Ringing: wavy lines on sides of part y-axis


#1

I have wavy lines on the y-side of my prints (due to the bed vibrating) like this
I slice with Cura and print at a speed of 40mm/s with an acceleration of 6000mm/s2. With what (speed)settings do you print and do you encounter this aswell? Should I tighten my belt more? Could my stepper be non-functional? The pulley is tightened really hard, so I don’t think that’s the problem.

I use REAL PLA and this example was printed at 220C, but I’ve now changed that to 190C, which is better.


#2

Those speed settings should be ok and are about what I use regularly. I’m not sure what would cause that. Have you tried printing the hollow test object I use in the videos? The reason I ask is that it might be helpful to see what it does on a thin wall.


#3

I too get waves in my prints and have been seeking ways to improve it. My prints don’t have the same pattern as yours and I’m suspecting it’s caused by different issues. FWIW, My acceleration is is set to 3000mm/s2, that’s what Marlin was set to out-of-the-box (Marty’s kit).

Check out this thread on the RepRap forum. They cover a number of possible causes and solutions.

I’m going to try lowering my printing temperature as you suggested, and putting my printer on rubber pads as suggested in this blog post.


#4

@abelom, I found a problem with my printer and wonder if you might have a similar problem. The Y axis motor mount is separating from the end piece.

I’ve got it glued and clamped tonight in hopes that I’ll be able to print a replacement tomorrow.


#5

@Rockey looks like poor layer adhesion there - I recently noticed a decline in print quality on one of my machines that I eventually decided was due to a partial blockage of the nozzle. I suspect your part was printed on that machine. It basically caused some under-extrusion so that there was not enough material to bond properly. BTW the cure was cleaning out the nozzle with a 0.5mm drill bit and that put it back to working well. If you have trouble printing a replacement let me know and I’ll be glad to send you one. Also if you want to play around with the design, the motor ends are designed in Sketchup and the source is kept in the /sketchup folder on github.


#6

I think you’re right. That piece did look like it was under-extruded. I’ve had good bonding with the PLA I’ve been using so I’m printing your y-motor.stl now. Hopefully that will do.

I won’t be using the design file at this time but thought I’d mention that I don’t see any y-motor file in the sketchup file on Github. I checked both the wilson and Wilson2 repos.

Thanks!


#7

It’s in this one -> https://github.com/mjrice/Wilson2/blob/master/sketchup/motor-idler-ii.skp


#8

Thanks @Rockey for the links. I’m having the same problem, primarily on the Y axis, and will be looking at doing the following:

  1. Switch to 16t pulley on the motor end.
  2. Move to a toothed idler pulley.
  3. Switch to a higher quality steel cord GT2 belt.
  4. Try raising/lowering the driver voltage (raising looks like it may make it worse).
  5. Try reducing the u stepping.
  6. Replace generic stepper driver with a better Pololu one.
  7. Replace stepper with a .9 degree per step version.
  8. Make it completely vibration incapable by stiffening, securing, etc.
  9. Make it more compliant with vibration isolation measures.
  10. Motor mount dampers. I already have cork padding on motors mounts.
  11. Examine stepper lead routing to reduce crosstalk. Can easily verify as a problem by disabling other motors.

The aluminum build plate is not connected with springs, which helped. I’ve already reduced acceleration substantially, max velocity, and jerk, which all helped.

Anyone have other thoughts?


#9

Since posting this, I’ve been busy studying and used all the free time I could afford to lose to 3d printing :slight_smile:
In the meantime I’ve also ordered new aliexpress lm10uu, which seem to glide so much smoother. I think it is because these are better lubricated too. What type of lubrication do you advise?

I have also made sure the pulley does not rock sideways on y-axis direction changes. For now I have put a small piece of left over zip-tie between the wall and the tensioner. I’m printing now and I don’t feel the bed vibrating anymore, so I’m sure the outcome will be good.

Just a side question: when you design and print thumbwheels and the like, what margins do you take for the place the nut should pop in?


#10

I use 3-in-1 oil whenever weird noises creep up.

I’ve been studying in much of my free time as well and I have some results to share. Word around the internet is that the "ringing’ is caused by mass at speed subject to sudden changes in direction.The mass of the stopped axis bounces or oscillates. thawkins’s response to this problem posed on the Printrbot forum made sense to me. I only came across this post today and I had already been chasing my tail with various settings as you’ll see below in results numbered 1-5.

In my tests I used larryj’s 20mm calibration cube. I’m using Cura. I’m convinced I should be using simplify3d, I just can’t bring myself to drop the $$$. I stared out trying to achieve quality at 60mm/s but changed gears 2/3rds the way through. In all the the tests temperatures were constant,layer height was 0.2mm and shell thickness was 0.8mm (2 layers thick), If I didn’t specify jerk or acceleration settings then I’m using Marty’s Marlin defaults.

There is much hideousness in prints 0-4, printed at 60mm/s. So much that’s it’s hard to discern the ringing/waves. In person I can see and feel them and they all suffer the artifact worse than print 5.

I don’t expect anyone to be able to read my chicken scratch (hand writing) or care about the round-about way I came to a reasonable result. I’ll just jump to the best result and share how I achieved that and share some of the things I’ve learned along the way.

This is a close up of #6 above. The best 20mm calibration cube of 11 that I’ve managed to print. Don’t worry, I haven’t written home about it.

In short, I achieved the best results by using 4 top and bottom layers and lowering the speed of the outer shell printing to 15mm/s. Here are the print speed settings I used form the Advanced tab of Cura.

Other findings:

  • (In my case) The imprint of the ringing/waves seems to be linear to speed. At 60mm/s the imprint may be 10mm wide, at 30mm/s the imprint may be 5mm wide.

  • I did tests with very taunt and loose (not slack) belts on the Y and X axis and it didn’t create any noticeable results in this artifact on the Wilson 2.

  • Reducing Accel and Vxy-jerk in the Control/Motion settings of the printer did have a slight affect on the amplitude of the waves but didn’t reduce there overall imprint.

Outstanding curiosity:

  • I’m curious if any firmware settings or slicer settings can tell the printer to slow down as it approaches such an axis stop.

  • I suspect that a reverse movement of an axis would damper this affect and I’m curious if one could print at higher speed it printing right angles of parts 30-60° offset to the cartesian plane. I kinda want to test this but I’m also very bored now of printing this cube.

Hope that helps someone other than myself. :blush:


#11

I’ll buy some 3-in-1 oil then.

The improvement on your cube looks awesome. Must have given you good feels.

Isn’t jerk the setting the derivative of acceleration: so how fast the print starts accelerating? I think Thomas Sanladerer did a youtube explanation of these settings.

I really like your elaborate responses on these forums, so definitely keep them coming. I always read them fully and try to use your findings in my settings.