Which controller for an i3 based machine?

I hope this is the right place to park this post as it's not about one controller.... (yet!) :-D

I'm gathering parts to build an i3 based machine. I have several options for controllers. RAMPS, Saguinololu, Melzi and a mix of Arduino/CNC controller and other components.

So far with all the reading I've done of late I'm not sure any of the three main controllers I've mentioned are any better or worse than the others with the possible exception of the Sanginololu having an issue with the USB power while also being powered by 12V.

Is any one better than the other in this job?

Thanks. in advance.

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TW

Edited 1 time(s). Last edit at 01/08/2017 06:14PM by Twmaster.

Production quality matters more than names. I had luck with cheapo Chinese made RAMPS and arduino Mega combos, but there are bad ones out there ( and not a few it seems )
Buying a Melzi, you can expect they were test-run before shipped. As I've read stories about the test routine was still on the board when it arrived. ( Let's call it half a$$ed quality control )

I'd look for a board from reputable source, maybe with some upgraded parts ( Polyfuses and power connectors are biggest issues )

I suggest you choose between the following:

1. Arduino/RAMPS (8-bit electronics) + LCD/SD card reader. Configuring the firmware will be a pain because you have to edit the source code, rebuild and upload it every time you want to make a change (this applies to all 8-bit controller boards). Adjusting the motor current will be difficult because you have to set the voltage on tiny potentiometers while measuring the voltage and taking care not to short anything out. The driver modules will be fragile because of the inadequate cooling and you may blow a few if you set the motor currents too high (but they are quite cheap to replace). The 5V regulator on the Arduino may overheat. Depending on where you get your RAMPS board from, it may have poor build quality. However, Arduino/RAMPS is cheaper than just about anything else, powerful enough to run an i3, and is probably the most widely-used controller electronics for i3-type printers.

2. Duet WiFi (32-bit electronics). Configuring the firmware will be easier because it's done using a text file on the SD card. Setting motor currents will be a doddle because it's done in software. You will get a web interface that allows you to control the printer from your PC, tablet or smartphone. Your printer will be much quieter when moving because of the 256x microstepping. But it costs a lot more than Arduino/RAMPS.

There are some 8-bit controller boards that solve some of the issues of Arduino/RAMPS (e.g. RAMBO), but they don't cost much less than the Duet WiFi, and some of them cost even more. The Melzi is an old design now and has half the flash memory of Arduino/RAMPS, which is insufficient to run some firmware configurations.

Edited 4 time(s). Last edit at 01/09/2017 04:44PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you for the info. I'm not new to Arduino/AVR hacking so tweaking the code is not outside my comfort zone.

I was leaning toward the RAMPS setup but will look into the Duet WIFI setup.

I'm not trying to do this build on the cheap. Quite the opposite. (Although I am not going to spend "stupid" money getting there.) I'm attempting to build a rock solid quality machine.

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TW