How to build a printer for detailed work? ie parts needed

I was recently thinking about purchasing a MP Ultimate but I have been hearing bad things about the mother boards often failing along with not much information about what settings I would need to enter into a slicer. ( I would like to learn more about the slicer settings but most my xp has been with Makerbot desktop software and settings already selected for Simplify3d but this is a post for another time)

I'm currently building a MP CNC, which can be used as a 3d printer. I really like the frame and was considering using it to make a 3d printer. I was curious what parts do I need to focus on to make sure the printer I build is capable of the same the level of accuracy. I;ve been told that it is primarily, in order of importance, the threaded rod/lead rod, drivers and then motor.

What kind of parts would I need to achieve the same level of accuracy? Which parts have the largest impact on your printer's level of accuracy? If you could provide me links or terms to specifically google the would be greatly appreciated.

Thanks in advance for any help or advice offered.

The same level of accuracy as what?

Accuracy depends on many things.
Stiffness of the frame - no distortion or sagging, no strong resonances
Mechanical precision - of rails/rods, bearings/bushings, threads and nuts - this includes smootheness of movement.
Precision of motors - full steps/1, precision of gearing
Precision of electronics - Quality of microstepping
Precision and quality of the hotend
Precision and quality of the filament
and last but by far not least the quality of the software for slicing and firmware.

All this is of no use if you are not capable of doing an accurate adjustment of all mechancial and electronic components.

To sum it up, there are dozens of factors that ultimately determine the precision and quality of a print, there are no single issues or parts that could turn a machine into a high precision instrument, but many issues that could turn an otherwise good machine into a pos if you do them wrong.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Yeah what he said.. but my two pennies worth:

If you want to print high precision then you need small nozzles and a lot of patience. Also consider using metal components and not plastic (injection moulded plastic is better than 3d printed, but its not comparable to metal).
Also a small printer is easier to achieve high precision with than a large one, errors multiply as the size increases, and not in a linear fashion.
There is a limit to FDM printing and what it can achieve, if you really need high precision then even a modest SLA machine will beat a high end FDM machine in terms of fidelity of highly detailed objects.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

MPCNC design will make a pretty slow 3d printer. Based on my little experience and a lot of research I'd recommend corexy or delta (using rails) based designs.

Edited 1 time(s). Last edit at 04/17/2017 03:26PM by newbob.

Quote
newbob
MPCNC design will make a pretty slow 3d printer. Based on my little experience and a lot of research I'd recommend corexy or delta (using rails) based designs.

Forget about deltas if you want accuracy. Or put it this way, the time you spend on a delta to get it accurate to within 0.1mm all over the bed would get to to 0.05 on a cartesian style machine. (I have 2 deltas) They are fast, the bed doesn't move, both of which are excellent properties. However there are loads more variables on a delta compared to a cartesian. Errors are non-linear, so if you get it right for a 50mm cube in the middle of your bed, it might not be right when you print at the edge of the bed. You can also get non linear visual artefacts due to stepper motor inaccuracies.

Forget about cartesians with moving beds in the X or Y plane, if the bed moves, it must be just in Z. Also lead screws / ball screws can introduce Z wobble unless you REALLY know what you're doing. A belt drive on Z seems to give fewer artefacts, you just need to make sure it doesn't fall down when the power goes off.

Forget about RAMPS / Arduino MEGA if you want really good results, I've pushed mine as far as it can go, and there are still visual artefacts due to segments.
Forget about Smoothie, it can't even do pressure advance (although I'm working on this at the moment).

My suggestion would be for an all metal CoreXY, using 0.9 degree steppers, running a Duet Ethernet/Wifi, remote extruder (Flex3Drive / Zesty Nimble), high quality linear rails, an enclosure that ideally you can control the temperature of, and a good cooling system (investigate Berd-Air).


Good luck with your search.

Edited 1 time(s). Last edit at 04/18/2017 12:29AM by nebbian.