What sort of hardware is required for bed leveling?
Two distinct types of bed leveling exist: hardware and software.
Software leveling means the controller software makes an analysis of the existing bed as it is and alters the print instructions to compensate for any flaws.
Hardware leveling requires the user to make mechanical adjustments to make the nozzle and the bed co-planar.
As your question does not specify which type of leveling you are inquiring about, I will cover both.
Software leveling requires a probe of some kind to measure different points on the bed. MatterControl's Automatic Bed Leveling feature is considered software leveling, and it makes use of the nozzle. The user places a piece of paper under the nozzle as it is lowered to the bed. When there is slight resistance to moving the paper, the probe is complete at that point. The process is continued at other points on the bed until a reliable model of the bed can be acquired. For Cartesian printers, three points is usually enough. For delta printers, 7- or 13-point calibration is more appropriate. Other printers with built-in leveling probes make use of a laser or force-sensitive resistors which probe the bed automatically instead of having the user do it manually.
Hardware leveling requires that the bed be able to be adjusted using thumb or regular screws. They are usually spring-loaded to keep tension, and will stay at the height at which they are set pretty reliably. A common method for leveling the bed is to use a piece of paper as described in the software leveling section, manually moving the nozzle over different points and adjusting the bed up or down until it is perfectly level. The whole idea is to make sure the nozzle moves on the same X and Y plane as the bed.
For more information, check out our article about bed leveling: http://wiki.mattercontrol.com/Bed_Leveling
EDIT: Link to article
so for auto leveling I don't need extra hardware.
how would it get over a problem I have had in the past, on getting all the corners the same level, I have found that at the center of the plate it is to tight [ this is just hypothetical ] as I have cured the problem, how would Matter Control handle this situation.
If the corners are level and the center of the bed is too high (assuming that's what you mean by "tight"), then it sounds like the bed is warped. In that case, MatterControl can't compensate; it requires a flat bed.
thanks Ryan that's what I thought. couple of other questions on this subject, does this also work with touch.
One this that puzzles me, the z switch, I assume this is the stop end, you say that it should be at the top, would this not cause the nozzle to keep pushing on the bed, or does the control software take this in consideration.
Actually, MatterControl's 7 and 13 point leveling was made to handle non-planar beds. We tested this on an old Type A machine with a severely warped acrylic bed (it was basically U shaped).
It does work on the Touch as well.
Thanks for all the help appreciated.
> One this that puzzles me, the z switch, I assume this is the stop end, you say that it should be at the top, would this not cause the nozzle to keep pushing on the bed, or does the control software take this in consideration.
If I understand correctly it sounds like you're asking if the Z limiting end stop plays a part in the bed leveling.
If the Z end stop switch is at the top of the printer, then the Z height (typically set in firmware or EEPROM) counts the steps from the switch to the bed. If you're using software leveling, the Z height can be longer than the actual print height since the leveling will keep the nozzle from digging into the bed.
If the Z end stop switch is at the bottom (or there are both), there should be an adjustable screw you can adjust so the Z switch does not trigger until just below the proper nozzle height so software leveling can still be used.
Yes, that's what I wanted to know, thanks Ryan