Two problems on an Original +

[Octo 0]

Hi,

 

I'm currently new in the 3D printer, and I'm working as a trainee for a FabLab in France, they asked me to repair a 3D printer which was assembled by someone else (also he's known to do some mistakes on that machine...), that's my first time on that kind of machine so after hours of work, I'm a bit lost, and my boss didn't assemble any of their 3D printers (they have, from ultimaker, a fully functional 2+ extended, and an original which needs to be calibrated (I'll work on it after).

 

So I see two problem, to see where the guy who has assembled the printer stopped, I printed an YXZ cube, but the result is really bad, sides are curved and letters aren't looking great, printed with PLA.

 

So I'm gonna tell what I did to try to improve the situation :

 

- calibrate X and Y with sticks (no problem)

- fixed a problem of PLA leak near the nozzle

- calibrate the plate, but I have a question, with the piece of paper between plate and nozzle, how much does it needed to be gripped by the nozzle ? That's hard to explain how I did to calibrate, but the paper is gripped by the nozzle but not that much, I can move the paper without any fold.

- Y X Z switches weren't calibrated properly, now they click where it needed

- screw properly motors, and look at belts to see if they are tighten, for the comparison, I look how tighten belts from the 2+ extended, and they are looking both the same

 

I have another BIG problem, and it's there I really don't know how to do :/

 

when I try to calibrate the plate on Cura, at the third position the printer head is not on the plate as you can see in the picture, so I think that can be the problem and I can't calibrate properly the machine

 

and the last part was today, just before I leave the fabalb, I started a print and I had to stop it, because the big bolt of the extrude wheel just fell off the wheel, so I tried to screw it again but if you're rolling the wheel, it gets unscrewed again... and I leaved after so I didn't disassemble the wheel to see what's going on.

 

I don't know if I'm stupid or if that's hard to enter in the 3D printer world in that way ^^

 

Well, I'm not gonna work on that machine till next tuesday, so is anyone have a solution for me, I can't use it right now.

 

Thanks in advance for your help

 

Edited March 16, 2018 by Octo

[gr5 2,069]

Did you find the assembly manual?  It's here:

https://ultimaker.com/en/resources/235-assembly

 

I suggest you look only at the feeder section to make sure that looks right.  No bolts should be falling off.

 

Is that Z the bottom layer or top?  If top then you are underextruding - tension the feeder spring to about 10mm length.  If that's the bottom then you need to level a tiny bit closer to the nozzle - forget about the paper - just turn the 3 screws about 1/4 turn CCW to move the glass up .12mm.

 

The X and Y just look like not enough fan.  Try lowering printing speed to 30mm/sec for ALL printing speeds.  Try lowering the temp to 210C and maybe lowering it further from the TUNE menu to 200C (maybe) and see how it looks.  It might start underextruding if you go too cold.

 

Is the fan working?  The X and Y look like not enough fan.  You want the fan blowing on the part, but not too much on the nozzle.

 

What is your infill?  Don't go over 24% for this print.  100% infill could cause the problems I see.

 

Your belts are just a tiny bit loose.  They are probably fine but consider printing belt tensioners like this one:

https://www.thingiverse.com/thing:19892

 

If you put the print head in the corner and pluck the long belts they should have  a pitch (you can use a guitar tuner) around 50-200 hz.  For the short belts you should loosen the motors and push down quite firmly - 2kg force and re-tighten.

 

Don't say bad things about the previous person who built it.  Everyone makes mistakes.  You will make mistakes.  I will make mistakes.  It's how we deal with them after that show if we are a good person.

[gr5 2,069]

This gives you an idea about bottom layer squish.  The harder you squish the better the part will stick.  That yellow part will stick like hell.  These show how high the head was (a guess) when it printed the bottom layer assuming the nominal was 0.3mm layer height for the bottom layer  The numbers show what I think are the ACTUAL height above the glass.  0.3 (nominal) is too high in my opinion as parts will come loose.  The blue skirt is about perfect for most prints.  Black one is leveled much too high.  yellow one is okay if you are worried your part will come loose (for example if you will be sleeping while the print is running and it's a very large print).  Usually I am for the blue - quite a bit squished.

[Octo 0]

Thanks, so I had the opportunity to work on both printers (the other one, that was just a Z problem, now it's ok), so what I did today :

 

- re-axle Y X Z (and let a bit more space between nozzle and plate, I putted not that much space when I did calibrate before, not enough to get the paper "surf" on the plate)

- disassembled/assembled the "extruder" wheel (it seems to don't get unscrewed by itself now)

- tighten both motor's belt

- started to print the cube at 30mm/s speed, but I stopped it, I still get curved shape.

- tried to tighten all belt, but I don't get greater results than before.

 

the fan is working, I'm gonna print tomorrow the belt tensioner from your file

 

here the setting of cura :

- layer height 0.15

- wall thickness 1

- top/bottom thickness 0.8

- infill density 10%

- gradual infill steps 0

- print temp 200

- build plate temp 60

- flow 100%

- print speed 60mm/s (tried 30)

- travel speed 120mm/s

- brim width 8mm

 

thanks everyone for helping me !

[Octo 0]

well I did today a lot of things again to be sure :

 

- fixed X Y Z

- fixed Z switch (I saw it was broken, it was impossible to tighten the screw properly, and the switch moved during the torture test, so I did Z another time, I added a nut, and now I think that's ok)

- fixed Y motor, it was a bit hard to move it with my hand

- aligned pulleys again

- tightened all belts (and no need of external piece)

 

another issue that was reported by the person who assembled the printer, the head is leaking PLA, so tomorrow I'm gonna disassemble the head. (a picture of the zone where PLA leaks)

 

here's screenshot of the last printed cube (right side). I didn't take a picture of the torture test boat, but from cura it was inaccurate, some layers weren't aligned, but with simplify that's fine.

 

 

 

 

Edited March 21, 2018 by Octo

[gr5 2,069]

You never answered my questions.  I still have the same questions but now regarding the newer Z faces above.

 

7 hours ago, Octo said:

I didn't take a picture of the torture test boat, but from cura it was inaccurate, some layers weren't aligned, but with simplify that's fine.

That sounds like you got a slip in X or Y axis.  That's caused by a loose pulley.  You have to tighten the hell out of all 6 pulleys on each axis.  If you use an L shaped hex tool it should hurt your fingers to tighten it.  A lot!  Very tight.  So tight you are afraid because the tool is twisting.

 

Quality is getting better.

 

Those Z's are underextruded.   If bottom layer then you still don't have leveling correct I think.  If top layer then you have underextrusion issues and ignore me about leveling.  I think your feeder spring is too loose.  You want it compressed to about 10mm when you close the feeder on filament.

 

I also see some horizontal lines in the X and Y in the photos just above.  Those are caused by the Z axis not moving consistently.  Sometimes it moves too far and then it moves not enough.  When it doesn't move enough you get a line because it's overextruding on that layer and plastic sticks out the sides.

 

Usually to fix that you need to clean the Z screw - remove it, clean with WD-40, put it back together clean and then add only one drop of grease on the z screw.

[gr5 2,069]

Regarding leakage.  It could be anywhere but usually it's where the nozzle meets the brass tube.  To assemble this properly you have to have these touching as if it leaks then the filament will run through the threads easily.

 

So I believe you need to put the nozzle in the block first, then the brass tube until it touches the nozzle inside the block.  At that point they should be touching.

[Octo 0]

6 hours ago, gr5 said:

You never answered my questions.  I still have the same questions but now regarding the newer Z faces above.

The Z face is at the top of the piece

6 hours ago, gr5 said:

 

That sounds like you got a slip in X or Y axis.  That's caused by a loose pulley.  You have to tighten the hell out of all 6 pulleys on each axis.  If you use an L shaped hex tool it should hurt your fingers to tighten it.  A lot!  Very tight.  So tight you are afraid because the tool is twisting.

I'll try to tighten them more

6 hours ago, gr5 said:

I also see some horizontal lines in the X and Y in the photos just above.  Those are caused by the Z axis not moving consistently.  Sometimes it moves too far and then it moves not enough.  When it doesn't move enough you get a line because it's overextruding on that layer and plastic sticks out the sides.

maybe that was due to the Z switch which was broken and moving a bit, isnt it ?

 

And maybe it depends of the software, cura wasn't perfect for printing the boat hull (one or two layers were shifted, but all the rest were fine and aligned) whereas simplify where it was perfect

[Octo 0]

Here's a picture of boat, left side cura, right side simplify, the version the fab kept isn't the last one btw 3.0.x. Even if I had to stop the impression with simplify it looks like it would be in good shape not like curz version

And here's a picture of the block head, I think that wasnt screwed correctly if that's not enough, is that possible to use teflon here ? Dont look at the heater block, I unscrewed it, I think the leak is coming from the connexion between the screw and the grey plastic part

Edited March 22, 2018 by Octo

[gr5 2,069]

The "grey plastic part" is a material called PEEK.  That's the PEEK part.  No don't use teflon here as teflon degrades quickly as it gets above 200C.  It gets very soft and mechanically needs support.  The peek helps provide that here.

 

The peek part is brittle and the threads can get destroyed kind of easily if you take it apart from the brass dozens of times.  Years ago, the official way to stop leaks there was to print some ABS.  Just 1/2 meter is fine.  The abs slowly cooks (over maybe 15 minutes) into a kind of gunk that will seal that leak nicely.

 

Yes you definitely have X or Y shifts on benchy.  I hope you didn't file a flat anywhere (like on the motor shaft) as that can cause this back and forth shift.

 

How is the play in your head?  With the print head assembled if you push on the nozzle back and forth but not hard enough to move the steppers - how much does it move?  Hopefully undetectable amounts (less than 0.1mm).

 

The reason cura and simplify3D were different had to do with speed and acceleration.  The newer Cura I think messes with acceleration maybe.  Which is fine - you just need to tighten the hell out of the set screws in the pulleys.

 

Did you measure the length of your feeder spring?  when filament is installed and it is compressed what do you get?  I ask because you are having some underextrusion.  Something is still wrong with the feeder (most likely - it could be the hot end).  It's pretty good but it should be able to pull on that filament with 5kg force.  It think you are getting around 1/2kg force.  You could test this by making sure the filament is only half way down the bowden so it's loose, then close the feeder and pull hard while holding the gear still.  You should be able to pull with about 5kg force before it slips.

 

 

[gr5 2,069]

On the most recent Z picture above - on the Z on the left - you have a gap on one side of the Z but not the other.  That is caused by backlash.  Also known as "play".  That's usually in the belts being loose.  If you weren't underextruding you wouldn't notice it but you do have some play and you should fix it.  It's about 1/2 mm probably.  This is the least serious of all your issues.  Most serious is the loose pulley.  Then fix underextrusion.  Then fix leak.  Finally fix the play.  Even less important I suppose - clean the Z screw so you don't get those horizontal lines.

[Octo 0]

3 hours ago, gr5 said:

Yes you definitely have X or Y shifts on benchy.  I hope you didn't file a flat anywhere (like on the motor shaft) as that can cause this back and forth shift.

I don't know, I'm trying to apply your advice and what the manual or what I see on internet says

 

Quote

How is the play in your head?  With the print head assembled if you push on the nozzle back and forth but not hard enough to move the steppers - how much does it move?  Hopefully undetectable amounts (less than 0.1mm).

I can't say right know, this morning I cleaned pieces, the screw for peek and heater block is a bit damaged apparently (I didn't work there this afternoon), peek was fine as its "screw" part, nothing special from the interior.

 

Quote

 

The reason cura and simplify3D were different had to do with speed and acceleration.  The newer Cura I think messes with acceleration maybe.  Which is fine - you just need to tighten the hell out of the set screws in the pulleys.

they are using simplify more than cura, I did create a custom profile (from the original 1) because the + version isn't recognized in simplify. In fact I just created a function to get the plate working.

 

Quote

 

Did you measure the length of your feeder spring?  when filament is installed and it is compressed what do you get?

I don't know, I'll let you know tomorrow

 

Quote

You could test this by making sure the filament is only half way down the bowden so it's loose, then close the feeder and pull hard while holding the gear still.  You should be able to pull with about 5kg force before it slips.

I'll try tomorrow

 

3 hours ago, gr5 said:

Most serious is the loose pulley.  Then fix underextrusion.  Then fix leak.  Finally fix the play.  Even less important I suppose - clean the Z screw so you don't get those horizontal lines.

I screwed pulleys a lot, do I have to unscrewed, to equilibrate again and screw it again ? Or that's not necessary, because for me, belts are looking tighten as they on the original 2+ or what I see everywhere, but I could be wrong, and if I put a tensioner that's too tightened, and I suppose that's not good too.

Because I've disassembled the printer head, maybe I'll fix the leak.

 

For the underextrusion I'll let you know, I'll look at the feeder and the spring, and I'll test with your 5kg test

 

for the play, I'm sorry, but I'm not sure about what you mean by :

3 hours ago, gr5 said:

How is the play in your head?  With the print head assembled if you push on the nozzle back and forth but not hard enough to move the steppers - how much does it move?  Hopefully undetectable amounts (less than 0.1mm).

Do I have to see the nozzle move or the whole block of the printer head ?

 

Tomorrow it's my last day in the fablab, but I can work with them without being a trainee, and I really do want to fix that machine, and learn about 3D printer, and you're also helping/teaching me a lot !

 

Btw they have the original to fix too, my boss changed the material, and nothing is coming from the head while printing, when he changed the material the print head was smoking, maybe he will let work on it, I hope he broke nothing, I think there's a clog, the smoke was smelling burnt plastic, and they also have two others printers that need fixes, I think two dual extruders from flashforge, well we don't care about them for now

Edited March 22, 2018 by Octo

[Octo 0]

The feeder spring is 1cm long, so that's ok from what you said before

[Octo 0]

And another post, the screw (I dont remember its name) is damaged as I said before, that can explain the leak, I have to clean it up properly, but I think i'll not stop the leak if that's the problem... When it was assembled the screw was a bit not straight.

 

I know you don't like the fact I'm blaming him, but from what my boss said he was proud about the fact he finished much more before than the other team on the original. And now look the only thing I didnt is the case itself, that's not a problem, I'm learning but when it's about ego and dont care that much about if the machine is built well, that makes me a bit upset, that's not his machine...