Show all posts by user
Discuss here what makes your printer moving.
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
I reckon putting the feedback on the filament and not on the output shaft is more useful for accurate printing. But I am afraid about the additional delay that might cause to the loop (which may make it unstable). On the other hand, filament-grinding or no-filament conditions may be inferred from anomalous conditions of the loop (error higher than a threshold?). Ideally, filament path error shoby misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
No, I did not notice any relevant variation. However, I have not performed a dual-technology test (using a second optical encoder attached to the same shaft). So I might be fooled by my own perception. Recently I saw the project Mechaduino that does a big effort to compensate the errors of their magnetic encoder. Mecaduino I have tested drivers 6612 and L298N but I am waiting samples of thisby misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
I have used SOIC8 adapters from eBay Then press fit into square hole in a plastic part like thisby misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
Are you reading the I2C or the analog output? My experience is that measure is quite accurate. I use the recommended magnet, if not I have no experience of what might happen. Please note there are a couple of capacitors in the recommended schematic.by misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
Order 3 sample magnets from AMS website and you'll have them delivered in a couple of days for free.by misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
Take a look at the AS5601 too, as it provides regular AB encoder outputs too.by misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
But even in that case (only one axis moving) you'd need to store the current count of one axis before the next one starts to move, and do not forget restoring the original count for that other axis, and do all that on time ... I do not think multiplexing a single QEI would be very convenient, plus most of the 3D printing moves involve multiple axis.by misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
I like to have at least 400 counts per revolution, but resolution depends of the wheel's radius. I would aim at a filament length resolution of at least 0.1mm.by misan - General
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
I would favor the idea of doing the counting with the idler (or with an additional wheel just for that purpose). This way you measure actual filament feed. If the gear is eating the filament or the filament somehow slips then it is not counted though motor output shaft is moving. If measured, a too-high error signal can alert you of extruder trouble. That combined with current measurement can givby misan - General
Re: "Unnamed" plotter XY mechanism revisited - 8 years ago
It seems an interesting proposal. Belts can work in parallel planes, no belt crossings. You just need a fair amount of idlers :-)by misan - Mechanics
Re: Pololu geared DC motor 30g prototype extruder - 8 years ago
Quoterklauco ... I have no idea what mistake I did, but I burned 2 TB6612 drivers - their capacitors blew directly upon connecting 12V. Other people had the same experience. I guess it is due to defective/under-rated capacitors on some boards.by misan - General
Re: RepRap iTopie - A Prusa i3 evolution - Development discussion - 8 years ago
These corners in the red circles are cut this way so the part can sit flat on the hole it has to fit. CNC machining leaves round inside corners due to the diameter of the tool. These 45 degree cuts inside the corners take care of that limitation. That feature is usually taken care of by the CAM software that creates the machining code out of the DXF file, so it is not part of the design.by misan - General Mendel Topics
Re: Did anyone used linear hall sensors on BLDCs for position sensing? - 8 years ago
Hi Tarjeik, It is my understanding that this model is used for a piston pump . I assume the figure of 70mNm of maximum torque has to be close to these motors ability (but that is just a guess). What I have done is to set a magnetic encoder for them as that seems to be the most DIY friendly encoder. I did deal with Nidec USA and I definitely want to hear from you in case you get any data coby misan - Stepper Motors, Servo Motors, DC Motors
Re: Did anyone used linear hall sensors on BLDCs for position sensing? - 8 years ago
It is funny you ask me, because I have been asking to Nidec about specs and pricing without much luck. They do have humans there, and I talked to a nice guy but the info just never gets through. I even mentioned I am consulting for several companies that might consider using their motors but no matter that, I can't get any datasheet from manufacturer. So for now my advice is for you to look forby misan - Stepper Motors, Servo Motors, DC Motors
Re: Ayuda: Imposible mover motores - 8 years ago
Cuando se resetea la impresora al llegar al final de carrera es porque el final de carrera hace un cortocircuito entre +5V y masa. La solución es corregir la conexión, típicamente el final de carrera va entre masa y una entrada pero en la RAMPS hay tres pines para cada uno, el otro pin es +5V. Si un final de carrera queda cerrado cortocircuitando entre +5V y masa no hay manera que el Arduino coby misan - RepRap en Español
Re: Weird pulley pitch - 8 years ago
Thanks, I am afraid that is what I am going to do. Any source for GT2 pulleys with 1/8" bore?by misan - Mechanics
Weird pulley pitch - 8 years ago
I have motor with a built-in pulley like the one in the picture below: I thought it was MXL(0.08") but it is actually smaller pitch (maybe 0.04" or 1.2mm) and I cannot find suitable information about belts for that size. Does anyone have an idea on where to find a source for belts? Thanks, misanby misan - Mechanics
Re: Ayuda: Imposible mover motores - 8 years ago
La conexión tiene que ser entre C y uno de los otros (habitualmente NC). Un cable a NC y otro a NO no te sirve.by misan - RepRap en Español
Re: Motors don't move RAMPs 1.4 + Arduino Mega 2560 + Sprinter Kliment + Pronterface - 8 years ago
Marlin should work with your hardware if the test code works. But it needs to be configured properly. You need to adapt it to your needs and hardware Stepper motors hardly are to blame. They are quite durable and resilient.by misan - RAMPS Electronics
Re: Motors don't move RAMPs 1.4 + Arduino Mega 2560 + Sprinter Kliment + Pronterface - 8 years ago
Arduino IDE stepper motor library and examples have nothing to do with RAMPS and they are not expected to work with it.by misan - RAMPS Electronics
Re: modifying Prusa i3 for syringe pump - 8 years ago
You could use a stepper motor for the syringe pump replacing the one from the plastic extruder. You will need to calibrate the pump accordingly to your needs. For getting rid of temperature you can set minimum temperature limit to 0. There are other firmwares that are open source too.by misan - Firmware - mainstream and related support
Re: Ayuda: Imposible mover motores - 9 years ago
los finales de carrera están mal conectados y hacen un cortocircuito en la alimentación, por eso se desconecta el arduinoby misan - RepRap en Español
Re: Marlin CoreXY functionality? - 9 years ago
I am running Marlin for an H-bot CNC machine. It all is good but I have the impression the XY feedrates seem slower in COREXY mode (but Z axis feedrate looks good). Is it possible that due to the corexy kinematics the actual speeds are somehow reduced? (I do not see that problem when not using corexy on another machine).by misan - General
Re: Conectar cama caliente a 24V - 9 years ago
En ese caso estarías aplicando 24 V a la placa RAMPS, pero el polyfuse amarillo está especificado sólo para 16V máxmo, por lo que puede decidir arder. Por otra parte no dices si tienes otra fuente de 12V para alimentar el resto de la impresora, puesto que si le aplicas 24V a la otra entrada también vas a tener problemas. Si tienes una fuente de 12 V puedes emplearla para alimentar la entrada deby misan - RepRap en Español
Re: Vertical table Cnc - 9 years ago
Gravity pull can me countered with some counterweight, but that will add moving mass to your system. At any rate, if you look for CoreXZ it is basically a working implementation of your idea.by misan - CoreXY Machines
Re: BLDC design - 9 years ago
Thanks dc42 for chiming in. I have tried to keep things simple but I mostly agree with your points. Quotedc423) there is a maximum current (the rated current of the motor) that you can put through the windings without the motor overheating, because of the resistance of the windings. To allow more current, you have to make the motor bigger so that you can use thicker wire having lower resistance.by misan - Stepper Motors, Servo Motors, DC Motors
Re: Did anyone used linear hall sensors on BLDCs for position sensing? - 9 years ago
Since I asked the question first I have gone through several tests. Working together with a motor manufacturer some samples were created including an additional linear hall sensor to the usual three digital sensors used for commutation. I cannot recommend that setup, as there is always to be one part of each turn where the linear sensor signal will be non-monotonic which will create a difficult tby misan - Stepper Motors, Servo Motors, DC Motors
Re: BLDC design - 9 years ago
If I understand correctly, torque is proportional to coil current, so theoretically you could get the desired torque at any speed as far as you can supply the desired current to the windings. Unfortunately, there are two reasons that is not possible: 1) the cycle time a coils is energized is reduced as rotational speed increases, this makes it more difficult to achieve the desired coil current,by misan - Stepper Motors, Servo Motors, DC Motors
Re: Is the new Arduino Due compatible with RAMPS 1.4? - 9 years ago
Linuxcnc code seems to show that Linux and RT tasks are quite compatible. In fact some people are using Beagle Bone Black (that also includes a RTU) for controlling 3D printers or CNC machines while it can deal with TCP/IP and/or wifi at more than reasonable performance out of a single ARM processor. Of course all that does not have much to do with the original question on this thread :-)by misan - RAMPS Electronics