My Trials and Tribulations and Fun!

dr_tetrode

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Hi,

This is my way of sharing the 'fun' with my printer. A little history, I spent months trying to decide on which one? Cost only, capability only, or combination. Then a magazine I read, had about 30 of them lined up and compared. The number 1 was the Prusa i3 mk2. In kit form, it was priced in the middle, but the capabilities seemed and were very good. So I order it. It arrived, yeah! 1 box, a little heavy, but, intact and all the way from Europe. Assembly followed, what fun! I really enjoyed the process, lots of learning went on, learned to take my time and follow the comments on the website, for each assembly step. Some kept me out of trouble, some told me why what I just did was not quite the correct way of doing it, and then I had to re-do. It took me about a week of evenings, and a Saturday. In the end, I ran the calibrations, and it worked! I was shocked! and delighted. This was about 2 years ago.

Working from memory, no pics, there were many items printed, some successful and some not. The beginning of the trial, was, early on, I was printing something, and since it takes time, I went to bed. Woke up in the morning, and found the spool of filament laying on the printer and the print stopped! It had fallen from the holder and hit the print bed. OK, bad print, peel it off, and start over. More items printed, and I began to see some issues with the prints sticking to the heated bed. Hmmm... tried all kinds of tweaks in the slicer, got some to work, but not all. Hmmm.... the front right quadrant feels cooler to the touch! Oh oh, that is not good. This is about 3 months ago. So, saved up and ordered a new heated print bed. In less than a week it arrived! Yeah!

And with that, the trials begin!

Scott ;-)
 

dr_tetrode

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Hi,

OK, first lesson learned, when the spool falls, I need to create and always use a physical locking mechanism to hold my spool on the supports.

So far, I have used only PLA filament, and have been happy, it is corn starch based, so it is not water proof. Second lesson learned, about a year ago, don't make a vase out of PLA and expect it to hold water for flowers! Ooops, three days later my wife is asking where the water was coming from?

And, on to the trial. I had to do a partial disassembly to install the new heated bed. So, shutdown the printer, unplug power and moved to the work surface. Fire up the laptop nearby so I can see the documents from Prusa. Begin disassembly, take lots of phone pictures, to show where cables, nuts, bolts and pieces go. Pictures are good for me, memory of where things go, not so much, sometimes.... And I get the bed off with out issue, didn't loose any parts, and got the bed back on without issue. Had to look up the hook up on the Prusa website, and it was shown in the newer model, i3 mk2s, but, it was there and it worked. Got the printer reassembled, and started to run the calibration routines. It says it was calibrated successfully. Oh, good.

Now let us set the Z-axis, and get the print head close to the bed so that the first layer of PLA sticks to it. I am a little high, so adjustments are made. Looks right, so let's try a simple hexagon print, gaming stand. Hmmm.... looks like spaghetti on the bed! X-axis doesn't sound smooth when moving! It seems to be moving in large steps, rather than in the small steps it should.

Next, power off, open electronics box, and pull and put back every single connector! This printer sits in the garage for 2 years, so contacts might be dirty? Nope, power up and I can still hear the movement of X is off, ie. in large steps.

This is currently where I am at, printer not working correctly, in the X axis, the Y and Z axis are fine. Extruder is fine. Need to figure out what to try next.

Thanks for reading! Don't take this as complaining, just a history and log of this problem.

Scott

Some pictures, mentioned above. I have put in 8 pix, from Google Drive, with 8 links.

Not seeming to work, hmmm... must go look and see how this is done ;-(

 

dr_tetrode

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Another attempt at putting in pictures related to above post on Friday, Feb 1st. I have include a single photo with the link given by Google Drive. Can we see it?

Scott ;-)
1_Heat Bed Connection.JPG
 
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dr_tetrode

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OK, that worked, in a way, you can 'open image in another tab', so how do I get a thumbnail to show from an URL????

Confused,

Scott ;-)
 

Rhaven Blaack

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Scott,

I fixed it for you.

To upload a photo. First have the photos saved on your desktop. Then, click on the "Upload a File" button. Click "Choose a File" button, Goto where the photo is. Double click on the file and it will upload automatically.
 

dr_tetrode

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I am assuming, that the above post is true, so this will be the post with pictures from the 1 Feb. post.
2_Old Connector.JPG
Above is the old head bed connection, showing the orange filament used to support the wires during movement.
4_Roller Y axis assembled.JPG
Y axis roller that had to be disassembled to remove head bed.
5_Roller Y axis.JPG
Above is the parts of the Y- axis roller, so I don't forget how to put it back together. ;-)
6_Underneath.JPG
Here you can see the belt that had to be undone to remove the orange block in the middle that is attached to the heat bed.
7_Parts.JPG
The new parts, out of the box.
8_Connection New.JPG
The new connections, on the head bead before install.

This part of the process went pretty smooth. Was able to remove and replace the head bed, hook it all up and it started and passed the self test. The fun began with the XYZ calibration process!

Scott
 

dr_tetrode

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XYZ calibration tribulations, and success!

OK, part of moving the printer or changing anything is, run the Self Test, which passed, and the running the XYZ calibration which verifies that the frame is square with the bed and the height of the nozzle is close. Ran these and passed.

X axis sounded funny, like it is skipping, and when printing PLA, it seems to be doing that. Also Z axis has to be adjusted in software, more than 1mm, and that is too far.

Result looks like this:
10_Bad_results.JPG

Many attempts were made, last week, gave up and walked away for a few days. Went back Saturday, and started in the morning. Managed to think about it correctly, and moved the proximity sensor, P.I.N.D.A, away from the bed to put the nozzle closer, as it should be. Sorry, no pix on that. Still having trouble with X axis, so I figured out from the instructions from Prusa, on how to re-burn the firmware on the printer. Just in case something flipped a bit somewhere in the drivers for the servo motors. That did not help at all. Grrrr...... Then I saw an article suggesting lubrication on the bars and linear bearings. I have been oiling them every couple of months, so I ran my finger on the bars where the linear bearings run, and found DIRT!, that would not move. Hmmmm...... I then spent a little time cleaning the metal, removing the dirt and re oiling, and lo and behold, it is now working! Yeah!
11_Success_Reindeer.JPG
Here is the killer print, 4 reindeer puzzles on the bed at once, this is the print that convinced me that I had head bed issues, when I ran it before Christmas, the front right quadrant, would not stick, and the print head would push the first layer around and make a big mess of plastic spaghetti!

12_Success_TrayJPG.JPG
This is a flat bottomed! tray, to hold paper craft tools! I could not get one to be flat bottomed from the time before the bed replacement.

10_Bad_results.JPG13_Success_HexBases.JPG
Failure on left, success on right! Hex bases for paper miniatures....

So, this has been my journey, with my 3d printer, lately. Happily, back in business, and starting to look for things to print!

Like any technology, it takes a while to get it to work, since we are at the beginning of the home 3d printer learning curve.

Lessons learned.
1. Keep the rods clean, since I am in the garage, and have plenty of dust, oil and wood dust, form hard deposits...
2. Slow down when making adjustments to calibration, I was thinking in the wrong direction, and made things worse for a while.

Happy Printing,

Scott ;-)
 

Revell-Fan

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You are doing fine! :)
Limit is 6 per post. After upload the photos can be deleted or moved locally and the post will still work?
That's the old limit (the thread is from 2012). Now it is 10 per post. You may alter your posts indefinitely by clicking the "Edit" tab. The pictures appear as text inbetween "ATTACH" brackets. :)
 

dr_tetrode

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Well....

I tried a larger project, 2oz. paint jar holder, that ran for 13 hrs, overnight. Checked just before bed, all was well. This is what I found in the morning.....
IMG-1810.JPG IMG-1811.JPG IMG-1815.JPG

First picture is the screen, note run time.... Second is the result, uggh! Third is what caused the result, the print shifted for some reason.

Looked into causes, belt, motor, on X axis, that is a maybe. Then I saw a note, a cause could be the 'silent' mode in the Prusa i3 mk2, the very same mode I changed the printer to, just before bed. Maybe that is it.

So, running a different print, now.

Lesson learned: Don't switch to 'silent' mode on a big print.

More learnin' going on!

Happy Printing!
Scott ;-)
 
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zathros

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Very interesting. I will say, from observation, and some practice, find a way of covering up the X,Y,and Z bars to avoid contamination front dust, and or dirt. Their metal will cause them to have a negative polarity and attract anything floating in the air. The accumulation of the debris will possible cause either the rollers to "bump" or such a spot, or actually transfer the spot to the roller. Basics on these things is to establish a sparkling clean environment.

Stepper motors driving a toothed belt will always cause vibrations. You may be able to mitigate that will softly wheels, on an arm with a spring to to take and absorb the belt's oscillations.

Considering how much effort you have put in, you're getting good knowledge, and will soon get the results you wish. Just as a thought, is that machine bolted to a strong table, or sitting on one? Bolting it down will transfer much vibration away from the 3D printer. I helped a friend a dial in a small CNC milling machine, one of the tiniest I'd ever seen, (about the size of your 3D printer) and he was so frustrated because he could not get a nice finish on anything. After I helped him built a proper table, then bolted the table to the floor, and the machine to the table, the finished surfaces were almost mirror like, I also had him slow down his cutter speeds, I don't know why people tend to run at such high rpm's equating that with a better finish.

The only part of the latter statement that would apply to your set up is how firm the base of your machine is mounted to the table, and how secure is your table to the floor, ultimately, how bouncy is your floor. Concrete floors are best, but for you applicable, any good solid floor should do, a heavy table will fix much, and making sure "foreign object debris" (FOD) does not accumulate on the ways (axis rods) is important. Seeing that they are steel, I would suggest getting "Way Lube". It is an oil, not a great, and the viscosity is such that it will stick to the surface, but not puddle on the ends of the bar. It does not evaporate, and does not have the negative quality that grease has. "3-in-1" oil works great too, it is essentially sewing machine oil. :)



3-in-1 oil.JPG
 

dr_tetrode

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Thanks for the inputs! I have been using 3 in 1 oil, all along. I have had the printer in the same environment, for 2 years, so it takes a while to build up the FOD... I agree with you on cover, next big project is relocating and building a full cover. Garage gets cold, in winter and the breeze from opening the door, will warp a print, so I need to build a box.

Currently, machine is sitting on a 1 1/2" thick piece of granite, but, with the factory supplied felt pads on the feet. I wonder if removing them and somehow tying it down to the stone, would help?

The step that occurred in the bad print, I believe occurred because I changed the mode of operation from 'High Power' to 'Silent' and the 'Silent' has an issue, software I think, that I did not know existed. I saw a note online, for my specific model of printer, that said this happens. ;-( The step occurred after that change, so I think is was self induced. ;-(

Belt with springs, won't happen, the belt has teeth, and I don't think there can be any flex in the belt for the precision I am getting. I can print, what is called a 'plastic bearing' that has 6 internal herring bone gears, contained in a ring with herring bone teeth, and it will rotate immediately when it comes off the bed, so the 3 axis movement precision is there. See below.

"Way Lube" sounds interesting. Where can that be found? Sound like something from machining for lathe bed ways.

Thanks for the input, nice to hear from someone in the machining real.

I have had a few successful prints, after this one, but, haven't tried that particular one, yet.

Happy Printing!

Scott ;-)IMG-1821.JPG
 

zathros

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"Way Lube' can be found at "Ace Industrial" hardware stores, or order it off Amazon. It's hard to buy small amounts of the stuff, but a machine shop might sell you a cup for $10 bucks. ;)
 

dr_tetrode

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Thanks for your input. Things are much better now. Have not found Way Lube, but did clean and 3-in-1 oil the rods in X-axis.
Things I found not right after the heat bed replacement.
1. X-axis stepper motor shaft to gear, had slipped, this I believe was the main issue with X axis problem. See pix 1.
2. X-axis idler pully is slightly skewed, and I found this on the internet article, so I tried to fix that by insering a bit of nylon zip strip between the screw for the idler and the frame. Not sure this helped. See pix 2.
3. Found that one corner of the heat bed was not tight, causing the flattness and calibration to be off. See pix 3.
For #1. I had to take X-axis apart so I could get the belt off, and then set the gear in the correct positionn and re tighten the set screw.
For #2, attempted to wedge the idler axle/screw to a more 90 degree to travel, position.
For #3, tightened the mounting screw.
Next, off to calibration. I learned the hard way that the PINDA probe has an LED that must be lit, before calibration or the Z-axis drives all the way down until the motors stall! yikes!. Had to disconnect and reconnect the cable, and it started working. When working properly the LED goes out, when in proximety of the head bed. So now with basic calibration done, had to adjust for the exact height above the bed for the nozzle, they call this the Live Z adjust. Just squished enough to stick to the bed. Yeah! all done. And we had success!

Next printed a new spool holder that won't allow the spool of filament to fall.

Next printed some sanding devices, for paper crafting. These I found on Thingiverse.com and they have nuts and bolts that fit perfectly when inserted. M5 - 20mm. I was impressed with the fit. See pix 4.

We we are back in buisiness.

Scott ;-)
 

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dr_tetrode

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Ooops wrong picture above for number 3! #2 should be pix 2 and 3. Item 3 is in this post.

Is there a way to edit a post, after posting a reply?

Scott ;-)
 

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zathros

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Yes, to EDIT your post, after posting, click on "EDIT", go to "Advanced Model" and you will see the options for removing pics, and adding new ones.

Glad you have had success. Personally, I would make a all metal 3D printer as plastic will eventually loose it's shape for too many reasons to list. Running out of years and drive to build one of these. The first one I worked one was back in 1986 when they were "secret", it's actually an old technology. I would also only build a printer that could make Nylon parts, as they are actually usable. You will learn much with this, and could make a bigger machine using this one. :)
 

dr_tetrode

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Thanks for EDIT tip. I agree with your assessment of the printer, I purchased it as a hobby purchase, I am fascinated with the idea and capabilities available today. Plastic on the printer is ABS, so far so good. I can print all of the parts my self, and as soon as I build a chamber for it, I will. I like the idea of self replication! I need to keep the area the printer is in, warm, when printing ABS. That is driving the need for a 'chamber'. Currently working in PLA. Experiencing some thermal issues, even there. I noticed that when I get 'greedy' and try to put many items in a print run, that the ones out near the edges seem to curl because they are cooling off, before the next layer gets deposited, and this cause some failed prints because the material curls up and the print head hits it next time around and move it. So lesson learned, print in the middle of the bed, where the temperature stays warm and even. It is a learning tool for me. I need to learn 3D cad, to do what I really want to do. That has been a high bar for me to get over. The printers out there today, I think, can print nylon, some even do carbon fiber filled filament. But, as a hobby, I am having fun. Problem is, I have found another hobby, here! Enjoying both.
 

Gandolf50

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You can hit the bed with a hairdryer, or a hobby heat gun and keep it warm while printing and it will help. I would NOT recommend 3in1 oil at all, tends to gather dust and dirt and turns nasty... I always use non-petroleum based silicone lubricant, which won't attack the plastic parts and can be sprayed on a paper towel and applied to your rails, and with the included straw shot into bearings and around bushings... You might need to apply more frequently than with an oil or lube, but you won't need to worry about dirty grease getting into your parts.