Hi guys!

For this topic, I have two problems with my 3d printer.

1) My Z axis speed is very slow. I have a system with two Z axis motors and it happend sometimes that I want to level the X axis by rising it all the way up. My lead screws are 8mm/revolution. To see how slow my Z axis is moving check this video at minute 1:20 [www.youtube.com] (this is not my printer) . Can you tell me please what should I set in my Marlin firmware to have a speed of movement like in this video? [www.youtube.com]. When my Z axis is homing, I have the same slow speed.

2) Second problem is refering to heating my hotend. When I connect my printer with Repetier host and I hit the Print button my printer behaves normally. Hotend is heating up without any problem and the print starts having no problem. Though, when I hit Print from SD card on my LCD my hotend starts to heat up and when it's around 210 degree(from 215) my LCD shows Printer Halted, please reset the printer.
This problem i have it only if I'm trying to print from SD card. I have a power supply of 25A at 12V with good wiring connection and the cartrige is 25W. Trough Repetier it takes 2 minutes and 20 seconds for the hotend to reach 215 degree celsius and start to print. And the temp is increasing every second like 40, 43, 45, 49, 54, 58, 62 and so on. Same increase in temperature I have it when I hit print from SD but around 210, 214 LCD shows Printer Halted.

Regarding to my first problem I played with the next variables:

// Homing speeds (mm/m)
#define HOMING_FEEDRATE_XY (50*60)
#define HOMING_FEEDRATE_Z (12*60)

//
// MOVEMENT SETTINGS
// @section motion
//

// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT {100,100,400,500} // default steps per unit for Ultimaker
#define DEFAULT_MAX_FEEDRATE {200, 200, 30, 25} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {3000,3000,400,10000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 3000 // X, Y, Z and E acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000 // E acceleration in mm/s^2 for retracts
#define DEFAULT_TRAVEL_ACCELERATION 3000 // X, Y, Z acceleration in mm/s^2 for travel (non printing) moves

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK 20.0 // (mm/sec)
#define DEFAULT_ZJERK 0.4 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)

Now when I hit autohome is moving much faster. But this happend only when I do autohome. When I move axes from repetier or from LCD the speed of the Z axis is still slow. Can someone explaine me why?

About my second problem I changed some parameters here. Still I have printer halted.Please reset when I want to print from SD card.

#if ENABLED(THERMAL_PROTECTION_HOTENDS)
#define THERMAL_PROTECTION_PERIOD 400 // Seconds
#define THERMAL_PROTECTION_HYSTERESIS 10 // Degrees Celsius

/**
* Whenever an M104 or M109 increases the target temperature the firmware will wait for the
* WATCH_TEMP_PERIOD to expire, and if the temperature hasn't increased by WATCH_TEMP_INCREASE
* degrees, the machine is halted, requiring a hard reset. This test restarts with any M104/M109,
* but only if the current temperature is far enough below the target for a reliable test.
*
* If you get false positives for "Heating failed" increase WATCH_TEMP_PERIOD and/or decrease WATCH_TEMP_INCREASE
* WATCH_TEMP_INCREASE should not be below 2.
*/
#define WATCH_TEMP_PERIOD 200 // Seconds
#define WATCH_TEMP_INCREASE 2 // Degrees Celsius

It's incredible how many bugs Marlin have. Incredible. This become frustrating. Can you advise me guys please? Anything will be helpfull. Thaks!

What is the max temp setup for in your firmware? If its close to what your heating too it will trip it everytime.
If you heating to 215c and the limit is 220c then you will fail everytime. I have my max setup to be about 50c more than my ABS temps of 240c.

If the axis is slow then speed it up in the firmware. Too fast and the motors will stall and scream at you. Also keep the acceleration down on the Z axis so it doesnt mess up.

Have you calibrated your Z axis yet? If you tell it to move 10mm up does it indeed move 10mm?

My max temp is:
#define HEATER_0_MAXTEMP 275. So I don t think this is the problem. What is weird is that this problem occur only when I want to print from SD or I order(from LCD) to the printer to have a 215 degree temp to the nozzle. Because it's not a problem to print with repetier, I heated up the nozzle about 220 degree and then disconnect the printer from PC and I tried to print from SD. In this case, printer start to print but after few seconds on my LCD: Printer halted. Please reset.

About setting the speed of the Z axis. My settings are those one that I posted above. What happends with this settings is that everytime I home the printer all gets well. My z axis move fast enough and I'm happy. But if I try with repetier or by LCD to rise or descend my Z axes it's like a turtle. It's take like 7 second for 10mm. My X and Y axes behaves the same when I home the printer or I manipulate them trough LCD or Repetier and I'm happy with that speed. The problem is only on Z axis. And yes, I roughly calibrate my Z axes. With T8 threadened rod, using Prusa calculator I must to input 400 steps per unit as you can see in my second post.

I dont know there because I dont use repetier.
Maybe try using Pronterface and see if its the same.

But I don t have any problems when I try to print by a host. In my case, problems occur when I'm using the LCD.

Are your Z axis rods M8 threaded rod or M8 4 start leadscrews ?
M8 threaded rod at 1.25 pitch should be 2560 steps/mm at 1/16 microstepping. 4 start leadscrews would be 400 steps

[www.aliexpress.com]

These are the ones.It says there: Nut turn a circle move 8mm. But not this is what matter for me. What matter is that I see them moving like a turtle when i want to raise or descend Z axis from LCD or by Host.

So, let me explain to you guys how I solved the first problem. I know that for many of you this is obvious but for many beginners this is a real issue. If you want to set the speed of a specific axes, first you should know that the speed you set in firmware is different from that one in your host(Repetier in my case) and it's different from the speed set in LCD. When you set the speed on the firmware, the setting applies only when you home de printer. If you try to control it from LCD or by Host, you'll se that the setting does not apply.

For setting the speed of a specific axes in firmware you should change the next settings in Marlin:

#define HOMING_FEEDRATE_Z (8*60) If you don't like 8, set with another value. Do not change the value 60
#define DEFAULT_MAX_FEEDRATE {200, 200, 100, 25}
#define DEFAULT_MAX_ACCELERATION {3000,3000,150,10000}
As Floyd sayd, try to keep your acceleration down for the first time and then increase it slowly until you're happy.
If you change the values only here, you'll see that these only applies when you home your printer.

To have same speeds of axes when you control the printer with your host (in my case Repetier) go to Printer Settings -> Printer and you must to modify the value of the Feed Rate. If you have everything set until now you'll be happy. But now try to use your LCD to move axes and see that settings don't apply. Strange hah? That's because you must to do one more setting in firmware: Go to Configuration_adv.h on // @section lcd
#if ENABLED(ULTIPANEL)
#define MANUAL_FEEDRATE {50*60, 50*60, 15*60, 60} // Feedrates for manual moves along X, Y, Z, E from panel

And that's it guys. Happy printing.

Now I need your help to solve my second problem, the one with Printer Halted. As I said I have this issue only when I'm trying to print a model from SD card. If I preheat the nozzle with the command from LCD, it will do so but if I hit Print from SD, printing will begin and after few seconds same error occur. And if I want to print from Repetier everything is fine. I printed from exactly the same SD card, exactly the same STL file on another printer and everything is good so I don't think the SD card is broken. Do you think that I should make some changes in Configuration_adv.h at section SD card? Could be there my problem?

What type of display/sd do you have?
The arduino 5 volt regulator is only rated at 500mA and some displays need too much power.
You may need to supply an external 5 volt power source.

This is the one that I'm using
[www.aliexpress.com]
I bought it from here.

I just test my LCD on a prusa i3 mk2 original and it's fully functional. When I hit Print from SD everything was fine, temperature reach printing temp, bed the same and the print was a success. I'm using same LCD, same SD card and same Rambo board. So again, I suspect Marlin for being my problem. As I said........it's incredible how many bugs exist in Marlin. What can I modify, what can I do? Thanks.

Ok, so I solved also the second problem. The problem was that my STL files were created in Cura for another specific 3D printer. And I said hmmm. Why I'm not creating my own STL file. After I did this in repetier everything turns to be fine. Thank you guys for advices. You help me alot. This topic can be closed now and I hope will help other people.

Quote
DOYT
So, let me explain to you guys how I solved the first problem. I know that for many of you this is obvious but for many beginners this is a real issue. If you want to set the speed of a specific axes, first you should know that the speed you set in firmware is different from that one in your host(Repetier in my case) and it's different from the speed set in LCD. When you set the speed on the firmware, the setting applies only when you home de printer. If you try to control it from LCD or by Host, you'll se that the setting does not apply.

This is why I asked to try it using Pronterface and not Repetier. I assumed it was the software messing you up.

Oh my god thank you so much, I've been going crazy trying to figure out what setting in configuration.h controls the travel speed. I had no idea that there is a separate setting for LCD travel speeds and that it is in configuration_adv.h. This stuff could really be made a lot more intuitive!