# Marlin Change after change Z screw with LeadScrew

Posted by khaf_0
 Marlin Change after change Z screw with LeadScrew February 06, 2018 02:36AM Registered: 3 months ago Posts: 3
hello all,
i wana use leadscrew T8-R8 on my pursa i3 3d printer,and i get Marlin from Github,
Now what change i have to do on marlin for use this leadscrew?
thanks for replay
 Re: Marlin Change after change Z screw with LeadScrew February 06, 2018 08:08AM Registered: 12 months ago Posts: 645
Here is a calculator for that exact reason

I changed lead-screw to an T8-2 (8mm lead-screw 2mm rise per rotation)
// Z Axis 3200, / 2mm pitch lead-screw = 200*16 /2 = 1600 :: (STEPS_PER_REVOLUTION_Z / PITCH_OF_Z_ROD)

My old setup
// Typical stepper motors have 200 steps per full step/rev = 1.8°/step, so 1/16 micro-stepping = STEPS_PER_REVOLUTION_E = 3200
Belt
// X-Y Axis 3200, / 20 tooth, / 2mm pitch = 200*16 / 20 / 2 = 80 :: (STEPS_PER_REVOLUTION_X / IDLER_TEETH_X / BELT_PITCH_X)
// Z Axis 3200, / 8mm pitch lead-screw = 200*16 /8 = 400 :: (STEPS_PER_REVOLUTION_Z / PITCH_OF_Z_ROD)

Edited 1 time(s). Last edit at 02/06/2018 08:12AM by Roberts_Clif.
 Re: Marlin Change after change Z screw with LeadScrew February 06, 2018 08:32AM Registered: 3 months ago Posts: 3
thank you Roberts_Clif,
hen i change DEFAULT_AXIS_STEPS_PER_UNIT z to 400 and when i move printer on Z Axis for 10 mm(with LCD Volume) printer move = 5mm?!
its correct?
 Re: Marlin Change after change Z screw with LeadScrew February 06, 2018 10:36AM Registered: 12 months ago Posts: 645
Quote
khaf_0
thank you Roberts_Clif,
hen i change DEFAULT_AXIS_STEPS_PER_UNIT z to 400 and when i move printer on Z Axis for 10 mm(with LCD Volume) printer move = 5mm?!
its correct?

What??? If you move the Z-Axis up 10mm it should be 10mm above the bed.

Question when I move my Z-Axis to the bed then raise it 20mm i can slide a 2mm block under the nozzle barely.

Do you have the listing of where you bought the lead-screw. And what controller are you using as some have jumpers that have to be installed.

Edited 2 time(s). Last edit at 02/06/2018 11:06AM by Roberts_Clif.
 Re: Marlin Change after change Z screw with LeadScrew February 06, 2018 03:39PM Registered: 3 months ago Posts: 3
thank you
i change DEFAULT_AXIS_STEPS_PER_UNIT to 800 and now its fixed,
when i move Z-Axis 10 mm , nuzzle move for 10 mm,
i use driver 8825 on ramp,
maybe this different is for driver steps ,1/32 or 1/16

// Z Axis 3200, / 8mm pitch lead-screw = 200*32/8 = 800 :: (STEPS_PER_REVOLUTION_Z / PITCH_OF_Z_ROD)
 Re: Marlin Change after change Z screw with LeadScrew February 06, 2018 07:52PM Registered: 12 months ago Posts: 645
1/32 Steps would definitely make the difference
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