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@dast asked me some questions offline so here are the answers. griffin gcode: This is slightly different from standard Marlin. I'm not sure all the differences. But keep in mind that the Marlin on the UM3 is 99% identical to other versions of Marlin. Some differences: UM2 and UM3 Marlin has the ability to do E axis movement either in mm^3 or mm linear. Most printers do mm linear but the UM2 introduced a feature where you tell the *printer* the diameter of the filament instead of the slicer. I think this was reversed back to "normal" method on the UM3 where the slicer knows the diameter of the filament. G2 and G3 commands (same as G02, G03) are not implemented in Marlin. At least I don't think so. the link above says it is but I'm 90% sure they are not. They certainly aren't used for 3d printing as STL format does not support arcs. Just flat triangles which form lines when sliced. I could be wrong - they might be supported. G0 and G1 are implemented identically in Marlin but in general Cura does one for move and the other for print just to make it easier to read. Marlin moves the 4 steppers in 4 dimensional linear space. So if you move x,y,z,e steppers all at the same time and you move them 1,2,3,4 mm respectively then they will move 1x, 2x, 3x, 4x as fast such that we move in a straight line in 4D space. This is important because all the different axes have different acceleration limits and velocity limits. So if for example the X axis has double the acceleration limit of the E axis and you move them both 1mm at the same time then the E axis will set the max acceleration for that gcode move. Because it's limit is half that of the X axis. But if you are moving 1mm in the X axis and only 0.1mm in the E axis now the X axis sets the acceleration limit for the move. This way the path in 4D space is linear. If the E axis moved at max acceleration it would get to it's end point long before the X axis and you would get overextrusion at the start of the move and underextrusion at the end. Back to your last question: The E value is normally the distance to move in mm of filament so Cura needs to know the diameter of the filament and the layer height and the line width and distance to move the E axis the correct amount for a lines segment. On the UM2 (and maybe on the UM3? I don't know anymore) the E values are usually in cubic mm^3. So moving from position E10 to E11 would extrude 1 cubic mm of filament (the printer needs to know in this case the diameter of the filament but cura wouldn't need to know). There are other details I'm leaving out. Like if the flow value on the printer is 150% then it moves to E position multiplied by 1.5. If cura has a flow value other than 100% then it modifies the E values in the gcode. The gcode that starts with F in a move sets the "feedrate" which is the speed in mm/minute so G0 F600 Sets the speed to 10mm/sec going forward. G0 X10 Y10 F600 E10 does the same thing as G0 F600 X10 Y10 E10 In other words it changes the printing speed *before* it does the rest of the command no matter where the F is located. Because the feeder almost always moves much slower than the other axes (in mm/sec) the feedrate usually determines the speed of the X or Y axis (whichever is moving farther).

Most of them are here. This has gcodes for other firmwares as well so follow just the marlin ones: https://reprap.org/wiki/G-code And also read this excellent guide by Daid: The UM3 has 2 computers - a linux board and an arduino board. The arduino board runs Marlin and does the "low level" gcodes but some of the gcodes sent to the UM3 are interpreted by the linux computer. Those are all detailed best in the code sitting on the UM3. All the code on the UM3 is interpreted so you can just look at it. It's very easy to read. You don't need to be a programmer - you just need to be able to read english as there are lots of comments. You can search around for know gcodes like those Daid spoke about and then there may be more in the same or similar files. So in summary: ssh into the UM3 and look around.

It's a long video, I know, sorry. But I packed in everything you need to know to be an expert at getting parts to stick to the glass better. In the video I pick up an entire printer by the little UM robot. If you follow any 2 of the suggestions you will have an improvment but if you follow all of them you will never have a part come loose again.

It would be nice if you could post some pictures of what the "inner structure" looks like and what it looks like in slice view (both good and bad). Well it sounds like it isn't your cad model so it will be harder to fix but I'd try a repair service. netfabb free repair service is here (you have to create a free acocunt first): https://service.netfabb.com/login.php Also look at the things in the "mesh fixes" section of cura and try disabling all of those. In particular make sure "union overlapping volumes" is disabled.

In cura the print bed is shown with a checkerboard pattern. These are 1cm by 1cm. Check to see if this agrees with your part. If it does and you slice it then it will have gcodes scaled to mm. If you then print it and it's 5X too small there is something wrong with your printer - it's not taking gcodes scaled to mm. For example: G0 X100 Y100 E0 G0 X120 Y100 E2 The first command puts the print head at position 100,100 and then the second command moves 20mm to the right and extrudes 2mm of filament. These values are all in mm. Maybe your printer is in some other unit? Maybe you have the steps/mm set up wrong on the printer.

This is almost always a slipping pulley. Does your printer have belts? That go over pulleys? If so tighten the hell out of the set screws that keep the pulley from slipping on the shaft. Also mark the pulley and the shaft with a marker to see if it is moving after your next layer shift. Usually it's the pulley that is hardest to get to such as the one on the motor.

I thought someone might answer by now. In general I get better quality if the speeds are all the same - every speedup or slowdown causes over or underextrusion and I get these bumps like this. Also printing slower is better as then the pressure is lower in the nozzle and less likely to splurt out like this. So set all 7 or so printing speeds to be 25mm/sec (I know - slow) to see if that helps. Leave the travel speed >= 150mm/sec.

Is this from sketchup? If so here is some advice. Mostly just follow the advice about inside versus outside surfaces (right click in sketchup and swap): https://i.materialise.com/blog/3d-printing-with-sketchup/ If it's not sketchup or if you didn't create the model, maybe try: netfabb free repair service is here (you have to create a free acocunt first): https://service.netfabb.com/login.php

Yes it only gets more dense near "top" surfaces which can be in many locations of your model. I wish it got thicker on walls and floors for strength as well. Still it can save time in printing and makes the top layers quite nice. There are 3 related settings: infill density gradual infill steps gradual infill step height Try 50% for the density, 1mm for the step height and 10 for the number of steps. Moving down from the top, each step it uses half as much infill. For a cube the setting is pretty much useless. You can instead just add one or 2 more solid infill layers at the top of your part. For something like a pyramid it's quite useful. It makes quick partial infill up the sides that get thicker as you get closer to a top surface. Similar to what bones look like on the inside.

@IRobertI - any advice here? My advice is to go to thingiverse and look at other people's designs.

@tom356 - right now I don't think there is a way to do this so you could slice the part twice and save it in two files - one with every layer "ironed" and one with none of the layers "ironed". Then you could cut and paste the ironed layers of layer 15 and layer 35. You probably should also insert a G92 EXXX where XXXX is the position that the extruder was at on the most recent move on the previous layer. You should do this each time you switch from the ironed gcode to the non ironed gcode in either direction. So you would have to add 4 G92 commands. If you don't do this you will get some under or over extrusion at the layer changes. I'm not sure how much. It could be a huge amount. It sounds kind of complicated but you would learn a lot about gcode and how that works and if this project is for printing MANY parts you would save a lot of time. If this project is for printing only one part then maybe you should just iron the whole thing.

@jies You got a new power brick? That made no change?

I've had these break twice now on my (beta) S5 and soldered them back on and they work great. Also be aware you can disable auto leveling (I don't do autoleveling on my UM3, only my S5).

Select them both and then right click and it's something like "merge". Before you do that you might want to assign them to different extruders or assign one to control infill pattern or whatever your purpose is for merging two STLs.

You can push the head around when it's not busy doing stuff. when the printer is just idle the servos almost always power down. For example before you start a print or after the print is done. You can tell when the servos were powered off because it always does a home first thing when it applies power back to the servos. The clicking is a common issue on UM2, UM3, S5 printers. it is not serious but you can try to fix it. I haven't fixed all my clicks. That's probably related to one of the 2 long Y axis belts and one of the 4 Y axis pulleys on those long belts. Or maybe a short belt. Try to figure out which corner of the printer it's coming from when you push the head forward and back by hand. Watch the belts carefully over the pulleys. See if the belts are lined up with the rods just above and below them. They should be. You can loosen the set screw on a pulley and adjust it so the pulleys on the same rod are as far apart as possible and then retighten but tighten the hell out of those set screws because you could end up with a worse problem: missed steps - caused when the pulley spins on the shaft occasionally.

The UM3 is prefectly good enough. It's a great printer. It's a little slower than the UM2 and a little faster than the S5 (in general, bigger is slower). Personally I would look around for a used one because I am cheap. I have 7 Ultimaker printers and they are all great but my favorite are the UM2go printers. They do most of the work. S5 is my second favorite but I use my UM3 almost as much as the S5.

What material exactly? I have printed ninjaflex on heated glass bed with extremely thin layer of PVA glue and it was fine. If you use glue stick then take a wet tissue and spread it around evenly. The tissue will remove most of the PVA which is what you want. I'm not sure but I think ninjaflex is TPU.

Yes. 3dsolex nozzles meant for UM2 will work with any e3dv6 compatible printer. They are M6 threads and the same length as the old standard e3dv6 nozzles.

I don't think this exists. I was going to suggest going to 4 layers instead of 3 but you already suggested it. 🙂 Note that 4 layers instead of 3 will take the exact same amount of time as printing the first of the 3 layers at 50% (but a little more material).

If you don't mind making the part slightly smaller you can fix this by lowering the part slightly. Go to menu "settings", "configure cura", and uncheck "Automatically drop models...". Then click on the part, use the move tool and change Z position from 0 to -0.3 or so. You can play around with how far to lower the part under the bed. This should make the bottom more flat. I use this feature all the time.

Does it have a perfectly flat roof? If so maybe you don't need support. PLA can bridge quite well. What material are you printing with and what material are you using for support? Are both materials PLA? "roof support" is only if you have BAM (break away material) or PVA. It creates a solid "roof" just under the model instead of an open support structure.

You can definitely pass through the nozzle but don't go so far that you scratch the teflon which is typically at least 2 nozzle heights away from the tip of the nozzle. These are acupuncture needles. They have a pointy tip. I like hypodermic needles a little better as they have a sharp edge and can scrape the inside of the nozzle tip nicely. I have been meaning to cut or grind the tips of my acupuncture needles flat to see if that works better. Or maybe at a tilt (like hypodermic needles) instead of a point in the center. I find a cold pull is usually good enough for cleaning inside a nozzle but if you have a bit of sand or fiber in there then pushing the blockage up into the heat chamber of the nozzle using a needle followed by a cold pull works great. But in reality this hasn't been an issue the last few years for me. Another trick for cleaning a nozzle is to burn everything (remove nozzle from printer first of course) over a gas stove. Don't let the nozzle get red hot. Just hot enough to produce black smoke.

Are you saying it does the print correctly? But the prime tower wrong? Are you saying it's trying to heat a second extruder for the prime tower but there is no second extruder? Or are you saying it applies an X/Y offset when printing the second nozzle? Please be more specific about the problem.

@kmanstudios has done many 5 day prints on his UM3 printers. Any suggestions, kman? My first suggestion is to change the angle on support from 50 to 60. This will reduce the amount of support needed greatly. Also for this print it looks like you can set the "support horizontal expansion" to zero. In general ANY problems you have with PVA are very likely caused by moisture in the filament. Unlike ABS and PLA, PVA and Nylon absorb water quite quickly (e.g. 60% humidity for 2 days is probably enough to partially "ruin" your PVA). So I recommend you put the spool of PVA on your print bed, set the bed temperature to 80C, put a towel over it and let it sit overnight like that (10 to 20 hours). Also loosen some of the pva a bit on the spool so the outer layers can dry even more (typically I would expect only the outer 10 meters of filament to be exposed to moisture). When done and it cools below 40C, put it back in a sealed bag with desiccant (it's good to buy those rechargeable boxes of desiccant - around 250 grams is good). When printing things that are longer than 24 hours or when the humidity is above 50%, keep the filament in the bag while printing with only 3cm unzipped at the top of the bag and with desiccant inside the bag. Keep the bag and filament sitting on a table behind the printer in a small area so the spool can't fall over.

I'm very biased because I sell them. But if you ware worried about nozzles clogging then I would get a 3dsolex core because the nozzle can be removed, cleaned out, and put back into the core. Plus you can buy more than one nozzle for the core.