Not sure what I'm doing wrong here....

[tom 0]

Yesterday I put the latest marlin firmware on my machine and decided to give pronterface a go as I was having issues connecting to the printer from RepG. I'm generating my code with netfabb and I keep getting a similar result while printing. I've tried slicing with ultra, high, and standard settings. So at this point I'm not sure what it is since its staying fairly consistent. As you can see the majority of the first layer looks like its pressing in firmly but there are sections that always seem to blob up. I've replaced the tape where the print is located between each print and re-leveled the bed a couple of times just to try and keep as many variables out of the equation as possible.

(Note: the large cone and string is where I happened to stop the print and lower the bed and the material free-flows out for a moment.)

[Daid 306]

Looks like you are starting to low, during the first layer the tip should float a tiny bit above the bed, but these results look like what you get when the head is "in" or on top of the bed without clearance. It has trouble getting any material out so the pressure builds up in the head, from time to time some will come out, and once it's "open" you get a LOT of filament, explaining the cone.

[tom 0]

I figured it was probably something simple like that, was hoping not that simple haha, kind of silly of me. I screwed each corner of my bed down by one turn and the print seems to be going much better now!

Thanks.

[Daid 306]

I figured it was probably something simple like that, was hoping not that simple haha, kind of silly of me. I screwed each corner of my bed down by one turn and the print seems to be going much better now!

Thanks.

You're welcome. A "Z adjuster" might help you when this happens again:

http://www.thingiverse.com/thing:11982

There is another one, with instructions on how to remove the metal plong from the microswitch. This increases Z start accuracy even more. But I cannot find it right now.

[IRobertI 520]

I'm guessing Daid is thinking of this one:

http://www.thingiverse.com/thing:11033

I use it and it's a big improvement. Just remember which way you're turning the screw while waiting for the click of the switch... Not that I'd know what happens if you make that mistake or anything. I'm sure it wouldn't crack the casing on the switch in two or anything like that. Nope, I have no idea at all what would happen... :oops:

[joergen 2]

I'm guessing Daid is thinking of this one:

http://www.thingiverse.com/thing:11033

I use it and it's a big improvement. Just remember which way you're turning the screw while waiting for the click of the switch... Not that I'd know what happens if you make that mistake or anything. I'm sure it wouldn't crack the casing on the switch in two or anything like that. Nope, I have no idea at all what would happen... :oops:

you can also adjust the z axis while it's printing py manually turning the connector a couple of click... it feels wrong (as a beginner) to turn a powered stepper motor by hand, but a great tool to get the first layer perfect.

[owen 19]

Looks like you are starting to low, during the first layer the tip should float a tiny bit above the bed, but these results look like what you get when the head is "in" or on top of the bed without clearance. It has trouble getting any material out so the pressure builds up in the head, from time to time some will come out, and once it's "open" you get a LOT of filament, explaining the cone.

Thanks. I've had that problem on and off for a while and never knew what it was.