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KOSSEL DELTA manual calibration in Repetier (last update 17-01-2017) by Mind Map: KOSSEL DELTA
manual
calibration in
Repetier
(last update
17-01-2017)
5.0 stars - 3 reviews range from 0 to 5

KOSSEL DELTA manual calibration in Repetier (last update 17-01-2017)

X-Y dimensions correction and CURVATURE CORECTION influence

This is what complicates calibration on delta printers.

When we change "Diagonal_rod_lenght" it influences curvature and when we change "horizontal rod radius" we change XY movement.

That is why we need to check bouth when we are calibrating.

If we are gonna print toys and vases we can only focus on curvature corection. But if we are gonna print parts for other machines we need both.

temp (not finished yet)

By increasing "horizontal_rod_radius" we increase XY movement., INCREASE "diagonal_rod_lenght"

By increasing "diagonal_rod_lenght" we increase last three numbers in 4 point calibration., INCREASE "horizontal_rod_radius"

MOVEMENT CURVATURE CORECTION: Standard 4-point delta calibration MEASUREMENT

Put paper in the middle of glass.

Manually drive hot-end so low that you feel nozzle stoping the paper (Point 1) OR use Script 1.

If you reach may down position (Z=0) increase Zmax in EEPROM.

Write the Z height number down.

Go to Point 2 manually OR use Script 2.

Write the Z height number down.

Go to Point 3 manually OR use Script 3.

Write the Z height number down.

Go to Point 4 manually OR use Script 4.

Write the Z height number down.

Lets look at the numbers! Ideal is that ALL are as close as possiable!

Delta printer kinematics

X, Y and Z directions on delta printer:

Delta

Zoom

Test end-switches

In Repetier use code M119 for getting status info

x_max=L, X switch not covered

x_max=H, X switch covered

test all 3 to see all are electricaly OK

this must be confirmed before using first HOME command

In Repetier EEPROM settings

Alt+E

Steps per mm: 200 (if DRV8825 drivers are used)

Homing feedrate

Homing speed

10 - first tests

40 - normal

Extruder 1 - steps per mm

190 - for DRV8825 on MK8 extruder

Mechanics - constants

XXL, Rods: 410mm, diagonal rods length: 410,0 horizontal rod: 233,00, Rods: 475mm, diagonal rods length: 478,0 horizontal rod: 235,00

XL, Kossel 750 1515: DELTA_DIAGONAL_ROD: 333,5mm DELTA_EFFECTOR_OFFSET: 33,0mm DELTA_RADIUS: 161,7mm DELTA_CARRIAGE_OFFSET: 25,0mm, Kossel 750 1515 - 06-11-2015: steps/mm: 80 diag. rod: 334,0 Zmax: 263,0 horizontal rod: 165,00

Print size

XXL

rods length = 410mm, effector with hot end on top, Zmax = cca 400mm, print diameter = cca 320mm, effector with hot end below, Zmax = cca 345mm, print diameter = cca 320mm

rods length = 475mm, effector with hot end on top, Zmax = cca 375mm, print diameter = cca 375mm, effector with hot end bellow, Zmax = cca 322mm, print diameter = cca 375mm

rods length = 500mm, effector with hot end on top, Zmax = cca 348mm, print diameter = cca 375mm, effector with hot end below, Zmax = cca 295mm, print diameter = cca 375mm

GENERAL IDEA

What is calibration of 3D delta printer?

1. Printed model dimensions are correct in all 3 axis., We change DIAGONAL_ROD_LENGHT as needed.

2. Hot end in center bed position "knows" where is print bed., Z-height calibration

3. Hot end moves horizontaly over print bed., We change HORIZONTAL_ROD_RADUS as needed.

4. Extruder in pushing correct amount of filament in hot end., We change parameter EXTRUDER1 STEPS PER MM in EEPROM.

Enter/edit scripts

Enter scripts

If we want we can enter/save scripts for faster work. So we dont need to type g-code commands so many times.

Script 1- CENTER

Script will move nozzle 10mm over glass (Point 1) and then lower to 2mm over glass.

G1 X0 Y0 Z10 G1 X0 Y0 Z5

Script 2 - X tower

Script will move nozzle 10mm over glass (Point 2) and then lower to 2mm over glass.

G1 X-105 Y-65 Z10 G1 X-105 Y-65 Z5

Script 3 - Y tower

Script will move nozzle 10mm over glass (Point 3) and then lower to 2mm over glass.

G1 X105 Y-65 Z10 G1 X105 Y-65 Z5

Script 4 - Z tower

Script will move nozzle 10mm over glass (Point 4) and then lower to 2mm over glass.

G1 X0 Y105 Z10 G1 X0 Y105 Z5

DRV8825 stepper driver

set poti voltage to 0,6V to limit the current

Current Limit = VREF × 2

So, for example, if you have a stepper motor rated for 1 A, you can set the current limit to 1 A by setting the reference voltage to 0.5 V.

X-Y dimensions correction

In general:

Take a paper and draw a line. Mark center point and 2 points left and right 200mm apart.

We need to do this before curvature movement correction. We do it by changing DELTA_DIAGONAL_ROD / Diagonal_rod_lenght in EEPROM - Repetier firmware., http://minow.blogspot.si/

Manually move hot end +/- 100mm and observe how much nozzle actually travels.

Change DELTA_DIAGONAL_ROD / Diagonal_rod_lenght setting in EEPROM accordingly.

Movement is to big, INCREASE Diagonal_rod_lenght, Home and measure again

Movement is to small, DECREASE Diagonal_rod_lenght, Home and measure again

Standard 4-point delta calibration SITUATION NO.1 - JUST ONE POINT IS OFF

Correct it by moving end stop lower or higher

Measure all 4 points and write it down.

Better?

YES, Move it more or less as needed., Repeat the proces ...

NO, Move end-stop in other direction.

Standard 4-point delta calibration SITUATION NO.2 - HEAD WANTS TO GO LOWER IN THE MIDDLE

Table

Situation

Decrease HORIZONTAL_ROD_RADIUS in EEPROM settings.

Home printer.

Measure all 4 points and write it down.

Repeat the proces ...

Standard 4-point delta calibration SITUATION NO.3 - HEAD WANTS TO GO LOWER ON THE SIDES

Table

Situation

Increase HORIZONTAL_ROD_RADIUS in EEPROM settings.

Home printer.

Measure all 4 points and write it down.

Repeat the proces ...

Standard 4-point delta calibration FINISHED (ALL DISTANCES ARE SAME)

Table

In the above situation offset Zmax in EEPROM for the same number. So decrease for 1,2mm the number that is there.

Measure all 4 points and write it down.

They should be 0 or very close to 0.

Real life example

Table - 1. measeurement of 4 points

Point 4 (Z tower) number correction.

Here the nozzle is going lower than on X and Y points. So we need to rise Z tower end stop.

Here the nozzle is going lower than on X and Y points. So we need to lower Z tower end stop.

For 1mm change we need to turn the Z screw twice.

Table - 2. measeurement of 4 points

Better. But I need to do lower it more.

Table - 3. measeurement of 4 points

Better again.

lower X end stop - 1/4 screw turn rise Z end stop - 1/2 screw turn

Table - 4. measeurement of 4 points

Now tower are OK

We have concave nozzle movement. So we need to decrease HORIZONTAL ROD RADIUS parameter in EEPROM.

Repetier > Config > Firmware EEPROM Configuration

ALT + E

Was 170. Decrease to 168.

Table - 5. measeurement of 4 points

Better. Need to decrease more.

Was 168. Decrease to 166.

Table - 6. measeurement of 4 points

Almost perfect. Gut enough for me.

As you see you have to play with it. Try what makes the situation closer to ideal. It will never be perfect, but it will be good enought.

You dont do this many times. YOu do it ones per month or when you see nozzle is to close/far from the glass.

But even then you can use Z-BABYSTEPPING function on printer LCD, to rise/lower nozzle in real time (while printing).

End-stops positioning

Why do we need it?

By changing end-stops position we influense the movement of hot end over the bed.

When there is need to move end stops here is how you do it

Zoom

How do we use them?

- By turning the screw in CW direction (RED ARROW) end stop will phisically move UP. - Home printer. - Nozzle will move HIGHER over glass near that tower.

- By turning the screw in CCW direction (BLUE ARROW) end stop will phisically move DOWN. - Home printer. - Nozzle will move LOWER over glass near that tower.

Use this when making calibration.

Extruder calibration

This calibration is much simpler.

Our gool is to extrude correct length of fillament.

If we manually move extruder for 100mm it needs to push/extrude 100mm of filament.

EXAMPLE:

Filamet should be in extruder.

Remove plastic tube from hot-end.

Cut the filament at the end of tube.

In Repetier use M302 code. (Cold extrusio alowed.)

In Repetier manually move extruder for 10mm just to see if it moving and that you are using right direction.

Cut filament.

Manually move it for 100mm.

Extruder will push filament.

Cut the extruded filament and measure it.

I got 51mm.

So I am missing almost 100%.

In EEPROM settings I need to double variable Extr. 1 steps per mm, 370 -> 740

I got 103mm of filament.

Let do it again.

740 -> 720

Cut filament.

Manually move it for 100mm.

Measure.

I got 101mm., Gut enough.

Z-height calibration (hotend/nozzle in center position)

Measure distance between nozzle and bed (glass) when hot end is in Home position

about 258mm on my Kossel XL

We need this distance to start setting Z-height

EEPROM (Alt+E): Z max length: change existing number with measured one + 2mm

262mm in mine case.

We added 2mm so we alowe nozzle to go lower than bed!

BE CAREFULL NOW YOU CAN HIT GLASS WITH NOZZLE

Put the paper over glass.

Manually move nozzle so it touches paper (bed center)

First move it for 10mm.

When closer use 1mm.

When very close use 0,1mm.

I dont use 0,01mm.

In my case Z position it was 1,2mm.

This means that hotend (nozzle) would go 1,2mm bellow bed in the bed center!

Manually move nozzle left/rigt (X direction) to see what is it doint.

We need to determine is hotend (nozzle) moving into or away from bed.

Our gool of course is that movement in X and Y direction is parallel to bed.

In my case it moved a bit up when moved to X+120 and X-120 position

This means  I need to decrease Horizontal rod radius in EEPROM settings.

Try it for Y direction too.

Firmware settings Repetier

LCD (Configuration.h)

#define FEATURE_CONTROLLER 0 no LCD

#define FEATURE_CONTROLLER 2 classical LCD

#define FEATURE_CONTROLLER 11 graphical LCD

Bed heat manager

Pazi:Hot end in heater bed imata ločeno nastavitev tipa regulacije temperature.

Manager = 2 > Bang-Bang control SPREMENI V EEPROMU!

Hot end naj ima nastavitev na 3 torej PID, drugače temp močno niha.

Extruder default PREHEAT PLA

#define UI_SET_PRESET_EXTRUDER_TEMP_PLA 230

#define UI_SET_PRESET_HEATED_BED_TEMP_PLA 60

LCD: change button direction

ui.h:#define UI_ENCODER_A 31 //CD default == 33; WORKS #define UI_ENCODER_B 33 //CD default == 31; WORKS

Change printer name

configuration.h :#define UI_PRINTER_NAME "Kossel XL 750"

LCD: "dec" message

#define EXT0_DECOUPLE_TEST_PERIOD 0 in the latest release to disable decoupling test completely. But maybe better only increase #define DECOUPLING_TEST_MAX_HOLD_VARIANCE 20