how can i create a solid bottem/top?

[roald 2]

hello everyone,

every time when i try to print something, the printer lay the lines not close enough together.

what results in some little gapes/raster in the top and bottom layer.

how can i fix this ?

 

[illuminarti 18]

Are you really printing at 0.02mm layers? That's incredibly thin. Also, you might want to set the first layer height to be a bit thicker to make sure you get a good first layer down.

In general, the gaps are due to under extrusion, you might check whether the extruder is assembled correctly. Perhaps post some photos of your hot end and the extruder motor assembly, so we can see if everything looks right?

[Dim3nsioneer 558]

In addition to the underextrusion I see your skirt lines do not touch each other. This is a typical sign of a to large distance between nozzle and printbed at the first layer. So maybe cross-checking the bed leveling with the famous sheet of paper might be a good idea.

To eliminate the underextrusion, precise measuring of the filament diameter is a good starting point (e.g. with digital calipers).

Finally it is recommended to have a multiple of the nozzle size as shell thickness (i.e. 0.8mm or 1.2mm).

 

[IRobertI 521]

In addition to the points above your holes also look oval (I'm assuming they should be round). I would tighten the short belts to help with this. Undo the four screws holding the stepper motor in place, press down firmly on the stepper and then re-tighten the screws to lock it in place. Do this for both steppers (the ones with belts on them).

 

[roald 2]

first thank you all for the help. today i have make a new print with other settings and i had make some pictures and videos of the results from the test print.

first layer

http://youtu.be/4T4FaOS2zV8

second layer

http://youtu.be/EDxQfAQCEsE

as you can see i can only make a solid bottom when i print really close to the platform and extrude enough filament to splash the lines to fill the space between the lines.

 

[illuminarti 18]

You might try tightening the screw on the extruder tensioner spring a bit. It looks quite loose. There should be about 11-12mm between the back of the block and the washer behind the screw head.

You might also try printing hotter - up the temperature to 240, and see if that helps the plastic flow better.

Also, check that your fan isn't blowing on the nozzle tip and cooling it - that can also make it much harder to extrude. You might try printing without the fan on at all, and see if that helps.

 

[gr5 2,268]

It looks like you are doing fine. Those videos show perfect first 2 layers. A piece of normal paper is .1mm so if you are levelling the bed and you are off by .1mm that makes a big difference so it is tough to get the first layer perfect but you managed it somehow. Also keep in mind that heating up the nozzle enlarges it by about .1mm. Also your print bed is not flat - it's warped a bit as I can see the first layer is thinner in spots where the print bed is higher but this is typical of the UM Original. If you really care about that (I don't) you can buy a sheet of glass. Read about "printing on glass" if you go that route.

Now your photo of the top is not so good. It looks like underextrusion and also pillowing. The pillowing is probably caused by your non-standard fan shroud. Many people say to print your own fan shroud but the one that comes with the UM is outstanding. The fan that comes with the UM doesn't create much pressure - only speed - so it works terribly with constricted shrouds. Pillowing is a bizarre thing but every time, (EVERY TIME) people increase their fan the pillowing goes away. It's very complicated and I don't feel like explaining but I will if you don't believe me.

The other fix for pillowing is to print 10 layers and eventually it usually fixes itself. But more fan is a better fix ("more cowbell!").

But your bigger problem is underextrusion on the top layer. I think tightening the spring might help. Make sure your filament isn't tangling. 11.5mm spring length when compressed is what I use - Illuminarti has a 11mm (he tighted it up a lot). You could have other feeder issues: knurled bolt isn't lined up to get a good grip, your black delrin plastic disk might be worn, there could be wood particles jammed in the feeder, etc. You might want to open it up and check it out - it should be able to pull 22 pounds if the filament hasn't reached the print head.

 

[roald 2]

i was forgot to tell that the print on the picture is printed without cooling it is because my transistor is blown and a new one is in order. (i think that's why it pillows on the top)

i check the distance of the spring and it is 14mm and i can fasten the screw no more than that because the axis from the wheel hit the end.

also i had reassembled the part on the foto and check of everything is oke.

 

[illuminarti 18]

It should still be possible to tighten it more, I think. When you fasten the filament, the wheel pushes back into the body, tightening the spring further still. The limit on tightening the screw isn't the position of the wheel, but whether the screw is bottoming out on something.

 

[illuminarti 18]

Yes, the pillowing will go away with better cooling.

 

[gr5 2,268]

i check the distance of the spring and it is 14mm and i can fasten the screw no more than that because the axis from the wheel hit the end.

 

11.5mm is with it closed and with filament loaded. Maybe your screw is too long? You should be able to get 11.5mm with filament loaded and feeder closed.

You could also test the pull strength. The feeder should be able to pull 22 pounds of force on the filament.

 

[roald 2]

illuminarti your right, when i push the feeder with my finger, the wheel come inside the body (see picture) and i tightening the screw from 14 first to 11,5 now. it looks like it helps a bit the gapes on the top are less

the second thing that i will make better is my belt tension.

when i watch the movie about belt tension i realize mine is to soft but the problem is there is no space any more to tighten it with the screw its on the end en the screw eats a little in the wood (see picture)

 

[IRobertI 521]

For the belt tension you'll find plenty of alternatives over at Thingiverse: http://www.thingiverse.com/search?q=ultimaker+belt+tension