Vertical lines

What might be the cause of these vertical lines? I get them in both X and Y sides.

... could be mechanical 'artifacts' from the belt teeth in a not perfect fitting groove in the gears ... or when feeding the belth with the toothed side over smooth rolls ...

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Viktor
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It's belt related...

... exactly - somewhere the teeth are 'hopping' and changing tension and position of the head ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

yup. every time a tooth hits the flat of the idler, you get a bump. (I see them on my friend's prints) Either nophead or one of the other reprap "ninjas" suggests twisting the belt to engage the idler with the flat on the belt, in order to reduce and/or eliminate the issue. Not sure myself since I'm just now finally building my printer, but it makes sense. I'll probably do the same until I start printing my own replacement parts, at which time I'll be using a toothed idler.

Edited 1 time(s). Last edit at 02/05/2013 07:01PM by xiando.

The one in the first photo looks quite different from the second one which I also attribute to the belt.
What I have noticed is that even when belt related lines / waves are not an issue, there is slight banding. Your problem could be the same.
So far, I attribute the second banding (which also is much finer than belt banding) to the infill displacing the perimeter outwards a bit where both meet. I used a single perimeter, by the way.

I found the my X and Y idler wheels had bumps on them from the printing. By sanding down the bumps, the result is much better. I can still see it but it not nearly as bad. I suspect that if I went to metal idlers and finer tooth belt this would completely fix the issue.

@zveck, are you using printed or machined pulleys? If printed, I think you might also find a reduction by using machined pulleys. They're pretty inexpensive, so it's something you might consider if you aren't already using them.

Hi Zveck,
I'd recommend you replace the printed idlers. I switched to double-bearings as idlers a long time back. No need for fender washers with this arrangement either. I've also reversed the belt over the far side idler (also a double-bearing arrangement) so the smooth side of the belt passes over the idler. I'm not sure how much of a difference reversing the belt actually makes, but it doesn't hurt. I've dug out an old pict that shows my idler set-up. Easier to show a pict than explain. I've since replaced the y-motor bracket, removing the need for the front idler completely (just something to consider).


No front idler now, using this y-motor mount.


If you're concerned about how much trouble it will be to replace the idlers, then if you find some way to secure the printer to a baseboard you can unscrew the relevant threaded rod (take your time!) without taking the printer apart, then slide on the bearings as you thread the rod and all the relevant nuts back on.

Keep at it! :-)

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