Rough, wavy surface, motor vibrations
Dear Repetier support
Dear Forum members
I have a problem:
I have built a self-designed quite large Ultimaker-Style 3d-Printer, for the electronics, I´m using an Arduino Due with a RADDS-Shield an 1/128 RRD Silencioso stepper motor drivers.
Here is an earlier render of my printer, I´ve changed some things, for example the belt tensioners are replaced:
The problem that I´m having is that the motor is vibrating when moving, so i see vertical lines at straight walls and wavy patterns at curved objects (like in these photos). I´ve postet some pictures here: http://forums.reprap.org/read.php?336,393221,page=7
I can hear and feel the motor vibrating when moving, the wave patter doesn´t match with the belt weidth (GT3 3M) and it doesn´t match with the full steps of the motor.
It looks like the motor stops moving every few micro-seconds.
The motors are connected to the XY-carrier quite stiff with stiff couplings and strong tensioned belts, so the motor vibrations directly transmit to the extruder. If I decouple the motors, the mechanics are very easy to move, so the problem isn´t coming from here.
I´ve heard that Repetier uses an interrupt for reading sensor values and for communication and during this interrupt, Repetier doesn´t send stepping signals, that would explain the virbrations.
I´ve already tried to change the stepping mode from 1/128 to 1/32 and changed the motor current as well as the decay mode, same result.
There has to be a way to make the motors move smooth.
Dear Forum members
I have a problem:
I have built a self-designed quite large Ultimaker-Style 3d-Printer, for the electronics, I´m using an Arduino Due with a RADDS-Shield an 1/128 RRD Silencioso stepper motor drivers.
Here is an earlier render of my printer, I´ve changed some things, for example the belt tensioners are replaced:
The problem that I´m having is that the motor is vibrating when moving, so i see vertical lines at straight walls and wavy patterns at curved objects (like in these photos). I´ve postet some pictures here: http://forums.reprap.org/read.php?336,393221,page=7
I can hear and feel the motor vibrating when moving, the wave patter doesn´t match with the belt weidth (GT3 3M) and it doesn´t match with the full steps of the motor.
It looks like the motor stops moving every few micro-seconds.
The motors are connected to the XY-carrier quite stiff with stiff couplings and strong tensioned belts, so the motor vibrations directly transmit to the extruder. If I decouple the motors, the mechanics are very easy to move, so the problem isn´t coming from here.
I´ve heard that Repetier uses an interrupt for reading sensor values and for communication and during this interrupt, Repetier doesn´t send stepping signals, that would explain the virbrations.
I´ve already tried to change the stepping mode from 1/128 to 1/32 and changed the motor current as well as the decay mode, same result.
There has to be a way to make the motors move smooth.
Comments
Thanks for the fast response.
I use 24V for the motors.
I did some further investigation with this printed octagon:
Octagon
X-Side
Y-Side
X-Y-Side
X-Side with measurement
X-Y-Side with measurement
This part is 10 mm high, print settings are 0.2 mm layer height, 3 perimeters and 25 % infill.
Every 3 mm, the printing speed has changed:
0-3 mm: Default 66 mm/s, Outline Underspeed 40 % (26,6 mm/s)
3-6 mm: Default 100 mm/s, Outline Underspeed 40% (40 mm/s)
6-10 mm: Default 133 mm/s, Outline Underspeed 40% (53,3 mm/s)
(I use Simplify3d for slicing, so the "outline underspeed" means that the outermost perimeter is printed with 40% of the default speed, the middle perimeter is printed at 60% and the innermost perimeter is printed at 80%. )
As you can see, the distance between the waves is longer at the higher printing speed. To be exact, a double printspeed results in a double wave length. (maybe this isn´t clearly visible at the photos, but I can definitely see it here)
In my opinion, this shows that the waves are generated at a fixed time interval, so only the Due or the firmware can be responsible for it.
The linear bearings I use are running absolutely free nearly without any friction or slip-stick-effect. The belts also can´t cause this problem because if so, the wave pattern would have a fixed wavelength, which isn´t the case.
Any further ideas?
Only for the case that the interrupt causes this problem, is there a way to modify the frequency of the interrupt (the time between the interrupt) without rewriting the whole firmware?
I didn´t find any "#define interrupt_time" or something like that yet.