Stopping a Bad Print

[hiker7777 0]

I have a Ultimaker 2 printer and the print job started off well but then had many microfibers all over the place. 

I paused the job but I want to completely start over. How can I do that? 

 

I am making face parts for health care worker who are caring for coronavirus patients. I'm a newbie. I'm not going to 

bed without success. Help. 

[gr5 2,267]

1) Please take a photo.  I have no idea what you are talking about.  Microfibers?

2) You can just hit the power switch if you want.  In the pause menu I seem to remember an abort option.  Anyway then just clean things up and start over.

3) PPE is complicated.  Are you sure you will be printing a design that will actually be used?  There are lots of problems with many of the designs floating around out there.  Did you speak to a doctor?  Are you printing a design that multiple nurses or doctors approved of.  It's great that so many are helping but let's not create things that won't get used.

[hiker7777 0]

Thank you for your response gr5. I attached a photo when I should have done that before. 

 

I did not see an abort option. I saw "resume print" "change material" and "tune" 

 

So I ended up resuming the print job and will try again.  

 

Thank you for asking about the PPE. The person in charge has given out over 150 face shields already and Rhode Island 

Hospital called him and is asking him for more.  It's not junk 3D material and if it was I would also try to stop the process. 

 

With the lack of federal help, more librarians and teachers are volunteering to print the parts that are needed to make face shields.   

 

I really do appreciate you getting back to me so quickly. I am reading the manual and learning a lot. These printers are amazing. 

 

Thank you and be safe. 

 

Here is a link with a student explaining the process. 

https://www.wpri.com/health/coronavirus/west-warwick-students-creating-ppe-to-donate-to-health-care-workers/

[gr5 2,267]

You can abort I think within the TUNE menu.  I didn't check, sorry.

 

So it looks like you had a layer shift to the left.  If you look carefully you can see that most of the part printed fine for several layers then it looks like the part is duplicated (in a silly string kind of way _ to the left.  In particular there are 2 ear hooks and the wavy-string stuff is to the left for both ears.  About 1.5 inch to the left.

 

OIL

 

There are a few possible causes.  One is that you just need to oil the rods.  With power off push the print head around to the 4 corners.  The movement in X and Y should be about the same.  You should not be able to push it with one finger but if you use one finger on each hand, try pushing with one finger on each end of the rod going through the head and it should be easy to push it (printer might slide a little on the table but usually not).

 

If the X axis is much worse then this may be the only issue.  Anyway use some oil to clean the rods with tissue or paper towel and then after removing all oil add only one (one!) drop to each of the 6 rods in the gantry.  Push the head around.  If you feel an improvement you might be done.

 

PULLEYS

 

More common (maybe - well quite common anyway)  are loose pulleys.  They may be fine 99% of the time but when there is a little too much acceleration they can slip.  Each of the 12 pulleys have a set screw.  Your printer should have hopefully come with a long hex driver with a green and black handle.  You need to tighten all 12.  Actually just the 6 on the X axis.  The 4 pulleys on the long belts are easy with an L shaped allen wrench or the hex driver.  Just push the head around until you can see and access the set screws.  However the most likely pulley to slip are the 2 on the short belts on the X axis (which are the X axis?  just push head left and right and you are moving X axis belts and stepper motor).

 

Those 2 pulleys are the hardst to get to.  If you have a hex driver you can do it without taking anything apart.  If you absolutely can not make phone calls and get access to a hex driver (2mm hex driver) you will have to remove the cover over the X stepper.  There are I think 2 screws holding each stepper cover - screw head is outside printer.  Only uncover X stepper (right rear corner).  You may have to completely remove the stepper to tighten the pulley set screws.  I have never had to do this as I have a long hex driver.

 

TIGHTEN THE HELL OUT OF THESE SET SCREWS!  You want it scary tight.  So tight that the tool twists.  If you are using an L shaped allen wrench it should hurt your fingers.  You should see red marks on your fingers after from the short length of the L.

[gr5 2,267]

Oh - and again - it's completely fine to just hit the power switch on a UM2 at any time.  The printer is tough.  It can take it.  You will of course have to start the print from the start.  Actually there is a "continue print" option if you install tinkerMarlin but that's advanced and not worth it for short 1-hour prints like these.

[hiker7777 0]

gr5   Thank you! That is very very helpful. 

[hiker7777 0]

And I did find it, you have to hit Tune to find the abort button. Thank you again. 

[geert_2 558]

Depending on the firmware-version the "Abort" on the UM2 can be plainly visible during printing, or in the "Tune" menu (I have both).

 

In some UM2 there was an issue with driver chips overheating: then they would shut down for a few moments until cooled down, and then continue. Mostly with the Z-axis (up-down). I had this on one printer a few times in hot weather, when doing long print runs. I reduced maximum current a little bit, and since then it never happened again. I am not sure if this could happen to the X- or Y-axis too? But first try the other solutions, and only consider this as a last resort if the other things wouldn't help.

 

Not only no oil, but wrong oil on the rods could cause issues too: I once had "thin oil" that soon dried into a sort of very sticky gum. So much so that I almost couldn't move the head anymore, it was almost glued to the rods. That caused skipping too. Then I cleaned the rods thoroughly with isopropyl alcohol. And now I use surplus hydraulic oil, as used in hydraulic test benches and machinery. I don't know if this is the best oil, probably not, but at least it lubricates well, has anti-corrosion additives included, and it never dries out. It works for me. I just regularly refresh the oil because of the dust that gets collected on the rods. When lubricating, do not pour oil on the rods, but rather add it to a tissue, and then wipe the rods with the tissue (without touching the belts). You do not want oil dripping all around in the printer: it would destroy bonding to the glass.

 

[hiker7777 0]

Where can I buy hydraulic oil? 

 

[geert_2 558]

15 minutes ago, hiker7777 said:

Where can I buy hydraulic oil?

 

At big oil companies, but I don't think it is a good idea to go buying a vat of 160 liter...   🙂

And there are so many different specs for different purposes. I just use hydraulic oil because I had it for my hydraulic machine (and it is on-spec for that hydraulic machine, not necessarily for any other equipment).

 

If I had to buy fresh oil, only for the printer, I would probably go for something close to the official Ultimaker specs: some light machine oil, like used for lubricating bike chains, fine equipment, tools, and similar. You can find that in car-accessories shops, or do-it-yourself hobby shops (at least here in Europe).

 

No car engine oil (=way too thick), no ultrathin dislodging oil (could be corrosive and does not lubricate well), no real sewing machine oil from a textile shop (this is the one that turned into gum here), no brake fluid (this is no oil at all, but a different kind of high-temp liquid), no grease (too thick), no high-temp oil,...

 

Note that I am not related to the Ultimaker-company, so my words are not the official company policy; it's just my personal experience as customer and printer-owner.

 

[gr5 2,267]

2 hours ago, hiker7777 said:

Where can I buy hydraulic oil? 

 

Any light oil will do.  I use "3-in-one" oil.  "sewing machine oil" is a good choice.  Don't use vegetable oil as it will go rancid but any petroleum oil will work.  Don't use WD-40 as that is for cleaning things - it's not so good at lubricating.