1 Topic by Thooto (edited by Thooto 2016-08-28 16:19:56)

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Topic: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

Hi!

I just got this 3D printer and for now I'm very happy with what it printed so far.

However I noticed that circles are not printed perfectly round, look more like ovalish to me and thus I can't create accurate objects...

This problem is very similar to what happens to some Da Vinci 1.0 owners (and other 3D printers also) however since mine is the Junior I can't find any suitable tutorial to fix the problem...

Any idea on how to proceed? The picture is taken from the front so X-axis is left-right and Y-axis is up-down.

Thanks a lot,

Thooto

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2 Reply by Thooto (edited by Thooto 2016-08-28 16:27:22)

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Re: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

Update: kind of found a solution thanks to a comment on a YouTube video. It suggested to tighten up the belt for the Y-axis (bed axis), and this solved the problem at 90%. The test circles I printed are no longer lemon-shaped and look good enough to me (even though there still is the same effect, but minimized).

Here is the video: youtu.be/AF0wNn1oUiM and the comment is from Gimpdiggity:

I adjusted the x-axis today and did a quick test print of a circular item.  A tiny better, but still noticeably not a circle.  Figuring I was going to probably end up exchanging this printer for another, I figured what the heck and tore into it.  It's actually not difficult to get down to the y-axis belt.  The four screws that hold the glass bed in place, then three screws that are visible under the glass are all that's necessary to get to the belt enclosure...then that enclosure just snaps off .  Once I was in there, I noticed that the y-axis belt was VERY loose compared to the x-axis belt.  I couldn't really see back in the back (I didn't have the case disassembled) so I grabbed my phone and took a picture of the spring assembly that keeps the y-axis belt tensioned.  It has a screw (same T10 as all the others) behind it that you can't see.  A quick half turn to loosen that screw and the entire assembly snapped back a good 1/8th of an inch or so...that screw had the whole assembly so tight that the spring that keeps tension wasn't even actually doing anything other than remaining compressed all the time.  I loosened it a bit more and let it settle, then I tightened that screw back down. 

A second test print resulted in about as close to perfect as a circle can get!!!!  Awesome!!! 

I'm running a second test print of a more substantial object right now to make sure, but I think I've got the problem sorted, and I won't have to be sending this one anywhere after all!!!!

This gave me a great improvement in the shape of the circles, yet not perfect. I think if I tighten them even more maybe it'll be good.

3 Reply by Anthem

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Re: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

This is exactly what my circles were looking like, too. See my other thread on the topic: http://www.soliforum.com/topic/14991/pr … iagonally/

Glad to hear that you were able to tighten your Y axis belt and it helped. I've messed around so much with my Jr that you can barely even call it a Jr anymore (I fried my firmware, replaced the board with RAMPS, swapped out the hotend with an E3D Lite6, and am currently planning an upgrad to dual extruder and also tinkering with replacing the Y axis entirely and extending the Z axis.

After all my tinkering,  my holes are coming out OK, but there's still a little bit of skew like in your photo. It's good enough to produce usable parts though.

I wonder, what slicer are you using? Are you using the stock XYZWare? I've been wondering if certain slicer calculations aren't partly responsible for this added skew.

4 Reply by jwalker55

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Re: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

Thanks for posting this. I am having this problem too and the next place I was going to look was under the bed! Mine are printing exactly as shown in your first post. I'll post back with my results.

5 Reply by jwalker55 (edited by jwalker55 2016-09-04 02:32:09)

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Re: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

So I did what was suggested in the youtube comment posted above. Took the bed off and checked the belt and found that the belt wasn't loose at all, and was about the same tension as the x-axis belt. For giggles, I loosened that screw that holds the spring-loaded part that helps keep tension on the belt but it was already pushed back as far as it could go. Not really sure what else there is to do. I've greased the shafts, but not sure there is anything else that needs greased? My circles aren't as bad as the pic in the original post, but they're not great either.

6 Reply by Edwin

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Re: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

Could this problem have been the cause that the Pully toothed belt is not tightened properly on the axis of the stepper motor?

We had this problem with exactly this appearance have often and in many cases what this is the reason.

7 Reply by chorobe

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Re: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

I've tightened both my x and y belts but my circles are still messed up to the point that you cannot use it to print objects like a bolt and nut that go together.  How tight do you guys tighten the belts? I wonder if I have not tightened them enough...

8 Reply by Thooto (edited by Thooto 2016-10-07 12:56:12)

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Re: Da Vinci Jr. 1.0 - rounds not round (nearly fixed)

Hi !

Sorry for not having posted anything lately. But reassured to see I'm not the only one having this issue.

I am using the XYZ slicer. I didn't try using another slicer because I saw there was a poor support for the Da Vinci Jr.

However in the software the circles appear perfectly round. So I really don't know what could cause that.

It really looks like the y axis "forgets" to move until a certain position haha. Then catches up the lag.

@chorobe I tightened the belts strongly. Not at the point of breaking them however.

@Edwin I also though of this. However I tried moving them separately from the motors and it seemed impossible as they are glued. Also I think that the deformation would end up way bigger, because the belts already apply a strong pressure to those pullies and may make them slip. I'll retry and let you know.

Thanks smile