Posts made by devleon

Also, that print doesn't seem like it's printed with a 0.2mm layer height, the lines seem quite thick. Maybe 0.32?

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

@devleon I've found it very difficult to photograph these patterns myself. Not got great lighting yet but I have had to get macro extensuons and cheap tripod!

Well, I do have a macro lens and a tripod, and can probably mcgyver some lighting, let's see what I'll come up with

@DocTrucker
I'll try to print a part in a similar color and hold it just like it was held in the photo. Then we'll see if it hides the Z-wobble or not

@4lathe said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Sorry. The first maestro and direct drive together have created a poorer surface finish than previously. Anyway I don't want to interrupt your thread but I still see small micro interruptions on your surface finish. They may be less than .5mm but still look like small vibrations or fluctuations in extrusion. I have something similar and was just hoping to get a finish like that cube you posted. Watching your results.

Hmm. Wierd. Maybe it's related to different speed/accel/jerk settings and how Duet probably handles things like acceleration differently in comparison to marlin?

Regarding the very small surface artifacts, that's my cheapo 5015 blower fan vibrating. Without the fan running, it's gone, but of course I can't print PLA without any cooling. I have a replacement in the mail.

@4lathe said in Rippels and Ghosting on Y-Axis of converted Ender 3:

@devleon after all this, I would love to find out what the ender was like that produced this cube you posted above. That is a great print imo. Was it pure stock? If do we know its not the wheels or the bearings or sag, etc. My ender 3 has only been modded with direct drive and the duet maestro. It definitely printed at least simple things better before the mod. https://cdn.thingiverse.com/assets/c9/8d/6f/3e/d5/featured_preview_speedDrive_cube.jpg

This is where I got the picture from, a direct drive mod: https://www.thingiverse.com/thing:3816051

They definitely done plenty of upgrades to his printer already, as it's outlined in the description.

I wonder what you mean with when you say your ender 3 printed better before you did the mod. Are you saying it's printing worse with the Duet?

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

What country are you based?

I'm from Germany.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

My gut instinct at the moment is get some decent bearings in the wheels and replace the "tyres" with the heavy duty poly carbonate wheel rather than delrin. After rubbing your finger up and down the guide slot to ensure it hasn't been nicked or damaged.

I almost forgot, I tried to find some poly carbonate wheels on amazon, and there's only one seller that has them and the very first review complains about how bad and low quality the bearings are and that from 10, already 4 had failed after around 20 hours. So.. Yeah no.

And anything I order from china now won't arrive for a couple months sadly...

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

You mentioned a 2mm pitch on your screws but I think that's a 2mm pitch with a 8mm lead? In other words turn the screw 360 degrees and the x axis moves up by 8mm rather than 2?

Yeah, 2mm pitch with 4 leads, so 8mm with one full rotation.
The new (and more bent one) is 2mm with a single start, and the stock (old) one is 2mm with 4 starts.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Even if not the pitch on your parts of the "defect" looks more like 1.0-1.5mm rather than 1mm?

Not sure what you want to hint at? The new print doesn't seem to have any regular occuring defects. However, I also just measured the distance of the ripples in the cube that I printed right after upgrading to the direct drive, and with the bent 2mm single start lead screw... The distance is exactly 2mm, except for the wobbles at the bottom, which for some reason are closer together at around 1mm distance, peak to peak.

I tried to relate any ripples on the new print with a 8mm distance, but found nothing that would match it.

@droftarts said in Rippels and Ghosting on Y-Axis of converted Ender 3:

@Corexy @devleon Z isolators are a thing, and have been for a long time with lifting-x-gantry bed-slingers, as the X/Z axes are over constrained when the Z lead screw is bolted to the X axis, and it’s even worse if the leadscrew is constrained at both ends. Any eccentricity of movement fights the linear rail for position of the X axis. The Z isolators decouple the Z axis from the X axis, and allow the X axis to ‘float’ on the Z, while the linear rail gets on with its job of guiding the X axis.

Thanks Ian! Yeah, I've heard of them before, and saw them on a couple i3 style printers as well, but it seems they all require a linear rod to ride on, which I don't have in my setup, and I'm not quite sure how to adapt it to what I'm using.

In their design, creality uses oval holes and spring washers between the brass nut and then suggest in their manual to not tighten screws holding the brass nut too far, so that there's still some play in the Y direction. You can see in the picture below.

However, they only made the hole oval in a new revision, and I have a version of the bracket that has a completely round hole that allows for no play at all. I even had ordered a new plate directly from creality, but got the old version again. I tried to explain to the customer service that I wanted the new part, but they didn't understand what I wanted. They asked if I wanted extra holes Plus, I couldn't mount any standart brass nut to this anyways.

The X/Z-bracket I'm using right now also has oval holes, and allows for some movement along the y-direction, but only if not tightened fully. I will experiment with adding some washers and even spring-washers and will see if I can get a compromise between play in x/y but not y.

I appreciate the input from everyone so far!

Well, I put in the old leadscrew (T8x8), and a matching anti-backlash brass nut, which already had a LOT less play than the T8x2 brass nut, and I fiddled around with the frame and eccentric nuts until I got the least amount of bumps, with still all rolls rolling.

This is the result:

Sure, it's still not perfect, but I think it's definitely getting better Finally, some progress...
I think as I next step I'll be installing the linear rails in Z then, see if it improves even more, since I could still feel very very tiny bumps, which also explains the line in the top third, which has been in all of my prints so far.

Just a very quick update, I have removed the leadscrew and slowly moved the x-gantry up and down the z-axis. I can feel a very, very light bump in regular intervals. Guess it must be one of the wheels. I will try if I can figure out which wheel it is.

@Corexy said in Rippels and Ghosting on Y-Axis of converted Ender 3:

That's definitely Z banding, almost certainly due to the X gantry wobbling on the X axis. I'm actually surprised it isn't worse with the direct drive extruder weight added.

I mean, it is "worse" in a sense now because the pattern is more clear and consistent, instead of being irregular.

@Corexy said in Rippels and Ghosting on Y-Axis of converted Ender 3:

I'd really look to that dual Z axis, either dual or single stepper.

Will order some parts for it, probably just two steppers with integrated lead screws.
First im going to install the linear rails on Z though, as this should already help a lot with sagging.

@Corexy said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Also, is the lead screw fixed at both ends? Some manufacturers like to leave the lead screw nut bolts slightly loose on the bed mount/bracket so that it allows a bit of "off center" movement of the screw without pulling at the Z axis. Others sometimes leave the screw completely unsecured at the top for the same reason.

I did at one point had the lead screw fixed at both ends, and the brass nut tight on the mount. This got me really bad Z-wobble, because, who would have thought, the leadscrew is bent.

The last print was done with the lead screw free at the top, and during fast Z-movements (like probing), you can clearly see it wobble and that it's bent. Bummer, I just got it new a couple days ago! The brass nut is also a little bit loose on the Xz-bracket, allowing for slight movement in X and Y, but not Z.

Once I get an actual non bent leadscrew, I will fix it at the bottom, gantry and top.

@Corexy said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Actually, I can tell you first hand that a wobbly table certainly doesn't help anything.

So, I went to the hardware store and got a granite plate, with around 13kg. I will place my ender 3 on that soon.
In the meanwhile, I've placed the ender on a sturdier table.

Anyways, without further ado, here's the direct drive!

Can you tell which print is which?

The left is the one with direct drive - same GCode.

Let's light them up! This is the cube from before the direct drive upgrade (the right one):

Let's now compare it to the cube printed with the direct drive:

Hoo... Hooray? At least it's consistently bad now, with a very clear pattern.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

At least 4 areas for optimisation being investigated here and improving one can easily make another look worse when all thats really happening is you are reducing a randomising effect by curing one issue which was hiding the magnitude of a second. Very frustrating, but it's the nature of the beast.

So, you were right Two down (irregular extrusion and VFA), two to go (z wobble, ringing).

I guess I'm batteling something in the Z-Axis now, right? Like a bent lead screw, bad bearing or bad wheel.
Or could it still be extruder related? It seems like a too low of a frequency of banding to be able to come from the BMG, but I'm not sure. Also, upon closer look, I can see many of the same artifacts in the same heights.

Anyways, I think for my next step, I'll be swapping in the old stock leadscrew (T8*8mm). If the pattern stays the exactly the same, I know it's not the leadscrew or related parts and I should take a closer look at the extruder. I"ll also experiment with using normal brass nuts, the anti-backlash one, and a POM one, which should be here any day now...

On a related note, both leadscrews are definitely bent. Does anyone know where I could source a good quality, non bent lead screw? I'll have a look if I can source something locally.
Edit: Trying to find a lead screw online and they talk about left threaded and right threaded... Uh.. Also, I seem to only be able to find T8x1.5...

Thanks for the link, I'll consider it. I might just get two nema 17s with integrated lead screws instead, though, just like on the prusa. I know that both steppers will not be aligned after they loose power, but for that I could just copy the "stall into the top until aligned" routine that the Prusa does too.
That way I don't have to worry about belt tension and a complicated setup on the top of the printer (where I would like to store my hotswappable tools anyways).

@Corexy said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Seriously mate I'd watch the money you throw at that printer...I'd save linear rails etc for a larger cube framed printer, too much for an E3 IMHO.

Well... Too late haha. I already have all the rails here. I'm still well under the cost of a new Pursa Mk3 though.. So there's that..

I just watched the video, and it's very similar to another video I followed just recently. https://youtu.be/AN0MlQMMew0
My axis is perfectly aligned with the frame, and when I measure the distance from the top bar to left and right, it's the same. Before I had followed that video, not all my wheels on the X axis would grip the extrusion, even when the eccentric nut was tight. Now all the wheels grip the extrusion, so it seems all is lined up well.

What I'm going to try next is to put my printer on the floor instead of the ikea table, as it is still a bit wobbely. Maybe the ringing is coming from the table! Ideally, I should get something like a very heavy granite plate to put under the printer...

@Corexy said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Speaking of couplers....if yours are the stock ones they are known to fail. Might pay to change them and fit the retaining clips. Forgot to mention that earlier.

I changed them a long time ago... I agree, the stock ones are pretty bad...

@Corexy said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Possibly somewhere I can help at last...

I've just ordered the Ender 3 pro as a backup printer, and at first sight I ordered the dual Z axis (single motor belt drive model) mod kit. I would say not quite certainly but highly likely that your X axis is sagging, especially as the previous poster notes delrin wheel wear.

This guy's got some good tips:

https://www.youtube.com/watch?v=4bFYH0X3qjk

If you watch all his vids, he goes into how to tension those wheels and align the chassis. I've got a feeling some of your problems lies there.

Regarding extrusion, that's a pretty short bowden tube with some pretty big settings.

I would try less retraction and also slower. I've seen reports of really slow retraction speeds working well...why not try 4mm retraction at 15mm/sec? Can't hurt to try.

I think you've got a couple of problems, both mechanical and settings. That guys performance build video would be a good place to start.

Hope that helps!

Thanks, I'll watch his video. As I will go direct drive for now, my retraction settings will be completely different anyways. But I'll try slow and high retraction speeds and see if it makes a difference!

I do agree though, my x-axis definitely does sag on the right side a little bit, which is why I have to have the wheel a bit tighter to reduce (not eliminate) wobble. Do you already have your dual z-axis mod installed? Could you link me to it? What do you think of it?

I hope the linear rails for Z will also reduce the x-axis sagging, after all the the carriages have no play and should provide sturdiness.

Thanks very much for the detailed answer!

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Do you mean you have seen others do better

Yes, a couple examples include this, this, this, this, and I could continue on... These were all printed on an Ender 3, so I know it can do better.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Ringing/ghosting - you've mentioned your stock pully a few times.

As I mentioned too, I've already replaced my stock belt on Y with a GATES-LL-GT2, which wasn't cheap either. It sadly made no difference compated to the stock belt, and I have not yet replaced the X-Axis, and it barely shows any ringing/ghosting. I will soon swap the X-Axis belt too.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

That said as the pitch changed with speed I think this maybe a mode of oscillation in your frame somewhere.

I agree with you here, the frame must vibrate / oscillate somehow. I have already ordered some parts like T-Brackets and V-Slot corner brackets to make the frame more sturdy, but it will take a while for them to get here.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

More drive current on the motor will likely reduce the amplitude of oscillation of the motor around it's target position. Keep check on how warm the steppers are.

Both (X and Y) steppers take 1.68A, and I'm currently running them at 75%, so 1.26A. I had also tried 85%, but they only got louder and hotter and the pattern didn't change. With 75%, they get to around 40-45 C after 2 hours.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

With no z axis screws connected the axis should move up and down easy with no tight spots. The wheels should be tight enough to the rail to limit wobble, but not so tight as to overload the bearings.

It moves up and down very easily, doesn't get stuck anywhere, and has no woblle. The extrusion is smooth, and yes, I do see some wear on the wheel, but it's minimal. I haven't checked the bearings individually yet, but will do so. I will try to source some polycarbonate wheels too.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Linear rail z maybe asking for trouble with an extrusion based machine as you are likely to end up spending an age trying to align the two rails close enough to each other to get the axis running smoothly. A bit like the issue Tom3D discussed on YouTube when trying a twin linear rail y-axis setup on another bed slinger.

You're right, there's going to be lots of fiddeling around to get everything to move smoothly, but people have done it before, and I think I should be able to achieve it too, even if it takes a while.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

You may also need to (as far as possible) de-couple (in x/y-plane) the z nuts from the motor and idler ends of the x-axis. A popular mod on P3Steel machines.

Can you elaborate a bit what you mean? I think what you mean is to allow the Z-Nut to move a bit in X/Y? The XZ-bracket I'm using for my brass nut already allows for some adjustability in the Y-Direction when not fully tightened. I've tightened the screws just enough so that it won't wobble in Z, but will allow the lead screw to move the brass nut in Y (and a little bit in X).

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Your "///" pattern is often referred to as "Vertical Fine Artifacts" or VFA. Somewhere in this forum there is a link to a long thread on a Prusa forum about trying to tackle them.

Yeah, I've stumled upon that thread as well. It's long, very long, and I've already read some pages.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

here seem to be a few quality stepper motor brands rising up at the moment. LRO are making noise on twitter

The steppers I have right now are definitely not the highest quality. I would be willing to invest better ones, however I found nothing when I searched for LRO steppers on Google. Could you link me to their shop or somwhere I can buy them?

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

I'd be a little cautious about definitively saying it was vibrations from the fan causing issues. I'd wonder if for example it was more electrical noise? Can you check for electrical noise and would you know what to look for? Ensuring there is good continuity from your stepper motors (and maybe hotend) to the mains protective earth would be wise first principles step.

The pattern was definitely gone once I disabled the fans, and I can definitely feel the fan vibrating everything quite violently when it's running. It's a super cheapo 5015 blower fan, and it shows.
How could I check for electrical noise? I have a multimeter, but no oscilloscope. I will also check ground continuitiy.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

likewise on the noise front can you lock your toolchanger and run with the magnets off in a trial?

I was suspecting that some of the vibration came from the magnetic mount as well, so I had it very firmly clamped down so that absolutely nothing could move, and it made no visible difference. I have added even more magnets now, and the new piece I just finished printing for the direct mount is also a very tight fit, so there's absolutely no wobble there.

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Irregular extrusion. Direct is easier as you are about to find out! Have you run the calcs to check the stepper can run at the commanded speeds? I suspect the loud odd noises you mention on some retracts are skipped steps. Have you already checked e-steps carefully (slow extruder drive with nothing after extruder), linear & non-linear extrusion correction, before doing detailed pressure advance and retraction calibration? Ideally the retracts should be minimal but slightly excessive to avoid occasion stringing.

The new pancake stepper (17HS4023) will arrive this evening, and I'll install it tonight together with the BMG for the direct drive. Could you explain how I can calculate the max speeds it could handle with the BMG? Since this is a new stepper, I will also be redoing the e-steps calibration. Maybe I'll also do the non-linear extrusion correction, but from what I've heard, it doesn't really make that much of a difference?

@DocTrucker said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Final point... Plan your experiments or you will spend way over the odds on this. Try to find ways of quantifying/measuring the issues you can see. Tackle maintenance issues (scored wheels, bearings etc) first and always check system for loose bolts, couplers, and signs of wear. I have - as most of us have - got history of missing a simple problem while searching for a complex one. Be warey of compairing your prints too much to others. Some are dishonest with lighting to hide artefacts etc, but to be fair I've not seen too much of that on this forum. A walk around TCT Show last year and I saw many worse examples of ringing than what I thought was critical on my machines on both demo machines and parts trying to sell commercial level services.

You're absolutely right. I will try not to change too many things at once to keep things comparable, even if it takes more time. I will check my whole printer for wear and see if I can find something obvious.

You could be right about hiding artifacts. My prints too look flawless when viewed from a certain angle, but look totally different when viewed from another angle.

Thanks again for your very detailed answer!

Well, I'll report back once I have my direct drive installed and tuned in. Let's hope it makes a difference!

@4lathe said in Rippels and Ghosting on Y-Axis of converted Ender 3:

In the top 1/3 or your pic from post at 5:58 it appears that their are small maybe .5mm marks like a start stop in the lines vertically. Am I nit seeing that correctly?

Yeah that's the pattern I meant, and it's caused by the 5015 blower fan. In the top third I disabled the fan, it looks better there.

@4lathe said in Rippels and Ghosting on Y-Axis of converted Ender 3:

https://www.thingiverse.com/thing:3241793

Thanks! I've also designed a quick mount for my magentic mount. Let's hope it can support the BMG and a pancake stepper.

@4lathe said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Direct drive definitely an improvement.

Well, maybe I'll print some parts to go direct drive then. I have all the hardware I need after all. Which mount did you use?

@4lathe said in Rippels and Ghosting on Y-Axis of converted Ender 3:

When I looked at your usb microscope pictures, it looked like my first layer artifacts. If you look at your first layer with the same magnification that you did on the walls, do you see the same small pattern?

Do you mean the ///\\ pattern on X or the ringing on Y?
For the pattern on X, I found the cause to be the vibrating 5015 blowers on the hotend. Without the fans running, I don't get the artifacts anymore. I will be upgrading to better quality blowers, or if I go direct drive, maybe a different type of fan.

@4lathe said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Also I had seen that other thread and read all of it hoping for a solution. Instead it ended with him printing abs and abandoning the problem.

Yeah, I didn't get that either. Doesn't really make sense that a different filament would suddenly get rid of the ringing completely. Also, I definitely don't want to print with ABS.

Well, as a next step I will probably go to direct drive to solve the extrusion inconsistency.
For the ringing in Y, I'll wait for someone to chime in on the belt video I posted above, and I might try the other linear rail mod that puts the belt onto the side.

@4lathe
Yeah, I saw your thread as well. I will try printing faster in the next days. I also already increased my current to the motors from 70% to 80%, but that only made them louder - plus again, the ripples are only on my Y-Axis, and not X, even though they use the same motors from the same lot from the same manufacturer. Maybe I need to get into the TMC2660 datasheet and adjust things from there.

I actually don't see any ripples on the first layer. The first layer for me lays down perfectly flat with almost no artifacts, other than a tiny bit where the infill meets the perimiters. I only get the ripples on the y-axis, just liked you showed in your last pictures.

Regarding belts an idlers - I'm using a linear rail for y with 3 toothed 16T idlers. The whole linear rail upgrade pretty much replaced everything : Aluminum plate, linear rail, high quality gt2 belt, toothed idlers. The only thing I haven't changed so far is the motor and the pully. All that, and it made barely any difference. It doesn't make sense to me It's frustrating.

Something I noticed however - when I look from a very small angle directly at the idler at the back, I can see the belt slightly moving up and down. How come? I tried to tension the belt as tight as I could. Maybe because the belt is slightly higher and not parallel to the extrusion? It's the same in a stock ender 3.

https://www.youtube.com/watch?v=x6kNXtgr0QY

Maybe I should try another y-rail mod that moves the belt to the side?

Or maybe, it's just a weakness of the frame? I have ordered some parts to stiffen the frame, but they will take quite a while to arrive here.

On a different note, Is your extrusion also inconsistent, or better with your direct drive setup? You've only mentioned the ghosting/ripples so far, so I wasn't sure, and I'd love to get some input on someone with a direct drive setup, before I upgrade to it, lose my dual BMGs, and then I realize it was all for nothing... Edit: Just looked at some of your pictures and it definitely looks better. Maybe I'll make the swap to direct drive...

Edit:

• Another Thread I found with similar problems.... Their extrusion looks much more consistent than mine though, so there's that...

@Phaedrux said in Rippels and Ghosting on Y-Axis of converted Ender 3:

Here's a good quality 5015

https://www.digikey.ca/products/en?keywords=259-1829-nd
Canadian store front mind you. But model number sunon MF50151VX-B00U-A99

Thanks, found them too while I was searching just now. They are pricey, but hopefully worth it.
I do have a 24V system though, and they are 12V. Would it be okay just wiring them in series, or should I get a voltage converter?

Well, disabeling interpolation only made the steppers louder, but didn't change anything. However, turning off my partcooling fan did finally made a change. Seems like the ///\\ pattern was caused by vibration of my cheapo 5015 blower fans. Does anyone have a reccomendation of a good, silent and non-vibrating 5015 blower fan? I guess the ones from china are probably all equally crappy.

Edit: Thinking about the unregular extrusion and irregular layers....
Maybe it's the nozzle? Maybe it's the PFTE tube itself?

Can't be the heatbreak, since it's an all the way through style hotend, so the PFTE tube is right ontop of the nozzle. But I also have an titanium heatbreak, so maybe I could try that too?

I also checked all couplers, they don't give.

A new day, and i just finished a print with the Y-Splitter removed.

And on the left is the cube with the removed Y-Splitter.

A tiny bit better maybe? Not really though. Well. Not sure what to do now.
I'm going to try disabling interpolation and changing microstepping to see if that makes a difference in the ///\\ pattern.

The last thing I can do then is to swap the extruder motors, remove the backlash nut, wait for the POM nut, and upgrade the Z to linear rails as well. Maybe even do a Dual Z?

Edit: Doing a print now without interpolation. Oof, the motors are already way louder.