so what causes this?

[printbus]

Is there a setting to control how the printer decelerates towards an edge?

The acceleration settings apply to both the acceleration and deceleration phases of a movement.

[DanCope]

I've been following this thread with some interest and have been doing a little digging on the web. The general opinion seems to be that it's a mechanical problem and, as has been mentioned here, one that can be somewhat improved by slowing down travel speeds and tweaking the accel/jerk parameters.

It also seems to me that this problem is specific to Cartesian coordinate systems. I haven't yet found any complaints about "ringing" on delta type machines. Can anyone confirm that delta machines are immune to this ringing problem?

I think you are right, I have also found more information about stepper motors in general now that I had a better idea of what to look for. The 'Vibration Problem' section on this page seems to describe the problem we have. It kind of seems it's just a limitation of these motors.

I imagine delta printers don't show this issue because of the way it drives the motors. It is probably less likely to bring a motor to a sudden stop and any vibration would be absorbed differently into a print than straight across an axis.

The acceleration settings apply to both the acceleration and deceleration phases of a movement.

That makes sense. I would guess there is a lower limit to how slow it could go before it stops the motor completely so even decelerating slower might not help in terms of a sudden stop.

[AbuMaia]

As far as I know nobody's come up with a universal metric for determining "proper" belt tension. I did find one tool for measuring tension on Thingiverse, but I've not tried it yet.

[AbuMaia]

Do you see ringing on the inside of the box as well? That's what I would expect if it had something to do with the extruder.

[printbus]

Do you see ringing on the inside of the box as well? That's what I would expect if it had something to do with the extruder.

On the holes and notches in thin sidewalls, yes it is on both the inside and the outside. Whether it is on a corner, a hole, a notch, outside or inside, it's always on the right hand side looking at an upright surface. At least on my small test print, I know that's the exit direction of movement.

In other words, it's not that the same ripple is showing up on both sides of an extrusion. I should point out that with at least the test print I'm currently using for this, "thin wall" is still fairly thick - it's 1.75mm. I'm seeing Simplify3D use three passes for this 1.75mm wall.

[gmay3]

From my experience, I'd say you know the belts are tight enough when you tighten each belt by pulling on the motor as hard as you can with one hand and use the other for tightening the screws to keep it in place. I wouldn't use tools or clamps since they can apply exponentially much more force than you'd expect and you can't get a good feel for how tight things are compared to your hand.

[DanCope]

Just to add some more data to this. I am experiencing a similar issue to OP. I found this nice test object by ocrinus (http://www.thingiverse.com/thing:277394) which will show up both X and Y axis ripple. The X and Y letters are aligned to their respective axis.

I am printing with a Prusa i3v, 0.1 layer height. First print is with default settings.



Second print is with Jerk lowered to 15 (from 20) for the bottom half and then Jerk 10, plus AMaxX/Y down to 500 on the top half.



It is more noticeable in person, although the lower speeds do make it less visible. My guess would be that it is caused by rocking in the motors when they stop? It always ripples in the direction of movement, as printbus says above. It also looks fairly consistent between both axes so I wouldn't have thought it had much to do with give in the framing or vibration to the print head (but hey, what do I know ).

I am in the process of tightening the belts some more to see if that helps at all.

[TopJimmyCooks]

I would love to know what effect those astrosyn motor dampers would have on this.

[truly_bent]

I've been following this thread with some interest and have been doing a little digging on the web. The general opinion seems to be that it's a mechanical problem and, as has been mentioned here, one that can be somewhat improved by slowing down travel speeds and tweaking the accel/jerk parameters.

It also seems to me that this problem is specific to Cartesian coordinate systems. I haven't yet found any complaints about "ringing" on delta type machines. Can anyone confirm that delta machines are immune to this ringing problem?

[printbus]

I've been following this thread with some interest and have been doing a little digging on the web. The general opinion seems to be that it's a mechanical problem and, as has been mentioned here, one that can be somewhat improved by slowing down travel speeds and tweaking the accel/jerk parameters.

It also seems to me that this problem is specific to Cartesian coordinate systems. I haven't yet found any complaints about "ringing" on delta type machines. Can anyone confirm that delta machines are immune to this ringing problem?

I continue to have questions on whether this issue is strictly mechanical.

Assuming it is primarily a mechanical problem, the extent of the rippling will be driven by the amount of weight being manipulated during printing. True, deltas are typically moving less weight, but someone could possibly have a poor design for a delta with a printhead that is excessively heavy. If so, that might still exhibit some of the same issues. EDIT: Thinking about it, that printer might have other print quality issues than the rippling... I really don't know.