gr5

project file please. 🙂

I think you are getting either over extrusion on layers with the holes or underextrusion everywhere else. 1) My guess is speed changes. I would mess around with speed changes. Maybe lower the speed because it has to slow down for those holes as they have sharp corners. Or maybe not speed changes. 2) Maybe it's retraction related as it has to do a retraction to jump across each hole. Maybe during retraction the filament inside the nozzle heats up a little more and so extrudes a little more? Again - lowering speed will help as the temperature of the filament will be more consistent if theory #2 is correct.

Okay I don't mention the software. I think I used putty? Or actually I think I used my linux machine. What operating system do you have? You need different software for each machine. Hyperterminal should work if you already have that. Putty I think will work. There are probably over 300 programs on the PC that are good terminal programs through a "COM" port (assuming you have a PC. I'd just google it. I *do* talk about proper baud rate. Olimex website also talks about baud rate and how to hook up cables (seemingly backwards as TX connects to RX!).

It's a 3 pin cable. Not sure what the 4 pin cable does. I'd just get the official one if it won't take too long. There are many other cables that work. They are all called "usb to serial cable" or something like that but some are 5V and some are 3.3V and I'm not sure which you need or if it even matters or if it can damage the olimex or what. Google can help with that of course: "which serial cables are compatible with olimex lime2?" As for software - PLEASE READ MY WEBSITE - lol!

As far as I know, Ultrafuse 316L is nothing like Nylon. The reason PLA is so easy to print and so beautifully is because it's softening temp is at 52C. With air temp around 30C (just above a 60C print bed) you only have 22C of cooling that causes shrinking. Nylon hardens around 120C. Around 90C difference from typical air temps just above build plate. So about 4X more shrinking! It's not quite 4X harder to print because Nylon is also more flexible which helps. Printing the part on the short end is a very interesting idea. Maybe add some supports. HERE'S A WHOLE NEW IDEA! Print the part 5mm above the stage and support it with tree supports. In cura preferences you can uncheck the box that says something like "automatically drop part to build plate". Then click on the part and select the move tool and set the Z value to 5mm. Slice and see what kinds of support you get. You want support structures that aren't well connected in X and Y so that when the part itself starts shrinking the support moves enough to not stress the connection to the bed. There is a feature called "raft" which can also help. It does all this for you (moves the part up 1mm or so and builds a raft underneath that can flex a little.

As I explain on the website you will need to connect the other end of the serial cable to a computer such as PC, Mac, Linux and you will need software on that computer to see the output coming from the Olimex board.

Everytime you boot your olimex it spews out tons of information. It tells you what OS is booting, what drivers are being installed, what services are starting up. Also eventually the UM software starts running as well including the recovery programs and it spews out stuff as well to the console. Every. Time. You. Boot. Until now that information just goes to those 3 pins and is never observed. So you leave the SD card in the olimex and power up and look at all that info you have been missing all this time. That's the first step. Read it all - look for error messages - try to see where things go badly (usually near the end). Post the result and let me look at it.

There's a lot of info on my page about UBOOT because I spent many days getting past that step. The good news is that you guys don't have any UBOOT issues so skip all that. There's also tons of info about UBOOT on olimex out there on the internet, lol. Olimex goes way beyond just Ultimaker printers.

Okay so there is a LOT of information at gr5.org/unbricking I describe what software I use and the problems I had getting the software working the first time. You can also google "olimex serial cable f" and "software" and "mac" or "windows" or whatever and there are helpful people out there. Please look at my website. I spent many hours creating it and got feedback from people such as yourselves and updated it many times. Unfortunately it's a bit of a mess but I have cleaned it up a few times so it's not too too bad. I explain what to look for when it boots. How I managed to examine the partitions, discover which partition doesn't mount, reformat, still doesn't mount, repartition, reformat, get things working, finally get the install to work. Issues other people had. Comments from Ultimaker experts. And so on.

Great. If nothing else the errors on boot will tell you a lot!

There's a thriving community of Olimex lime2 users out there with active forums and tons of helpful advice about, well, everything Olimex related. There are other versions of linux you can install (I've done it) you can install all kinds of software on your olimex. It won't hurt your printer - the printer just won't do anything.

In this image you can see which pin is rx, tx and gnd:

So this first picture is from Olimex - it's their lime2 product line and it's the closest I could find to the one in the ultimaker by far - the other boards are just completely different: And here is the board on the fbrc8.com website: Note that the two white connectors at the bottom of the UM version are over an area that says "USB" and in the olimex lime2 it has 2 metal connectors that look like USB connectors. In the UM version on the bottom right are 3 holes and a white outline. On the lime2 there is a power connector mounted there. On the top of the UM board from left to right is a micro USB, then an hdmi connector. UM version has the same micro usb and then an empty spot labelled hdmi so they simply never loaded the connector but it has hdmi capability there. So this is a similar board but it has some key differences. But here's the thing! On both boards next to the ethernet connector are 3 pins. On the lime2 board it says "DBG1" (debug 1) and clearly has 3 male pins sticking up. On the UM board it's harder to see - I don't see pins sticking up. What do you have there on your boards? Anyway that is where you connect the serial cable. The serial cable gives you complete control - you can watch it try to boot up, you can see all the messages, once it fails you can log into the computer as root and look at things. Execute commands. Reformat, repartion, etc. most implortantly you can see exactly what it was doing when it crashed and you can see fatal and non fatal errors.

Looking at the photo of the olimex board on the fbrc8 website I see next to the ethernet connector it says "UART0". Next tot he writing I see 3 black things that look like connectors or something. Maybe they face the other direction or maybe they are female connectors and you need the "serial cable M" (F is female, M is male). UART is another way to say "serial port". Somewhere on here there is likely a way to access the serial port as this is helpful for Ultimaker firmware engineers.

From their perspective, you have bad blocks on your Olimex and it needs replacing. End of story. My perspective is different.

You can contact various support people including the people at fbrc8 who assemble the USA printers or the people in The Netherlands who are also experts. They will most likely all tell you the same thing: you need a new Olimex board - the smaller assembly of red boards. I can see that fbrc8 sells them for $371 (USA sales only). Buying these outside of USA will be a similar price: https://fbrc8.com/collections/ultimaker-3-spare-parts/products/olimex-board-um3 I'm just trying to give you a cheaper solution. Anyway it doesn't hurt to open a ticket with fbrc8 if you are in USA or directly with Ultimaker if you are outside USA but I think they will just tell you to replace that board which I'm sure will indeed fix the problem. If you have hundreds of hours of time and are good with software you could deconstruct the image that goes on the SD card and look at all the code. You can see the part where it says "2 minutes left" which I'm 90% sure is a static message and isn't the actual time but a guess of how much time is left. You can see what operations are going on at that point. I strongly suspect at that point it is trying to copy all the firmware from the uSD card onto the "hard drive" of the Olimex and it's getting fatal errors. I could be wrong - it might be doing other things like initializing the wifi card or something. My suspicions are based on experience with other UM3 and S5 printers which also have Olimex computers with SSDs that seem to fail a few blocks after some time and which usually can be restored by repartitioning and reformatting. But there are many other possible failure modes.

I have an older UM3 with older unix board made by Olimex so I don't know the answers to your questions. There have been supply chain issues and I assume olimex stopped supplying ultimaker with their boards and so Ultimaker had to scramble and come up with an alternate solution. It looks to me like they designed this board themselves. Maybe. I strongly suspect your flash memory has a few bad blocks and needs to be repartitioned and reformatted but I don't know for sure. I'd definitely take things apart and look at the other side of that red board. Maybe an hdmi port or serial pins on the other side. Personally, I don't have much money/budget to fix my UM3 and S5 so in my particular situation, I would take it off (the red board) and look all over for serial connection pins. They would likely be labelled RX TX G if they exist. If not you almost certainly need to replace the red board. Is your printer still under warranty? Is this a company printer?

Yeah I'd try to look at the boot log meaning I would try to figure out how to get a serial cable hooked up so I could watch it boot. But I'm cheap. If the printer is under warranty you can get them to send you a new linux board. If the printer is not under warranty but it's a company printer you can have the company pay for a new linux board.

I still think higher temps are better as that will reduce the upper layer shrinkage. Other ideas: - Enclose the printer to get the air up to around 40C - Redesign the part so that the upper layers don't pull so hard - maybe use selective ribs instead of solid top? Maybe you can do a hexagon pattern (in your design - or you can disable "top skin" in cura and use a hex infill pattern. - Use brim as this is exactly what brim is supposed to reduce. - Contact magigoo - Try pva glue - Either: A) Use the supplied glue stick, spread it around very very thin and sparse leaving areas with no glue. Then take wet paper towel or tissue and spread it around evenly (and also remove most of it). B) Mix Elmer's wood glue about 1 part glue and about 10-20 parts water. Mix it well. I use a jar with a lid so I can shake it over the sink. Then use a small paint brush to spread it on the print bed. A or B will make your parts stick extremely well. I don't have a metal flex plate so I don't know what might go wrong. You could check the "bambu" printer discussion. Or better, Prusa discussion as they have a huge following and lots of those printers have flexible metal. I really want to know what you learn. I print with Nylon all the time and it's one of my favorite materials. Very very tough material, temp resistant, and you can dye it any color super easy.

Or maybe Ben will learn something and share it here.

If stuck on the 2 minute remaining for more than 5 minutes power cycle the printer.

I got my S5 working again after it had bad blocks on the flash memory aka the "hard drive". I had to manually repartition and reformat it but the newer recovery images do that for you. The bad blocks are noticed. They are mapped. So they are locked away to never be seen again but you have to recreate any damaged files or partitions. So this is a good process to make your printer last for years longer.

I love breakaway but sometimes the part shape doesn't allow for it.

@nallath

Sorry for the huge delay in replies. If I don't reply feel free to send me a DM with a link to the topic.