Pretty much none of the vendors stick to any specific colour code for the wiring in their motors, and some vendors will even change the colour code on their motors from batch to batch. You will want to test your motors to see which coils are which, and wire them as appropriate. As long as you get both coils hooked up to the necessary outputs, their orientation doesn't matter too much, as you canby Cefiar - Controllers
If you're not using microstepping you will probably want to turn down all the acceleration values in the firmware, and get the drivers providing the right amount of torque. The standard acceleration values in Marlin are fairly aggressive for even for many normal printers at 16x microstepping. Note: If you don't use microsteps, then expect each "step" to be fairly large, and that your machine wilby Cefiar - RAMPS Electronics
The Arduino 5V supply will be powered from USB. That 5V supply is the same supply that runs all the 5V components on RAMPS. The only way around this is to unplug the ATX supply. Note: The USB port on your PC should handle the fact that the USB device already has it's own power. At least, the specs say stuff about it, so unless the PC doesn't follow the USB spec (and hey, some don't) then it shoby Cefiar - RAMPS Electronics
Actually RAMPS ties the grounds of both heatbed and main electronics inputs together, which is NOT ALWAYS 100% guaranteed to be safe or prudent. If you're running two PSU's, always check there is no voltage difference between the grounds before connecting them to a board.by Cefiar - Controllers
Which thermocouple boards are you using? RAMPS by default doesn't directly interface with thermocouples, so you need an interface board of some kind, and there is no set standard for them. Some use analog comms from the interface chip, and some use digital (and not all the digital ones use the same protocol).by Cefiar - RAMPS Electronics
@crdu - He's NOT using an ATX PSU, as per his first message. @APuckNut - 10Amp is plenty. Note that this is for the mains side, not the DC side. You will probably find that 5Amp is more than suitable to run the PSU. BTW: 5A at 110V = ~550W (minus some losses in the PSU) which is way more than your PSU should be drawing.by Cefiar - Controllers
It should be simple. But if you're not absolutely sure, get some advice from an electrician. Note: You can buy IEC sockets (computer/kettle cord connector - called IEC C14 connector) with switches and fuse holders in them for very little. You then wire this up to your PSU (make sure to get the Active/Neutral/Earth right), and just use a standard IEC cord to connect it to the wall.by Cefiar - Controllers
Dunno what the user did to break the BBcode parser, but this post has a broken HTML tag that causes most everything below the first image to go haywire:by Cefiar - Administration, Announcements, Policy
Your directory name has Unicode characters in it. This might be causing issues for perl.by Cefiar - Slic3r
If you're going to cut down the mains 240VAC down to 24VAC, you may as well just use a toroid transformer suited to the job (with a 10:1 winding ratio) to do it and avoid all this really unnecessary (and probably a hell of a lot more expensive than the toroid) switching gear to get it to switch with the precision you want. Also: Trying to force something to switch part through a cycle will leadby Cefiar - Controllers
No problem Tobben. Glad to help. FWIW: The only embarrassing mistakes are where you fail to learn from them and repeat them again.by Cefiar - Controllers
Well this is a RAMPS electronics forum, not an ultimaker electronics forum. You might want to ask on their forum or post in the general electronics forum, where others might see it.by Cefiar - RAMPS Electronics
There's a bunch of tables for EPCOS 100k thermistors, and that's because while they may all be made y EPCOS, and may all be 100k max resistance, various models have various beta curves. I've got a bunch of EPCOS 100k thermistors that work fine on table #7, and read too low when using table #1. I'd look through the other tables and see if any are "close" to what you've created. You might find thaby Cefiar - Controllers
Running the hotwire should be simple, assuming that the current it requires isn't too much for the MOSFETs and that it'll work at the voltage you want. eg: you might want to replace the heated bed MOSFET and use that output as it'll handle more current than say the one used for the extruder. The main thing will be getting the G-Code into a suitable format. FWIW: The Hackerspace I'm a member ofby Cefiar - RAMPS Electronics
RAMPS is a shield, but yes, there are "lots" of shields out there, while RAMPS is just a specific one.by Cefiar - RAMPS Electronics
Where did you get the thermistor that is in the hot end you have? If you can find the correct table for it (or calculate it) then you'll get much better results. You may find that the calibration is still off (eg: 240 when it's say 200) and that your temp readings are not as accurate as you'd like.by Cefiar - Controllers
Where did you get a "Ramps 1.5.7"? I ask because the wiki page only lists V1.4. I know of a 1.4.2 that was made by GRRF, but not of other versions.by Cefiar - RAMPS Electronics
Compare the voltage between the ground on the PSU and the ground on your laptop, without the Melzi connected to the laptop. If there's a significant difference, that could be your issue. I would suggest using a high-voltage AC scale first, then working downwards, then try DC. I would also recommend NOT touching the ground of both devices with anything but the probes till you're sure there isn'tby Cefiar - Controllers
The Mega needs replacing. You've fried the analog input for the hot end on the Mega board.by Cefiar - Controllers
Definitely a good thing. Q: Are we using mod_expires at all, and if not, could we consider setting it up? We can then improve the amount of client side caching that is done on things like images, javascript, css, etc, by forcing their cache expiry times to be longer than they currently are. This should reduce the amount of fetched traffic everywhere. eg:by Cefiar - Administration, Announcements, Policy
Correct. I've since edited that to be a bit more explicit, as it wasn't 100% clear. Hopefully it's now clearer.by Cefiar - RAMPS Electronics
It'll depend entirely on where you sourced your motors as to what colour wires you need to use. Unfortunately motor manufacturers do not use standard colour codes across all stepper motors. eg: I have a bunch of motors that don't have Black, but have Yellow instead, and the two coils in the motor aren't anywhere near paring shown in the diagram. Have a look at If you get stuck or confused, pby Cefiar - RAMPS Electronics
Should work. My local hackerspace did the same with a laser cutter after the default hardware bricked itself. It's now running a custom board but it was running RAMPS for a while. Biggest issues driving external stepper drivers is: 1. Logic level. 2. Signal pulse length out of Marlin (I think it's adjustable - external drivers tend to have optos in them, so you want to have longer pulses to acby Cefiar - RAMPS Electronics
The standard "Discussions" page in the wiki aren't really for stuff like the forums. They're for discussions about the content of the page, and getting it fixed. ie: They're aimed at editors, etc. IMO for us, having that tab named "Discussions" is therefore misleading. Perhaps they should be changed to "Page notes" or something that would be more meaningful? Or simply disabled altogether? Thaby Cefiar - Administration, Announcements, Policy
You might want to look at this: This stemmed from various people on the CCHS (HackMelbourne) Google Group setting one up. Here's a link to the announcement thread which has further discussion on it:by Cefiar - Australia, Melbourne RUG
The fan is actually an output (not an input). The fan is usually D9, but it's possible to change the pins to rearrange the outputs, or to use D9 for something else (eg: a second extruder). The standard RAMPS has a 5A PTC fuse that runs the Arduino Mega, the stepper motor drivers, and the D10 and D9 outputs. The standard RAMPS has a 11A PTC fuse that runs the D8 output. Note: Some variants of Rby Cefiar - RAMPS Electronics
The link Traumflug posted is the latest schematic that RepRap.org has. If there is a later one, you need to talk to the people who sold you your RUMBA board (or the people who designed RUMBA) to either supply you a later schematic, or to update the RepRap.org wiki with a later schematic.by Cefiar - Controllers
As A2 and Learner have sort of mentioned, if you're going to twist wires, you should: 1. Twist your motor wires (per coil) as well as your endstop wires. 2. Twist the endstop wires the opposite direction to your motor wires. This should reduce interference between the motors and endstops. Also, by twisting the motor wires "per coil" you keep the motor twisted pairs 'balanced". Unless someoneby Cefiar - Controllers
BTW: The IBM PSU I was referencing above is one of two that are actually in each server. They're both identical and you can run them independent easily. From what I understand, it's also possible to run them off completely different voltage levels (eg: one PSU @ 110V, the other @ 240V), as long as they support it. What you say is very true about those PSU's in regard to dirty power. Also, many (by Cefiar - RAMPS Electronics
Traumflug: I've had fuses blow in much less than a second when drawing more current than they're expected to carry, especially if they're fast-blow types. Sure, PTC fuses may take this (but then again, I'd not run them at 24V since some of the ones people put on boards aren't rated for use above 16V), and slow-blow fuses should be fine too, but whether a fast-blow fuse will go depends entirely oby Cefiar - Controllers