Refine Print Quality

[nambass 2]

Hi everyone!

Well my DIY UM2 Extended are printing but the quality is not as expected. I also tried a new feeder (youmagine.com/designs/alternative-um2-feeder-version-two). I started to print PLA with Cura Normal settings and the result was poor. I then slowly reduced the feed rate to 95%, then to 80% and eventually end with 75%. You can see on the images it still looks like either over extrude or getting too hot. The fan speed was 100% from the start.

I can continue to play some more but thought you guys might be able to fast track finding my solution.

[ekh 3]

It seems to me that the cooling is not sufficient.

Maybe the nozzle temperature is too high,

Also consider the minimum layer time in Cura

[nambass 2]

Well, The current setting for Cura: minimum layer time is set to 5 sec. I printed at 205 degrees.

I will reduce the temp as well to see how this works out.

[ekh 3]

You can check if the fans cool sufficiently.

Make a tweak to pause the print and park the head so the nozzle is free of the part but a fan sends air over the part to cool it.

Wait half a minute then resume printing.

Try 3 tweaks for each 2mm print height, if cooling is the problem then it will look better in that area.

I  have printed small buttons, and they easily looks like your print wihout reducing nozzle temperature and increasing min. layer time.

It can also be a bad quality filament, or the filament contains water that makes the plastic expand after being printed due to many small water wapor bubbles in the print.

Edited July 6, 2015 by Guest
Spelling

[gr5 2,173]

Hey congrats on building your own printer!

Are your fans working?  Do you have one or two?  Are they blowing (and not sucking?)?  Are they on full power by the time it does that first bridge (a few mm up?).  By default Cura doesn't turn the fans on until something like 5mm (depending on the version).  You need 100% fan before you get to that first bridge.

Also I recommend you check your nozzle temp using this video.  You might need to print at a much cooler temp such as 190C (although I usually print at 210 or 220 and can get better quality than this)

 

Edited July 7, 2015 by Guest

[gr5 2,173]

Also for the very top - what I see there - that top cube - is normal - you can fix it by one of two ways:

1) cool head lift - not the best solution but a huge improvement. The side effect is that you will have some easy-to-remove strings.

2) print 2 of these parts at the same time. That will allow the top cube to cool. Or just print a 10X10mm tower right next to your part.

Also please note your country in your profile settings.

[gr5 2,173]

How are your long and short belts? Are they tight? That's going to be your next issue I think once you get this cooling thing worked out - by the way it might just be bad filament - some filament is hopeless.

UM2 has hidden springs inside the blocks - they are the same spring you can find inside a clothes pin.

[nambass 2]

Hi gr5. Thanks for the reply. I will most check the temp test as per the video you mentioned.

as for the fans, well yes I have 2 fans blowing down. I also checked that.

What I did was to manually set the fan to 100% as the print begins as well. Si the fans are the normal fans running at 100%.

The belts are normal lengths and are quite tight. What I did found from time one of the belt spools come loose slightly and I was thinking of using locktight to make prevent this from being a constant problem.

As for your recommendation on the that top cube - I am missing you an that one - could you explain some more please?

I am confident the issue is heat and will try the 190C and give feedback. Other than this, the machine is nice and I quite like it a lot.

[gr5 2,173]

It may be bad filament. Some filament just doesn't bridge well or do overhangs well.

Regarding the top square - there is a checkbox in cura under cooling called "cool head lift". Check that and it will improve the top square but add strings to it. You have to just try it.

The strings will be easy to remove.

Then after you try that, model up a cube and add that to cura next to your pyramid. click on the cube, click the "scale" icon. click the lock icon so the x,y,z are unlocked and scale to 10mm by 10mm by 30mm tall (or whatever height your pyramid is). Put this tower next to your pyramid, then slice and print (also make sure "one-at-a-time" is set in tools). What will happen is as it is printing the top of the pyramid it goes over to the tower and while printing the tower, your pyramid has a chance to cool. It makes a HUGE difference in quality for that top block.

[gr5 2,173]

You still have other issues, maybe you don't have a good qulaity nozzle.  I recommend getting one from e3d online.  You didn't say what country you are in.  If in england definitely try e3donline.  If in usa try gr5.org/store.  If other country do 3dsolex.com.  PLEASE SAY WHAT COUNTRY in your profile settings. If in france then there's a better place. What country?

Edited July 8, 2015 by Guest

[nambass 2]

Well, I am living in Windhoek, Namibia.

It seems the PLA prints now is getting quite good and I am happy with the progress. I then tried to print ABS - and had to reduce my nozzle temp down to 200 and the feed rate to 70%. is still not perfect and definitely have signs of overheating/over extruding. What I did find is that the cube I tried to print is 16.5mm instead of 20mm.

If seen a few comments on the forums that one need to scale in cura. My question is- should I not try to calibrate marlin. my X and Y axis steps per minute is 78.74.

The width and height of my printer is standard the only dimension I changes was the height. so theoretically the standard x and y steps should have been correct.

[nambass 2]

I just tested it, I connected Simplified3D and defined the printer as Ultimaker. I then set the X Axis to move 100mm and meeasure. it only moved 60mm. the same with the Y Axis.

here is my steps per min settings in my firmware.

{78.74,78.740,200,282}

[gr5 2,173]

Well, I am living in Windhoek, Namibia.

I updated your profile settings. I hope you don't mind. Feel free to change it back.

I don't recommend switching plastic types very often. ABS will cause all kinds of problems with your PLA printing (nozzle clogs mostly but also make the teflone wear out faster). You will be best off if you stick to one type of plastic for at least 100 prints. Everytime you switch you are likely to encounter major headaches.

the steps/mm has nothing to do with platform size. It has to do with the type of stepper motor you use, the qty of microstepping (controlled with jumpers on PCB). Also the diameter of your pulleys.

[gr5 2,173]

I just tested it, I connected Simplified3D and defined the printer as Ultimaker. I then set the X Axis to move 100mm and meeasure. it only moved 60mm. the same with the Y Axis.

here is my steps per min settings in my firmware.

{78.74,78.740,200,282}

 

So increase by a factor of 100/60. So use:

{131, 131, 200, 282}

You should also calibrate the Z axis and the extruder. To calibrate extruder remove filament so it is only half way in the tube. Mark it with a pen. Have S3D move 100mm and make sure the filament actually moved 100mm.

[gr5 2,173]

If you change the steps/mm by using the control panel, make sure you save the values or they don't get saved when you power cycle. I usually use pronterface to do this. I don't know how to use S3D but hopefully it allows you adjust and save steps/mm also. Or you can do it in the Marlin build.

[nambass 2]

Hi gr5

As for the update of my profile - thanks for that - I do not mind!

I will most definitely calibrate the axis. I basically have only ABS and want to print 99% ABS. The only reason why I started with PLA, is it seems to print easier. But most of the stuff I want to print will be ABS components anyway and is all filament I have except the half spool PLA.

I also use pronterface for the comms with the printer.

[nambass 2]

gr5, on the video you posted earlier. what is the point of it, meaning what count should the be optimal count. because the filament can melt anything from let say 200 and up. but it does not say 200 will give the best quality. and on the other scale, 250 may be too hot for slow printing.

I am just trying to get a understanding or a golden rule for printing ABS.

Another question: should I consider adding a door om my UM2 extended.  smaller parts should print fine, but long prints seems to warp.

The last issue is making sure cura is configured perfect. please comment on my settings:

Edited July 9, 2015 by Guest

[gr5 2,173]

I really don't like using different speeds for shell versus infill, etc. So I would set these to zero so they default to print speed:

infill speed

top/bottom speed

outer shell speed

inner shell speed

Just those 4. Having the printer change speeds between shells or between infill and shell can cause issues - I wouldn't mess with that until it's time to shave off a few minutes on a 5 hour print and you are an expert.

I notice it says gcode flavor: ultigcode. I don't know if you mentioned this but is this using ultimaker2 marlin? Or ultimaker "normal" marlin? Because ultigcode won't work with normal marlin. For normal marlin you have to choose "rep rap".

Your other settings look fine.

Print ABS is tricky. It warps severely. It clogs easily. It's best to enclose the whole machine so it heats up to about 40C inside. You need PVA glue (found in glue stick, wood glue, or hair spray) on glass. You need to use the brim feature in cura. You need to use much less fan for ABS - I usually do 30% fan max for ABS and if there are no overhangs I do zero fan.

I recommend not printing too slow. 30mm/sec at .1mm layers at 255C will clog your nozzle for sure. If you go above 240C you need to keep the speed multiplied by the layer height above 6 - so 60mm/sec at .1mm layers or much better, 30mm/sec at .2mm layers.

You also need to print hotter. I recommend starting at 245C to start with. If you have bad layer adhesion (parts break too easily along layer lines) then you need to do either less fan, hotter nozzle thickness, or possibly change layer thickness (I think .1 to .2 is ideal - any thicker or thinner and you *might* get layer adhesion issues where the previous layer isn't melting into the new layer).

Also for ABS you need a very hot bed to prevent warping - 110C is best but 100C is good enough if that's the hottest you can get to.

[nambass 2]

Thanks for the feedback.

I noticed on the Gcode Flavor I only have the following options:

UltiGCode

Reprap (Marlin/Sprinter)

Reprap (Volumetric)

Makerbot

BFB

Mach3/LinuxCNC

[gr5 2,173]

Marlin is the firmware that comes with all Ultimakers.  So that would be one option.  Ultigcode works fine for UM2 but I really don't know if it works for UMO+ as my UMO has a different controller board.

I mean ultigcode definitely won't work on my UMO. But maybe it works on UMO+? Part of my doesn't think so. Another part of me thinks... maybe.

Edited July 10, 2015 by Guest

[nambass 2]

Well my controller is UM2 so I guess I stick to UltiGcode.

I calibrated the X, Y, Z axis as well as the extruder using pronterface. The movements was finally spot-on.

Funny though, I now generated a new test print (the same 20mm cube) and it still print 16.6mm

does not make sence to me.

I also had to reduce my extrusion feed to 70% as it was totally over extruding - Or I will have to increase my speed. I was printing at 245 degrees, 60mm/s and .1 layer.

You will see at the lower part the excess filament and on top there is still signs of excess filament. Also the center bubbles out a bit. the sides are smooth though

[gr5 2,173]

After you calibrated the x,y,z did you save to eeprom? If not and you power off the printer you lose those values. This does *not* look like a cube - I think maybe your Z is off. That is why it was overextruding because Z axis is not moving enough. Probably by about 2X. Maybe a jumper is wrong and you are doing 8 microsteps when you thought it was 16?

[nambass 2]

Well my prints starting to improve after I saved all the new settings to EEprom. I added a door to the printer and also when printing longer prints, cover the top with a platic bag. Here's a photo of my printer and also the handle I printed today for the door. The handle was printed at normal settings (layer height = 0.1) I then tried to print somthing with a larger footrint and needed a new cover for my phone anyway. So I printed this cover using ABS: http://www.thingiverse.com/thing:897683

I found the base was quite solid and rigid, but the sides easily torn apart. The cover was printed with the door closed, the bag over the top, and the following settings:

Layer height: 0.2

Shell thickness: 0.8

Nozzle: 0.4

Bottom/Top thickness: 0.6

Infill: 80%

Print speed: 50mm/s

Fan: Off

Bed: 73 degrees

Nozzle 250 Degrees

Filament flow: 95%

The initial quality looked similar to the handle, but was just weak. It may be poor quality filament but in case something is wrong with my settings, I would love to know that.

[gr5 2,173]

You are getting quite reasonable results now! Congratulations - I'm glad you got this printer "tuned in". I recommend some kind of top cover as well but one that lets a little air out the back so it doesn't get > 50C.

[nambass 2]

Thanks gr5

I did that, but still having the problem that the plastic seems not to melt into each layer. Even though I am printing at 250 nozzle temp. can it be due to poor quality filament or is there still something wrong with my settings?