I decided to build my own printer. Will use core xy cbot from open builds as its seems to be very scalable. My question would be
Can the Nema 17 handle 16" in the xy?
Is the rumba board the best option out there?
I appreciate any experts out there and your recommendations
Id really recommend going with a 32bit board like an AzteegX5 or SmoothieBoard
400mm should be OK for a nema17. Can also gear it.
I’d avoid the RUMBA at all costs.
@ThantiK is it that bad ? What are the main issues with the Rumba ?
Yep. We have a 14", 24" and 1 meter CoreXY with men’s 17 for X and y. Z is a different story depending on bed weight.
@Mark_Moissette_ckaos , every RUMBA board I’ve ever run across has been a huge pile of buggy shit. I don’t know what’s going wrong with their production, but there’s always a certain portion of the board that’s just borked.
@ThantiK thanks for the infos ! Off to 32 bit land then 
Will a printrboard work? I have one to spare? Are there any good guides someone would recommend for this type of build?
@Ariel_Yahni_UniKpty , it may take about more configuration to run a printrboard due to the AT90USB processor; also some of the source code for marlin may not have the right pins configured, and you may have to fool around with pins.h
@Ariel_Yahni_UniKpty , it’s pretty easy to get the printrboard reflashed. It would be a perfect donor board.
You can always the that Marlin junk behind and go repetier. The online configuration utility shows two printrboards defined.
Due+RADDS is a good option.
@James_Armstrong …hmm, marlin junk. Lets look at the commit logs: https://github.com/repetier/Repetier-Firmware/commits/master – Last commit was July 13th of this year. So since 2014 there have been a grand total of…wait for it…4 commits!
Marlin…on the other hand: https://github.com/MarlinFirmware/Marlin/commits/Release
Well, let’s just say it’s plain to see which one is more up to date on the latest.
They don’t really use the main branch for developing, 32 commits in the last month. . The 0.92 branch is where all the development is going on and has many commits. I know a few people that would like to debate that but I’ll just let it go. I’ll go with Ryan and say the duet or RADDS with RRF will be the next wave to jump on.
If you must use Marlin, make sure you have the watchdog enabled… It’s very dangerous to run with that disabled. It got turned commented out a few years ago because an Arduino IDE version was causing trouble with it, and never got turned back on in the main branches when the IDE problem was fixed. It’s off by default in all the online configurators and almost every fork. This is completely unacceptable with software PWM, because it can stick your heaters on 100% power of the firmware freezes. Only Ultimaker forks and very fresh downloads from the main fork consistently have it on. Seriously, go check now if you have it enabled, it’s embarrassingly unsafe to have no watchdog with software heater PWM.
Repetier is much more optimized for performance than Marlin, and has good support and a healthy level of activity. My only real gripe with it is that there’s no good delta auto-calibration option. But it beats the pants off Marlin in terms of max speeds, motion stuttering, etc. (Almost as good as Sailfish, heh.) I know a lot of people who do initial delta calibration in Marlin and then plug the auto-cal values into Repetier so their printer will run fast enough. That says something.
As of right now, the dc42 fork of RRF is seeming like a winner overall. Good attention to safety, 32bit processor, works on Due+RADDS and Duet, excellent delta auto-cal.
@ThantiK
Never had an issue with mine, and I haven’t exactly been nice to it.
Though, now you guys have me nervous
I never got Marlin working properly on my somewhat big printer. I agree with +Peter van der Walt , Repetier is boring, but reliable.
@Ryan_Carlyle , rofl – considering your comment, you should check out the Marlin commit made 20 days ago. Watchdog was recently reenabled as a default.