Solved Need to Disassemble Hot End and problems with z-height

with S3D I occasionally get a "finding overhangs" that never ends. Leave it overnight.. come back to "finding overhangs" and a blasting CPU fan.
Sometimes If I just scale it a micrometer or turn it a degree and it works gangbusters. Sometimes it works if I just close S3D and re-open.

Oh yea... on the subject of slicing. I decided I would throw a
M300 S440 P200 as a "layer change G-code"... yea... don't do that. Oh my god.. I started it and left... came back 2 hours into a 6 hour print... BEEEP!........ BEEEEP! 4 more hours. Had no idea that little crystal would be that loud.

 

OK guys, so I was watching it print. And it appears that the nozzle is catching on the print as it prints, causing it to shift positions. It is catching ever so slightly on the ridges of the layers. Any ideas on how this can be fixed? Printing in ABS right now at 235 nozzle and 80 bed. No warping evident. Surface of print appears not smooth, like raised lines as it goes back and forth, printing at high resolution. Sorry the photos arent the best but hopefully you can see the lines where it caught and got shoved.

 

That can be slight over extrusion. too thick. I used to see that all the time. Now I don't. Assume its the Esteps. But it could be a z problem?
Does it get worse as it goes up?

 

well, judging by my perimeter I dont appear to have wagon wheels unless they are fricking microcropic lol. It is a super flat layer tho. do you think my z offset might be too low?

Def, what are Esteps? Also if it is a Estep or Z step/mm issue where could I find those?

Thanks for the super fastness lads

 

Hey guys its gotta be something with the rods. Just watching it lay down a first layer. increased z offset to 1.3 from 1.1 and it just "caught" on something and shifted.

 

You can VIEW AND EDIT your steps in the EEPROM. This is for "fun" only. They will reset to firmware norms when you power off and on.

You can find EEPROM viewer in most software front ends.

A Z step is the amount of steps (wiki stepper motors) it takes to raise the Z axis 1 mm. This is all mathy with the diameter of the rod and pitch of the screw (you have 8mm rods). The answer to Z steps is 2560 only. Unless you change rods.

An E step is the amount of steps it takes to turn the hobbed bolt enough to move the filament 1 mm. That is NOT to extrude 1mm of filament. to move the solid unfettered 1.75mm cold filament 1mm. This number is like... 723 or something from factory.

To permanently modify E steps (again... do not modify Z steps, they are hard 2560) you need to modify the firmware in the arduino IDE.
http://help.robo3dprinter.com/Wiki/RoBo_3D_Firmware

to calculate your extrusion, you can do a LOT of trial and error.. or.. do some maths http://reprap.org/wiki/Triffid_Hunter's_Calibration_Guide
there's a calculator out there that can math for you. Its got strange nomenclature though.

THe picture is of the line in the code that tells the machine what each axis uses for its steps. the last one is extruder steps.

 

When manually moving the extruder by hand from left to right, it starts to feel resistance and get difficult at about the halfway point. Could this be a bed leveling issue?

 

Ah ok so estep is extrusion steps. Got ya. Good info to have on hand, but I dont think those are the issues at the moment. It seems mechanical in nature as it just did it again when not over any filament whatsoever while laying a first layer.

 

Dunno.. is it hitting the bed? Even then, it should slide. it will get tight at the ends because of the angles on the pulleys.
What caught on where and shifted which?

 

I'm loading a pic now of where it gets much more difficult to slide on the rod.

 

man its like... all mechanical in nature.

 

Hey guys I am also uplaoding two videos to youtube to link here for ya

 

Hey be nice now, I'm a newb at this I only got car experience, not crazy robot machine plastic buildy thing experience

 

also not a man

 

also an idiom...
so.. you're pushing towards the right and it becomes hard to push there?
well, that's not right, but it wouldn't make anything drag. unless you hear GRIND or it stops moving, its not really interfering.
your pix aren't too clear, but it looks like you might be extruding too much.

 

Well I finally busted out the calipers. I'm 1.69 mm higher on the right. Gonna fix that and give it a go.

 

so should I try dropping the extrusion multiplier?

 

bam - Its all about the precision measurements, instruments, and calibration. Software is gravy. Get all the hardware square and the stock settings in the OEM software will get you where you need to be.

 

You can try that to see what happens. BUT, a proper calibration is always in order. it seems a bit out of some people's depth, but it's really simple. Its simple maths.