Itty Bitty Double FLEX V2

[clough42]

I've been playing a lot with Auto Bed Leveling and Mesh Bed Leveling on a non-makerfarm printer.

ABL really doesn't work on my system. (Probably because it isn't setup correctly.
I'm a senior software engineer... It should be easy.)

Which firmware are you using? I have working config files for a couple of versions of Marlin if it would help.

[gddeen]

Which firmware are you using? I have working config files for a couple of versions of Marlin if it would help.

I'm using RC6 4/20/16 ... I had configured auto bed leveling on that but it doesn't DO anything.
I switched that to Mesh Bed Leveling with a Z Stop. (You have to level it with a piece of paper.
It ignores the Z-probe for G29 S1 or S2.) And somehow M420 S1 has to actually enable it???
It doesn't really 'say' in the code. (firmware. One is supposed to know.)
BUT, RC6 lowers the probe and smashes it into the bed (ignoring the z-probe) with a G28 X Y:G28 Z
---

Mesh bed level really doesn't know where the probe is. It assumes one levels with a piece of paper.
But it now uses the probe (but doesn't know if actually isn't even over the bed, how high, etc. Nightmare.)

Auto Bed Level knows where that probe REALLY is. But, takes the nozzle and grinds it into the bed (because
it actually isn't doing any Z adjustment...)

--

However, I went and fixed the firmware. But, my X axis NEEDs to be level or all heck breaks loose. So I shove
a shim to try and get the nozzles level... They are perfect right now. I'm using MBL not ABL. I have a Z min stop,
a Z probe, min and max stops all around.

[clough42]

I'm using RC6 4/20/16 ... I had configured auto bed leveling on that but it doesn't DO anything.
I switched that to Mesh Bed Leveling with a Z Stop. (You have to level it with a piece of paper.
It ignores the Z-probe for G29 S1 or S2.) And somehow M420 S1 has to actually enable it???
It doesn't really 'say' in the code. (firmware. One is supposed to know.)
BUT, RC6 lowers the probe and smashes it into the bed (ignoring the z-probe) with a G28 X Y:G28 Z

Huh. That's weird.

Here's the Configuration.h file I'm using with RC3 on my 12".

https://github.com/clough42/Marlin/b...onfiguration.h

If you use this, check the thermistor settings. I'm running an industrial silicone heater and some other odd stuff.


And this is my start GCODE:

M80  ; power on
M42 P5 S255 ; light on
M190 S[first_layer_bed_temperature] ; wait for bed to heat up
M104 S[first_layer_temperature_0] T0 ; start heating T0
M104 S[first_layer_temperature_1] T1 ; start heating T1
G1 Z15 F120 ; lift nozzle
G28 ; home X and Y axes
G29 ; auto bed level
G1 X313 Y12 F15000 ; move to side
G1 Z0 ; Level for wipe
M109 S[first_layer_temperature_0] T0 ; wait for heat
M109 S[first_layer_temperature_1] T1 ; wait for heat
G90 ; absolute
T0 ; extruder 0
G92 E0
G1 E12 F50 ; extrude
G1 X0 F15000 ; wipe
G1 Y15 ; slightly forward so other wipe won't overlap
T1 ; extruder 1
G92 E0 ; reset extrude
G1 X0 E12 F50 ; extrude
G1 X250 F15000 ; wipe

[gddeen]

Thanks.

- Filament was ALWAYS breaking and getting crumpled up in the hotends.
I fixed this by building a pipe from the hotend to the base. There was too much play.

- Keeping the nozzles level is now the biggest trick. Setting it once, easy enough. But I need
something slightly faster, accurate and repeatable. Now I shove a shim, tighten, move to bed,
measure, move back up and repeat until close.

- I've got mesh bed leveling working and setup up BED Z and he other parameters.
I fixed that by just turning on SAFE_HOMING. A G28 uses the probe. But, when almost anything
happens, MBL is turned off again. M502: G29 S1: G29 S2: M500 sets it on.
(But the Z axis isn't rotating like it should... Which is OK. The bed is level to .15 anyway.)

- I went to 24V it just took way too long to heat up the bed. (Had to adjust PID and PWM rates
so extruders don't burn out prematurely.) All fans get PWM modified to run at half current or so.

-------

I'm back to the point where I can use the printer again.

------
Next I'll fix ABL...

[gddeen]

I can BARELY tell the difference between YOURs and mine...

config.jpgUntitled 6.jpg

[clough42]

I can BARELY tell the difference between YOURs and mine...

config.jpgUntitled 6.jpg

I can see why that might be confusing. They're pretty close.

[gddeen]

I like just printing OOZ Shields too.

2016-05-13 09.26.47.jpg

[gddeen]

This test print is a little better...

2016-05-13 09.50.24.jpg
I find several type of 2 color dual extrusion objects. Side by side stuff (embedded) and overlapping.

I use two different types of nozzles, one very pointy and one flat.

Questions:
I set my steps per unit to 660... I find a flow rate of 80% in Cura (not from printer) works well.

- Should I remove nozzle, set to extrude 300mm, measure and repeat until it is exactly 300 mm?

Or, should I calculate 80% of the cross sectional area by length (volume) and use THAT as length?

- Different filaments PET-G, verses pure PLA, verses other PLA have different flow
rates at different temperature/pressure extrusions. Noticably so... I use flow rate
on the printer to correct (that affects RETRACTION!!!)

A) Is there a formulae for setting temperature / flow rate?

B) Does one switch to hardware retraction or just overkill it in cura so lowering the flow rate won't leave filament too close to the nozzle causing more ooze?

- Changing 660 steps per mm unit to 614 decreases or increases the amount of filament extruded?

// GDD // Explanations are here: http://reprap.org/wiki/Triffid_Hunte...ibration_Guide
    // GDD //----------------------------------------------------------My Settings ---------------------------------------------------------------------------------------
    // GDD // NEMA 17 with standard pitch M8 threaded rod:
    // GDD //(200 * 16) / 1.25 = 2560
    // GDD // NEMA 17 with SAE 5/16" threaded rod. It has 18 threads per inch (25.4mm / 18):
    // GDD //(200 16) / (25.4 / 18) = 2267.7165355
    // GDD // E-Steps: small_gear (motor) drives big_gear turns hob_bolt friction pushes filement.
    // GDD // e_steps_per_mm = (motor_steps_per_rev driver_microstep) (big_gear_teeth / small_gear_teeth) / (hob_effective_diameter pi)
    // GDD = (200steps/rev x 16microsteps) * (80teeth / 20teeth) / (6.325 mm * 3.14159) = 644.2
    // GDD James Clough (Manufacturer of hob gear & Itty Bitty Flex Extruder) suggests starting at 615


    // default settings

    #define DEFAULT_AXIS_STEPS_PER_UNIT   {80,80,2560,660.0}

[clough42]

Gary,

I get the best results with two identical hot ends. If you're trying to mix and match, you can probably make it work, but you're making it harder on yourself. I find that the same filament needs different settings in different hot ends--even temperature. ABS that prints great at 245C in a 3mm Hexagon may need 255C in a 1.75mm E3Dv6 to get the same layer adhesion.

I guess the real question is what you're trying to accomplish. If you want to play with a 3D printer, by all means buy whatever strikes your fancy and have fun tuning and trying. If you want to make things with a 3D printer, I recommend getting a matched pair of genuine E3Dv6 hot ends in 1.75mm and climbing the learning curve once.

As far as adjustment, I get as close to 1:1 filament movement as practical with the E-Steps setting in the Marlin firmware and then tune from there based on how the prints are turning out. I don't typically tune in the slicer. I just dial the E-Steps up and down with the printer control panel. If the top is a little overfilled, I turn it down. If it's got gaps, I turn it up. If I have layer adhesion problems, I make sure that my extrusion width is at least 120% of the nozzle size, and then turn it up slightly or raise the temperature.

If you're using my hobbed bolts in a 4:1 drive extruder (all of the Itty Bitty extruders) I recommend starting at 615. My printers are all set between 600 and 625. The differences are probably just due to the tolerances on the 3mm and 1.75mm filament I have.

James

This test print is a little better...

2016-05-13 09.50.24.jpg
I find several type of 2 color dual extrusion objects. Side by side stuff (embedded) and overlapping.

I use two different types of nozzles, one very pointy and one flat.

Questions:
I set my steps per unit to 660... I find a flow rate of 80% in Cura (not from printer) works well.

- Should I remove nozzle, set to extrude 300mm, measure and repeat until it is exactly 300 mm?

Or, should I calculate 80% of the cross sectional area by length (volume) and use THAT as length?

- Different filaments PET-G, verses pure PLA, verses other PLA have different flow
rates at different temperature/pressure extrusions. Noticably so... I use flow rate
on the printer to correct (that affects RETRACTION!!!)

A) Is there a formulae for setting temperature / flow rate?

B) Does one switch to hardware retraction or just overkill it in cura so lowering the flow rate won't leave filament too close to the nozzle causing more ooze?

- Changing 660 steps per mm unit to 614 decreases or increases the amount of filament extruded?

// GDD // Explanations are here: http://reprap.org/wiki/Triffid_Hunte...ibration_Guide
    // GDD //----------------------------------------------------------My Settings ---------------------------------------------------------------------------------------
    // GDD // NEMA 17 with standard pitch M8 threaded rod:
    // GDD //(200 * 16) / 1.25 = 2560
    // GDD // NEMA 17 with SAE 5/16" threaded rod. It has 18 threads per inch (25.4mm / 18):
    // GDD //(200 16) / (25.4 / 18) = 2267.7165355
    // GDD // E-Steps: small_gear (motor) drives big_gear turns hob_bolt friction pushes filement.
    // GDD // e_steps_per_mm = (motor_steps_per_rev driver_microstep) (big_gear_teeth / small_gear_teeth) / (hob_effective_diameter pi)
    // GDD = (200steps/rev x 16microsteps) * (80teeth / 20teeth) / (6.325 mm * 3.14159) = 644.2
    // GDD James Clough (Manufacturer of hob gear & Itty Bitty Flex Extruder) suggests starting at 615


    // default settings

    #define DEFAULT_AXIS_STEPS_PER_UNIT   {80,80,2560,660.0}

[clough42]

This test print is a little better...

2016-05-13 09.50.24.jpg

Yes, that's a lot better. It still looks a little overextruded to me. Here's an example of one I pulled out of my scrap box:

IMG_2552.jpg

This one is definitely underextruded. I think it was printed with eSteps set at 610. The top isn't quite filled in and the centers of the letters aren't closed. But it is clean.

There's a little curling of the bottom layers where the 45 degree overhang is because I wasn't running a cooling fan for this print.