Diminished Quality

No matter what I’ve done setting or calibration wise, I cannot achieve the same quality that I did when the printer was new. I’ve had the A250 for little over 5 months now, and there’s a huge degredation in print quality. Here is an example of one of the first prints I did when the printer was new (right), and same print today. Using the same gcode file. Printer was just re-leveled, e-steps calibrated, using same filament brand (matchbox), but nothing seems to help! Are the linear motors at the end of their lifespan?

While you could be having rail problems they generally fail obviously. I’ve been running mine pretty much non-stop for over a year and mostly on cnc which is the hardest on the machine without problems other than having to adjust some play in the rail brackets.

Have you checked for play in the linear brackets?

Checked that the all your screws are tight?

Have you replaced the nozzle? The nozzle has a limited lifespan which can be shortened considerably when using abrasive filaments like wood or glow-in-the-dark to name a couple.

Also may want to make sure your filament is dry.

-S

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Thanks for the reply. The brackets are all snug, no looseness that I can detect by giving the a good prss, and screws are all tight. I do change nozzles (and print bed) pretty regularly, that nozzle was brand new for the test (only a couple small PLA prints thru it). Filament moisture shouldn’t be an issue as I live in desert climate (<25% RH year round, 19% at the present).

Do the linear motors require any maintenance? Other than those I can’t think of anything else that could be causing the issue. I would add, that after prints complete and the bed is being moved forward, there’s a clunk sound (from the Y axis linear motors). Don’t think this is related, but I’m not sure.

It’s just really disappointing that the quality has gotten to that point.

Even 25% humidity can still affect the filament depending on how and where you store it. Also it doesn’t always come properly dried. Different batches of same filament can react differently (not usually, but does happen). Never know when a brand uses a different supplier/manufacturer.

You could take off the bed and make sure the y axis are moving identically still.

You can lubricate the drive screws inside the rail, but I really don’t think that that’s your problem or will make a difference. It’s recommended to do yearly. I need to but still haven’t gotten around to it.

Here’s a thread about maintenance: How to maintain the snapmaker in perfect condition?

-S

I’m certainly reluctant to start opening up the motors to grease them, as its not been a year, and still under warranty.

I store my filaments in vacuum sealed bags with 2 desiccant packs.

Hers’s another strange example. Trying to print a 8 sided object. A strange chatter right at the seam, which smooths out around the back. Not sure if the print head runs clockwise or counter. So not sure if the chatter is forming at the start or end of the layer, I assume start. And also a ridge forms at about 1cm up from the build plate. Happening with both Cura and Luban.

It’s quite easy. You can just remove the ends of the steel strip. The strip tensioning tool came in the toolbox for reassembly. Unless you are incredibly clumsy with a screwdriver you should not be concerned about voiding your warranty.

In fact, if the module fills up with dust or detritus and that is a cause of failure then that would void your warranty as you are expected to clean them out periodically. If you are not using CNC though you are not going to find a large build up of dust inside with under a year of use. If you begin using CNC though plan on doing that check somewhat regularly.

We need to go back to basics here. Think calibration cubes. There’s no need to print large objects only to confirm the issue still exists.

It’s either a) a filament problem b) a partial clog c) a calibration error or d) a hardware error.

We need to start limiting that down.

You seem quite certain it’s not A, so maybe the next step is to verify you can easily push filament through the hotend with it hot and the door open so the gear is not biting into the filament. It should take no more than the weight of your hand for it to extrude at a good rate.

If that’s the case make sure the filament isn’t catching anywhere like on the tower or through the enclosure.

That could easily be determined by watching it print, which you need to plan on doing until this is corrected. It’s amazing how useful watching the print process is for determining what causes a problem.

I can’t tell from that object if it’s over or under extracting, a simple calibration cube print would be useful to do. Pay careful attention to the first layer.

I’ve found that one of my best problem finding tools is listening. I’ve stopped several failing prints because “that sounds different”, and looked over to see that something had shifted or been knocked over. I can’t really describe why it sounded different, just the tone of the linear modules seemed off. Some articles I’ve read said you can even hear excessively wet filament making hissing and popping sounds, but I haven’t encountered that.

So I swapped the linear motors around (Z<–>Y) and replaced the X with a new spare I had. Results are much better, plus I don’t hear that “clunk” sound on the Y rails when the print finishes and bed is pushing out. I’m not sure what conclusions to draw from this. When I dissembled, everything was tight and right, so not a matter of anything loose.


That first layer is overextruded, either bump up your Z .05 or .1 or your flow or esteps is off.

If the clunk you were hearing is roughly halfway down the travel and you have one of the original kickstarter machines there was a manufacturing defect where the 2 leads were different pitch causing a skipped step about halfway down.

But that was a manufacturing issue and would not suddenly appear.

Did the clunk sound like anything in this thread?

Specifically this video:

Important to note is in the video when the clunk happens the whole plate moves, it’s not just a sound, it’s a large movement.

The clunk is at the exact same point but a lower tone, and built plate doesn’t jump. I’ve had the clunk since day one, its not a new sound (printer is only 5 months old).

e-steps were just redone, so maybe Z need adjusting. And to add that was printed using Luban “Normal Quality” setting, so layer lines are somewhat visible.

I’m still convinces 2 or more of the linear motors need replacing, the ones previously in Y axis.

I think I share that conclusion, unfortunately.

An incentive to buy the new rails…
I have the lines too… so this has been most useful, although I need to investigate.

Here’s what mine sounds and looks like. Seems to stutter back a tooth halfway, then resumes forward. This is a pretty recent machine (May 2021)

A suggestion for something you might check: Is your nozzle assembly tightly attached by that set screw inside the filament drive chamber? If that screw is a bit loose, that could cause these issues. It might loosen at high temp, even if you had it tight before heating nozzle. Just a thought of something to check.

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