gr5

Cura chooses the center of the bed based on bed size. So bed size is the problem. For example if you tell cura your bed size is 200 by 200 then it will start the print centered on 100,100 but if your actual printer is only 150 in X then it will start your print centered 2-3cm more to the right.

Link doesn't work for me. Maybe it's an illegal extension - maybe you need to zip it up or tell your web server to allow files with the extension ".curaplugin". Or better - why not put it on github??

Well the "advance" feature definitely helps at higher speeds. It's a bit hacky and does not deliver the correct advancement of extra and less extrusion when slowing down and speeding up. But it does help a bit. It was popular on non-bowden printers that had lower accelerations but now that the UM3 is out and has lower accelerations than UM2 maybe it's time to turn this feature on for the UM3.

That does not look like a print with excessive retractions. Is it possible you sliced for 0.4mm but have a 0.25mm or 0.5mm steel nozzle on there instead? As that would explain it right there. I would try removing the nozzle and the bowden and with the hot end hot - manually feed some filament through the core to see how much back pressure there is. On the UM2 the teflon would fail due to being at high temps for hundreds of hours - it would get soft and then when compressed it would squeeze the filament and add lots of friction. On the Um3 the teflon should never get above 100C so it shouldn't deteriorate. Ever. But maybe it was always bad from the start. It could be that Carl cut the teflon a fraction of a mm too long and when compressed in the core it squeezes the filament too much. This would be obvious if you do my test. Another possibility: the temp sensor is reading high and the nozzle is 20C cooler than we think it is. That's all I can think of right now. This is not a common problem - at least no one is reporting what you describe. So far. with many hundreds shipped. But doing this quick test would be helpful and informative. If you were in USA I'd have you ship it to me and I'd do the test myself. Carl is pretty crazy busy keeping up with shipments.

It's called "ensure models are kept apart". Uncheck that.

I have and sell hardcores. I help Carl with support for them. I'm hearing maybe 2 issues? 1) There was a problem with some hardcores where after the print is over it won't retract the filament out of the hardcore. Carl knows about this now and all newer hardcores don't have this issue - basically the upper portion of the hardcore (on some - I think maybe 10%?) was too small - smaller than the ptfe inner diameter - such that the melted filament has a larger diameter, then solidifies, then won't retract more than 10 or 20mm before getting stuck in the "trumpet" or in the top few mm of the heatsink. If you have this issue I'd send it back and get a replacement. In USA contact me at thegr5store@gmail.com. In the rest of the world you can contact 3dsolex or contact your reseller. 3dsolex is just carl and one or two assistants who don't know much about 3d printing. So really it's carl you'd be talking to if you contact them. If this is an issue it's very obvious - you can't get the damn filament out - you can't get the damn core out. One solution is to use a hot knife and cut it off just above the trumpet (heat exacto knife with flame). Another solution is to remove the bowden, cut the filament, and with the nozzle hot push it downwards with some tool until it is inside the trumpet so you can remove the core. 2) The other issue is where it consistently stops printing during your print. This *might* be due to excessive retractions which makes sense as it starts happening when it starts the letters. Every printer is different and it matters how tight your bondtech is but typically the same spot of filament should be safe to go through the feeder 10 times. 20 times and you have a very good chance of it grinding to dust and failing. Try restricting retractions to 5X on any give spot of the filament. To do this you have to know your retraction distance which I think defaults to 6.5mm but just type "retraction" into the search above settings and look at what that value is. Then copy that value to "minimum extrusion distance" and then set "maximum retraction count" to 10 (no more than 10 times - same piece of filament through extruder). 2b) Or it could be 100 other issues but retractions seems most likely 3) Note that the default 6.5mm retraction works quite well with hardcore so I recommend sticking with that.

In machine settings I think you can set the bed size - just adjust the bed size to the actual size of your machine and it will print in the center.

In cura settings (not profile settings) there is a checkbox to keep your cube from moving everything else away. "allow overlapping volumes" or something like that. sorry too lazy to check right now. dxp actually has a great idea - just set top and bottom thickness to the length of your ends.

I get similar results. On a UM2 which has higher jerk and acceleration I can print faster and get the same corners but it's the same basic trend. This is one reason why Cura likes to do faster infill speeds, then on the inner shell it slows down to get a perfect outer shell.

It is faster. I've printed certain items at 200mm/sec. Let's do the experiment first. Plus the acceleration, at least on the UM2 is much higher then printers with head mounted extruders. The UM3 has much lower acceleration due to it's heavier print head. So the UM2 at 50mm/sec can beat other printers at 100mm/sec because they are printing something where the head rarely actually gets above 50mm/sec.

@ghostkeeper probably knows the answer to this one.

I haven't had this problem. I usually use cura 15.04 for my Um2 but occasionally I need a cura 3.X feature and it's worked fine for me. However I have heard the advice to add M25 to the end of gcode files for the UM2. Supposedly that helps the UM2 know that you are at the end of the file? I don't understand it exactly.

This. Please do it tinker's way. That way you don't have to worry about bed clips and making blobs in the wrong spot. And as a bonus you learn more python maybe? Also people are going to want positive and negative offsets and tinker's method works for both positive and negative offsets unlike your original design which always does G92 Zxxx.xxx where xxx.xxx was always zero - now xxx.xxx can be positive or negative values and can be the current position if offest is zero.

By the way - other people disagree with me - so I'd love to see you do the experiment to prove me right or wrong. I just print everything around 30 to 35mm/sec and don't see so much rounded corners - but maybe I don't print cubes much so...

The bowden pushes on the filament like a spring and there is a roughly constant pressure in the nozzle as you print so every time the print head slows down it over extrudes. and it slows down on corners. The lower the acceleration and the lower the jerk, the more time it spends on the corners. The simplest solution is to set the print speed to the jerk speed. That way it won't slow down. The term "jerk" is a bad term here because physicists have a very different definition for that word. What it means for Marlin (the firmware in all UM printers and in 90% of printers out in the world) is the speed the head slows down to on corners. Marlin takes the velocity vectors for the movement going in and out of a vertex (a 3 dimensional velocity) and subtracts the vectors and takes the magnitude of that. for 90 degree corners that means the speed at each corner can not exceed square root of 2 times jerk speed (so if jerk is 20 then 14mm/sec is max corner speed). For very gradual corners like in a circle with many segments - that speed approaches infinite. Typically a very slight change in direction might have a jerk limited junction speed of 1000mm/sec (basically unlimited). If you increase jerk too much your printer will skip steps and your prints will have layers above that don't match the layer below basically ruining a print. The easier solution is to just slow things down. 25mm/sec should be more than enough. You can compensate by doing thicker layers. It's fine to print the infill much faster than this. Please try this as a test and let us know. You can even do this test live - if you slice for 100mm/sec then in the TUNE menu the % speed will match the speed in mm/sec and you can play with the speed in the TUNE menu without doing any math. Or you can slice at any speed you want and do the math to figure out what speed you are getting when you multiply by the %. Anyway consider printing the cube and in the TUNE menu try 100% speed for 10 layers, then 50%, then 25%, then 10%, each test for a few mm of the print and mark the changes with a sharpie maybe and keep notes and let us know what you discovered.

I'm dissapointed no one helped you on this. If you google around there are instructions on how to do what you want. You can do exactly what you want. I'd set the infill to 100% and then load a cube into cura and make sure you set the cura preferences (not model settings) such that you can have parts overlap the same volume. Then you can stretch and zoom that cube until it encopasses the volume where your dogbones are skinnier. You also have to disable forceing Z=0 all the time - also in cura settings (not model settings). And you can increase Z so your cuboid is now above the build plate. then there is a trick to tell cura to do different infill settings inside that cuboid. I forget where this feature is - I think you select the cuboid and either right click on it or maybe it's something along the left edge of the screen. I've seen a youtube video I think from didierkl aka didier klein maybe - also explaining this feature. Anyway the last step is to tell cura that the infill should be 0% inside that cuboid.

Usually you fix this by lowering the temperature which makes the pla more viscous so it leaks less. And also slowing it down so the pressure in the nozzle is lower so it leaks less. I recommend playing with these 2 parameters in the TUNE menu until it stops stringing or until it strings much less. Actually the print on the right with the least stringing looks the worst - something wrong with the Z I think where it didn't move the right distance and it then over extruded some of the layers - what kind of printer is this? I think it has a problem with the Z axis sticking.

It's a minimum, not a required height. So if one minimum says .06mm and the other says .08mm then you go with the .08mm.

Also I also recommend you minimize the pla cooking temp (although pla can take it for hours - still) by setting the bed to maybe 10 degrees below desired temp with the WAIT for temp method. Then set the nozzle to desired temp (no waiting) and the bed to desired temp (with waiting) and finally the nozzle to desired temp (with waiting).

Did you check to see if there is no driver for the E1 connector?

OH! I think I know the problem. Many UM2 PCBs were shipped without the second extruder driver. They simply did not solder on the chip for E1. Look at your motherboard carefully - the stepper driver chips are somewhat prominent. Square chips. There is X,Y,Z,E0,E1 so 5 identical connectors - there should be 5 identical chips near each of these connectors except the one for E1 may be missing.

I just noticed that Y_STEP_PIN is defined many times in pins.h. Are you sure you got the right one? Where MOTHERBOARD==7?

@TOMTFX - you copied the 3 pins from E1 (the values 47,48,49) into Y pins? So for example you left the min/max pins alone but changed the 31 to 49 and the 29 to 48. Are you sure you left the 26 and 28 alone? Then you built Marlin successfully? And then you downloaded it onto your printer? And then rebooted and did a FACTORY RESET? (factory reset shouldn't matter but some settings (I think not pins) are stored on the eeprom and you need to do a factory reset sometimes to get everything copied properly from firmware to eeprom)? And you also remembered to move the Y cable to the E1 connector? And then what? The Y axis refuses to move? @tinkergnome - is there some step I skipped? Is there some other code he has to edit other than pins.h?

I don't know the A8 but most printers have 0,0 in the front left corner but a few (especially delta printers) have 0,0 in the center. Cura has to support both types of printers. I suspect you want 0,0 in the corner but cura is centering the part near the corner. If I'm right then go to machine configuration in cura and there is a checkbox somewhere that determines if it's 0,0 in center or 0,0 in corner. You want to change that checkbox.

Never heard of this. Usually a restart is caused by the power supply. Usually this only happens if the bed is drawing a lot of power. The bed should be off when selecting material, right?