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poor first layer  

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bill.b
(@bill-b)
Active Member
poor first layer

Im pretty sure i already know the answer to this, ive searched but i couldnt find exactly what my problem is. i dont know what its called. im pretty sure its bed calibration. the paper method was not working for me. so, i went out and got some machined feeler gauges. i use a .229mm feeler gauge. but, it could also be my settings in slic3r. im getting very inconsistent prints with slic3r. maybe its an adhesion problem. i lay down the glue for pla but still sometimes it doesnt stick. i put the glue on when the bed is cold and let it sit for 10-15mins then heat it up. its frustrating. the settings provided with the driver package are different from the settings in the gcode files on the sd card. even when i mimic the settings exactly, i still have this issue. and i understand those settings are for that particular print. but, certain settings should be ok to use across the board. only with slic3r. when i use cura, i dont have this issue. i want to say its my layer height. which, for this print, was set at .23mm.

whats happening is, the first layer is being laid down, it sticks ok, but then starts lifting up. at.23. at .30. and at .35. however, when i print the marvin from the supplied gcode, its fine at a .35 layer height. i mimicked the settings to no avail. i started fresh and im using the .1mm profile for this print. i tried slowing the speed, didnt work. when it lays down the first layer, i get these tiny little mountains as it lays the pla. the 2nd layer and every layer after that is fine.

another thing, im getting a lot of chatter with the bearings on semi faster prints. my belts are tight and the bearings are tight. not sure what could be causing that either. possibly, my belts really arent tight enough?

any help or pointing in the right direction would be appreciated. btw, ive only been printing for like 4 days. no experience at all with 3d printing, but, ive ran cnc machines so im somewhat familiar with the gcode. and my printer in on point and level. already checked that.

Posted : 23/03/2016 5:13 am
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: poor first layer

Hi Bill

Firstly clean the glass and re-apply 2 layers of glue; one layer in each direction.

The calibrate the bed again.

When slicing, set the first layer to 0.25mm and all other layers to whatever height you want to print at.

Set the bed temperature to 5 to 10 degrees higher than you had before.

If that doesn't work, then clean the nozzle. The photo does show poor layering.

With regards to the noise, you could try the "Quiet" setting, but when printing faster, the "High Power" option is possibly better.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Posted : 23/03/2016 7:52 am
bill.b
(@bill-b)
Active Member
Topic starter answered:
Re: poor first layer

Thanks Peter!

I'll give your suggestions a try. I did check the nozzle and that is clean. Good tip on the 2 layers of glue in both directions. I've only been putting one layer of glue on

Posted : 23/03/2016 2:28 pm
bill.b
(@bill-b)
Active Member
Topic starter answered:
Re: poor first layer

I did something better than clean the glass. I went and got a mirror. Although, it has a beveled edge, I made it work for now until I can find a mirror with a straight edge.

I also found that my y axis assembly was loose. Causing odd layers. This was my own fault. I didn't tighten the screws right enough. I didn't know how right I could make the nuts with the plastic parts. But, I tightened them real well. Then, my y carriage was twisted. Twisted it back. Decided to tighten the belts on the x and y. No more bearing chatter. I don't know much about 3d printing, but I know how to fix a machine haha.

I re-calibrated the bed using the diagonal method ( http://reprap.org/wiki/Leveling_the_Print_Bed )

Took about a half hour. Decided to print This bad boy (from a post on this forum http://www.thingiverse.com/thing:115671 )
I just wanted to see if the print would stick with no glue. Nope haha. But I got a nice first layer. Applied glue and it printed perfectly.

I'm going to enable auto bed leveling in the firmware and get myself a npn inductive sensor (which is why I went with an aluminum backed mirror) calibrate that and hopefully only have to do minor adjustments here and there.

Thanks again for the tips Peter!

Posted : 26/03/2016 1:04 am
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: poor first layer

Hi Bill

That's great, well done!. Be careful with the mirror as it will be regular glass and if it breaks (usually when removing a part), it could shatter.

Not sure that the mirror silvering will be sufficient for a height sensor. What I have seen are 5mm square copper shims on top of the build plate, but we won't know about the mirror unless someone tries it...

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Posted : 26/03/2016 8:55 am
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