marlin lcd feedrate

i recently changed one of my axis ( z axis ) stepper driver to a thb7128 driver board... the printer has been running fine for quite some time now.. the problem i am facing is that i am not able to jog the axis using the lcd module... the x and y axis jog fine but the z axis just misses steps ...

i there somewhere where i can change the feed rate of the z axis in marlin for the lcd ? i cant seem to find a separate configuration setting for that... am i missing something?


thanks

The configuration.h file for the Marlin firmware has a series of lines in it each with 4 variables on it. The order is X,Y,Z,E (one for each axis and the extruder). The one you are asking about is#define DEFAULT_MAX_FEEDRATE. It interacts with acceleration and jerk.

That said, I'd bet your issue is the current setting rather than the firmware. The exact setting of Vref for this chip will be different than on the Alegro chips. I'd try bumping the Vref up and down to see what happens. If the chip is set up for 1/32 micro stepping, and you had a 1/16 chip in there before, you will need to change the steps per mm settings in the firmware. A lot of this depends on exactly how the board you have was designed and configured.

Edited 1 time(s). Last edit at 11/05/2013 07:35AM by uncle_bob.

yes but these feed rates define the way the printer prints..... but when you are jogging the printer using the lcd and rotary switch the feedrate differs and it makes the z axis skip steps....

The LCD knob changes the feed rate multiplier (same as with M220). If you are dropping steps when turning this up, then perhaps your current levels from your driver boards are marginal. You can see if turning them up a bit might help, but do it in small increments. Set them too high and your motors will get hot.

The LCD will let you go to some very crazy settings if you decide to use it for that. The assumption is that you know what you are doing when you override the firmware settings. It's not got a lot of "we won't let them do that" logic once you decide to do overrides.

The feed rate is specified in mm per second. The stepper works in steps per mm. The steps used are the microsteps on the motor. The normal defaults are for 16X micro stepping. If your driver is set up for 32X micro stepping (as it probably is) then your steps / mm calibration will be off by a factor of 2X. That will throw your feed rates off by 2X as well. The solution in this case is not to change the feed rates, it's to get the calibration back where it belongs.

The torque needed from the X, Y and Z axis motors isn't all that great. I've messed with a lot of feed rates and never had that mess them up. Acceleration limits what can or can't happen. You can indeed crank them (feed and acceleration) way up, but they will be silly fast for any sort of accurate printing. The dynamics of these printers aren't good enough past a certain point. It's much easier to have motor troulbes due to current mismatch than it is due to feed rate settings (with the axis calibration correct).

@uncle_bob

thanks for the great explanation.... i think i am not posting my question clearly... my stepper drives are set for 16x and all the feed rates are okay when the printer is printing either from usb or from the SD card.... that is not the issue...

the problem comes when i try to move my z axis using the lcd's digital encoder ( click knob ) .... that s when the z axis start skipping.... I know in proterface or repetier you can set the stepper motor speed for jogging in the software itself... without affecting the speed in the firmware... I am searching for a similar setting for the LCD....

thanks for all your replies... I hope i have clarified the problem...

I believe the settings in configuration.h for max speed and acceleration apply if they have not been overridden. Pronterface and Slic3r set their own max speeds.

mine have been fiddled a number of times:

#define DEFAULT_MAX_FEEDRATE {200,200,2,44} // was {250, 250, 2, 22}
#define DEFAULT_MAX_ACCELERATION {500,500,5,1000} // was {1000,1000,5,1000} // 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. // prev 2000,2000,5,2000 => 500,500,5,100 // back to 1000 on E
// try z feed at 4 (not 2) and z accel at 20 (not 5), back to orig
#define DEFAULT_ACCELERATION 250 // X, Y, Z and E max acceleration in mm/s^2 for printing moves, was 500 -> 250 11/1/2013

Edited 1 time(s). Last edit at 11/06/2013 09:46PM by uncle_bob.

@uncle_bob

Actually the feed rates and acceleration settings don't somehow apply when using the rotary switch.... That is what the problem... it is driving me crazy... i want to use the printer without my laptop but this issue is not letting me do it...

You're talking about using the jog feature of the LCD panel? In my experience, the feed rate is as fast as you turn the knob. Turn it slowly and it moves slowly; faster and it moves faster. I don't know if there's a setting for this, but it's a feature I almost never use, and I print headless often.

The only time I ever really use the jog is if I have to hit the reset button, and I want to raise the hot print head away from the print.

You can always go into the C code and put a limit on it. It is open source.

Hello, I had a similar issue (for manual speed from LCD rotary encoder) and found that this setting (below) give me good result, may be you could try it.


// Feedrates for manual moves along X, Y, Z, E from panel
#ifdef ULTIPANEL
#define MANUAL_FEEDRATE {50*60, 50*60, 4*60, 60} // set the speeds for manual moves (mm/min)
#endif

Sorry, I forgot to mention that this setting is in configuration_adv.h


Hello, I had a similar issue (for manual speed from LCD rotary encoder) and found that this setting (below) give me good result, may be you could try it.


// Feedrates for manual moves along X, Y, Z, E from panel
#ifdef ULTIPANEL
#define MANUAL_FEEDRATE {50*60, 50*60, 4*60, 60} // set the speeds for manual moves (mm/min)
#endif

That variable does not show up in the version of configuration_adv.h that I have. Is it supposed to be part of the standard file?

Hello, It is in the latest marlin_v1 as of October 30, 2013 from GitHub, I have attach the original file...

I have not updated mine since September, it may be new.

-----------------

Now that I look at it a bit more carefully, it's been a while (ummm ... errrr ... 6 months ... ) since I updated mine ... really should do it more often. Note to self - date on the .h files is not a reliable number.

Edited 1 time(s). Last edit at 11/08/2013 09:20AM by uncle_bob.

i tried compiling the new marlin .... but it gives a error with the ultipanel enabled ... my last version was from july and it works fine ..... one more roadblock.....

If you are switching to the newer Marlin *and* have thermistor 6 for any of your sensors - be very carefull. They have changed that table a *lot*. It should be nearly the same as table 1. That used to be true, it no longer is. Your temperatures will shift quite a bit when you put in the new table.

-----------------------------

After some back tracking, my tables ultimately trace back to MakerFarm. They aparently forked the table 6 data a while back. So not an issue unless you are going from their fork back to the main version.

(yes that's a total thread hijack ... sorry about that).

Edited 1 time(s). Last edit at 11/08/2013 12:34PM by uncle_bob.

RepRap Forum to the rescue once again! This information was exactly what I was looking for.

For reference, I am now running Marlin 2.0.5.2 and the relevant section in Configuration_adv.h looks like this:
#if EITHER(ULTIPANEL, EXTENSIBLE_UI)
#define MANUAL_FEEDRATE { 50*60, 30*60, 4*60, 4*60 } // Feedrates for manual moves along X, Y, Z, E from panel

My E3D BigBox printer has different gearing ratios on the X and Y axes, and the Y axis sounds much nicer at 1800 mm/min than at 3000 mm/min, which was the default.