gr5

If you are printing this cold (which is fine!) keep the speed around 20mm/sec.

When you put the UM on it's side it's pretty obvious. I think it might have been only one screw - maybe two. Anyway it's the screw that is CLEARLY holding the cover on the the metal box. We are talking the bottom covers, right? It's very simple. Compared to changing the battery in my watch which required me to watch two videos? This is amazingly simple.

This is begging for a plugin. The plugin could for example have one temp at the bottom and another temperature at the top and you could have the plugin linearly interpolate in between. I nominate Jonny!

I know someone who got an email the moment his UM2 was shipped. My email came 2 days after it was shipped. But I just decided to do a test - I went to DHL and put the "R" number in DHL and it showed my package! So try it.

You make convincing points. It *could* be backlash/play. Or it might be something else. play: So are all the belts tight enough to get at least a very low audible pitch? Like the bass string on a string Bass (or higher - higher pitch is fine also) and also it might be play in the head or nozzle. With the nozzle cold (or your fingers protected) push the nozzle around and see if there is any play before the rods start moving. The head could be loose or the bearings that attach the head to the rods could be loose. Assuming not play: Inner diameter circles are *OFTEN* smaller than desired. I think as you lay down the layer, the PLA pulls a bit like a rubber band and the circles are "pulled" in towards the center. Also if your model only has say 10 line segments on a circle - well that decagon is effectively now a smaller circle as each line segment cuts into the circle. Plus PLA shrinks. Combine those 3 properties and you get smaller circles. You can fix by increasing your temperature - a lot - try 240C but only for the first layer. Once the first layer is almost done put it back to what you had before. Also you can try raising your bed height by a tiny bit (loosen the 3 thumb screws by a half turn maybe). This will squish the bottom layer a bit more making it closer to the .4mm wide "strings" that Cura intended. Although I might not do this last thing as the infill bottom layer looks quite good. Third point: 25% overlap is for wimps. Go for 50%, 100%, 200%, 300%, lol. Personally I use 15% and it usually works fine for me. At least on blue tape it works fine - haven't printed a bottom layer hole on glass yet.

If you loosen both pulleys on either end of the rod, then the rod can slide around and the pulleys can slide inwards. If you push both pulleys out as far as they can go and make the rod flush with the edges and then tighten the pulleys then the rod will behave but you might get a little clicking. If you move one or both pulleys in away from the edge just a few mm then maybe can you compromise where the rod is free to slide a little bit but not enough to fall out one side and the pulley's stop clicking. These pulley's positions have 2 purposes: lining up with the belts and also holding the rod from falling out. On the UM1, the rods were held with end caps so on the UM1 you could position the pulleys where they belonged. On the UM2 you have a little less freedom but if it is designed right it shouldn't matter much.

Start by taking this cover off. I did it a few days ago. Was very easy to do: In the top right corner you can see the 2 gray ribbon cables Daid was talking about.

At 190C, if I want a good looking print, then I print 20mm/sec (very slow!). I have to print slow when I print this cold. On the other hand I *often* print at 240C. The plastic flows nicely! Like honey instead of toothpaste. And I can print nice and fast e.g. 100mm/sec is easy. At 190C I can often print at 50mm/sec but I'm afraid to leave it alone and walk away because under-extrusion is SOOO easy at this cold temp. So instead I just slow it down more so I can walk away without being nervous.

It's actually very easy. It's so easy you can do 10 different things and they will all work. So for example you could always print straight onto the glass with the bed at 70C with no gluestick and for small parts this will work pretty well. If you don't want to wait for 70C you can also print at cooler temperatures with or without the gluestick. If you find your part comes off too easily you can use gluestick. If you are printing something that is artwork that sits on a table and you don't care about the bottom, you don't have to use the sponge to get the glue smoother. The problem is: there are many choices and most of them work in most situations.

This is a little worrying but I have not damaged my glass yet. Plus you get 2 sides so you get 2 chances. Also glass is not very expensive - you can get it cut to size from your local glass manufacturer. Having said that - what is the most gentle and easiest is to print at 50C on glue stick for parts that don't warp too much and print on 70C glass plate if part is large (keeping it over 55C keeps the pla soft so it can't shrink/pull very hard). Then to remove the part - the most gentle way is to wait for it to cool and if you can't remove it easily with your fingers, then soak it in water for a few minutes and the glue will dissolve.

The bottom of the prints with glue seemed quite mirror finish I thought but maybe my memory sucks. Maybe because I used warm (50C) glass?

Are you talking about the spelling "Dhaid"? His name is actually "David" but he goes by Daid on the forum. You are welcome to call him David if that is easier. I call him "Daid" so that people who don't know his name don't get confused.

You *could* lower the bed by .05mm which might reduce the click/slips but I wouldn't bother. I actually like this "feature" (is it a bug?) for the first layer as I get a perfect first layer. The clicking occurs occasionally because there isn't room to put all that filament. But then... for the remaining layers... clicking is bad. I know my test showed you could go up to 103mm/sec .2mm layer at 230C but that is an unobstructed hole. If you are doing normal printing the pressure is probably a little higher as you are pushing the plastic down onto the layer below. So I would keep it under 50mm/sec. Plus maybe my extruder is slightly (20%?) stronger than yours? I doubt that but it's a possibility. Did you use the same UM blue filament that came with your UM? All filament colors (and manufacturers) have different viscosity at a given temperature. I know you think printing faster should be less plastic but when you speed up the feed rate it *also* speeds up the extruder "axis". Marlin does 4 axis linear printing - it prints straight 4 dimensional lines where the Extruder is the 4th dimension. Why it worked in the morning, but not the afternoon? I have no idea. Probably something about the bowden. Or the extruder stepper was too hot in the afternoon? I really don't know. It shouldn't make any difference.

Some day. It's a pretty easy test for anyone to try. I was going to try nylon last night but ran out of time. Possibly tonight but I have lots of things on the schedule for tonight.

Maybe the glass has a coating? I doubt it. Try heating your print bed back up to 75C and clean with a putty knife or cloth or something. - George

Please post a picture of the ".4mm gaps". This could be caused by many things. The most likely is something called backlash which has the tell-tale pattern of every other line is touching, and then a gap (touching/gap/touching/gap repeats across the top). There are many things that cause backlash - the easiest to check is belt tension - usually short belts: Here is a photo showing backlash and how it was fixed: http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=14396 The very next post explains what causes the pattern.

Dans le coin en haut à gauche de cette page, il devrait y avoir un lien qui dit "galerie" ou quelque chose de semblable. Téléchargez votre photo là-bas. Puis, vous lancez un nouveau message et cliquez sur "mes médias" pour insérer votre image.

The log doesn't help much. MINTEMP and MAXTEMP are indicators that something is wrong with the temperature reading. This can be serious as if the values reported back are wrong in the low direction, the Marlin would normally add more heat to get it to the correct temperature but this could bring the heater up to 250C and damage/melt your PEEK part (the brown plastic). The most common error for a 1 year old UM is that due to printing, the wires have been moving around a lot as you print. Now they may be damaged. Usually near the print head. Usually inside the connector. But there are other possibilities - the small circuit board on the print head can go bad also. Also the fan cable signal can interfere with the temperature reading - especially if you are not at 100% or 0% fan speed (speeds in between turn the fan on and off very fast). So make sure the heater wire is an inch or so away from the temp probe wires before they get to the amplifier board (between the aluminum block and the tiny amp board. Also your heater itself may have stopped working. Some things to try - heat your head up to 95C and test with water on a q-tip or similar (or water on a finger) to make sure it doesn't boil at 95C and *does* around 105 to 110C. Move the print head to the 4 corners of your print area while the head is hot - leave the head in each corner for a second. See if this tugging on the wires generates MINTEMP or MAXTEMP. You don't need to be printing to get these errors - simply having the head set to 180C and then a wiring fault will trigger this and display it on the Ulticontroller. If you don't have an Ulticontroller then I don't know how to test for this - I guess you could print just the skirt of something that just barely fits in the platform.

What? The fan on the electronics board caused ... what? Caused the platform to wiggle? What was the solution? I hope you didn't just unplug it!

It's very common to get a clicking sound related to the belts riding up the pulleys slightly and slapping back down. It is very difficult to see but easy to fix - you loosen the tiny screw in the pulley and then line the pulley up with the belt better: slide the print head close to that pulley so the black plastic block gets close - then you can see where to line it up). Basically straight over/under the metal rod.

I meant "Marlin". I fixed the post. Thanks for pointing that out. Yes, you are right - you definitely were successful in changing the acceleration.

The next time you turn it on, set it for 95C and wait until hit its there but while waiting put some water on the print head and make sure it doesn't quite boil. If it does, and the UM is reporting say 80C or 50C or 20C or 0C, then shut it off before you melt your peek part.

It could be the arduino also. Someone had a problem with their arduino that was causing one of the axes to only go one way. He probed the arduino pin and saw that it was the arduino at fault. His situation was different though in that it was very consistent and didn't require "warming up" before it started doing it.

It would only cause it to stop moving in one of the directions (towards the limit switch that is falsely triggering).

1) Where did you get the UM2 schematic? 2) Good detective work on the DIGIPOTSS_PIN define. Do you think this is a bug? Do you think I could mess with this and rebuild UM2 Marlin?