Wavy wall if print speed is not very low?

Hello together,
I just receaved my new TAZ 5 and now I’m trying to calibrate it :slight_smile:
I had a quick look at Cura and printed a hollow test cube for wall thickness test, but then I switched over to Slic3r because I feel more comfortable with it. The first cube with Slic3r had a wavy structure on the walls (all 4 sides equal). I compared parameters between Cura and Slic3r, now I know it’s the print speed.

See the picture attached, from left to right you can see following print speeds:

  1. 10mm/s
  2. first half of cube 15mm/s, then 10mm/s
  3. 25mm/s

The first two cubes on the left are nice smooth, but the right one is “wavy”. You can see it best in the middle of the side wall.

Printing at 15mm/s maximum on outer perimeter sounds quite slow to me, what can be done do get higher print speeds? I was not able to track this error with guides found with google… Maybe bearings? I noticed that the original bushes has a “lot” of visible play to the rods?

It is the loose fitting IGUS bearing that is causing the ripple. I have been fighting it on a new Taz 5 myself. In fact, I have the same problem on an old Taz 2. I have replaced the rails and bearing with hardened rails and metal bearings on the Taz 2. That cured the ripples but led to a strange texture on the surface of the parts. I had to go back to the plastic bearings to eliminate the texture.

No amount of bearing preload or adjustment has really helped on my machines. It really hampers the part quality on the Taz. My Mini doesn’t seem to suffer the same problem. The bearings are not sloppy on that one, for some reason.

You can reduce the ripple by loosening the bearing holders on the bed and X carriage and lightly spreading them away or towards each other and re-tightening the bearing holders to add a little pre-load and reduce the wiggle.

Let me know if you come up with a solution. At this point, I am looking at piercet’s axis upgrades to get rid of this problem.

I did some research, I think we can’t blame the igus bushes for all the play in the axis…
First, the bushes are designed to be press-fitted into a H7 bore with a force of 700N (70kg). I guess, our printed bearing holders can’t achieve that :wink: So the inner diameter will be bigger than expected.
Second, our rods seems to be not that precise. My ones are 9,97mm diameter, which equals 10h9 so there is room the get better here. igus recomends h6-h10.
A qick and easy replacment should be to replace the rods with 10h6 ones and change the bearings to RJUM-01-10. Same bearing type, but with metal casing so the press fit isn’t needed for tolerance to rod. Maybe even RJUM-11 with reduced tolerances…

But I think it should be OK with good LM10UU linear bearing. I head a look at our 3D printer at work (German RepRap X400). It has 12mm rods with LM12UU bearings. Absolut no feelable play, runs smooth and no problems with surface ripple. OK, you can get 4 TAZ 5 for one X400, so I’m not surprised :laughing: I will try to find out which manufacturer they use…

12/5: I have a surface waviness problem. I’m getting significant waviness on large horizontal surfaces like ripples on water - like if you take a glass of water and tap its side. It’s really bad. This is regardless of temperatures and speed, though these items have a minor effect. I can somewhat change the nature of the waviness by moving parts to different locations on the bed and by changing plastic colors.
I make large parts and quickly wore out the stock bearings. I replaced them with Misumi linear ball bearings and hardened shafts about 6 months ago, I recall. The bearings were carefully mounted to ensure easy action along the full range of travel.
It seems my problem is harmonic vibrations. I can feel them by resting a finger on the bed or extruder. I believe know the solution; it’s old-fashioned sintered bronze bushings. I gotta find me some that will fit the Misumi 10mm shafts. If anyone has found and installed bronze bushings, I would appreciate your insight.

12/6: I’ve ordered a dozen sleeve bearings from Amazon ($50 including shipping). I can’t find a direct replacement of the same size as the current bearing (which would be very heavy anyway). The bearings are SAE 841 (sintered bronze) 10 mm ID x 14 mm OD x 25 mm L. I’ll design/print sleeves to bring these new bearings to the size of the current bearings (19 mm D x 29 mm L). I’ll edit this post with my results.

Would be awsome if you could post pictures from now and after you did the bushing-mod!

I just replaced the Misumi linear bearings with sintered bronze sleeve bearings and CURED my surface waviness problem (see my post in this thread from 12/6/2015. See photos.

The first photo shows the extent of the rippling I was getting on large horizontal surfaces. I had replaced the stock plastic bearings with Misumi linear bearings and hardened shafts on the X and Y axes months ago. I was careful to ensure that the bearings moved freely. I noticed that the bearings did rumble a bit. After installing a .5 mm nozzle recently and while printing a part with a large horizontal surface, I was getting the rippled surface as seen in one of the photos. It was awful.

So, I ordered sintered bronze bearings from Amazon (see photo) and designed/printed some ABS sleeves to bring them up to the size of the original plastic bearings (19.2 mm OD x 29 mm L). The final photo is the surface I am now getting - smooth as can be! I replaced all three axes while I was at it. The bearings are smooth and silent. The printer is much quieter now.
Surface Ripples Misumi Linear Bearings.jpg
Surface Ripples Bronze Sleeve Bearings.jpg
Sleeve Bearing Parts.jpg