Nozzle gets smashed against the bed

@fcwilt

@fcwilt said in Nozzle gets smashed against the bed:

But the motion did not stop?
When the pin is in the down position how far below the nozzle does it extend?

Yes the motion stoped.
The pin gets +- 3.3mm below the nozle

Well if the motion stopped how did the nozzle hit the bed?

Frederick

fcwilt

And you enter the value just as displayed.

Frederick

MJCT

@fcwilt

@fcwilt said in Nozzle gets smashed against the bed:

Well if the motion stopped how did the nozzle hit the bed?

the problem now is that this thread is getting to long and I’m starting to get confused with all the questions. Kind off... you where asking about the G30, when I home the Z, When I start the machine....???

Well, I entered the value as displayed “G31 P25 X25 Y0 Z0.229”

Seems to work at the beginning. First layer a little bit far from bed, corrected it with baby steps, and printed the rest of the first layer fine.

Second layer moved a lot above what was expected and started to print in the air.

May be the “G31 P25 X25 Y0 Z0.229” was right from the beginning and the problem is Cura?
What other slicers do you use for reprap?

Now I’m going home, long day! Thank you all, I really appreciate all your effort!

jay_s_uk

If it moved further than expected, have you got your z steps correct for your machine?

Phaedrux

@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

MJCT

@jay_s_uk

@jay_s_uk said in Nozzle gets smashed against the bed:

If it moved further than expected, have you got your z steps correct for your machine?

Yes, I tested it before I started asking questions. Any way If you read this
"Well, I entered the value as displayed “G31 P25 X25 Y0 Z0.229”

Seems to work at the beginning. First layer a little bit far from bed, corrected it with baby steps, and printed the rest of the first layer fine.

Second layer moved a lot above what was expected and started to print in the air."

you know that the problem is not Z steps

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