gr5

UMO is different but assuming you mean UM2... The 2 fans are wired in series (which they are not designed to do so if you buy a different model 12V fan definitely buy them in pairs and a different fan might not work well). The 24V goes across both fans at the same time such that each gets 12V. The 24V is pulsed on and off many times per second. When you ask for 0% fan there should be 0V across the 2 fans. 100% should be 24V across the 2 fans. When you ask for 50% the voltage pulses between 0V and 24V many times per second. Multimeters won't be able to measure the voltage accurately - you would need an oscilloscope - when it's not at 0% or 100%. 19V across one fan or both? Note that if you pull up the plastic shielding there are 2 connectors connected by a short wire. Those go to the 2 fans. Or they are supposed to. There is a 3rd fan in the back of the print head. That one gets 12V I think and is not pulsed.

For example if the metal cover has cut through the insulation on the switch wiring you should photograph that before contacting support.

I'm sure you can get a free switch but you should diagnose the problem first down to the part that is failing. It could be the board, the switch the cabling or the switch is not being pushed far enough. You can test all of these things very easily. Time to get started. Start by either installing pronterface and testing the whole system at once with your finger pushing the switch or better locate a multimeter and start by taking off the bottom cover (and while at it see if the cable fell off the board).

First of all - never ever remove the panels. Not side, not rear, not front, not top or bottom. Better to remove the metal cover. It comes off with one or two screws depending how old it is. Very easy to remove. Did you check if that metal cover is shorting out the limit switch cable? That happens a lot. Consider running this software: pronterface/printrun (it's free and an easy gui to use): http://koti.kapsi.fi/~kliment/printrun/ And I think it can tell you if limit switches are triggering or not - start with a working switch. It's important to get this working again. This is a very very simple circuit - either open or closed and easily tested - you can remove the connector underneath and test it with a multimeter pushing and releasing the limit switch and watching the resistance change from near 0 ohms to near infinite ohms. You might have damaged the wiring and you might have to replace all the wiring for this limit switch.

You may have to use different software to upload than Cura. Other's had this same problem and that was the solution. I'm not sure if printrun/pronterface can do it but one solution is to use the arduino IDE. Unfortunately you might also have to build Marlin to have the IDE upload it :(. Anyway get printrun from here: http://koti.kapsi.fi/~kliment/printrun/ If you go the Arduino IDE route there are tons of people (1000 for every one person on this forum) who will likely have the same question: "how do I load hex file using IDE without building first?".

Turn it off AND UNPLUG IT for a few hours. Usually they take a few hours to recover - I don't know why. I had one power supply that took a few days and it's fine now. 24 hours later it still refused to work. Also maybe you still have a short somewhere?

foehnstrum's theory has merit also. Something wrong with retraction.

Hi guys - I'm late to this thread. Reading all the posts from the start I've slowly picked a theory that explains everything and is trivial to test for. But a little tricky to explain. Plus the theory could be wrong. Anyway the super quick resolution would be to increase retraction from 4.5 to maybe 6.5. But there is a better solution... the problem definitely seems to be related to retraction. It's doing *some* retraction but not enough. I also think it could be partly temperature - the temp sensors can vary by +/- 10C but you lowered temp by 20C and although that helped it was not enough. So here's my theory. If you make sure there is no pressure on the filament (standard situation when printer finishes a print and is on or off). Then lift up on the bowden at both the print head and at the feeder and see if there is some play. It's easy to put the bowden tube back in such that there is play - even with that little horse shoe clip installed properly. To remove all play you have to know how the bowden holder thing works - but first realize that for every mm of play you have at either end of the bowden you need to increase retraction by the same amount. To reduce play (only if it moves up and down by at least a half mm) realize first that there are 4 metal blades in the bowden holder. Loosen the 4 long thumb screws 3 times (about 1.5 full rotations) so that there is about .5 to 1mm play in the entire print head. Then remove the horse shoe clip, then push down on the bowden holder ring. Only move the bowden in and out of the head while that is being pressed down by the other hand. Now push down on the bowden firmly and also lift the bowden holder ring. Then tighten the 4 thumb screws so that the head is tight. Now the bowden should be tight enough that it doesn't move even without the horse shoe clip. Reattach the horse shoe clip anyway (you don't want to lose it I suppose). If I'm wrong about play in the bowden at the head or at the feeder then alternatively simply increase your retraction distance by 1mm at a time and test again at 5.5mm, 6.5mm and 7.5mm.

What firmware are you using? There is for example the zmax parameter (max z speed) but I think there is a homing speed somewhere in the Configuration.h file. You could compare that speed between UM2 and UMO.

Yes. It needs to be 170C. You can either the nozzle to 175C or easier send an M302 gcode "allow cold extrudes". Do you use pronterface/printrun? If not you should use that to test your motors - it's very very simple to use and powerful for this kind of testing (e.g. it's trivial to send an M302). Download it here: http://koti.kapsi.fi/~kliment/printrun/

It could be the sensor. I've tested about 20 sensors and they vary by a surprising amount. Try this temperature test. Also consider getting an Olsson block (just google it) both so that you are testing with a fresh nozzle and so that it's much easier to clean the nozzle in the future. Also switching between abs and pla often is very very problematic for about 3 critical reasons. For example ABS doesn't come out of the nozzle easily when switching to PLA and it can line the inside of your nozzle making the effective nozzle diameter quite a bit less than the expected .4mm and making it hard for filament to come out. Or it can cause a full clog of course. ABS pretty easily cooks to a gunk that acts more like a hard wax than the properties of honey needed to get through the nozzle. I recommend sticking to one plastic (either one) for at least 100 consecutive prints.

E also? Well E is less current by default then the other 3 axes. I think maybe 1200 by default. If you connect to the printer using pronterface -- when it first connects it should tell you the currents on all the axes I think. You can change them and then do an M500 and I assume it will save the new default currents but I'm not certain. It might not be possible to save current as one of the savable settings.

That's the big cone with one dot - so yes that should be 0.4mm. I just don't know if you got one from the "bad batch". I doubt it but it's possible. Anyway I'm concerned that you may be simply printing too fast or too cold and I'm concerned that you don't know layer height off the top of your head - do you change this parameter often? I suppose if I changed it on every print I would lose track also. Here are my recommended max printing speeds - going over this can lead to filament grinding and/or underextrusion: ============== Hhere are my recommended top speeds for .2mm layers (twice as fast for .1mm layers): 20mm/sec at 200C 30mm/sec at 210C 40mm/sec at 225C 50mm/sec at 240C The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA.

I don't like carbon fill pla. At least the brand from proto pasta is not any stronger than Ultimaker PLA and it is not stiffer either. It has the same characteristics except it destroys nozzles and possibly also my lungs.

@lofrank what temperature, speed, and layer height are you printing at?

So it's possible that lofrank got the "bad batch" of nozzles marked as 0.4mm but actually drilled out wrong and in the range of .34 to .38mm. But unlikely. I think Carl and I sent out new nozzles to all the people who got one from the "bad batch". If you have a true .4mm nozzle you can put it side by side with the one from 3dsolex and photograph them with a cell phone camera - those camers can get close enough to actually test the nozzle diameter visually!

The nozzle markings are confusing as things have changed over the last 8 months. Some nozzles have small cones like the left nozzle in the photo here and some have the large cones. Once you've established that then count the dots... http://gr5.org/store/index.php/um/35mm-nozzle-limited-edition.html 1 dot=.25mm (small cone) or .4mm (big cone) (or limited edition .35mm) 4 dots=.4mm 6 dots=.6mm no dots=.4 or .8 2+1 dots=.8 1+2+1 dots=1mm The "dot" system will get less confusing as time goes on as Carl has great ideas to make this extremely obvious! No charts will be needed. Some day soon I hope.

I always do fan: min 100%, max 100%. fan helps things like overhangs and bridging immensely for PLA. For ABS you want much less fan if any at all. Fan helps overhangs greatly and it helps bridging quite a bit. It hurts the bottom layer though so you want it to come on gradually over the first mm or so.

It's rare that it doesn't take a dozen hours before you've figured out how to get consistently good prints - regardless of the printer - although the UM2 often works fine right out of the box. Anyway that part in that picture is really really tiny - can barely see it but I think it looks like maybe it stopped extruding? I mean most of it looks fine I think. Would be very helpful to zoom in a bit first. Anyway there are lots of things that can cause that - most common are having too many retractions or printing too fast such that the feeder grinds up the filament - check that out by opening the feeder, heating up the nozzle to 150C and pulling it out a bit and inspecting the part in the feeder. Also printing too hot can cook the filament into gunk - but this is very unlikely with PLA. Also you might have dust/dirt/wood particles (from feeder getting chewed up? examine and look for that also) getting into the nozzle and causing a clog. Your feeder tension might be too light. Also try printing 30% slower and 10C hotter - what are your settings for speed, layer height and temp?

Yes, what Joris said. Write a plugin. It will be awesome. And please share it! Note also that the newest versions of Cura (15.06.* and newer) have a totally different way of doing plugins and I don't know if anyone knows how to do that yet so I would go for the older version e.g. 15.04 and I'm sure all the work you did for the plugin will still be useful - I suspect converting plugins from 15.04 to 15.06 will be pretty simple once someone documents the process.

Post photos. I don't know if you modeled the cup as a cylinder and unchecked "top layer" or if you are modeling the width of the walls of the cup carefully? The first method works really well - espeically with a larger nozzle size. Most likely you are doing #2 and need to uncheck all the "fix horrible" boxes as stated above.

I had a similar sound and feel and it turned out that the belt had hopped one "gear step" on one side but not the other such that the two rods were not perpendicular anymore. I fixed it by loosening 2 of the pulleys on one belt and pushing the head to one side until both blocks hit the end then recentering and then retightening the pulleys. Tighten the hell out of those pulleys! The allen wrench should twist slightly. Also add a drop of oil to each of those rods plus the other rods in the outer walls. Any ordinary petroleum based light oil is fine but not wd40 which has lots of cleaning additives. Sewing machine oil, 3-in-1 oil, just ordinary oil. Not vegetable oil.

Actually I think this is a bug where if the walls are a little "too" close together it won't print infill. I've seen this on cylindrical parts also with a small cross section. Someone already posted this issue on the Cura issue tracker complete with sampel STL file.

150mm is more difficult - the upper layers are cooling and pulling hard and that lifts the corners of the bottom layers. But this is solved. You probably just need to add brim but here's my full answer... ========================================= lifting corners, curling corners, part sticking to glass 1) Make sure the glass is clean if you haven't cleaned it for a few weeks. You want a very thin coat of PVA glue which is found in hairspray, glue stick, wood glue. If you use glue stick or wood glue you need to dilute it with water - about 5 to 10 parts water to 1 part glue. So for example if you use glue stick, apply only to the outer edge of your model then add a tablespoon of water and spread with a tissue such that you thin it so much you can't see it anymore. wood glue is better. hairspray doesn't need to be diluted. When it dries it should be invisible. This glue works well for most plastics. 2) Heat the bed. This helps the plastic fill in completely (no air pockets) so you have better contact with the glass. For PLA any temp above 40C is safe. I often print at 60C bed. 3) heat the bed (didn't I already say that?). Keeping the bottom layers above the glass temp of the material makes it so the bottom layers can flex a bit (very very tiny amount) and relieve the tension/stress. For PLA 60C is better than 50C. 70C is even better but then you get other "warping" like issues at the corners where they move inward but if you are desperate it's worth it. For ABS you want 110C (100C is good enough). 4) rounded corners - having square corners puts all the lifting force on a tiny spot. Rounding the corner spreads the force out more. This is optional if you use brim. 5) Brim - this is the most important of all. Turn on the brim feature in cura and do 10 passes of brim. This is awesome. 6) Squish - make sure the bottom layer is squishing onto the glass with no gaps in the brim. The first trace going down should be flat like a pancake, not rounded like string. don't run the leveling procedure if it is off, just turn the 3 screws the same amount while it is printing the skirt or brim. Counter clockwise from below gets the bed closer to the nozzle. Don't panic, take a breath, think about which way to move the glass, think about how the screw works, then twist. This may take 30 seconds but it's worth it to not rush it. You can always restart the print. If you do all this you will then ask me "how the hell do I get my part off the glass?". Well first let it cool completely. Or even put it in the freezer. Then use a sharp putty knife under a corner and it should pop off.

These changes will make very little difference. In general glass is an improvement over blue tape but blue tape worked fine for many years as long as you clean it with alcohol to remove the wax. But you seem to have more serious issues. The back of the chair is starting to look better but the lower part is a mess and I can't tell what it's supposed to look like. It appears that maybe you have underextrusion so I would go 10mm/sec slower on the printing part (and yes 150mm/s on travel) and I would go 10C hotter - your temp sensor may be off by 10 or 30C and that can cause your printer to print too cool (or hot) and too cool means plastic is viscous (like toothpaste instead of honey) so maybe 10C hotter will help. I wouldn't go over 240c until you have things working well. Can you print something simpler maybe that I know what I'm looking at? A 1 cm X 1cm X 1cm cube maybe?