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More decimals for layer height.
Posted: Sat Dec 24, 2016 6:29 pm
by emperornero
Looking for more than 4 for those that want more z-step accuracy.
My MP Select Mini has layer heights of .04375 and .0875 and .13125 etc but unfortunately the slicer only allows for .0437 and .1312 for those layer heights preventing me from using those layer heights for cleaner prints.
Other printers may have this problem as well, but I only have 1 at the moment so I'm not sure.
Re: More decimals for layer height.
Posted: Sun Dec 25, 2016 9:16 pm
by NeilRG
You are requesting accuracy that exceeds most machines precision. Adding 'decimal places ' is meaningless if the lead screw pitch , microstep value the electronics is capable of, the minimum step of the motor itself can not deliver, and if you have a machine with dual z axis motors, trying to accurately resolve such small incements will no doubt drive you crazy .
Re: More decimals for layer height.
Posted: Mon Dec 26, 2016 9:12 am
by mroek
@NeilRG: I don't think this is about absolute accuracy, the problem is to be able to set the layer height so that it exacly matches the natural machine properties. Some machines can handle this better than others, but in any case it is always better if the number add up without any remainders.
This article explains it:
https://www.evernote.com/shard/s211/sh/ ... dcdd2d687e
Scroll down to the Z-ribbing chapter to read about it (or read the whole article, by all means, it is well written).
Re: More decimals for layer height.
Posted: Mon Dec 26, 2016 11:56 am
by arhi
it's not only height, there's a whole bunch of places where s3d is cutting the decimals
... and while most of the cheap printers run 8bit boards that can't handle high precision there are 32bit boards available that could use the higher precision in the code (the difference actually noticeable quite often)
viewtopic.php?f=23&t=6291&p=27296&hilit=decimal#p27296
Re: More decimals for layer height.
Posted: Mon Dec 26, 2016 12:02 pm
by NeilRG
mroek wrote:@NeilRG: I don't think this is about absolute accuracy, the problem is to be able to set the layer height so that it exacly matches the natural machine properties. Some machines can handle this better than others, but in any case it is always better if the number add up without any remainders.
This article explains it:
Scroll down to the Z-ribbing chapter to read about it (or read the whole article, by all means, it is well written).
You are conflating accuracy with precision. The limiting factors i cited remain and are confirmed by the excellent article you cite. You must consider the OVERALL resolution the system is capable of.
Best,
Neil