steppers, and IIRC I've seen that advised as the way to connect them.by jgilmore - RAMPS Electronics
It's because it's a threaded rod driving it, instead of a belt. It moves 1/20" for each rotation of the stepper (if you're using 1/4-20 threaded rod) as compared to belt drive, which for a 8 toothed pulley moves the bed eight teeth worth. Since the belt is 5mm per tooth, that's 40mm. That's just off the top of my head, and I disclaim any responsibility for the correctness of any numbers in the pby jgilmore - General Mendel Topics
For a mechanical switch, you don't need a seperate pullup resistor. The atmel chip has one built in, which is activiated by writing a "1" to the pin as if it was an output. Might have to do that before you set it as an input, I can't remember. In any case, you should have only two wires going out to your switch, signal and ground. If you wire it to the NC side of the switch, then you won't haveby jgilmore - General Mendel Topics
micromark.com has all sorts of drill bits. IIRC, you want a #88 drill bit for 0.5mm. Remember when drilling with bits that small that they snap really easily. Or so I've heard. Somebody advised me to "just hold the bit in your fingers and spin the workpiece." On the theory that when the bit binds, it just spins in your fingers and no harm done. It's worked for me so far - six nozzles later I'veby jgilmore - General Mendel Topics
There isn't really much (if any) of a downside to .9 degree steppers. There is, however, an upside - greater accuracy. You can use microstepping settings to make a 1.8 degree stepper behave like a .9 degree stepper, but the accuracy of the stepper is always 1/2 of a real step. So a .9 degree stepper will always be more accurate.by jgilmore - Stepper Motors, Servo Motors, DC Motors
Probably tcl isn't installed. I've had the same problem, installing python on windows can be a nightmare. I wish I could remember what the solution was, but I think I can tell you that the problem isn't skienforge, it's part of the python install. Specifically that tcl/tk isn't installed correctly (if I'm remembering correctly). Try downloading an older version of the python all-in-one installerby jgilmore - Skeinforge
Sane Handling of Endstop values: There are three very different scenarios where an endstop is triggered during a regular DDA movement. First, your g-code generation may be screwed up royally, or just not set correctly for your machine. Basically, your machine is being told to move outside of its physical envelope. If that's the case, then the proposed solution (tracking "supposed" position viby jgilmore - Firmware - experimental, borrowed, and future
Traumflug Wrote: ------------------------------------------------------- > I see. We're expected to compensate for unreliable > endstops in software. Yes. Hardware is expensive to fix, and has to be fixed on every machine. Software is fixed once and fixed on every other machine for free. It's far cheaper and more reasonable to compensate for unreliable hardware as much as possible in softwby jgilmore - Firmware - experimental, borrowed, and future
It's not in the aggregators, so I figured I'd post a link here. It's SAE, the bottom is tapered, a few other changes from the "original" on Thingiverse. here I've got it extruding, but not yet connected to the cold end - so it's strictly manual at this point. See blog for more details.by jgilmore - Reprappers
If your filament is curling, you may have a non-round hole. Reaming the hole out to be round again may be needed. See Nophead's post on reboring the nozzleby jgilmore - Reprappers
5/16-18 would be a better pick for the Z. You really don't need the extra resolution, and the extra speed may come in handy. 5mm is .236", so .2" is almost certainly close enough. The toothed pulleys should seem to be less than that though, as the belt's length is measured (sorta) from the steel reinforcing wire that runs down its back. That wire is going to be held off of the pulley's surfaceby jgilmore - General Mendel Topics
Maybe submit your file to the openscad guys as a bug report? That's a really unreasonable compile render time.by jgilmore - General Mendel Topics
I have no idea. I'm working on fiveD_on_arduino stuff, mostly because the only chip I've been able to get to work is a 168. I'm not really following the development of any other firmwares.by jgilmore - Controllers
Which firmware (and revision of that firmware) are you using? Some firmwares will pause every time, as they do no buffering. The amount of time such a firmware will pause is dependent solely on baud rate. Others do an fair job of buffering, though they still have problems with serial communications while printing. Others still are quite good at multi-tasking, and have large buffers to boot. Soby jgilmore - Controllers
Architect, the #undef is there primarily to prevent the compiler from spitting a warning at us. If you #define something, and later #define it differently, the compiler will warn you about that - primarily because it's very seldom done, and it can lead to very hard-to-find bugs. If, on the other hand, you really *want* to redefine something, you can use #undef first to avoid the warning. So thatby jgilmore - Firmware - experimental, borrowed, and future
Andrew, if you're considering manufacturing some boards, you can probably get away with burning just the bootloader. Most people will have to configure, compile, and load the firmware themselves. With the bootloader in place, this can be done with nothing more than the usb cable that's used for controlling the reprap anyway.by jgilmore - Firmware - experimental, borrowed, and future
That looks really nice. Good to 450C, recommended for thermoplastics. Drying time is quite high (8-12 hours) so should be easy to work with. Costs $47 though. You could do a lot of extruder barrels with that, but very pricey for an individual.by jgilmore - Plastic Extruder Working Group
Exellent! I wanted to make sure you had your eyes wide open going into this thing, it stinks to be surprised by how difficult something is, our chances of getting something out of your project are much better if you have some idea what you're in for. I still recommend the open servo project, of course. What sort of rotation sensors are you planning on using? I notice that you've planned for oneby jgilmore - Wanted
No one has successfully used plain DC motors for axis positioning on a reprap. Even with position feedback, it takes PID control to get things accurate what with overshoot and such. It's not a simple problem, commercial servo controllers use dedicated hardware PID controllers. As a result they can actually get positioning accuracy smaller than the detents on the position sensor. There's the "openby jgilmore - Wanted
What motors are you using? Can you currently get it to move? How? Is there documentation of the protocol used to control the motors?by jgilmore - Wanted
The amazon one you linked is a lubricant with PTFE, not really PTFE-only coating. I don't think that would work out well. The second one is recommended for "Rubber guides, sliding doors, furniture hinges, small mechanism in office machines and sunroof seals" which sounds like just what we're looking for. I couldn't find a price though, you'd have to call you local dow corning distributor and askby jgilmore - Plastic Extruder Working Group
Architect Wrote: ------------------------------------------------------- > How are your sensors wired? mine are 0V -> 4.7k > resistor ->sig->100k thermistor->5V this causes > the resistance to increase as it gets hotter, not > decrease as it seems the case in the temp look up > charts. If anyone else has this set up, I put > together a spreadsheet based on the Steinhby jgilmore - Firmware - experimental, borrowed, and future
The reprap makes parts by squooshing a string of pastic on top of previously squooshed plastic. That string is nominally .5mm across and is squooshed to between .5mm and .3mm tall. Thus the surface finish if you look at it closely it's made of squooshed plastic strings. And you can't make details smaller than 1 piece of string. And the geared extruders (both Adrian's, Wade's, and herringbone dby jgilmore - General
That's a good idea in theory, in practice I'd contact the seller and give them a chance to fix it replace them first...by jgilmore - General Mendel Topics
dazed.dnc Wrote: ------------------------------------------------------- > jgilmore Wrote: > -------------------------------------------------- > ----- > > I thought that the "cannonical" way do adjust a > > temp table for more accuracy in the range > you're > > interested in was to generate a table with many > > more entries than you really need (say, 50) andby jgilmore - Reprappers
I thought that the "cannonical" way do adjust a temp table for more accuracy in the range you're interested in was to generate a table with many more entries than you really need (say, 50) and then delete most of them. You can delete the almost all of the ones that are low (say, <150C) and keep all of the entries in the region that you print in. You have to make sure and adjust the value of NUby jgilmore - Reprappers
So you have to get shorter pins for the microstep settings, and have to remove the stepper controller to change the setting? Also I see you've set it up for full-stepping by default. I'd rather have a pull-up resistor instead of pull-down on MS1 so the default is at half-step. Most people run at least half-stepping, I think. Also I notice that you put the signal pin in the center of the endstopby jgilmore - Sanguino(lolu)