TR8X4 Lead screw tension nut

Hello All,

I have a homemade cartesian FDM printer and I finally ditched the c-beam carriage wheel assembly for a linear rail assembly. The rails and carriage are working fine. During the update a moved from an 8X8 lead screw to a 8X4 lead screw. I took it for granted that a tension nut or some kind of locking nut would be easily available for the 8X4 lead screw. I can not find one. Do these exist? This entire DIY 3D printer project has been fun but there are surprises all over the place. I have a lot of height/homing problems for Z because the coupling nut is two springy for the lead screw. I need to add a bracket to support the lead screw and a tension or locknut to remove the Z height variability.

looking forward to some insight or suggestions.

Robert

... can you post some images or sketches of your setup and the problematic parts?

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Viktor
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Hello,

I'm looking for a nut similar to the one below but for a TR8X4 lead screw and not the TR8X8. Ultimately I'm trying to fix the lead screw so that as the motor changes direction the screw does not shift. I have anti-backlash POM nuts on the carriage and that part is working fine.

I've searched tension nut, hex nut, collar, etc. and I can't find anything for the 8X4 thread.

Thanks.


[bulkman3d.com]

Started with a 8X8 lead screw to I decided to try the 8X2 shown in below Highlighted in Green.

// Typical stepper motors have 200 steps per full step/rev = 1.8°/step, so 1/16 microstepping = STEPS_PER_REVOLUTION_E = 3200 
// 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, / 1.25mm pitch leadscrew = 200*16 /1.25 = 2560 :: (STEPS_PER_REVOLUTION_Z / PITCH_OF_Z_ROD)
// Z Axis 3200, / 8mm pitch leadscrew = 200*16 /8 = 400 :: (STEPS_PER_REVOLUTION_Z / PITCH_OF_Z_ROD)
// Z Axis 3200, / 4mm pitch leadscrew = 200*16 /4 = 800 :: (STEPS_PER_REVOLUTION_Z / PITCH_OF_Z_ROD)
// Z Axis 3200, / 2mm pitch leadscrew = 200*16 /2 = 1600 :: (STEPS_PER_REVOLUTION_Z / PITCH_OF_Z_ROD)
// E-Axia 3200, / (11mm Gear OD * pi) :: (STEPS_PER_REVOLUTION_E * EXTRUDER_GEAR_RATIO / (PINCH_WHEEL_DIAMETER * PI))

It work for my 3D Printer as every time you would tap table you could see the nozzle lower with power off.
And most times starting up my Hictop 3D Printer would begin with a leveling of Z axis because the dual stepper motors were out of alignment.
One stepper motor would be lower than is should be for a perfect horizontal nozzle level across the bed.

An had no problems with leveling after the switching to 8X2 in lead screws.

My End result was to convert all my 3D printers to 8X2 to keep the horizontal nozzle height level across the beds

Edited 2 time(s). Last edit at 05/20/2025 07:37AM by Roberts_Clif.

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Computer Programmer / Electronics Technician

I was never able to find an actual 8X4 threaded metric tension nut so I made a locking collar. I took a 5/16 hex nut (7.93mm) and drilled out the the threads with a 21/64 drill bit. Then I added a set screw to keep it secured. ~ $1.00 in parts and some time.

That was very smart ! thank for the information

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Computer Programmer / Electronics Technician