Printable View
So I just assembled a prusa i3v kit from makerfarm, and I had a couple questions.
1)When I print something, the top of the part has gaps between where the filament was extruded. How can I fix this?
2)Is there a way to manually lift the z axis using the LCD? There are options to move the X and Y axis,but not Z. Is it in another place?
Thanks for the help, as I am new to 3d printing.
One more thing: Is there a way to see how much time is left during a print? The LCD says how much time has passed, but not how much time is left.
1) I assume you're using Slic3r as your slicing software? I found Cura does better at the top layer fill. Regardless, have you calibrated your extruder to make sure you're extruding the amount of filament that you should be?
2) Just select something other than 10 mm movement steps on the LCD. The Marlin software is set up to NOT allow Z-movement at the 10-mm increment. If you go to 1mm or 0.1mm, the Z-axis will show up as something you can select.
3) If you're printing from host software like Repetier-Host, you can get an idea of how much time is remaining. I don't think you have a way to see that on the LCD display.
Ok so I tried out cura and it seems to be working much better. However, on a few of the things that I have printed the printer has not returned to the home position, and it has just sat on top of the print and bobbed filament onto the finished print. Can I change something to fix this? Also, I am getting alot of strings after switching to cura. Do I need to mess with the retraction settings or is there something else? Thanks a ton for your help.
The gcode should include various printer commands at the end of the print. I'm not sure why these wouldn't be consistent in every print. You could open up the gcode files in a text editor and compare the lines at the end of the file. The commands at the end are something you can edit - look for them on the Cura start/end code tab and then select end.gcode. For reference, in the Makerfarm subforum dacb captured a Cura ini file in thread Cura i3v settings . Compare what you have in Cura with what he shows in the ini file starting at the end.gcode= line through the G90 line. If gcode files are new to you, the reprap wiki has a pretty good gcode reference.
On the stringy prints, is this filament that you've used without issue before? If so, you should be able to focus on retraction. If it is a new filament you're just now using with Cura, you might also have to try a lower nozzle temperature. I believe some filament is also stringier than others. I have one roll in particular that strings like hot glue pretty much no matter what I do.
Hi all first post here, waiting on my I3V10 (Friday :D) anywho I was looking through slic3r and pronterface last night and notice the section in the config that establishes how many top and bottom layers to print solid, could this be moved from the stock 3 to say 5 layers? would that solve it?Quote:
Originally Posted by printbus
It might help. Once you're printing, you'll realize you want to avoid full layers because of the time involved in printing them. The uppermost layer could also still have a grainy feel to it.Quote:
Originally Posted by paintz2007
There is another setting in slic3r to consider - in expert mode under advanced, you can manipulate the extrusion width for top solid infill. Setting that to something above 100% might help the problem.
I have two rolls of pla, and both are much more stringy after switching to cura. One thing I noticed was that Cura has the printer retracting much more than slic3r did.(when watching the printer the extruder turns much more). Will turning the retraction down help?
It would normally be the opposite. In other words, more retraction means you're pulling more filament out of the hot end chamber, so it should be less likely to string along. Cura does default to a hefty amount of retraction since the defaults are optimized for the Ultimaker's Bowden-tube extruder.Quote:
Originally Posted by UltraSaucy
Have you tried to compare settings you were using in Slic3r with the settings available in Cura? Maybe something like hop/Z-lift or avoid perimeter crossing is different.
ok so I slowed the speed that cura was printing at(it was at 150) and that seems to fix the stringing problem. however, about 3/4 through a long print (it had been running for about 4 hours) the extruder motor started to just buzz and not push the filament through. I adjusted the pot on the motor driver, but that did not help. When I removed the filament it worked fine, so I loosened the two screws that hold the filament tight, but that didn't help either. Any thoughts? should I loosen the screws more, or is the motor just overworked?Quote:
Originally Posted by printbus
From one problem to another, huh? 150mm/sec is a pretty fast print speed. There's probably a few who can do that on highly tuned machines, but I think most of with i3v's don't go above 100mm/sec. I do most of my printing in the 75mm/sec range as a compromise in speed, noise, and print quality.Quote:
Originally Posted by UltraSaucy
What happens with the extruder gears when the extrusion stops? If the gears stop moving, focus on the motor. If the motor is getting hot it could be overheating and skipping steps. If the heatsink on the extruder's stepper motor driver is getting hot, the driver chip could be overheating; some add a small fan above the RAMPS board to keep the motor drivers cool. If the set screw on the small gear loosens or falls out, the small gear can start to slip - especially as the printer warms up. Do the gears rotate manually ok, without any catching caused by damaged or clogged gear teeth? If none of these possibilities pan out, maybe try swapping a couple of the motor driver boards around as a last resort.
If the gears keep moving when the extrusion stops, you're likely finding the hobbed bolt is chewing a notch into the filament. Nearly everyone seems to battle this at some point, and several things can cause it. Adjustment of the guidler bolts might help, but I don't recall ANYONE ever finding that was all they needed to do. Califdan just concluded his problem was the stock spool mount creating issues as the filament spool emptied. A few have found bits of metal clogging the hot end. Some have found the extruder nozzle needed to be cleaned/reamed with something like a guitar string. Too low of a print temperature can sometimes lead to stopping at random. Filament can have diameter variances that can catch on the top of the hot end. A few have used vegetable or grape seed oil as a lubricant in the hot end. Aggressive retraction settings combined with retractions that occur too frequently will cause the hobbed bolt to rotate back and forth in the same area of the filament, cutting away at it. The channels in the hobbed bolt can get plugged with filament, causing the hobbed bolt to become ineffective.
In my case, all I would have to do to recover is pull the filament out of the extruder, cut off the damaged part, and re-feed it. I'd then print fine again for minutes, or for hours. My issues seem to have been overzealous retraction settings and a spool of filament with bumps in it just large enough to not pass into the hex hot end.
You can look at printer moves in a gcode viewer to see how often retractions are occurring. Sometimes the tail end of prints can be a problem since the print area often gets smaller and smaller, and retractions are occurring with less and less extrusion in between them. For my 1.75mm filament, I usually configure Cura for 1.2mm retraction distance and a minimum extrusion between retractions of 0.5mm; both settings are significantly different than the Cura defaults that are optimized for the Ultimaker printer. On long prints that don't have a complex perimeter structure, I disable retraction as a final precaution.
lol yea story of my lifeQuote:
Originally Posted by printbus
The motor stoped turning, and just twitched back and forth. When I removed the filament, the motor and gears turned fine. I put the filament back in and manually turned the extruder (using the lcd) and everything worked fine for a little while, but then it started to buzz again. I let it cool for a bit and then started up another print of something I had already sliced (in slic3r), and it worked fine for the first few layers but then it started to buzz again. Could it be that the Idler is pushing too hard on the filament? the filament isn't getting chewed up, and it is feeding ok when the motor turns, so I would say it is a motor problem. I havent checked to see if the motor driver is getting hot, but I will do a few more tests once I get home from school.Quote:
Originally Posted by printbus
IMO, about the only way that could be a problem is if the bearing in the guidler plate isn't rotating with the filament. I know I'm not the only one that had to clean up the bearing slot in the guidler provided by MakerFarm quite a bit to get the bearing spinning. Try marking it with something like a Sharpie and seeing if it rotates as you feed filament. If not, you need to fix that.Quote:
Originally Posted by UltraSaucy
You've ran through the extrusion calibration, right? If so, what kind of esteps/mm are you running? I just want to make sure you're not trying to drive the extruder motor unrealistically fast. A value of 900 steps/mm seems to be about the average.
I thought of a few more issues people have found related to extrusion stopping. They may not fit your symptoms but I'm going to capture them for completeness as a future reference. Depending on how washers were added as spacers to the hobbed bolt, some have found the bolts on the top two delrin wheels on the X-carriage can rub against the large extruder gear, causing at least intermittent problems with extrusion. Also, if the large gear wasn't tightened onto the hobbed bolt properly when it was installed, it can slowly tighten up towards the hot end and eventually cause the hobbed bolt to bind up.
Got mine running after a 5 night build, very impressed with the out of the box printing. Couple issues I need to track down ( corners lifting on pieces and on small areas it not cooling fast enough or is too hot, leaves a glossy blob almost)
The issue with the small perimeters being globby can be solved in your slicer settings. You should be able to choose a slower speed for small perimeters. Could also consider adding a fan and duct to your extruder if you don't have one already ( this notably improved my print quality)