Marlin ErikZalm z axis motor problem (works with T3P3)

Hello,

I'm pretty new in this "3D printer scene", I've got my printer now for over 2 weeks.
I've build the 3D printer (Prusa i3) within one week and now I'm calibrating etc. since last sunday.

Long story short:
Everything is fine with Marlin from T3P3.
Not fine with Marlin from ErikZalm.
The Z axis have problems when moving fast. (If too fast, it doesn't move at all and gives noises.)
The configuration of the mechanical part is identical to T3P3 configuration.
I didn't change the configuration_adv on both (I was sure that it doesn't need any configuration).

To be some more precise (probably most important part):
HOMING_FEEDRATE {50*60, 50*60, 4*60, 0}

DEFAULT_AXIS_STEPS_PER_UNIT {80,80,4000,360}
DEFAULT_MAX_FEEDRATE {500, 500, 2, 25}
DEFAULT_MAX_ACCELERATION {180,180,20,200}

DEFAULT_ACCELERATION 60
DEFAULT_RETRACT_ACCELERATION 60

DEFAULT_XYJERK 20.0
DEFAULT_ZJERK 0.4
DEFAULT_EJERK 5.0
They are all the same on both builds. (Triple checked.)


I have a Sanguinololu 1.3a with ATMega 1284p at 16MHz and 4 Ice Blue Stepsticks.
Using NEMA17 Motors from Wantai. Also connected (and working) is a Panelolu2.
As of the Prusa i3 the Z axis uses 2 motors. Both are connected to the Z axis connector on the sanguinololu.
The motors have to be OK, since it's working with the T3P3 firmware.

I hope to get some help here, I don't know where I might get help if not here.

Out of interest do you have EEPROM enabled within one version but disabled within the other? Sometimes the values stored in EEPROM can override those in the firmware.

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DuetWifi.: advanced 3d printing electronics

EEPROM on both enabled. (I checked to be sure.)

I think I know what it is/was but I don't know, why on one firmware and not the other.
The right Z motor have to deal with more drag.
Today I accidently held that threaded rod too strong and the same noise appeared.

The electrical resistance on both Z motors differs from each other, that might be a problem as well.
This don't explain why one firmware have no problem with it.
It works atm with the Marlin T3P3 firmware.

Edited 1 time(s). Last edit at 07/12/2014 06:36PM by Loader009.

I think I've found the reason for my Z-axis problem.
The motors are connected to the threaded rods with an alluminium... thing (don't know how it's named; see picture).

I have (because of unexperience) let the rod and the motor "touch" inside this alluminium "connector".
That is probably the problem. Now I've placed them with some space, so they don't touch each other.
That should help.

The right rod is still squeaking while turning. That's probably because I made some mistakes while getting the nut into the plastic.

I also still have to test another firmware, I just noticed the touching-problem and corrected it.
(Still trying to get a successful print with cura... Have to start from the beginning again >.< )

Edited 5 time(s). Last edit at 11/08/2014 12:41PM by Loader009.

Seems that the problem wasn't the "touching" of the rod and the motor..
The issue still exists. (With marlin ErikZalm firmware; same settings as used in T3P3.)


One motor seems to hang (Z-axis), so the other one moves "partly".
Because of this they get different heights.

I'm thinking of getting new plastic parts and new linear bearings. (Those which I got might be defective...)
New threaded rods will also be needed, sooner or later.

I've got the "Prusa i3 Achatz edition" from reprapuniverse.com (Achatz Industries).
After a little conversation the shop didn't react at all. I won't buy there anything ever again.
Also they seemed to save costs on the sanguinololu by shipping capacitors with less voltage than given in the wiki.

Hi loader

It could be that the stepper driver is simply not set high enough to overcome the friction - try turning up a small amount (1/8th of a turn) and see if that improves the situation.

Tony

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DuetWifi.: advanced 3d printing electronics

I'm sure that I tried that earlier and it didn't help

But I tested this anyway.
It looks like it works (almost) fine when it is "warm".
I let it about 10 times move up and down.
Sometimes it showed the issue temporarily (about 1s or less).

I turned the stepper driver about 1/8th (clockwise), it seems to have no impact but the issue didn't last as long as it did the first time this day.
I also have an "easy stepper" (got it this week). With this I am able to test a stepper driver. I also have a lab power supply (up to 30V/2.5A), this is how I plan to power this "easy stepper".
I will test that (hopefully) tomorrow and report.

Those stepper driver, I am also sure that I changed their places to look, if one of those might be defective. All driver seems to work fine...
Still, I'll test it tomorrow.

Edited 2 time(s). Last edit at 11/08/2014 01:32PM by Loader009.

I've tested and the results are confusing me.

First, the hardware:
Ice Blue StepStick -> [reprap.org]
2x Wantai Stepper Motors (NEMA17) 2.5A(U) (I can give the modelnumber if you need)

The motors have little differences in resistance... I'm kind of confused, that one of them seems to vary between 1.4-1.7 ohm.
(Bad soldering point? I had extended the cable of one motor.)

Also some of my results:
1. It seems that I haven't gave enough VREF for the motors but
2. maximum VREF of the driver isn't enough for highest speed and
3. for a better "start" I have to go nearly max of the stepper driver. It would overheat fast if I stay it this way.


I am sure that I did something wrong. I will start with the soldering point, where I extended the cable.
Can you give me some advice how it should not be (or be)?
(If you have a multimeter, could you look, how much VREF your stepper driver for Z-axis has?)

I could also make a video of the problem.

With the Easy Stepper (-> [reprap.org] ) I could also test different microsteppings.
- With all three MS inserted (1/16) it moved slowly. Using the button for "right" it moved fast downwards. "Left" button resulted in a monotone sound.
- With no MS insterted, it moved fast, but using the buttons or turning the pin to much to one side, it resulted in sounds without moving.
- The "left" button resulted always in a monotone sound. The "right" button was depending on the turn of the pin, too much turn of the pin resulted in different sounds.

Hi

For a "standard" Z axis you should be able to run at around 0.8A with no problems.

The microstep test you outline makes sense because as you move from 1/16 to full steps you would naturally get faster movement for the same step rate.

Have you tried swapping the drivers/motors to confirm they are correct - you mention potential hardware issues with soldering but you also say that different firmware gives different results which points to a configuration issue.

You should investigate using slower acceleration (and confirm that the acceleration you think you are using is the actual one by trying with EEPROM disabled during testing).

Cheers

Tony

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DuetWifi.: advanced 3d printing electronics

Ok.
0.8A, I will try to calculate the correct VREF.
I also understand the microsteps, because I understand what it is for.

I also will swap motors/drivers later. I swapped earlier the driver (before I had got the easy stepper) but now I am able to test more precise.
The motors... well, it's kind of hard (because of the cable length) but I will test that of course too.

I think that the accelleration is different on ErikZalm Marlin firmware, but I'm not sure. The configuration (the values) are the same (otherwise it wouldn't make sense to compare).

The acceleration is already slow, but as I said, it differs. I have to test that also v.v

#define DEFAULT_MAX_ACCELERATION      {180,180,20,200}

#define DEFAULT_ACCELERATION          60

My list to test:
1. swap driver to be sure they work correct
2. swap motors/check connection (maybe connection check at first)
3. firmware (marlin ErikZalm/T3P3) check, config and real acceleration


PS: Now I also have a "wireless USB" (iogear GUWIP204), that works with the 3D-printer. That makes it alot easier to work with the printer.

Edited 1 time(s). Last edit at 11/17/2014 03:24PM by Loader009.

Hey there, I guess you have not expected a sign from me ;D

Good news: The Problem seems to be solved.

There are many things which might had influence on my problem.

- holes for the M5 threatet rod of the X End Idler/Motor might have been too small (expanded them)
- one cable to a motor might have not been properly soldered (tested each and fixed the faulty one)
- too high feedrate for the Y axis? (I am pretty sure this was not the issue. But in the last firmware update/change I forgot to lower that and the issue was similar.)
- stepsticks gave not enough power? (I have recalibrated each one of those, they should be all fine now.)


At the end I have a working 3D printer... in theory, I still have to find the correct settings. (Temperature; calibration of the extruder; recalibration of the settings in the firmware etc.)
Sadly I have found nothing to the acceleration settings and top speed for the Prusa i3. (I know each printer varies but it is better to start with some good values, I have no clue >.< )

Well, thanks T3P3 for your help, now I think I can go on my own

Edited 4 time(s). Last edit at 07/07/2015 07:55PM by Loader009.