Dimensional accuracy,.. but only in the Y direction

[rhoogenboom 3]

Hi,

 

I'm wondering if other people have some experience with this. I have an UM3 extended and print 99.9% of my things sliced by Cura (4.2.1 at the moment)

 

I do some CAD drawing and pretty much always, my printed parts never fit. Despite my putting some margins in the drawings, I usually end up doing print-try-adjust-drawing and start all over again. Since for me this is all hobby and I have by no means any knowledge or experience how you should take fitting tolerences into account, I figured it is the best I can do.

 

But recently it just annoyed the heck out of me, because I had to adjust and reprint so many times, that it just didn't make sense anymore. So I had look on the forum on dimensional accuracy and calibration and I printed the 20x20x10 calibration cube.

 

Now reading the posts here, I only seem to find people that have a consistent X and Y calibration error. I have a different problem: my Y size is off, my Y size is pretty much spot on. 

 

So my test cubes (just a few of them but they seem pretty consistent):
1 - X(20.01) Y(20.18) 

2 - X(20.00) Y(20.21)

3 - X (19.94)  Y (20.06) - I played with horizontal expansion on this one, however that also impacts my X size too and decreases that too much.

 

So how do you calibrate only the Y? I need X horizontal expansion and a separate Y horizontal expansion,.. Or is there another trick?

 

I also did a print at the advice low 30mm/sec print speed, I measure in the middle, not the elephant foot first layer. It's a PLA print, this filament might be more susceptible to shrinkage, as the bottom and top layers seem to come out a bit, but with the current infill pattern and print form (equally sized cube), such shrinkage should be the same in both directions. 

 

One thing which might be the cause: I had this with my previous UM3 also: one of the slider bearings in the head is probably worn out. Now with my previous, I could really hear the head click when I would change direction. If I feel the head of my UM3 ext now, it does have a very very little bit of play. Meaning I can move the tip of my nozzle sightly from forward to backwards make the whole head move ever so slightly on the axle.

 

I have ordered a new set of bearings, so when they are mounted next week, it should exclude that as a cause. 

 

Any ideas or pointers are welcome.

 

Cheers,

 

Richard

 

 

 

 

 

Edited September 4, 2019 by rhoogenboom
Added attachment picture

[my3DBr 4]

I am getting EXACTLY the same problem in a UM2E. 

Everyday rechecking hardware for any king of source for this problem. No matter what I do, X is spot on, Y always bigger.

Ended up getting suspicious about firmware installed. I'm at this moment compensating in Cura for the Y, printing lower then 100% size.

 

[SandervG 1,521]

Hi @my3DBr, perhaps you can start a new thread describing your findings and perhaps you can include some pictures of your prints and measurements too. As you can tell, the above post is over a year old and we don't have much information from your post to provide some feedback on. Perhaps positioning on the build plate could be relevant, or friction on the rods. It is nice that you can compensate via Cura, and if it works it works, but I could imagine you would like to learn what causes the offset. Thanks! 

[my3DBr 4]

Hi @SandervG, thank you.

I did started a new thread but it did not reach people I don’t know why.

I will try there then.

I have new info, so I’ll put it there