Swaying prints.

#1

I have a Geeetech M201 printer. First one I have owned so be kind!

After various issues with the kit I finally got it up and running with a lot of help from a friend who has a couple of printers. The problem I have is that when printing anything over a few millimetres high the prints start to move. The best way to describe it is like a beach, ripples front to rear, very slight side to side but worst front to back. Hopefully if I’ve got it right there should be a picture of a small block. Dimension wise it’s spot on.

What’s been done so far, removed the metal plate and fitted glass print bed (weight reduction/reduced inertia), changed the Y axis (front to back) motor for a bigger one, replaced all the 8mm rods (some arrived as much as 0.8mm bent!), adjusted the stepper drivers to 1.2 volts.

Help?

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#2

Check your belts. They may be loose.

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#3

They seem tight to me but what tension? Played around a bit with the tension whilst running, blackened it until you could see and feel slight play then kept tightening until there was no free play in the tensioner then added a bit more. From a very slight bit of give to what I would class as a bit too tight it didn’t seem to affect it.

This is why I’m at a loss!

Next is swapping the motor drivers for TMC 2100, these are what geeetech have suggested?

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#4

check if the layer heights are evenly.
maybe a Z axsis problem

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#5

The guy that helped set it up initially drilled it hard home that the first layer is very important so spent ages making sure the bed is level even to the extent of bolting the printer to a perfectly flat surface so no movement of the printer and the first layer looks even colour no thick areas. Presume that’s what you mean?

Using Cura as slicer through Repetier.

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#6

Let’s see if we can take some variables out of the equation. Try printing at a lower speed (30 or less). Hopefully this would exclude inertia issues with the hotend carriage. If it’s mechanical, we will likely still see the waves

-S

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#7

Right, if I got it right you should see a 15 x 15 x 20mm cube that’s just come off the printer. Printed at 25mm/s print speed, 20mm/s outer perimeter speed and 15mm/s infil speed. Bed temp 65 and extruder 200 with PLA. X motor 32 deg C, Y motor 31 deg C.

Still showing ripples.

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#8

Ok, let’s go back to what Moorviper mentioned. Do your z-axis lead screws remain perfectly centered? ANY wobble? We are looking for a run-out of half the width of the ripple.

-Stefan

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#9

Ok, on to the printer. The Z axis are looking like their going round an oval dog track! Probably a slight exaggeration but at least 1mm of run out in each side! Going to strip it and see what I can do or if not it’s new screws!

Hopefully this might resolve the problem?..

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#10

Been messin for a while now, it appears that the threaded rods are not that bad but the alloy joints between the rod and the motor seem to be sending the rods out of line? Is this a common problem, the connector blocks not in line? I’ve lined them up as well as I can and sure the test block is much straighter than before, but because of all the probls I’ve had it could be me wanting it to be sorted!

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#11

Yes, the coupler could definitely be the issue. 1mm offset would explain the waves completely. If necessary, you could shim the lead screws with aluminum foil inside the coupler.

-S

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#12

Thanks for all the help here. I found the vertical rods were a loose fit in the bottom bracket, odd really when they are machined but there is a possibility that my mate could have made the hole bigger when he had it to get it working after I built it. I noticed the flex joint wobbling from the info on here then realised it was moving the vertical rods. Solution, mixed some epoxy resin glue, set everything up then put resin in the hole and slid the rod in. Rod doesn’t move now and the vertical sway on the prints has dropped off dramatically! Now looking at everything and found the drive wheel on the X axis is not true, the motor is true but the belt drive pulley caused a regular tight spot when you move the print head side to side!

It’s a steep learning curve but slowly getting there!

All I need to resolve now is why the printer locks up and stops around 20 - 30mm high on a 100mm high print!

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#13

Hi SIMONZ,

There is a really steep climb from 80% to 99% perfect prints. Consider yourself initiated! Glad to hear the waving stopped.

-S

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#14

Hi all,

Bit of an update really. Been doing a fair bit of playing since the issue of the swaying prints and now fitted a pair of 40mm fans to the hotend to cool the prints. After messing around with various ideas of ducting the air to the print not the hotend I came up with a fairly simple one that appears to work! The two prints apart from one having a change of colour after layer 5, are done with the same settings. See if you can determine which had the new fans working!

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#15

The fans!

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