Mendel Firmware Settings

Hello there. This will be my second post since my first one was very successful on here before.

So I have been building my own CNC machine / 3d printer and have everything physically built. I can move the motors with Repetier Host. They move in the correct direction. My problem is setting the step/unit ratio. The default was around 30 or so for the x and y and after running the calculations I have set them to 1009 each. When doing this, the motors will no longer move. They make a very high pitch noise like they are receiving the output but won't move at all. My question is two fold. First of all, I assume that Repetier uses mm as the default unit of measure? So in manual mode when I click to go "100" that would mean to move 100 mm right? If this is correct then should there be something else I change when using such a high step/unit ratio?

Here are my settings:

// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT {1009.45, 1009.45, 711.51, 167} // default steps per unit x,y,z,e
#define DEFAULT_MAX_FEEDRATE {500, 500, 10, 100} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {9000,9000,100,10000} // 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 1200 // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 1200 // X, Y, Z and E max acceleration in mm/s^2 for r retracts

//
#define DEFAULT_XYJERK 20.0 // (mm/sec)
#define DEFAULT_ZJERK 0.4 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)

You will probably have to greatly reduce you XYJerk and accelleration settings.
With a steps/unit that high you are asking the motor start spinning way too fast and that is likely stalling the motor.

---

___________________________________________________________________________

My blog [3dprinterhell.blogspot.com]

I put the XYJerk to 0.5 and the DEFAULT_ACCELERATION and DEFAULT_RETRACT_ACCELERATION to 60 and now it moves but in 4 small "chunks". It still sounds like it is stalling out though. The Z axis has the same motor and is much closer to being accurate btw.

I assume it's screw driven from the large steps/unit.
If the stepper is not enabled or better disconnected, how hard is it to turn the screws?
You don't mention what drivers you are using, If they are still stalling, either they are not providing enough torque possibly because of mechanical issues, or too low a torque setting on the driver, or the driver is overheating.

---

___________________________________________________________________________

My blog [3dprinterhell.blogspot.com]

I am using Marlin firmware on a Gen6 board. Yes it is screw driven. They turn very freely. Like I said too, the Z axis has the same exact motor and can go both up and down without problem. The motors I have is this one:
[www.interinar.com]

Have you adjusted the trim pots on the stepper drivers, if the current is too high or too low it can cause an issue.

---

___________________________________________________________________________

My blog [3dprinterhell.blogspot.com]

if possible switch to teacup firmware for this. the timings are critical for screw systems. i bet you are dealing with micro pauses from acceleration calculations.

or you can look for tonokip firmware that does not use acceleration, you will be limited to maybe 30mm/s but the pauses and system stalls should not be an issue.

Edited 1 time(s). Last edit at 05/28/2013 10:00PM by jamesdanielv.

I will try the pots when I get home first. If that doesn't work then I will try teacup and if that doesn't work then tonokip. Are teacup and tonokip compatible with the gen6 board?

You also need to reduce your max feedrate. 500 mm/s and 1009 steps per mm do not fit. max. frequency is 40-50khz, so max feedrate should be around 40 mm per second. I also doubt an acceleration of 9000 is doable.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

I tried many things but I eventually solved this simply by switching to teacup firmware which was quite easy to use. Everything is all set up now. Thank you for all of your help.