Auto level

Hi, I heard a lot about this auto level, how does it work exactly? Does it really improve the print quality? is it difficult to install? lastly, if I want to get one can someone recommend a link ? Thanks.

For it to work you need to have a IR probe which will measure distance between the hotend and the hot bed ,and store the distances so when you are printing ,you will always have a level bed(basicly you dont have to manualy level it) ,but in doing so it will reduce the life of your Z screw(if you use one and they are usualy not that expensive) becouse the it will move it up and down during the layer printing. as for the probe it depends on which printer you have . mybe something like this could work on any printer: [forums.reprap.org] but dont really know. It was made for Ormerod Printer

Heres an extreme example of auto bed leveling: [www.youtube.com]

Edited 3 time(s). Last edit at 04/08/2015 03:21PM by Darathy.

I am not familiar with IR probes. However I believe the first attempts at implementing probes in your printer simply involved an end stop attached via an arm to a servo mounted on your hotend platform. Issuing a command to your printer would rotate the arm from a horizontal position out of the way to a vertical position that put the end stop a few mm in height below the tip of your hotend and off to one side. You would then lower the platform down at various positions on your bed, triggering the end stop and giving you the Z-height of the probe at that position. Probe offsets would then be used to estimate he location of your hotend.

Today, I believe force sensitive resistors (FSR) are the most popular method of probing for delta style printers. You attach 1 sensor under the print surface of your printer near each of the 3 towers, connected to either a Trinket or a custom PCB (tridprinting.com or utlibots.com) designed for the system. The firmware on the PCB then waits for the resistance to change from anyone of the FSRs when the bed is tapped by the tip of the hotend. It is then connected as your Z-min endstop on your printer controller and triggers each time the board is tapped. The firmware also can signal LEDs for reference and will recalibrate itself after a few seconds should you add additional weight to your print surface.

For Cartesian printers, I believe the current status quo is inductive sensors for metal build plates. Think of it as a touchless version of the servo mounted end stop, only you no longer need the servo and the probe is intended to sit a mm or two above the tip of the hotend. Personally, I first saw this option on the metal Printrbot Simples, so I would start looking there for more information.

Ideally, you want to first learn to manually level your bed before switching to an autoleveling system. A well built and calibrated printer should not really need to be tweaked all that often, and the most common examples of when you would need an autoleveling function would be when you were swapping printer beds. For instance, if you were adding a heated bed underneath to print out some ABS. Though that example and my thought process might be more directed at delta style printers.

The only improvement autoleveling offers is eliminating the need for you to manually level the print bed before starting a print. If your printer is solidly built and doesn't need frequent releveling, autoleveling is sort of pointless.

Quote
the_digital_dentist
The only improvement autoleveling offers is eliminating the need for you to manually level the print bed before starting a print. If your printer is solidly built and doesn't need frequent releveling, autoleveling is sort of pointless.

Haha, so that's the lazy man's way out. So far I have been doing it by hand and my prints came out rather nicely, I am only wondering if it would offer a more accurate leveling to make my prints even better. Thank you all.

Edited 1 time(s). Last edit at 04/08/2015 07:55PM by rich1812.

Not so much the lazy man's way out as the cheap printer maker's way out. It is far cheaper to add an inductive sensor (about $5 at retail) than to build a solid printer.

One thing it would allow, and I expect to see it in a printer kit soon, is to eliminate bed level adjustment hardware altogether. If you have a working autolevel system, why bother including hardware to mechanically level the bed? That stuff costs a few cents and takes up space that could be used for increased build envelope...

I have made the autolevel on my prusa i3 hephestos, this works fine and im actually pretty satisfied, its set to print 0,1mm over the bed, and i feel the prints are a little more consistent and in great quality, however the travel speeds is a bug for me, you have to put it all the way down till the z-axis can keep up, something like 150mm/min in my situation.

But i would say go for it.

I use the servo engine and a microswitch way.

Quote
supernielsen
I have made the autolevel on my prusa i3 hephestos, this works fine and im actually pretty satisfied, its set to print 0,1mm over the bed, and i feel the prints are a little more consistent and in great quality, however the travel speeds is a bug for me, you have to put it all the way down till the z-axis can keep up, something like 150mm/min in my situation.

But i would say go for it.

I use the servo engine and a microswitch way.

Hi, Do you know if there is a kit of something like that available for the prusa i? I search eBay but found nothing. If noting, do you mind telling me what component are needed? A servo, probably Tower pro SG90? A microswitch, and ...? Thanks a lot.

I don't think there is a kit, but most people use a SG90 and a microswitch. If you do use the auto level some people just use the microswitch from the Z axis. Search thingiverse for a mount for your servo, some specific kits have mounts already designed. I'm in the process of doing this now, the mounts for the Folger Tech Prusa i3 don't work for me so I'm still looking for a better one, but I'll probably have to design one, they are simple enough.

I've installed auto bed levelling on my i3 and like it a lot! The way the z endstop adjustment worked on the original design was very unreliable resulting in first layers jammed onto the build plate or not adhering to it with all variations in between. ABL removes that hassle too, aside from properly levelling. The print now starts with a minimum of hassle ☺.

I've since changed to a bowden setup and completely redesigned the extruder. The wades extruder I adapted was too unstable, so there's no point in sharing the stl. See thingiverse for adaptations that work better for you, or design your own based on the wades design.

What you'll need:
- 9g servo motor
- servo motor arm to hold a microswitch
- microswitch, your current z endstop will do fine
- adapted extruder to hold the servo
- wiring to the ramps board, there is a special block of servo pins.
- changing the firmware to enable ABL, then decide which type, three point ABL, or ABL grid, I use the latter, marlin firmware
- an lc-display and settings in eeprom controlled by the menu is preferable. You can easily set the z height offset from nozzle.
- your build plate not only needs to be near level, but also very flat. Make sure that it is if you're using a metal build plate. You can measure the build plate flatness once the probe is installed using g28 then g29 in pronterface. It will output the deviations it measures and allows you to make mechanical adjustments, then do g28/g29 again etc. Once the deviation is below 0.1 mm, you can expect very consistend results. You can also expect to find weaknesses in the printer build too, but at least you've got the tools to measure it

There is an 5$ IR probe from pibot, I havent gotten the autolevel procedure under control but the probe seems to work.