Best posts made by troy_proffitt

I just finished building a new CoreXY printer with the goal of no 3d printed structural parts at all. The only printed parts are the enclosures for the controller boards and the extruder mount (dual BMG extruders).

I've been 3d printing for several years on both cartesian and corexy. A more rigid printer usually produces better prints. The best improvements were around bed stiffness. I recently went to the 3 independent "true level" setup with a 1/4 thick MIC6 aluminum plate + 1/4 tempered glass. Each z axis motor is controlled by an external stepper and has a 3:1 gear reduction for both higher resolution and higher strength (HERE is a vid of my bed setup). Since this vid, I've added 12mm smooth rods to each ballscrew to improve linear motion.

Attached are a few pics of my printer: !

@felt342

I am using THIS driver.

Here is how you wire it using just the expansion header:

ENA - goes to E2_EN on the header
ENA + goes to 3.3v on the header
DIR - goes to ground
DIR + goes to E2_DIR on the header
PUL - goes to ground
PUL + goes to E2_STEP on the header

Is this something that could be added to your beginning gcode (so you don't have to modify each time you want to print something)

The holy grail would be to use a fan speed variable in the slicer and convert tht to the value needed in the M42. For example if I set 75% fan in the slicer, the post -processing code would generate a M42 P9 S0.65, and if I set 50% in the slicer, the code would generate M42 P9 S0.6. If CURA can do an if/elseif similar to Prusa, I think I can figure it out.

Edit, it seems that CURA has a post processing plugin that will do a search / replace based on z height. I'll play around with this and reply back. This is a bit of a hassle, but should solve my problem. Thanks for your help!

I just recently got the triple z axis bed leveling working. It was a major pain to scour the Duet website / internet to figure out everything you need to do so I thought I'd document everything and put it in a single place. I am already using 2 extruders so my Duet Wifi board by default couldn't handle the 3 steppers I needed so I turned to TB6600 external stepper drivers. I connected them to the board using the expansion header using THIS diagram. Using E2,E3 and E4 Pins.

Here is how you wire them to the external drivers (using the Extruder2 pins):
ENA - goes to E2_EN on the header
ENA + goes to 3.3v on the header
DIR - goes to ground
DIR + goes to E2_DIR on the header
PUL - goes to ground
PUL + goes to E2_STEP on the header

Rinse repeat for E3 and E4 pins (I daisy-chained the 3.3v from the header to all 3 external steppers)

Now onto the config.g file. First you have to assign Drives 5-7 (in my case) using M569 and also update your M584 line to use Z5:6:7

M569 P5 R1 T2.5:2.5:5                                                              ; Drive 5 goes forwards
M569 P6 R1 T2.5:2.5:5                                                              ; Drive 6 goes forwards
M569 P7 R1 T2.5:2.5:5                                                              ; Drive 7 goes forwards
M584 X0 Y1 Z5:6:7 E3:4                              
   ; set drive mapping

The T2.5:2.5:5 part was tricky to figure out. Your external steppers won't do anything till you put that part in.

Where do you find all the assignments for motor #'s? Took me a while to find that, but here it is:

0 - X Axis
1 - Y Axis
2 - Z Axis
3 - E0 Axis
4 - E1 Axis
5 - E2 Axis (Expansion Header)
6 - E3 Axis (Expansion Header)
7 - E4 Axis (Expansion Header)
8 - E5 Axis (Expansion Header)
9 - E6 Axis (Expansion Header)
10 - 10 (LCD_CONN Header)
11 - 11 (LCD_CONN Header)

Ok! Now you need add the M671 line to config.g to give the coordinates to each of your leadscrews:
Z1 - X20 Y20
Z2 - X200 Y360
Z3 - X485 Y20

M671 X20:200:485 Y20:360:20 S1        ; Leadscrews at rear front, back middle and rear front

Lastly you need to update the bed.g file (please note that the order of your leadscrews and the order of probing in bed.g need to be the same)

G30              ; home Z by probing the bed 
G30 P0 X20 Y20 Z-99999 ; probe near a leadscrew
G30 P1 X200 Y360 Z-99999 ; probe near a leadscrew
G30 P2 X485 Y20 Z-99999 S3 ; probe near a leadscrew and calibrate 3 motors

I add a single G30 Probe after it homes x/y since it seems to give a reference z height before the actual P0-P2 probes (it raises and lowers the z less for some reason)

So after you add all this, just put the G32 command in your homeall.g instead of the code you originally had for the z and I believe that's all I had to do. Here is a video of mine in action:

https://www.youtube.com/watch?v=zqdJ47OT_BQ

I ended up teaching my self some basic Python and wrote a script myself. Hopefully this will help others that are wanting to use a CPAP fan or other servo type fan signals:

https://community.ultimaker.com/topic/35639-convert-fan-speed-to-servo-movement-post-processing-script/

I used that link extensively, but it didn't paint a full picture for what I needed.

I understand this is an old thread, but I'm trying to do something very similar and was wondering if this could be controlled from a Duet WIFI 2?