Nozzle gets smashed against the bed

Phaedrux

@MJCT said in Nozzle gets smashed against the bed:

you know that the problem is not Z steps

Please fill out the formula above for determining Z steps per mm and show how you arrive at 4000. Thanks.

MJCT

@Phaedrux
I tried to use the formula when I was using the config tool, but that value was provided by the manufacturer. But I will double cheek it tomorrow

Phaedrux

Who is the manufacturer? What type of printer is this?

MJCT

@Phaedrux

@Phaedrux said in Nozzle gets smashed against the bed:

Who is the manufacturer? What type of printer is this?

More on that tomorrow, I prefer to confirm first everything I say about a company on the web. It would be terribly unfair for them if I was making some kind of confusion.
The printer is a core XY based on V rails

fcwilt

@Phaedrux said in Nozzle gets smashed against the bed:

@MJCT said in Nozzle gets smashed against the bed:

M92 X80.00 Y80.00 Z4000.00 E96.94 ; set steps per mm

Z steps per mm of 4000 doesn't sound correct.

Z_steps_per_mm = (motor_steps_per_rev * driver_microstep) / screw_lead

That does not sound right. For a typical 8mm lead and 1.8 steppers the steps/mm would be 400. 4000 would mean a 0.8mm lead which doesn't seem likely.

Frederick

Veti

4000 is the default value in the configurator.
this value was used for one the first 3d printers which used m5 threaded rods.

here is a picture of the ones used some time ago.
https://www.instructables.com/id/3D-Printer-Lead-Screw-Upgrade/

most modern 3d printers now use a 4 start lead screw with a 8mm pitch which results in 400 steps per mm.

if your printer really has one of the old ones, you should swap that out before you do any prints, as it will result it very poor prints.

Veti

also you have a beta value of 4138. this is also the defaults and most likely wrong for your thermistor.
you need to find the correct value, otherwise you are printing at the wrong temperature.

MJCT

Hi,

Somehow, in the middle of all this crisis 400 sp mm transformed in 4000 sp mm. ~

The company information was : 1.8 deg (200 steps per rev), Leadscrew, Custom, Pitch 8, Gear ratio 1:1 and finally 400.00 microsteping.

When I was using the config tool I’m sure I’ve inputted 400.00, but instead of just clicking with the mouse at another area I probably pressed “Set”, and that reverts the value to the predefined 4000.00.

Lousy mistake that costed me dozens of hours and a lot of patience to all of us.

That’s why the G30 S-1 was returning values like 0.22... instead of 2.2... It was literally messing everything in the Z axis, tenfold.

Its now printing a test cub

MJCT

@Veti

@Veti said in Nozzle gets smashed against the bed:

also you have a beta value of 4138. this is also the defaults and most likely wrong for your thermistor.
you need to find the correct value, otherwise you are printing at the wrong temperature.

Yes, next step

jay_s_uk

@MJCT

We'll get you sorted

MJCT

The test cub printed just fine for a first print.

Once again, thank you all for your help.

fcwilt

@MJCT said in Nozzle gets smashed against the bed:

The test cub printed just fine for a first print.

Once again, thank you all for your help.

Hi,

Glad you got it working.

Remember in the future that one of the tests you should make is to use the DWC to jog the axes a known amount and verify with a measuring device that the movement was correct.

Frederick

MJCT

@fcwilt
Iep I understand that, and I did it, but because de dashboard buttons don’t indicate units, they just say "Z-5" for example, I made the mistake.

When that button was pressed, the Z axis moved exactly 5 cm which I confirmed as accurate with a tool (not 5mm as it should). But I was so angry and confused that I didn’t notice that the behaviour of the X and Y axis was different. For those the equivalent button only moved 5mm.