Just a note here: PWM only limits the power you draw, and NOT the instantaneous current drawn. This is because PWM is digital (pulse width modulation) and is all about switching something on/off enough times to approximate the amount of "power" that you would get with a lower voltage. As this is the way the MOSFETs are expected to work in all our electronics circuitry (on/off), it's the only reaby Cefiar - Controllers
you mean? That's parallel. Red to red, blue to blue, green to green, black to black. Series is where you need to figure out the coils (eg: lets assume coil 1 = red and blue, coil 2 = green and black, just like the diagram seems to do) and then wiring red on the second motor to blue on the first, and black on the second to green on the first, then connecting the remaining wires to their standaby Cefiar - RAMPS Electronics
Nige: Not cheap, but Radio Parts Group sells a 23A, 13.8V PSU for $125 inc retail (atm). It's actually made by Manson (SPA8230G) and meets all the safety regs, etc. Has a tiny trimpot on the bottom that allows you to adjust the voltage a tiny bit. Should do at least 14.5V, maybe 15V. While a lot of people recommend the SMPS boxes that come out of china, the issue with these tends to be: 1. Qualby Cefiar - RAMPS Electronics
There is a small regulator on the Arduino that sounds like it has died, or the track that provides the input voltage to the regulator is broken. This regulator provides 5V if you give the Arduino 7V or more on either the VIN pin or the barrel jack. If the regulator works, then the track between the regulator input and the VIN pin could be damaged. The 5V runs the Arduino, parts of the stepper dby Cefiar - RAMPS Electronics
Biggest issue with generic PC power supplies is that manufacturers tend to over-state the current limits that they are capable of, even the big-names in the Gaming PC after-market have been known to do it. eg: A PSU might be capable of providing 20A on 12V, but only if it's drawing 1A on the 5V rail at the same time, and ONLY if it's on clean power. Server power supplies usually work regardlessby Cefiar - RAMPS Electronics
The L version means it handles logic level inputs (5V) . If you get the non-L version, it won't work reliably with the Arduino. If you can get either of those online, I'd say go for it.by Cefiar - RAMPS Electronics
As per that page, I can definitely recommend the FDP8870 or the IRLB8743's. I populated all my boards with them, and have never had an issue with a MOSFET since. Note: A heatsink on the heated bed output MOSFET is still a good idea (as is a fan pointing at your RAMPS board), but you will not need as large a heatsink with either of these MOSFETs, as compared to the standard STP55NF06L's. One of tby Cefiar - RAMPS Electronics
You're measuring a voltage. If you have no power (voltage) applied to your electronics, you won't be able to measure it.by Cefiar - RAMPS Electronics
When you're measuring D8, are you measuring from one pin to the other, or are you measuring from the positive pin to the ground on your RAMPS board/PSU? RAMPS provides 12V ALWAYS on one pin, and switches the connection on the ground (using a MOSFET). Not all MOSFETs are created equal, and the ones shipped by default on the RAMPS boards (STP55NF06L) really aren't good for high current loads. Ifby Cefiar - Controllers
Romels33: Those aren't the same sort of connectors. These are the same power connectors that were used on PATA (and earlier) hard drives, old 5.25" floppy drives, etc. The connectors that burning_chips is talking about I have ONLY ever seen on the end of cables, and never for mounting direct on a PCB (right angle or otherwise).by Cefiar - Controllers
If the bottom end of the PTFE has deformed at all, you'll get weird clogging issues as the flow is not smooth. Note: For changing between ABS and PLA, I find Laywoo-D3 wood filament good as a transition filament. You need at least a 0.4mm nozzle else the wood particles tend to clog it, but since you're using 0.5mm, it should work fine. It extrudes well at ABS and PLA temps, and it's easy to seeby Cefiar - Australia, Sydney RUG
No, @happygoluckyaussie, you're wrong here. The only thing fixed about the bed is it's RESISTANCE. They don't just draw a fixed current. So, V=I x R, and P=V x I, you get P = (V x V) / R Doubling the voltage increases the power four-fold. FWIW: I'm one of the early adopters that's been running 24V systems for ~4 years. Note: Yes, you can do it, but expect twice the current, which means if yoby Cefiar - RAMPS Electronics
IF your motor has an intermittent short, this could be tripping the driver. Note: If you do not cool the driver chips (eg: heatsink and/or fan), they will overheat if they're driving stepper motors that require any reasonable amount of current. As such, it's advisable to make sure the stepper drivers have a fan pointing at them at all times, and heatsinks stuck to each driver chip if at all possby Cefiar - Controllers
Have you completely disconnected your PSU from power and left it for like 10 minutes to discharge? I've seen some cheap PSU's do weird things after power issues, and only letting them completely discharge seems to help.by Cefiar - RAMPS Electronics
I would look at: 1. The resistance of your hot end. 2. What the "FETs" are actually labelled as.by Cefiar - RAMPS Electronics
The +12V side of RAMPS is always on. The side that is switched is the -ve side. If you measure +12V on one pin to ground when the heater is on, but don't measure 12V across the hot end (from one pin on D10 to the other) while on, you most likely have one of the following issues: 1. D10 connector is faulty. 2. FET for D10 is failing or failed. You may also check it's actually a FET, as some venby Cefiar - RAMPS Electronics
D1 and D2 are the most obvious things, but it's possible you may have burnt a track as well.by Cefiar - RAMPS Electronics
It's a math calculation to get those steps/mm. You can usually work this out from the pitch of the threads, number of teeth, etc. Those values are really "microsteps/mm" in most setups, as a single step pulse only advances the driver a single microstep (according to how many microsteps you've got configured using the jumpers - if that's full steps, then each pulse will be a full step). So thisby Cefiar - Controllers
What stepper drivers are you using? A498x or DRV882x drivers? The specific driver chips require different jumper settings for each specific microstepping mode, which are specific to the actual stepper chip. Are the stepper drivers set for 1/16th microsteps (this is what the jumper settings are for? Those numbers in Marlin are fairly specific for fairly standard setups for drivers set up for 1/16by Cefiar - Controllers
It's not just based on the stepper motors, but the mechanical properties of the machine, and the operating voltage and current you're driving the motors with. There is no hard and fast way to work this out purely with math, because there are a huge number of unknowns in the mechanical system. eg: Do you know how much friction the bearings/bushings on your axes require you to overcome? What sortby Cefiar - Controllers
Also before you do that: Have you confirmed the jumpers are installed under all the stepper drivers? If the drivers are doing full-steps, you will definitely be going too fast.by Cefiar - Controllers
Try slowing down the max acceleration and max speeds of the motors in Marlin (or whatever firmware you're using). The defaults in Marlin (and other firmware) are NOT necessarily suitable for all machines, so you need to tailor them to your machine/motors/etc. I would simply halve the values one at a time till you get reliable operation, then you can work your way higher toward the last value youby Cefiar - Controllers
The 2 pins on D8 are a constant +12V supply and the FET which switches to ground. If neither pin has 12V on it, then F2 (the 11A PTC fuse) has tripped. If you're going to swap it for another fuse, I'd recommend either a 10A or 15A auto fuse. In the meantime, make sure that F1 and F2 do not touch each other. These devices work by heat and when they touch the heat transfers from one to the otherby Cefiar - RAMPS Electronics
D2 could have been put in backwards, or it may have failed and gone short.by Cefiar - RAMPS Electronics
Are these beds the ones that do both 12V and 24V? Could the people complaining it's slow be hooking the 12V up to the 24V pins? Also, if you're using electronics that have a PTC fuse, you may find that at high currents the fuse is dropping a volt or so. You might want to look at replacing the PTC fuse with a standard in-line fuse. Measuring the voltage across the bed at the electronics end is aby Cefiar - Controllers
This sounds like your drivers are fried.by Cefiar - RAMPS Electronics
This seems to be that the 5V regulator on the Arduino Mega you have isn't capable of putting out the power needed to run everything. The backlight on most LCD's use a lot of current, which is probably the part causing the most issue. Note that when you power the Arduino Mega via USB, the regulator on the Arduino Mega is not used - it gets 5V direct from the USB port. If you have an ATX PSU, youby Cefiar - RAMPS Electronics
I personally prefer the Arctic Alumina 2-part adhesive, as it's non conductive and non-capacitive. While Arctic Silver 2-part adhesive is supposedly non conductive, it's not non-capacitive. It shouldn't make a huge amount of difference, but I like to be careful. Note: Make sure to clean the heatsink and the top of the chip. Isopropyl works well. You want no residue of tape or any grease (skin oby Cefiar - RAMPS Electronics
If you're feeding the board 12V, then you should get very close to that across the hotend. If you don't have a thermistor hooked up, or Marlin reads too low a temp on the thermistor, it will not turn the hotend on. Note: Disconnected and very low temp are pretty much the same thing for a thermistor, which is why the software disables the output if it's "too low". If the thermistor breaks or a wby Cefiar - RAMPS Electronics
Try reducing the maximum Z speed in your firmware. Usually it's just the software telling the machine to go too fast for your motors/mechanical setup. Since the firmware has too high a limit, it allows this figure. The firmware should limit the movement to the max speed your hardware can handle.by Cefiar - RAMPS Electronics