gr5

You are over extruding a bit. The extra filament pressure builds up in the nozzle and occasionally a little extra spurts out and makes a little bumpy thing. This is the bottom layer and usually you *want* it to over extrude a bit. If you just ignore this and let it print the next layer up things should be fine. The bottom layer is affected by leveling - if you level slightly too far from the bed then you will get what looks like underextrusion plus your part won't stick well (if it all). If you level too close (this is good) you can get these bumps. Much better to be too close like this. On the next layer all should be good. If layer 2 is also a problem then maybe your shell width isn't an even multiple of your nozzle width - check that first in cura (which version of cura is it?).

Oh - that's strange. Why is it move so slowly to the right after it hits the switch? Is the Y axis ever moving at all? I'm wondering if the problem is simply that your Y stepper motor isn't connected at all. When you are doing that procedure - when it is homing X and Y *both* axes should be engaged - in other words you shouldn't be able to push the head in X or Y direction. So do this experiment - with power off or when you first power up, the X and Y axes should move easily if you push them around. But when running that procedure try pushing the head towards the back. Does it move easily? If so then your Y stepper has a broken wire or isn't plugged in or something like that.

40W and even 50W should be fine. Some low quality 40W heaters have all the heat out near the wires and none at the tip of the heater but the ones made by Ultimaker and 3dsolex should all be fine. Brass melts around 900C! There's no way you can have the back of the block at 900C and the temp sensor as cool as 210C, lol. Long before it hits 900C it will start glowing red hot and you will wonder where that "red light" is coming from. Now if your temp sensor falls out but the heater is still in the block, and if you have the older firmware that doesn't report "heater error" then, yes, I suppose you could melt the block.

Yes. That's what doodle3d does I think. At some point it's all loaded onto the SD card and you can disconnect USB mid print. But like I said - it takes something like an hour to load a 3 hour print onto the SD card (about 1/3 through the print).

That's an option also. I sell bowden's to Mexico. My store is here: thegr5store.com My bowden's are not UM stock. They have slightly larger inner diameter so you are less likely to have this problem in the first place. But really - it's not too hard to fix this using simply hot water and some existing filament. I've done this myself before. I had a friend help - having 4 hands instead of 2 makes it a little easier. We did not use gloves - just bare hands.

I think UMO has a dual amplifier maybe? Look at the UMO dual extruder kit - see if it comes with an ad595 board. I'm too lazy to look at my existing UMO to see if it has a board with 2 connections. Now if you are asking about UMO+ which doesn't use thermocouple but instead uses PT100 then I think you are out of luck. But there's no reason you can't have nozzle1 use PT100 and nozzle2 user thermocouple with AD595 board as the firmware lets you choose which sensor type but you need all the hardware to support each type of sensor.

Also measure the diameter of your filament. It should be less than or equal to 2.9mm. If it is 3.0mm filament - throw it all away - 3.0mm is too big for bowden printing and you will be doing this kitchen sink thing with every other print.

First completely remove the tube. Detatch it from the black plastic weave. Bring it to your kitchen along with a spool of filament. Straighten it out and try pushing one more time with fresh filament. If it still wont' come out it's time to add heat. You have a few choices - best is to find a large flat pan and pour boiling water into it. Wear thin gloves (if the water is too hot through thin gloves then you can let it cool a bit). Ideally you want around 70C to 80C. Let the bowden sit in the water for 1 full minute to get the heat all the way to the filament. take some *cold* filament and start pushing the hot filament out. Don't get too hot - 100C is too hot for PLA it will melt too much. Another choice is to use a hair dryer but it's easy to go too hot with a hair dryer.

Correct. If for example you have a 3 hour print it will probably take 1 hour to load the whole print through usb onto the SD card. So this option is available through a few suppliers like doodle3d.com but not through Cura which is more of a slicer than a printer controller. Maybe you should look into octoprint. If you buy a raspberry PI for like $30 you can put octoprint on it and control your printer that way - through a web page - it's very nice.

After you get it off (you know you can just leave it on there right?) heat up to 150C and turn that round steel nut raising the block up into the head and lifting the white teflon part into the aluminum cylinder which will tighten things up a bit. In fact check how loose the aluminum is and rotate until it is no longer loose and then add another 1/4 turn.

I watched @labern print some cheetah on a UMO recently and it's nice stuff. Not as flexible as their main flexible filament but it's pretty good. I didn't have to do much to get it to print nicely. He printed some "tank treads" and they were quite tall (100mm?) but still came out just fine. Maybe he can comment on print settings. He certainly didn't use any oil which I find helps quite a bit.

Yes there are about 30 possible causes for underextrusion and having filament enter at an angle or filament tangles on spool are two of them. But I'm not convinced he has any underextrusion issues as I haven't seen any pictures. Lots of people can upload pictures from mac no problem. Click the icon second from the right above where you write the reply text (image gallery), then go to the upload tab and just drag and drop a photo onto that area and post.

Are you using PLA?

@didierKlein - actually read above - someone already printed one and has the cad files.

@DidierKlein? If Didier doesn't want to help I would go to 3dhubs.com. They can refer you to someone local in Antwerp. You need two things - someone to create the cad model which is the expensive part. And then the printing is cheap and easy.

Ninja on Um2 - I forget but I think I used the "plus" feeder for this one:

Okay so this sounds like backlash (aka play). Backlash is usually something loose. Backlash is when you move X axis to the right to say position 100, it only reaches say 99. Then when you move it to the left back to 0 it only reaches say 1 (that would be 2mm of backlash or play). This is usually caused by loose belts or crazy enough, belts too tight causing very high friction. The reason it's different on the layers with the hole is that on some layes the head is moving clockwise and on the layers with the hole it's moving counter clockwise (or maybe the other way around) due to the hole making the slicing different. Coming at the layer from another direction makes the backlash more visible. To fix, with no power to XY steppers push the head around gently. Feel for something loose. Alternatively feel the friction and see if one axis is much higher than the other. Consider oiling only the 4 rods in the upper corners, but not the 2 that go through the head. Check the belt tensions - the UM2 rarely has loose belts because each of the 4 blocks has a belt tensioner inside but maybe one is broken. More likely your entire head is loose and the nozzle flops around a bit. Or maybe your friction is incredibly high on one axis.

Hi Titus - just make sure what you are trying to fix is this 16th step issue and not one of MANY other issues that cause vertical lines. The lines are diagonal on benchy only because the side of benchy is *almost* but not quite lined up in the XZ plane but is instead tilted slightly around the Z axis (normal rotation on the bed) and even more strangely the wall is tilted out of vertical! only because of both of those tilts do the lines show up as diagonal. Walls lined up with the printer won't show any lines at all.

What sander said. Also you can uncheck the "lock" symbol when scaling and only scale up one or two axes instead of all 3 but I dont' think that will help you. I think you need to scale the cad model.

Take it all apart - check the connections. The error is from the temp sensor - not the heater itself. The temp sensor is the smaller 2 wires. Check the resistance - it should be about 108 ohms at room temperature.

Usually blobs are reduced at lower speeds but I'm guessing you are already down to 10mm/sec, lol. More info would help (photo and post profile settings).

Could be a few things but I'm going to start with backlash and check some things. Does the pattern: 1) Stick out on the far side also? 2) or is the whole part shifted in one direction (left and towards camera) such the far side center band move *inwards* towards the center of the part? If #2 then it's backlash - something is loose or too tight. I'll tell you more after I hear your answer. If it's #1 it's probably over or underextrusion caused by speed changes at the hole - to verify slow it way the hell down - try 25mm/sec. Report back.

Try again to include a picture - the button second from right above your posting. It could be: 1) underextrusion - would be obvious if I could see the photo of your print 2) slicing problem (possibly due to error in model?) 3) This is common with non-pla plastics. Are you printing PLA? Easily fixed if printing ABS is causing this. 4) backlash/play - make sure nothing is wrong with belts - not extremely loose. With power to head off, push it around gently and before motors start moving is the head loose?

@nallath - I think this is a simple cura 2.1.2 bug that happens only with UMO (non ultigcode).

flexifil shore hardness 45D (about 95A) ninjaflex 85A So ninjaflex is a little softer and therefore probably is more flexible. It helps to watch a few videos of someone demonstrating how soft a ninja flex printed part is. That will help more than the numbers. Why is flexifil too hard? Can't you just print with thinner walls? Or less infill? Or a thinner part so that it is more flexible? Watch some videos of ninjaflex!