Unsurprising. The standard firmware has all sorts of limitations. It does work, which is the best thing that can be said for it. There is a reason that there's all sorts of alternative firmwares though. I'd recommend Teacup, mostly because that's the one that I'm familiar with. It has been run successfully on gen3 hardware, but I can't remember by whom. You'd have to ask for lots of help gettingby jgilmore - General
brnrd: It sounds like you're running into firmware limitations. Which firmware are you using?by jgilmore - General
Anything but Gen3! The nasty hack of driving the extruder stepper (the most critical torque-wise) with dual h-bridges instead of a proper current-chopping driver doesn't work very well. And that ignores the comms issues. If you already have it, it's not worth completely replacing though. Just buy another stepper driver board (pololu or whatever) and use that instead of the extruder's h-bridges.by jgilmore - General
Smaller is the way to go, rather than larger. There was a fascinating book I read awhile back, it was basically a taxonomy of self-replicators. An in-depth examination of the design space of self-replicating systems, and the various variables that define that design space. It looked at theoretical proposals as well as existing systems (biological). One of the interesting observations it madeby jgilmore - General
Speed Vs. Torque Vs. Resolution. A small stepper that can do 1000 steps/sec is the same relative speed/resolution as a larger stepper that can do 1000 steps/sec. How many steps per revolution a stepper is only determines what it's torque requirements will be and what sort of gearing is needed for that specific stepper. So the significant figures are "power per step" which is some mishmash of toby jgilmore - General
leviathan Wrote: ------------------------------------------------------- > Hello > Where can I checkout this ARM Cortex-M3 port of > the RepRap-firmware? > I'd like to port it to the LPC1343 which is > available much cheaper on "digikey.de" > > thx in advance > -lev Casainho says he has one, but.... He has reported that he's got a version of teacup working on the ARM, aby jgilmore - Firmware - experimental, borrowed, and future
Right. A quickly and with a lot of force does imply a lot of power. So any useful (i.e. cheaper but with same quality of printing) design would have to concentrate force in time - i.e. wind up and "click" into place. Which would imply a second motor and a solenoid. Which is getting far too complicated, time to give it up as a bad idea. I suppose it'll have to be left at "yes, it can be made chby jgilmore - General
nophead Wrote: ------------------------------------------------------- > I made an extruder with a tiny 24 stop motor and a > high ratio gearbox > > der.html. I used it recently to print a large > object, actually a 200mm diameter filament spool > using 0.8mm filament. The quality was not bad but > not as good as my other extruders because it can't > reverse as fast. Inby jgilmore - General
For getting a hole centered, there's nothing like turning the workpiece instead of the drill bit. I successfully made several combination nozzle & barrel pieces using nothing more than a hand drill and a c-clamp. Careful marking of depth was required, of course. But the basic procedure is to put the barrel in the drill, clamp the bit to the table, and have at it. If it vibrates when you toucby jgilmore - General
It seems more likely to me that the future is to go with an even higher gear ratio (like the 1:246 gearbox here) and a smaller motor, probably a cheap "tin-can" stepper with only 12 or 24 steps per revolution. That would be much lighter and much cheaper. The thing is that we're vastly under-utilizing the stepper motor in current designs. It's got way more speed than we need, it's a little lightby jgilmore - General
One possible mode of failure: If there's no inductive load, the current would spike quite quickly, and may defeat the overcurrent protection. I.E. the overcurrent mechanism might not be able to respond fast enough to prevent damage to the chip. Of course, that can't be the case here, because the oscilloscope has 4MOhm resistors, which would limit the current to a safe level anyway... In fact,by jgilmore - Controllers
Markus Amsler Wrote: ------------------------------------------------------- > That poses the question what belongs into the > firmware and what into the gcode generator. > IMHO the firmware should not modify the toolpath. It's actually in the g-code spec (such as there is one, I was looking at the documentation for EMC2) that the machine modifies the toolpath. Look at the "constant spby jgilmore - Firmware - experimental, borrowed, and future
Cefiar Wrote: ------------------------------------------------------- > With thermistors: > > 1. Make sure to measure the thermistor bias > resistor and feeling that in rather than trusting > the value on the actual resistor (eg. 4590 ohms or > 4780 ohms or whatever instead of assuming it's > 4.7k). This will correct a bit of skew in ANY > system. It may not be much at thby jgilmore - Firmware - experimental, borrowed, and future
I hadn't seen the Pololu a4988 breakout before, it's a new product. It'll work fine though. And it requires fewer external components. MS1 floats on the a4983 if it's not connected to anything. Not that we'd do that, as we'll be wanting some form of microstepping. I wish it has a pull up instead of a pull down. With pull down, you have a choice of full step or quarter step. If it had a pull upby jgilmore - Controllers
makergear Wrote: ------------------------------------------------------- > @Rooski We've got well over 500 hot ends in the > field. If you have questions, please stop by the > MakerGear IRC channel > (irc://freenode/makergearv2). I hang out there and > you can discuss products with MakerGear > customers. > > @Anthong Redbeard "I recommend AGAINST buying > anything thatby jgilmore - General
When you say "Teacup firmware successfully written to the motherboard" Did you do that using the arduino environment? If so, there's a handy-dandy little "serial monitor" button on the ide that will open up a little window. You can type into the line on top, and the results are displayed in the bottom part of the window. All you'll have to do is make sure the baud rate is correct. If you're usinby jgilmore - General Mendel Topics
Sublime: Good thought. It might work even better to connect a probe to an end of the X axis such that it's barely over the print bed. A probe connected to the print head itself might catch on the print. Unless, of course, you can make the print head itself the probe. Either electrically connected to the print bed (undesirable, as neither blue printers tape or kapton conduct electricity) or mechanby jgilmore - Firmware - experimental, borrowed, and future
Getting the steps/mm values from eeprom wouldn't be a huge performance hit. The DDA queue stuff is all in steps at this point anyway, so the conversion wouldn't be done at interrupt time. It would take a bit more code space, and some RAM to hold the variables. From what I understand, reading from EEPROM takes quite awhile. Maybe that was just flash though. Hrm.. Datasheet says 3.3ms typical writby jgilmore - Firmware - experimental, borrowed, and future
It sounds like you're trying to ask if you can "turn on" the extruder and never turn it off until the print is done. The short answer is no. There does appear to be some benefit to making the entire object from a single strand, but for several reasons we don't even try to do that. The main one is simplicity though. If you're doing a complex object with several "islands" as it grows, you'd have tby jgilmore - Plastic Extruder Working Group
This implies that the top and bottom of gears should have a fillet. Maybe the openscad involute gear script could be modified to do that automatically?by jgilmore - Skeinforge
aka47 Wrote: ------------------------------------------------------- > Interesting. > > Although we were getting the initialization > strings from the Firmware there was no response > thereafter. > > Having a thermistor LUT over a certain size (don't > know what the critical size is) appears to crash > the serial transmit and or firmware. > > So not really intuby jgilmore - Firmware - experimental, borrowed, and future
Actually, I think you're right, it was attached to an old thread. It was the one you mentioned in this post, under "some time back" Where you able to find my reply?by jgilmore - General
I replied to your other thread. Please don't double-post? (hrm... I don't know if "please don't double post" is an official policy, but I've seen a few people do it, and it can make the conversation very hard to follow. Maybe I should ask Sebastian?)by jgilmore - General
Is that one of the arduino version that don't officially support the sanguino, so you have to download the sanguino add-on? (check the sanguino website: sanguino.cc )by jgilmore - General
Wade Wrote: ------------------------------------------------------- > Actually, assuming you're limited by the head > speed of your Cartesian robot, the volumetric flow > of plastic through your extruder varies with the > square of the nozzle diameter (or your extruded > filament diameter, whichever you want to measure). I'm under the impression that nophead said it didn't reallyby jgilmore - General
You say you are using Gen3 electronics? Are you one of those unfortunate souls trying to drive the extruder stepper from the h -bridges on the extruder controller instead of from a proper stpper driver like the rest of the axises?by jgilmore - General
All of the metal in both designs will be at basically the same temp. So the molten plastic on the makerbot tip will extend up into the insulator, just like on the lincon electric tip. Oh, wait. nevermind. I see what you're saying. The makerbot tip has a PTFE tube inside the hot metal barrel, and you're saying that keeps the plastic from melting until it gets way down at the end. I wonder if thatby jgilmore - Reprappers
Should work just fine then. It's the right size, good enough torque, voltage low enough, and a correct number of wires.by jgilmore - Stepper Motors, Servo Motors, DC Motors
What size frame is it? Nema 17 or Nema 23 are the most common. How many wires does it have coming out of it? has all the specs you need to see if it'll work. Generally, if it's nema 17, has 4,6 or 8 wires, and has at least 19.4 oz/in of holding torque, you'll be fine. At least one motor with less torque than that has been used successfully, so even that is fine. The amp rating of your motor iby jgilmore - Stepper Motors, Servo Motors, DC Motors
skeinforge is for generating g-code from stl's or other shapes. It's designed to do one job, and do it well. It just generates g-code, and that's it. It does not send it to the machine, it barely has any way to view the gcode. OK, so it does have skieniso and skienview, but those are both pretty pathetic, really. Sufficient to tell if there's major prolems, I guess. for actually controlling youby jgilmore - RAMPS Electronics