very bad y-axis wobble on new wanhao i3 plus

[chgehrig]

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hello,

i recently bought my first 3d printer, a wanhao duplicator i3 plus. out of the box, the y-axis bearings made a terrible noise (seemingly experienced by a lot of buyers) and there was considerable friction when moving the print plate around. prints came out accordingly. i then decided to:

-replace the bearings with some drylin.

-recentered the y-axis guides. they seem completely straight, are parallel up to a tolerance of 0.2mm

now, the bed moves flawlessly and without any obvious friction when disconnected from the belt. when connected, there is the friction of the stepper motor, but i can move it just fine by hand. when i just lay the bed onto the support plate without any springs, it is moved by the motor without any wobble. however, as soon as i tighten the thumb screws (and get the bed level), the y axis wobbles so hard the whole desk shakes. in order to fix this, i have

-recentered the guide & motor for the y-axis belt. they are now as close to 90 degrees to the belt as i could get them. this made a very slight improvement. still very wobbly.

-removed the belt tension springs and tensioned it with cable ties. tried out two different degrees of tension. no difference.

other things i did:

-installed microswiss hotend

-“blueprinting” of z-axis

-added borosilicate glass (3mm thick)

-raised z-axis endstop accordingly. i experimented with several heights because i thought the spring tension would be responsible for an in/decrease in wobble, but to no avail.

everything else works wonderfully. all other axis are precise and wobble-free, the hotend is just fine, print bed adhesion is good with a pla-water mix, layer height etc all according to expectations. i put way too many hours into this problem already and can’t seem to solve it myself. is there any known fix? i know there are thick aluminium support plates to be had on the internet, but i am from switzerland and all the stuff would get ages to get here. i will buy one after i have tried out the remaining possibilities. also i am not sure the problem stems from a warped support plate, as it seems level even under tension.

i am using the printer for molds which will then be post-processed, so i don’t need very low tolerance levels. but the prints look like they were printed in a rally car on a particularly bumpy track. any help would be greatly appreciated.

p.s. there seems to be more wobble forwards than backwards.

[horsj]

What speed are you printing at?

[chgehrig]

currently 60 mm/s.

i am pretty convinced it is the guide bed: when i focus on having the print bed exactly parallel to the guide bed (and not level to the extruder), the wobble stops. can it be that the guide bed warps under the tension of the screws, and could that be the cause for wobbling? it is one of the flimsy stamped aluminium ones.

[Titjer]

Hello.

I think that you must check the voltage of the y pololus on the main board. Or ensure that it is well ventilated.

The voltage depends of the stepper and drivers.

Then, thereare several forums that explain how to proceed.

Jeremy