gr5

Contact Sander on the forums - sometimes he gives out a free UM2 for publicity: http://umforum.ultimaker.com/index.php?/user/423-sandervg/

No but you can improve the surface quality by unchecking "combing" feature and having the Z move up on travel on surface to eliminate scarring caused by hot nozzle moving across the surface. There is a really nice plugin for this - hopefully someone will post about it as I haven't used the plugin.

You can't start a new topic until you have validated your email. Check your spam folder for emails from this forum or validate again. To validate there is a huge "validate" button somewhere - I think on your settings page - the page about you: http://umforum.ultimaker.com/index.php?/user/39131-mmartin/ If you can't figure it out post here and one of the moderators will try sending you an email manually and you can reply to that. But that takes hours.

Increasing temp to 75C might help but I don't recommend it. There are better ways to keep the part down. 1) Squish bottom layer - the bottom layer "traces of filament" on the glass should be flat, not rounded. If they don't seem flat (wider than tall) then turn all 3 screws the same amount pushing glass closer to nozzle and restart. 2) Use Brim. About 10 brim passes for problem parts. This is the most important of all the advice. 3) Bed must be at least 40C or the plastic doesn't flow well onto the glass before freezing. 4) PVA GLUE! There are 3 popular forms of PVA glue: gluestick that comes with UM2, hairspray, wood glue. All 3 work great. For glue stick if you want it to be as strong as possible it's good to dilute it a bit. Easiest way to dilute it is to start with clean glass, then put glue stick down in alternating stripes so that half the glass is bare. Then pour or spray some water - about the amount of water in a soup spoon. Then spread this around with a tissue until the glue is very thin. Let it dry (it helps to have a heated bed). Wood glue is easier to use - dilute with about 10 parts water to 1 part glue and shake in a jar and reuse the jar. Paint the glue on with a paint brush and let dry before printing. A heated bed helps the glue dry faster.

I wouldn't print PLA hotter than 75C bed because it is then very delicate. PLA should stick very well at 40C. The advantage of 75C (or 90C) is now you are well above the glass temp and it acts like clay (aka plasticine). If you touch it then your finger print will be embedded. This just happens to the lower few mm but it keeps the corners from lifting. But this is a desperate technique not needed and has other (more minor but definitely there) undesireable symptoms. Instead coat the glass with a thin coat of PVA glue. The supplied glue stick works very well. Also wood glue (also pva) or hair spray (also PVA). But to get it even better, coat only half the glass with glue stick - then add about a table spoon of water and spread the mixture around with paper towel or tissue so that it's very thin. Then turn on the bed heat and wait for it to dry before printing. It should dry to an invisible layer.

DHL appears to employ elephants that sit on the printer edge to edge such that for a few people the X axis (or Y) rods aren't parellel when you open the box (and the 4 feet don't all touch the table at the same time). This gives the impression that the glass is saddle shaped from opposite corners (hold two pencils parallel and then tilt one and imagine what the print head does - one pair opposite corners high - other pair are low). You can fix this by putting the printer in a vice or something and straightening until both pairs of rods are parellel. Also sometimes the screws under the glass aren't set all the way down (trivial to fix!) which warps the glass until fixed (the glass springs back to flat once fixed). But for the most part you should have .05mm error at the most after leveling repeatedly (with the screws - not with the leveling procedure - that just gets you close) if you get a "normal" UM2. This is just from my own experience and reading stuff on the forums.

I had to leave suddenly - anyway cura always picks a larger ext-wid than the nozzle - up to 2X. Never smaller. So if you ask for a shell of .69 with nozzle of .35 it does it in one pass with equivalent flow of almost 200%.

Cura uses a combination of two things to determine the width of the "traces" or "extrusion width" as you call it. I'll abbreviate to "ext-wid". nozzle and shell thickness. If shell width is a multiple of nozzle width then the ext-wid is the nozzle width. So .35mm nozzle, .7mm shell gets .35mm ext-wid. If the values aren't multiples then it's more complicated. Cura tries to make an integral passes to get the correct shell width. So if shell width is say .88mm and nozzle is .35mm Cura might choose either two .44 passes or 3 .293 passes. Cura chooses the two .44 passes. It will go all the way up to 150% of nozzle size for ext-wid before switching to 3 passes. So a 1.06mm wall will require 3 passes of .35333mm each.

Not helpful as this changes depending on when the printer was shipped and no one is keeping track of Marlin settings for different shipments. And probably not important anyway. The orange photo seems to show a part with skirt but no brim. Brim is very important to keep lifting from happening. The green part shows brim. I agree the right side looks like it has gaps. I'm wondering if your glass is curved like a bowl. There are 2 problems that cause non-flat surface. The less likely one is that your X or Y rods are not parallel - your entire printer frame could be bent such that the pairs of rods are not parallel. Much more likely though and just as easy to fix - often the screws under the glass are not completely set - the tapered holes are not deep enough and the screw heads are pushing up on the glass. Check that. And consider drilling them out a bit more if the heads stick up.

Did you mark the motor and pulley around it also? The is the one that slips most often. If you marked the 2 pulleys on the short belt and they didn't slip then it's skipping steps. The most common cause of skipping steps is when the rubber belt rubs the frame but any friction can cause this. If the rubber belt is lightly touching the frame it's very difficult to detect except that every time the axis changed directions the belt twists the other way. If you see this then add washers or something to get the belt further from the wood frame by roughly .5mm. Or slide the pulley closer to the motor. Other causes of friction - end caps is the next most common. Try loosening one of the two on each of the 4 rods.

Is the print moving (not stuck to the bed) or is the print "leaning" to the front as the head gets closer and closer to the front. If the later then you need to tighten all the little black set screws in the pulleys. There are 6 (SIX!) set screws on the Y axis and the most likely ones that are slipping are the 2 on the short belts (the one on the motor and the one on the other end of the short belt.

Oh - and pillowing tends to be worse with thin layer heights - so a .05mm layer height is more likely to get the pillowing effect because the individual "strands" of PLA being laid down over the support grid are more likely to snap.

Surprisingly, both of your symptoms (bad overhangs and pillowing on top surfaces) are fixed with "more fan". Maybe your fans broke? The wiring inside the head is a bit fragile. Of maybe you disabled fans in Cura? If the fans are working I would then try lowering printing temp. Try lowering a lot. If you normally print 220C, try maybe 190C but print very slow - maybe 20mm/sec. Different brands and colors of PLA have different viscosity at a given temperature. Also consider buying some filament from another manufacturer. Some brands just aren't as good. What layer height are you printing? The ideal overhang quality has a sweet spot around .1 to .2mm layer height. If you go much thinner or thicker you get worse results. I'm not sure what the ideal thickness is but it's usually around .1 or .2mm.

I have a video that shows the same UMO running on 16 micro stepping Marlin (normal) and 32 micro stepping on a TinyG board. I hooked it all up and did the comparison tests and made videos. Unfortunately I did this at Ultimaker headquarters back in October and was told not to publish anything that could possibly have secrets. So I might have to blur the hell out of the videos. But that might be a fun project for this weekend. I also heard 64 micro stepping which is significantly quieter but I don't have any video of that. anon - Marlin can do 32 bit microstepping if you just tell it on the ulticontroller the number of steps/mm - just double the number and keep speeds below 150mm/sec (shouldn't be a problem). I think this will work better than pure interpolation. I mean I think it will sound quieter than having sudden changes in velocity in 16 microstep intervals.

Not for me. Slice view is always the same as what prints.

Xeno's advice might work also - if it works it will convert it to a solid part and then remove the top. Instead of spiralize though you could do the "magic" feature just next to spiralize and uncheck "top" and "bottom". Spiralize will give you a bottom to your part. Not sure if you want that.

If it's your cad model and you can edit it, then do what Daid says. Otherwise, set nozzle width to say .3mm and shell to a multiple such as .9mm or 1.2mm then look at slice view. You can go down to about .3mm without too serious loss of quality. You can go lower than .3 also. I would use the max nozzle size possible where it still slices properly. Don't forget to always change the shell width also. In fact for quick testing I would set nozzle to .3 and shell to .3 and if that works, gradually increase shell to .31 .32 .33 .34 until it stops working and then go back to the largest possible shell width. Then set nozzle to the same value and optionally increase shell to an exact multiple of nozzle size such as .93mm (for .31mm nozzle).

1) What the hell! Why don't you print it with that flat spot down - that ring with the 4 holes - make that flat on the glass. This will make all overhangs on outside surface of the "ball" less than 35 degrees from vertical (much better than 45!). Of course there will be some ugliness *inside* the "bowl/ball" but hopefully that's not as important. 2) Dyes significantly change viscosity at a given temperature. Consider lowering the temp for red pla.

What does the feature do exactly? I have a guess but I'll let you tell me. Definitely not. It won't affect distance between perimeters or width of traces. If shell width is .4, .8 or 1.2 and nozzle is bumped a little to .45mm it will do the same thing as if the nozzle is .4mm. It will extrude the correct amount for .4mm wide traces of plastic and place them .2mm inside the model and infill will be .4mm apart. The current cura slicer makes mandatory 3 different dimensions must always be equal: 1) plastic trace width for infill, top, bottom surfaces, shell 2) distance between shell (inner/outer) and between solid infill traces (e.g. top layer) 3) half of above 2 values is always equal to what you probably call "inset" - the distance between the center of the nozzle and the edge of the CAD model of the surface of the part. You can't change 1a versus 1b versus 2 versus 3. They all move together. It would be nice if you could change just some of these. Note there is also an "infill overlap percentage" feature. Maybe that is what you want. You can however scale your entire model in Cura.

print head is exactly the same. The um2 go has a smaller spool holder (only holds one spool of filament) and so needs less space behind it. I expect the other models will start getting this smaller spool holder when they run out of the "long" one that holds two spools.

I agree, it would be a great marlin feature and a feature that *everyone* would use at least once. If you want to resume a print on UM2 make damn sure the heated bed doesn't cool as the part will pop off. To resume, first you need to use pronterface to find the exact layer to continue on. Pronterface is here: http://koti.kapsi.fi/~kliment/printrun/ read all gr5 posts here: http://umforum.ultimaker.com/index.php?/topic/4213-ideas-for-recovering-failed-prints/?p=34788 post #9 here has specific code change example for um2 (ultigcode): http://umforum.ultimaker.com/index.php?/topic/5269-um%C2%B2-printing-more-than-24-hours-non-stop/?p=46704

This is a must have tool for me ($7 plus $10 for a can of butane): http://www.amazon.com/BBQbuy-Pencil-Welding-Soldering-Lighter/dp/B007A9YSPW/ref=sr_1_1?ie=UTF8&qid=1422549200&sr=8-1&keywords=butane+torch It can clean up thin strings instantly, make surfaces more shiny, heat an overhang/bridge area followed by gentle prodding to get it back up there (think belly of a horse sagging too much). It's my new "go to" tool for post processing. BUT be very careful not to overheat and burn the pla to a brown/black color.

Oh - having said all that - although the fan will help a bit I don't think it will help your issue enough to make you happy. You could get one of those butane torches and reheat that area of the bowl. That can make a huge difference in just a few seconds. You have to be very careful though as you can burn the red pla black if you linger too long. I have this one for $7 (plus $10 for can of butane). It is a "must have" tool for 3d printing: http://www.amazon.com/BBQbuy-Pencil-Welding-Soldering-Lighter/dp/B007A9YSPW/ref=sr_1_1?ie=UTF8&qid=1422549200&sr=8-1&keywords=butane+torch

It's an overhang thing. Overhangs are tough. The only help I can give you is to suggest the fan comes on sooner. By default it comes on 100% at 5mm. Better to have it come on at 100% by 1mm. If the fan comes on *too* fast then you have a different problem: you might get underextrusion because the head will cool to something like 190C if you go from zero fan to 100% instantly. The heated bed for PLA helps the PLA flow better and therefore stick better to the glass (the PLA cools just slightly more slowly and so it flattens better onto it getting good surface contact. There is a sudden threshold where below a given temp (around 30 or 35C) you get bad adhesion to the glass and above the threshold you get good adhesion. 50C is well above that threshold. No need to go to 60C for "stickiness" reasons. There are other reasons to go >= 60C but not for this particular bowl.

Oh by the way - once you select PRINT and choose a gcode file, if you go to the TUNE menu and set temps there, you can walk away for as long as you want and it won't start printing until you exit the TUNE menu.