The current leg of the Journey – discovery and maintenance
After 9 months of printing and all caught up on projects, it is time to reflect on the journey so far and plan some maintenance. Yes – plan.
I like my MK3S. I am not going to say I love it, because that's just weird.
It has been reliably printing with most print failures caused by the operator, and some by filament.
Printer/firmware quirks:
The knob on the control panel works backwards from what I am used too. Cursor/indicator on the left side of a screen should move up when the knob is rotated clockwise, not down. Even today, I usually get it wrong.
The detent on the encoder is very weak and I go past where I want to stop.
When I get it to the file I want, the file name does not always scroll, so I have to go past and back to it then it will scroll. I can't say for sure, but I think this has caused me start printing the wrong file.
External cable wraps look ugly, but I have a plan in place to fix that.
Noise during long Z-axis moves. I have plan to address this as well. No big deal.
No show stoppers here!
Layer colour change gets stuck in a loop if I forget to cut filament at an angle and it won't load. No way out except X button and job lost! It would be nice if after two tries it asked to unload and try again.
Bearings, especially Y-axis ones, are noisy. My kit did not come with any lubricant. My bad for not looking deeper into it and installed them as they arrived. Ouch!
My heatbed is badly warped. The 4 corners are high and the center is low. Picture a shallow bowl. Workaround - a piece of foil under the center of the steel sheet allowed me to finish my last project. I have action plan(s) to fix it. In my opinion, it is less than optimal design.
The cables to the heatbed and the clamp at the heatbed! Major problem here as my kit came with the fabric wrap and no nylon rod, so it eats thermistor wires. And yes, I did install the wrap 5-6 mm into the clamp. My appearance change to external cables will also address this.
Show stoppers!
Things that everybody knows but I had to learn:
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Steel sheet (smooth) can never be too clean. I swear that fingerprints magically show up on the bed while I am sitting there. So when I think I have scrubbed it enough, I do it again.
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Watch while the first layer go down to ensure it is adhering. My experience is that if I get the first three layers down, I can walk away knowing that it will complete successfully.
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I find that when I get a filament that does not have a profile in PrusaSlicer a good place to start is using the Prusament profile. So far all I have had to do is raise first layer nozzle temp 5 degrees and all works.
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Supports <>! But bobstro's settings help a lot!
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Stepper motor are noisy, but printing can be made quieter simply by orienting objects in such a way that the number of motors running at one time is reduced. If I have an object that has lots of long straight runs, I orient these along one axis, usually the x-axis which is quieter. I also rotate my infill in such a way as to reduce multiple motors as much as possible I often have to get up and check that the printer is still running..
My perception of the forums could be better. Not every newcomer to 3D printing came forewarned of it's issues, but may want it for rapid prototyping, or in support of another hobby. Be kind and look at each one as an opportunity to educate. I see opportunities for you to make this a great place. Seize them.
Maintenance tasks this time are to fix all the Y-axis issues with the printer and some of the visual ones.
Then back to printing until next maintenance window - X-axis and extruder
Does anyone have the STL files for the new heatbed clamp? They were not in the bundle I downloaded last week from the Prusa web.
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
Things I can agree with
1) Encoder wheel
It's not that the detents are too weak for me, it's that the click is too hard so it's really easy to move the encoder when trying to click something. I wish it just had a normal button separate from the encoder, I think that might be my first mod - swap the encoder wheel for up/down buttons and an "enter" key (I wish there was a "back/cancel" too instead of a "reset the entire printer")
2) Y axis noise
That bearing mounting system. U-Bolts? Guys. Why? It's the most tragic piece of slap dash hackery with so many ways for builders to kill their bearings. There's such ridiculously close tolerance between the frame and bed so I couldn't even get a shim in there to even out the bearing load. If I had to chose only one thing about the MK3S that grates me it's this. If you need to penny pinch so much there can't you even just use a flat strap to load them evenly?
My bearings are also nasty btw, I feel like we got a bad batch compared to all the reviewers of the MK3 because my printer is nowhere near what I'd call "quiet", even in stealth mode. They looked to be lubricated sufficiently when I got them, but they just feel super rough. I'm really going to need to invest in some new ones soon.
My steppers also seem noisy, but I think this is frame resonance not the steppers. Unless the steppers are just being driven at too high current. Not sure what's going on there... but the last point on this is that I can't get my Y stepper pulley aligned with the idler well and solving this is difficult asa there are 4 points at play between the bed mount, tension mount, stepper mount and idler mount. I need to spend some time with a file and some machine parallels to work it out at some point because rubbing up against the side of the pulleys is doubtless not going to help smooth movement.
The rest, wow if your heatbed is warped there's something serious going on and you should double check your build that the correct spacers are in all the right positions there and non slipped out of position during assembly. I actually feel like this is the best designed part of the whole printer but it is hugely painful to align and assemble when the bed is mounted to the Y axis. And Z axis is always noisy on most printers I've used because it's doing the most work. Luckily it shouldn't be moving a lot, and the nylon nuts will run in after a few prints at which point I found throwing some lithium grease in there made them much smoother.
Seriously... U-bolts. I can't even...
RE: The current leg of the Journey – discovery and maintenance
Seriously... U-bolts. I can't even...
Mark 2 line of printers used zipties 😆 There are printable Y axis bearing mounts on Prusaprinters and Thingiverse, many people like those.
Many people also swear by Nylock mod to get bed more leveled.
RE: The current leg of the Journey – discovery and maintenance
Seriously... U-bolts. I can't even...
Mark 2 line of printers used zipties 😆 There are printable Y axis bearing mounts on Prusaprinters and Thingiverse, many people like those.
Many people also swear by Nylock mod to get bed more leveled.
I honestly think a ziptie might be an improvement over being able to warp your bearing with a mere quarter turn too much on a spanner.
RE: The current leg of the Journey – discovery and maintenance
Things I can agree with
1) Encoder wheel
It's not that the detents are too weak for me, it's that the click is too hard so it's really easy to move the encoder when trying to click something. I wish it just had a normal button separate from the encoder, I think that might be my first mod - swap the encoder wheel for up/down buttons and an "enter" key (I wish there was a "back/cancel" too instead of a "reset the entire printer")Exact opposite for me, I can barely feel them. Up/Down buttons would be nice, unless they inverted the movement of the indicator so that up meant down and down meant up as the current encoder does. 😊 I wonder if that could be changed in the firmware?
2) Y axis noise
That bearing mounting system. U-Bolts? Guys. Why? It's the most tragic piece of slap dash hackery with so many ways for builders to kill their bearings. There's such ridiculously close tolerance between the frame and bed so I couldn't even get a shim in there to even out the bearing load. If I had to chose only one thing about the MK3S that grates me it's this. If you need to penny pinch so much there can't you even just use a flat strap to load them evenly?
My bearings are also nasty btw, I feel like we got a bad batch compared to all the reviewers of the MK3 because my printer is nowhere near what I'd call "quiet", even in stealth mode. They looked to be lubricated sufficiently when I got them, but they just feel super rough. I'm really going to need to invest in some new ones soon.There is something that people may not realize. When tightening this marvel of engineering it is possible to do it so that one side of the U-bolt is higher than the other. So much so that the heatbed will actually sit on it instead of the spacers. I noticed it when checking everything before tightening down the heatbed. This is where my background comes in handy. Read and UNDERSTAND what you are about to do FIRST. VERIFY during and after that everything is right. If unsure, there is no foul in starting over. My Y-axis is getting noisier slowly and so my decision to act now before any damage is done.
My steppers also seem noisy, but I think this is frame resonance not the steppers. Unless the steppers are just being driven at too high current. Not sure what's going on there..
A bit of both????
but the last point on this is that I can't get my Y stepper pulley aligned with the idler well and solving this is difficult asa there are 4 points at play between the bed mount, tension mount, stepper mount and idler mount. I need to spend some time with a file and some machine parallels to work it out at some point because rubbing up against the side of the pulleys is doubtless not going to help smooth movement.
This was the single most time consuming part of my build. That reminds me. I have to check whether the idler pulley are toothed or smooth.
The rest, wow if your heatbed is warped there's something serious going on and you should double check your build that the correct spacers are in all the right positions there and non slipped out of position during assembly.
I am confident of my build. I even took calipers to the spacers and they are all 5.51 mm. Kudos to who ever manufactured them.
I actually feel like this is the best designed part of the whole printer but it is hugely painful to align and assemble when the bed is mounted to the Y axis.
We can agree to disagree on the design of the heatbed. While it is OK, I think it could be better, but I am not a ME, Nor am I an expert in material sciences or thermodynamics, but I have seen heat warp things, and I spent my career solving issues that programmers, MEs and EEs could not possibly foresee once a product gets into an end user's hands, despite their efforts to user-proof something.
And Z axis is always noisy on most printers I've used because it's doing the most work. Luckily it shouldn't be moving a lot, and the nylon nuts will run in after a few prints at which point I found throwing some lithium grease in there made them much smoother.
Z-axis noise is probably mostly harmonics. During long Z moves most of the noise goes away if I hold the LCD panel. Someone investigated and found it was the LCD board vibrating and hitting the cover.
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
Seriously... U-bolts. I can't even...
Mark 2 line of printers used zipties 😆 There are printable Y axis bearing mounts on Prusaprinters and Thingiverse, many people like those.
Many people also swear by Nylock mod to get bed more leveled.
I may be wrong, but I thought I read somewhere that PR changed to the U-bolts from ties because of issues with using ties. Was it a good change? Jury is split on that one, but I saw these bearing blocks and maybe I will investigate into them before tearing my printer down. Don't know who/what Nylock is but I will check. thanks.,
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
well, I have my Y carriage all stripped down and initial investigation points to the Y carriage 4 corners all being higher than the center by varying amounts as seen using a steel straight edge and a back light. More precise measurements to be taken before I proceed. Since all 9 of the spacers were 5.51mm as measured with calipers, this variation was transferred to the heatbed, so even if it was flat to start, it didn't stand a chance once mounted. But a small diversion - my USB microscope finally arrived and I am anxious to check out why my brand new Textured steel sheet appears to have two distinct layers of different colour, any maybe even texture. Then back to investigation and re-assembling Y-axis. 3 pound hammer or flip it over? Tough call.. but first - ☕
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
This is not a how-to post. It documents what I found during tear down and what I am doing to fix any issues.
I checked the rods under a microscope and other than a very slight polishing where the balls ran, they are in good shape.
I discovered that a lubricant ( in my case, White lithium grease ) lightly applied to the rods will get into the bearings, past the seals.I will be taking photos of all three of the old bearings.
I am thinking of donating my U-bolts to a <> museum. I chose printed bearing holders instead. I used screws engineered for plastic to hold them in place. To lock the screws from loosening, I applied a small drop nail polish on edge of the screw head and the carriage. Paint will do as well.
I ignored Prusa directions, and some members advice, on how to mount the bearings, and "Did it my way". After installing everything back into the printer, and before connecting the belt, I took a video while sliding the carriage back and forth. Smoooooth, and quiet. I wish I had taken a before video for comparison. I will do that when I do my X-axis maintenance.
Yes! I am prepared and equipped to deal with my deviant behaviour to bearing mounting.
I found an issue with the grub screws on Y-axis motor as mentioned in another Topic.
I am keeping a diary what I find and do, with diagrams, photos and video for future reference.
Now to get a level flat bed. Maybe instead of MBL is should be MBF 😀
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
Normal cap head screws will screw into the holes for printed bearing mounts and will not come undone if screwed in from above with the thread going into the printed part and the holes are tight.
Some of us have replaced all the perimeter spacers with springs which allow very accurate bed levelling, I managed to get some 5 mm OD, 8 mm length springs, but these seem quite rare, the first ones I used which actually work just as well were 8mm OD, 20 mm length and these were introduced to some good side cutters to cut in half, just point the cut end down onto the frame not up onto the heated bed.
When levelling, make sure the bed is at printing temperature as it will flex.
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.
RE: The current leg of the Journey – discovery and maintenance
Thanks for your comments. I find your posts to be good reading and I often get good information out of them. I sense more "I did..." than "Someone did...". You don't make people feel stupid! Enough ego stroking 😀
Cap screws.... I agree. But I never threw any component I replaced in 40+ years WITHOUT scavenging what I thought might come in useful ) nuts, bolts, washers, springs, optics, sensors, lasers, HV/LV power supplies, you name it ). I had the right screws on hand, so I used them. Nail polish - just a habit.
The problem with springs for me is availability of correct type. People: please don't tell me I can get them from Amazon, Ebay, or Ali???? They are the reason small companies that used to carry "everything" no longer exist. I digress. Back to business.
Then main reason I am doing this is because my heatbed is not flat. I am planning on using a variation of the Nylock system. But will continue to look for suitable springs in case I need them, Just as I am looking for a replacement strategy for the LM8UU bearings. I can't say if either is better, but only what works for me.
Always at temp, but fortunately, until I acquire another printer, I only print PLA and PETG so I am sure I can reach a point where both will be happy and MBL will work.
I constantly find things that I think could be better, so I note them and plan for changes.
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
There is always the option of using a silicone tube cut up into suitable lengths and use these as springs.
And thank you for the ego boosting 😀 I'm a multi-skilled engineer and try to help people where I can and have always been like that.
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.
RE: The current leg of the Journey – discovery and maintenance
Links to Y axis bearing holders.
I have these and they have been on for over a year now, printed using PETG and found cap head screws in the supplied parts which screw in from above straight into the print and are just the right length for the end to show through the hole.
https://www.thingiverse.com/thing:1848700
Also a newer update:
https://www.thingiverse.com/thing:3009203
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.
RE: The current leg of the Journey – discovery and maintenance
@chocki
I see that someone is doing that on a mini. Saved the links
I fix things that engineers could not foresee and programmers <>.
I am too far down the maintenance path to change holders now, but maybe next time. My top candidate for future upgrade will require newly designed holders. I am way outside the box on this one. 🙂
Cap screws. What am I going to do with the thousands of screws I have? 😀 And the cap screws in the spares bag are not that easy to come by. Saving them for when nothing else will do.
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
Your also going to need a new Y motor mount that uses the PRUSA belt clamp as the Y axis stop, not the bearings hitting up against the end of their stroke (What a daft idea that was!).
https://www.thingiverse.com/thing:2942590
Also consider these as it makes it a lot easier to do maintenance on the X carriage:
https://www.thingiverse.com/thing:2779123
I've also replaced my X axis with these:
https://www.thingiverse.com/thing:3308841
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.
RE: The current leg of the Journey – discovery and maintenance
It's alive
- Y-axis is so smooth and quiet when the carriage moves
- Carriage is now flat
- printed bearing holders
- bearings installed my way 🙂
- Using nylock for bed mounting
- Self test OK
- XYZ calibration OK
- X/Y are perpendicular.
- Measured skew 0.02 degrees. Initial build was 0.04 degrees
On to flattening the bed and then first layer height. Printing withdrawal is setting in. Must...force myself...to take...time.
Y-axis is so smooth and quiet when the carriage moves
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
If your using a textured spring sheet, good luck with trying to get a perfectly level bed.
I spent weeks (Yes really - In between work of course 😀 ) trying to get a level bed, straight edges, calipers, glass blocks dial gauges and no matter how much I tried, I could not get a flat print. The 7x7 mesh bed levelling helps a lot nowadays so you won't feel as much pain 😉 .
But there is something about the textured sheet and possibly the magnets etc that just does not play perfectly with the PINDA
Here is a thread from over a year ago which left me with no hair!, after I pulled it all out 😣 : https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/first-layer-frustrations/paged/2/#post-116696
Nowadays, I found that if I use the following bed: https://www.amazon.com/FYSETC-Printer-Platform-Printing-Buildplate/dp/B07LBQ57WV
I can dial in a perfectly flat layer, the repeatability and accuracy is spot on, so I calibrate my printer with this, then I know it is set up correct.
Using this : http://lokspace.eu/3d-printer-auto-bed-leveling-mesh-visualizer/
I can get a seriously good (as good as it gets anyway) level bed with the FYSETC sheet, not the slightest twitch from the Z screws, but put the PRUSA textured sheet back on and you can see the Z screws moving as the X carriage moves across the bed after a mesh bed levelling run.
Since I almost exclusively use PETG, I just make sure it is squished down into the bed a little when printing on the Textured sheet and don't loose sleep over nit picking the variation anymore. I know the printer is as good as possible when using the FYSETC sheet, you don't even need to put PEI on it, but keep it just for setting up the printer. (OK I have three of these sheets, one with smooth PEI, one with buildtack and one with nothing at the moment).
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.
RE: The current leg of the Journey – discovery and maintenance
@chocki
as usual, thanks for your insights and links ( except the amazon one )
I haven't yet tried my textured sheet. I am using a smooth PEI sheet. Maybe textured sheet will the next part of the 'journey'. Or I could frame it and call it art!
It has taken me a bit of time to get this far, and I am not going anywhere soon.
Flat bed! I personally think that beds that are not flat cause more issues than people know. Don't everybody attack as this is my opinion and you are not going to change it. On my printer, using Life-Z my way, the square was on a low spot. MBL could not compensate because bed was too wavy. Try to get a good first layer under these conditions. 🙂 🙃 😉
I am using a combination of 2 methods to get my bed flat. I used nylock nuts and fixed center point and got it close by using another spacer to measure height of the 8 points.
https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_without_Wave_Springs
Once close, I used a straight edge and back light to get it fairly flat
To save on calculations I used:
https://pcboy.github.io/g81_relative/
to do the grunt work and using the 'turns' option I got it to the point where all nine points were 0 (zero). I can get even better if I had a protractor, as we are talking 1-3 degrees of rotation in some places
now that I have a known starting point, will do it again at my usual printing bed temp for smooth sheet and PLA.
Then hopefully on to Z-calibration and printing.
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
Printer is up and cranking out prints.
- First layer comes out as smooth as glass.
- Y-axis is so quiet.
Now that the Y-axis is so quiet, it is obvious that X needs some work, but the most interesting thing is now the power supply noise is annoying. Never heard it before. 🙂
My advice to anyone that has a printer ( or any machine ) that needs attention is:
" fix one problem at a time, verify, and then go on to the next one"
It may seem easier to tackle everything at once. You might get lucky or more likely you will get lost and spend more time wasting your time. What's worse is that when you need to seek assistance, anyone that wants to do so is going to have a hard time and you will get frustrated. Always be prepared to back out any changes you make if needed.
This applies to both hardware and software applications.
I have small things I want to address with X-axis, extruder, Z-axis, and LCD (in decreasing priority )
- research
- plan
- schedule
- implement
On to the next leg, whatever that is. ( but first I am going to enjoy some printing
Quality is the Journey, not the Destination. My limited prints->
RE: The current leg of the Journey – discovery and maintenance
Glad to see you've got a well working printer. I'd keep the textured sheet for PETG and TPU use exclusively, keep PLA well away from it, but definitely give PETG a go on it if you haven't yet.
Also sounds like your trying to achieve perfection, so whilst you are printing, have a read of this thread: https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-user-mods-octoprint-enclosures-nozzles-.../stepper-motor-upgrades-to-eliminate-vfa-s-vertical-fine-artifacts/
You may hate me afterwards 😉
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.