Metal plus experience & questions

[i-make-robots]

Hello, Printrbot & co.

I've been tasked with making a user's guide for students at a local HS. they have two Metal Plus printers. I'm hoping you can answer a few questions and take note of my experience so far. I have built at least one of every generation of Prusa printer, up to the MK2S.

Right away, I was surprised that finding information on the metal plus is very hard on your site - the model no longer appears in your top level menus, and only comes up in a few google searches.
I downloaded Cura 15.04.2 and installed without issue.

the printrbot firmware page was very confusing. I tried to click the image of the app thinking it was the app because I'm stupid. Then I tried top click the download link and was offered the Mac version. I'm on Windows, so... I'm sorry, this needs work to be more me-proof.

The Cura app has a bed leveling routine that doesn't appear to be made for the metal plus. It drives the nozzle down to all four corners with total disregard for the inductive probe. In the right hand corners the probe is not over the bed so it serves no use! Adjusting the inductive probe closer to the bed and re-running does not bring the nozzle up to prevent contact with the bed.

The message on screen in the Cura leveling wizard says to adjust the screws on each corner of the bed... which would make sense if this were a spring loaded system from 2014. As this is an all aluminum chassis with no flex, I'm not sure what to do here. The NEMA17 motors for the Z axis are locked at this stage, so I cannot easily adjust the z height to confirm level movement across the bed. There is no live-z adjust as in the Prusa MK2S

The Cura leveling wizard has buttons for Up and Down that appear to drive in the opposite direction - clicking up brings the nozzle closer to the bed. Is this intended?
By default the printer moves to the center of the bed, approximately 1500s microns above the bed. After adjusting (in 200 micro level steps!) to a short height above the b

Please: At what baud rate is this printer running? I tried to connect to it with Arduino and received no response at any baud rate. Which is atypical! I also see that Pronterface and Cura both seem to be actively hiding the connection settings.

Please: What method do you recommend to adjust the nozzle height relative to the bed? My first layer is obviously too high and the print does not stick to the bed.

PS: posting a link to printrbot's main website gets me "Your post looks too spamy for a new user, please remove off-site URLs." lol wut?

[i-make-robots]

Subsequent to previous post, I have attempted to adjust the probe height to see if it changes the print at all. It does, which is good. Tweaking to perfect the settings is challenging - getting a 1/4 turn from a pair of nuts without also turning the probe... I have the nozzle at ~100 microns from the bed, same as I would for a prusa (just barely get a piece of paper under the nozzle).

Cleaned the kapton surface with rubbing alcohol, attempted a PLA print... nothing sticks to the bed. All default print settings. confirmed 210c print temp, 0.4mm nozzle, 1.75mm dia filament, good extrusion... seems to be blobbing up around the nozzle.

[Mooselake]

We're an unofficial forum from back in the days when Printrbot didn't provide much support for their printers. With the newer printers Printrbot now has their own support site and forum. There are, however, several users here with various bent metal Printerbots so somebody should be able to help out. This is still where the cool kids hang out

Kirk

[RetireeJay]

I see Kirk beat me to this disclaimer: "to clear up what may be a mistaken impression, this site, printrbottalk.com, is not affiliated with the Printrbot company. It's run by volunteers who have Printrbots in order to share knowledge and help each other out. No one at Printrbot monitors this forum."

Having just recently looked at some of Prusa's world-class documentation, I can see why you're frustrated with Printrbot's haphazard approach to documenting their products and retaining documentation for future use even after the next model comes out.

Do you know what electronics board is in the school's Printrbots? If it's Rev G, then Printrbot expects you to be printing from the cloud and using a Mac. Very few users on this forum have taken that route. If it's Rev F, maybe we can help you some. But Kirk and I are dinosaurs who don't understand this new-fangled probing thing.

[novice]

...I downloaded Cura 15.04.2 and installed without issue.]

While this version will work, 15.04.6 had/has fewer glitches for me

...The Cura app has a bed leveling routine that doesn't appear to be made for the metal plus. It drives the nozzle down to all four corners with total disregard for the inductive probe. In the right hand corners the probe is not over the bed so it serves no use! Adjusting the inductive probe closer to the bed and re-running does not bring the nozzle up to prevent contact with the bed.

Success with the Cura Wizard for leveling is iffy, may I suggest in Cura you go to File>Preferences>Print Window and choose Pronterface UI, rather than Basic to bypass using the "Bed Leveling Wizard" for any desired movement.

Once you have connectivity with the Pronterface UI, you should be able to issue an M501 to determine if M211 X254 Y254 Z254 and M212 X20 are correctly set for your model. Bed dimensions should be the same as M211 in your machine settings within Cura for proper X and Y location probing

With the suggested Start Code below, your printer should correctly probe the bed prior to each printing, however if the bed is way out of level, tramming with paper under the corners may still be necesary.

G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G29 ;Run the auto bed leveling
G1 Z10.0 F{travel_speed} ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E3 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
;Put printing message on LCD screen
M117 Printing...

I believe that by using the arrow keys in the Pronterface UI that will also correct the reversed direction issue you mention below with the Wizard

The Cura leveling wizard has buttons for Up and Down that appear to drive in the opposite direction - clicking up brings the nozzle closer to the bed. Is this intended?

Please: What method do you recommend to adjust the nozzle height relative to the bed? My first layer is obviously too high and the print does not stick to the bed.

Try setting the probe to just trigger with the hot tip gapped snuggly by a simple piece of paper and then fine tune with M212 if necesssary.
Threw my Kapton Tape away as it proved tempermental with PLA for me, believe for someone just sorting things out blue painters tape will have less issue if cleaned properly by alcohol.

Let me also add while homing each axis by selection of appropriate button in Pronterface UI is not necessary; should you choose to, X and Y must be chosen before Z will be allowed.

[daveculp]

Have you seen the getting started page? http://printrbot.com/project/metalplus/