schafe

After 9 or so hours of printing the results are confusing. In one photo you see the under extrusion is visible. I can see the extruder skipping backwards at the 80% rate I set before heading to work. I think it is at 4.8mm3/sec now. I slowed the speed to 70% and can still hear and see skipping at 4.2mm3/sec. I'm not going any slower. The screen says there are still 10 hours remaining. In the other photo you see a new development. The retraction is on and I can see the extruder moving backward for the retraction step. However, almost always there is a small blob of plastic hanging from the tip. This results in the many blobs hanging from the side of the print. What changed? I just realized that now I am going slower I may need to lower the temp. It is very confusing and slightly frustrating to use a group of settings one day and get perfect results only to use the EXACT same settings the next day and get random results. With the popularity of the "Almost always missing layers / underextruding" topic I can only conclude there is a gremlin lurking somewhere in the machine. I begin the next paragraph with this statement. I am a conspiracy nut. Conspiracies are everywhere. I'm intrigued by the silence from Ultimaker on this issue. If I were them I would not admit there is a problem with their new baby either. Without a doubt, there are people who are considering purchasing a UM2 reading these topics deciding where to put their money. Without a doubt, there are competitors reading these topics to gain an advantage. It is nice that Ultimaker doesn't seem to hold grudges when someone is critical in their own forum pages. For those reading this deciding where to vote with your dollars/euros, etc I offer this. Do I think I made the right decision buying the UM2 as my first 3D printer - yes. Do I think the gremlin will be eliminated - yes. There are simply too many people working to figure this out who don't even work for Ulitmaker. Do I think the UM2 was brought to market prematurely - yes. I stated in another topic that I was happy for everyone at Ultimaker. It is nice when people succeed - still true. I am also really impressed with my new friends in the Ultimaker world. Its cool that a geek from Iowa can connect with peers world-wide.

How about changing the main screen on the printer when something is printing. Eliminate the line showing what is printing. I already know that because I selected the file to print. I would like to see "Now printing layer 37/517."

Nice new profile pic.

I'm still plugging away at this problem. Turns out there are several wing/weight/power calculators on the web. All have concluded it will have to fly fast if at all. I have decided on plan B if it doesn't fly. Redesign the thing eliminating most of the plastic skin. Keep the carbon fiber arrows but make plastic ribs. Cover with monokote or maybe balsa. I will stick with plastic sections where there are features that are difficult to cover or are nicely detailed like the engine nacelles, wing roots, base of the rudder, etc. I will likely keep the nose plastic for the cockpit window detail. This should make it much, much lighter and still be 100% to scale. The other night I printed a section at 60mm/sec, .1mm height, 100% flow at 250C. (Am I correct that you take the speed times the layer height to get the rate everyone is referring to in the "Almost always missing layers / underextruding" topic? If I have this correct then I was printing at 6mm3/sec.) I was using a filament I purchased from Makershed. The result was perfect. Last night I started a 28 hour print with the above settings and the same filament. I noticed this morning the extruder is skipping although I could not see any gaps or holes. I slowed the speed to 80% before going to work. We'll see what I come home to in a few hours. If the above math is correct this results in 4.8mm3/sec. Unless someone says otherwise, I decided not to update my C-130 file on YouMagine and will likely delete it. I'm pretty sure no one wants to spend the weeks and filament required to print this thing, especially knowing it won't fly. I wouldn't be in this mess if I could only find a ready to fly C-130 that got good reviews. I've been all over the internet with no luck. I think cargo planes are neat and you rarely see them in RC.

Good morning Europe. Iowa is going to bed. Long live the Jamacian bobsled team. Stupid Gravity. So do I earn a warning post for this??? Yes, it took several attempts to get this spelled properly.

After some "comfort beer" all I can say is Stupid Gravity!

Well crap, or as I recently learned, blarp. I've spent the night looking into weights and foruming with the RC "experts." It looks as if it is going to be too heavy, way too heavy, even before I add the electronics. I already have the motors and speed controls so I'll likely press on after some "comfort beer." This is the first time people all over the world will know about one of my failures. It will at least look neat in my garage. I know you can fly an anvil with enough horse power. Maybe I can add helium bladders to the thing. Hydrogen might be better. Nice combination. Hydrogen with electronics that spark a little from time to time and batteries which burn violently. Bigger motors might be the next thing I try. I will have to reconfigure the motor nacelles for larger diameter props. So much for 100% to scale. Along with bigger/heavier motors comes bigger/heavier batteries and bigger/heavier speed controllers. There has to be a point where enough horse power and money can get this thing in the air - maybe off of a cliff or roof-top. My wife is supportive, although she thinks it is weird that I spend hours watching the thing print, recently along with the olympics. On a positive note, I did get excellent results recently with the Ultimaker blue that came with my printer. 65mm/sec, .1mm height, 100% flow and 245C for an 8 hour print.

I used Cura's support feature. The tip of the nose was the very last point to print. I actually think it would print ok without support since the inside of the nose is not very important. I'm going to make the nose thicker to allow for a build up of layers without support. The motor nacelle was printed upside down from the way it looks in the photo. I built the support for the air intakes in Blender rather than use Cura's support feature. It turns out the small gaps and holes are a result of the underextrusion problem that many people are trying to figure out. I'm going to slow my speed to 65 to see if that helps the problem.

Well crap. After several hours of reading I find there is no solution. I thought my "geek factor" was pretty high. There are people working on this who are way better than me. About the extrusion %. I am printing at 107%. Less than that, and any horizontal layer that is filled in with parallel rows get noticible gaps between the rows. Enough of a gap that if I printed a cup it would not hold water.

I purchased the silver in the print from makershed, against the recommendation of illuminarti in the lead time update forum. The places he suggested were out of any colors I wanted. That may also be partially to blame. After the cleaning I printed a part with the filament that came with my UM2. Perfect results. I previously had good results with the makershed filament until I cooked it. How about acetone. I can get that just about anywhere.

Here are a couple of prints from my C-130 project. I'm very happy with the results so far. You can see the excellent detail of the cockpit windows. I can't claim this as my own work. The detail comes from the original mesh I purchased which is intended for use in a video game. The nose took 17 hours to print at 75mm/sec and .1mm height. I was originally hoping for 100 and .15 but it seems that is too aggressive. In the nose you see small gaps and holes. I think these gaps resulted from a nozzle which had burned PLA inside. I am very concerned about the weight of the plane. In one picture you see where I added "ribs" to the mesh. I did this because I wasn't happy with the bonding between layers and the whole thing felt flimsy. The thin sections are .8mm and the thicker areas are 1.2mm to 1.6mm. Oh crap - more weight. :shock: As I am satisfied with a section, and know it will print, I will add it to my C-130 file on YouMagine. There are about 60 sections. I know there are programs which calculate the power needed for a plane of a given weight and size. Once I get finished with the sections I'll have to look into that. There are also lots of "experts" who know RC aeronautics better than I do. Spring is coming quickly. At this pace I won't be ready until late summer.

Here is the photo from my extruder over current problem. I followed your instructions gr5. but if the above link doesn't work look in the gallery for "Extruder over current retraction gaps." You can see the gaps and holes in the print. The topmost layers are where I had the temp set to 250C. You see the change in shininess and there are almost no gaps. Knowing now that the problem I was having was from too much extruder current I looked into other issues. I cleaned the extruder mechanism - it really seemed ok. I then completely disassembled the nozzle and cleaned it as best as I could. I heated it up to 230C and used progressively larger drill bits to ream out the nozzle. (Only slightly burned my fingers.) I quit with a bit diameter of 1/8". I then used a needle to clean out the nozzle tip and finally used a copper wire strand that measured .37mm. I have the extrusion level set at 107% because when flat layers are printing at 100%, and it is filling in the area with parallel rows, I noticed there are very small gaps between the rows. These gaps are large enough that if I printed a cup it would not hold water. It's almost as if Cura moves the nozzle over .405mm for each row. I suppose it could be that the nozzle is slightly smaller than .40mm, but then the .37mm copper wire wouldn't fit. 107% squirts enough out that these gaps go away although I can still see the individual rows. I think the problem originated when I was printing PLA at 260C. I was VERY happy with the finished look - nice and shiny with layers fused nicely. I went to work with the printer still going. My wife later aborted it when she noticed the nozzle had plugged and there were drops of black goo on the print that smelled burnt. I guess I cooked the PLA. When I cleaned out the nozzle I got quite a bit of dark goo out. I suspect this goo was making for poor heat transfer to the PLA I was trying to print in the photo above. 6 weeks now and I still havn't figured this thing out. Why does everything have to be so hard? :???:

gr5 you mention changing the current for the extruder. Where is this done? I am having problems with the extruder skipping backwards. At first I thought it was slipping on the filament but now I guess it is the program doing this. I have the extrusion set at 107%. Setting the temp of the PLA to 250C helps but I know this is too high. The result is pockets or holes in my print. I have a photo but can't figure out how to include it.

Got the bill from DHL today. $88.77. Stupid government. I hope they put it to good use, not something pointless like a new gold toilet seat on Air Force One. I am curious. Please tell me that I am not the only person who sits and watches the printer go for hours - usually with a beer in one hand.

Two more ideas. I'm not very patient. How about heating the bed as soon as the printer is turned on? I suspect this does not happen now to prevent burns to the hand or maybe save energy. Maybe just go to 50C. It could be an option to turn on/off. I would also like to have the option in CURA to slow the print speed when the support reaches the main object. I have slowed it down to 10% when these points meet and was pleased with the results. I would also like to slow it down automatically when flat angles are being printed on the object.

I got the glass plate today from DHL. Still no bill for import tax. Until the plate arrived I had been using a 1/4 inch sheet of aluminum with blue masking tape that I modified to work with the clips. I actually think I will leave the aluminum plate in place as I have had good results so far.

Yep, noticed the problem switching to PLA. I had many layers that look like the nozzle clogged and then opened again. I hadn't considered cleaning the tube and drive motor. That is a good suggestion. I was also printing at the default temp for PLA. What do I use to see the gcode? I have not figured that out yet.

You may remember Jonny that I am attempting to make a C-130 Hercules for remote controlled flight. After re-researching the topic I'm not 100% sure why I went with ABS. What I read today indicates that PLA has better bonding between layers and is stronger overall. It might be that I was concerned about softening in the summer sun - better not make it a dark color. I also am experiencing warping with ABS. I am at the point with the plane that I want to start printing it. I think I'll try PLA next. I had been making the sections of the plane thicker adding "ribs" to prevent warping and help the layers adhere. I'd really prefer to keep things thinner and lighter as I am concerned about the overall weight of the plane. Right now the skin averages .8mm thick.

I am having problems getting ABS to adhere well to previous layers. This is happening mostly with prints that have very thin walls, .8 to 1.6mm, but happens with small sized prints as well. I have not yet enclosed my UM2. I have tried changing the layer height from .15 to .1 with no effect. My print speed is 100 mm/s. I am using the default temps of 90C on the bed and 260C for the extruder. Thanks for any advice.

That's easy for you to say. In other words, "Um, what?"

I have had 2 prints fail because the filament stopped. Once because it got bound up on the spool and once due to a clogged nozzle. The printer keeps on going assuming everything is normal. If this happened at the end of a really long print it would be a bummer. I have 2 ideas I think make a good solution. Add a pause function to the print routine. This would be nice when you need to remove a stray fiber or goober on the nozzle. Once paused there is an option to rewind the print using the control wheel. The rewind function would stop extruding but the print head would run backwards and you could return to the point where the filament stopped flowing and take off again. There should be a speed option so you could rewind really fast until the head got close. It would also be nice to have the head travel to the front of the machine for cleaning. Once clean, have a manual extrusion option to verify the filament is again flowing properly. Seems easy to me with no parts to add, just a software upgrade. The second option is to add an encoder somewhere along the filament path. As the filament travels along, the encoder verifies it is actually moving and allows the print to continue. Once the encoder detects no movement it will pause the print and move the head away to allow for cleaning. Or it might sound an alarm but continue printing so you could check what is going on. A few minutes after the alarm it will then pause. Seems more difficult adding another component which could create problems and is likely impossible on existing machines.

I understand that enclosing the unit to keep the print area warm is a good idea when printing ABS. I have not made an enclosure yet, but will soon. This seems like a good option for something to sell so people don't have to make their own.

Or is it possible/advisable to print without the plate. Maybe on tape with the bed heat turned off.

So close . . . yet . . . My printer arrived. No bill as of yet from DHL. No glass plate either. I'm majorly bummed!! I raised the bed and looked through everything 3 times. I took the day off I was so excited. I guess its time for beer. I will send Sander a PM. In the mean time, what should I try to get from a local glass shop, or is it even possible to get the right thing from a local vendor?

I called DHL on Monday using a number I found on the internet. They wanted my SSN because the declaired value of the shipment was more than $2500 - I ordered 2 extra rolls of filament. I don't completely understand, but it seems that DHL has a generic number they use for clearing customs when the value is less than that. There was no mention of an import charge, but I suspect I'll get a bill in the future. Due to the federal holiday on Monday there was no customs activity. I received a voice mail this morning from the same DHL rep I spoke to yesterday saying my package would be delivered tomorrow. I don't know when Makershed will get more printers in stock, but if you can wait I would suggest ordering from them. I had an $80 charge from my credit card company for a foreign transaction. I wasn't expecting that. Now a possible import fee. That money could buy more filament. Oh well, live and learn. . .