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Fine-tuning & Increasing Performance of your gMax Printer

PostPosted: Sun Jan 01, 2017 1:34 pm
by PianoPrint
After owning the gMax 1.0 and converting it to the gMax 1.5 XT+ I have come to understand quite well how this printer works, and what it needs to print incredibly well. The gMax printer is a very well made printer. If you take the time to understand what the printer needs, and fine-tune it, it will reward you with even more reliable and stunning quality prints.

Below are shown some critical high performance areas that once fine tuned, the print results will leave you smiling in satisfaction.

I did not want to develop each topic below as it can be pretty extensive. However I have dealt with all of the topics while upgrading the printer. I'm not showing or suggesting something new here. In fact all of these topics have been covered throughout the internet extensively. However this information can be found in scattered places and there is not one spot where all can be addressed at once. Perhaps this can be a good place to start.

So if anyone is interested in developing either topic, I would be glad to share my knowledge with you.

Addressing some of the topics below will give you dimensionally accurate and smooth prints (of course depending on your slicer settings as well).

Thank you

Topics for Discussion

1. Squaring the X, Y, Z axis


2. Making your Z axis Level to the frame


3. Acurizing / Calibrating steps per minute X, Y, Z


4. Extruder Filament Calibration – Extruded Length


5. Calibrating Filament Extrusion Multiplier - Calculating the Setting


6. Acceleration X&Y Jerk Settings - Ringing Reduction


7. Calibrating Your Heater Block Thermistor – PID Auto-tune (E3D V6 or J-Head)


8. Surveying & Mapping your Heated Bed for Thermal Gradient (cold spots & print warping)


9. Modifying Marlin Firmware & Updating to your Ramps 1.4


10. Mounting the E3D-V6 Extruder


11. BluTouch Installation and Calibration- setting your Z offset


12. Stale Filament - Drying your Filament - Popping filament & not sticking to bed



.

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Sun Jan 01, 2017 10:43 pm
by flrock
Is be interested what you're doing for numbers #4 and #6.

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Mon Jan 02, 2017 5:24 pm
by PianoPrint
4. Extruder Filament Calibration – Extruded Length

I typically use Symplify3D Machine Control Panel for this one as it has some short cut buttons on the jog controls that makes life easier. In case you do not have Symplify3D you can use any Communication port like Repetier-Host etc. All will do the same to input commands.
Heat up your extruder to the temperature that you print for the type of filament that is in the extruder (example PLA 205 C).

1. Measure 150mm with calipers and place a mark on the filament as shown in picture.
2. In Symplify3D Machine Control Panel click on the Extrude 100. If you do not have Symplify3D type in the command line:

G92 E0 then send
G1 E100 F90 then send

Note: You can do the same as above from the LCD panel. Go to move Axis, choose Extruder, move 10 times 10mm. I have found this to not be as accurate as with thr command line or Symplify3D Machine Control Panel (it can be off as much as 1~2mm.)

The filament should move 100mm. Measure again the mark to verify as shown in picture. If it is within 0.5 ~ 1.5mm it is close enough (personally I prefer it to be less than 0.5 mm). If not, do the following:

Go into either the Marlin you uploaded or from the LCD screan, under Control, motion, Esteps /min and read the current value, for example 96 steps/min. This is your existing steps/min

S= Steps
S=((What we asked for) / (what we got)) x (existing steps/min)
Example if your extruder measured 99.51mm and you asked 100mm then:
S=((100 mm )/(99.51mm)) x ( 96 steps/min) =96.47 steps/min

This is your calibrated new steps per unit value.

If you have enabled EEPROM in your Marlin you can store the value from the LCD directly.

if you want to enable EEPROM in Marlin, in "Configuration.h" file remove the "/" before the "#define ":

Example
"................

#define EEPROM_SETTINGS
//to disable EEPROM Serial responses and decrease program space by ~1700 byte: comment this out:
// please keep turned on if you can.
#define EEPROM_CHITCHAT

.............."

if you do not have EEPROM enabled then you will have to go to go to Marlin under the “configuration.h” file and modify the following value highlighted in black bold below. Then you will have to upload the firmware to your printer in order to store it into memory.

Example
"................

//for gmax 1.5 + Uncomment below
#define DEFAULT_AXIS_STEPS_PER_UNIT {80.377, 80.370, 406, 96.47}

..........."

If you do not want to upload the Marlin firmware you can type the following in to your command line and it will save the value into EEPROM:

To see what is the value of the extruders steps per minute type "M501 E0" and press enter
To change to the new calculated value type "M92 E96.47 M500" and press enter

That should save the values to the EEPROM

I hope this helps

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Mon Jan 02, 2017 7:10 pm
by PianoPrint
6. Acceleration X&Y Jerk Settings - Ringing Reduction

This is not as straight forward as plugging in numbers.
What I have found to influence ringing in prints usually boils down to the following:

1. Large mass of components. In this case the extruder and the Y print table
2. High x/y jerk settings
3. High acceleration values
4. High print speeds
5. Stretched X/Y belts
6. Loose X/Y belts

Each printer is different and you have to look at all of the above points one by one. There is not much you can do for the mass of the print head and print bed, unless you redesign it. It is what it is as this printer is huge so even a redesign is not going to help that much because of size. So that leaves you with tuning in all the other values.

Try printing with speeds below 30mm/sec on the outer layers. You can go faster in the inner fill layer but not by much. Make sure your belts are tight and print a “Z” clip that actually helps absorb some of the vibrations. The default X/Y jerk for this printer is rather high so I reduced it to 8. The accelerations for the X/Y are fine at 600mm/s.

To test your printer settings and calibrate your filament multiplier, speeds, jerk and acceleration you can design a test print with 1mm thick walls as shown in the picture and use it as a calibration print. If you need it let me know as I can make it available.

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Wed Jan 18, 2017 10:42 am
by PianoPrint
One thing that helped me reduce, and in some cases remove the ringing was to replace the Y print bed belt with a wider one. I went from the original 5mm to a 9mm GT2 belt. Now the bed moves are crisp and solid. I believe that this upgrade is a must for the heavy print bed of this gMax printer. I am vary please with the results.

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Sun Jan 29, 2017 12:37 pm
by flrock
Any chance you can tell me what printing speeds you're using for your "other" section on S3D? I'm having issues where some prints are great while reprinting with the same settings on the same model has given me failures.

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Sun Jan 29, 2017 3:10 pm
by PianoPrint
flrock wrote:Any chance you can tell me what printing speeds you're using for your "other" section on S3D? I'm having issues where some prints are great while reprinting with the same settings on the same model has given me failures.


In S3D for:

For PLA and PETG

Default 35mm/s
Outer 50%
Solid 50%
Support 70%
x/y 50
Z 50%

Also,
Do a filament diameter measurement and calibrate your multiplier.

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Sun Jan 29, 2017 8:39 pm
by flrock
PianoPrint wrote:Do a filament diameter measurement and calibrate your multiplier.


My multiplier was off by a measure of 12mm for an extrusion of 100mm. I'm unable to save the changes as EEPROM is disabled and the firmware I downloaded from gCreate (gmax 1.5+ single extruder with BLtouch) is kicking back error codes that aren't involved with the changes of enabling EEPROM, CHIT_CHAT, and default PLA temps. As of now I'm manually inputting the changes.

Is there a way to download the firmware from the actual printer?

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Sun Jan 29, 2017 9:05 pm
by PianoPrint
The multiplier is changed in S3D and the firmware is downloaded from the PC to the Ramps 1.4 through the Arduino interface. You save the multiplier into the profile of S3D exclusively for each brand and type of filament.

Re: Fine-tuning & Increasing Performance of your gMax Printe

PostPosted: Sun Jan 29, 2017 9:13 pm
by flrock
PianoPrint wrote:The multiplier is changed in S3D and the firmware is downloaded from the PC to the Ramps 1.4 through the Arduino interface. You save the multiplier into the profile of S3D exclusively for each brand and type of filament.


Just so I am clear. I command 100mm to be extruded, it actually extruded 88mm. That gave me a number of 1.13 is this what I am to add in the multiplier in S3D? If so, why would I need to multiply it by 96 steps/min?