Strange Moire like texture on prints [SOLVED]

rbjam83

@doctrucker I'm starting to think this is some combination of stepper motor/driver setting issue.
The Titan seems to be fine.

timothyz

@rbjam83 Here's something to try because I have a hunch, try setting your microstepping on the extruder to 8 instead of 16.

My intuition says that that would isolate it to either the extruder, motion axis, or firmware.

-Tim

Phaedrux

How recently did you get the Titan Aero? Older batches had issues with bearings failing and causing all sorts of intermittent problems. Do you see any rust like residue around the bearings? Does it ever make any clicking or squeaking sounds?

E3D will send you replacement bearings free of charge if you request them. Made a world of difference for me.

I would also try increasing your motor currents for X and Y to 85% of their rated max.

rbjam83

@timothyz Just printed two more cubes, in one X and Y were set to x8 microstepping without interpolation, and on the other, I did the same with the extruder motor. Nothing. No change.
But I'm reading other threads about more in depth settings of the stepper drivers. I'll try some of those later.

rbjam83

@phaedrux I bought the Titan just three weeks ago from Filastruder. I'ts already from the new batch and the bearings are fine.

timothyz

@rbjam83 Have you tried upping the current to 1.4 or even 1.7 as rated? If you don't drive with enough current, I think steppers tend to cog more, you really need current to microstep well. (Anyone correct me if I'm wrong)

Phaedrux

@timothyz said in Strange Moire like texture on prints:

@rbjam83 Have you tried upping the current to 1.4 or even 1.7 as rated? If you don't drive with enough current, I think steppers tend to cog more, you really need current to microstep well. (Anyone correct me if I'm wrong)

I would agree. I get smoothest motion when driving ~85% of rated current as recommended by the setup guide.

rbjam83

@phaedrux FINALLY!!
It was the motor current that was too low.
I never would have guessed it, since I was operating on the "but I print slow" mind set.

Thanks everybody! It really was quite the learning experience for me.

Now I can go on with the rest of the tweaks...

3DPMicro

@rbjam83 that was the my first question
Looks good now go have fun

dc42

I'm glad you solved it. Microstepping is not accurate at low motor currents, because of the interaction between the detent torque and the torque resulting from current.

Can you tell us the rated current of the motors, the current you were using originally, and the current that resolved the problem?

rbjam83

@3dpmicro I know. And I did increase the current from 800mA to 1000mA and got no improvement. As I said, I had the wrong mind set about this. I was doing incremental changes when I should have gone bigger.

rbjam83

@dc42 The full spec of the motors are as follows:
Steps / mm: 200
Rated Voltage: 3.4 V
Rated Current: 1700 mA
Phase Resistance: 2 ohms
Inductance: 3 mH
Holding Torque: 40 N

Initially I was using 800mA when the issue fist presented. I then increased it to 1000mA to no effect. It was only when I went to 1400mA that the texture disappeared.

dc42

@rbjam83 said in Strange Moire like texture on prints [SOLVED]:

@dc42 The full spec of the motors are as follows:
Steps / mm: 200
Rated Voltage: 3.4 V
Rated Current: 1700 mA
Phase Resistance: 2 ohms
Inductance: 3 mH
Holding Torque: 40 N

Initially I was using 800mA when the issue fist presented. I then increased it to 1000mA to no effect. It was only when I went to 1400mA that the texture disappeared.

Thanks. Do you know whether it was the XY motor currents that made the difference, or the extruder motor current?

paboman

@rbjam83
current was to low for extruder motor or XY Motors ?
thx

rbjam83

@dc42 It was the X and Y motors. The extruder motor was ok, it is also a different motor (its the slim 0.9 deg sold by E3D).

Phaedrux

What brand and model? Just for curiousity.