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Topic: Backlash fix - z rod pushing well nut out

Hi everyone,

I'm trying to apply the well nut backlash fix to my SD 3 but I'm having the following issue, when z goes to 0, the bed pushes the well nut out of the rod. I'm currently printing a cage to fix it to the existing holes in the platform but I might be missing a solution here?

Thank you.

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Re: Backlash fix - z rod pushing well nut out

A picture helps but I get what your saying.  It won't give you as much cushion but I have seen them run the other way. 
(Flip it over)

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

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Re: Backlash fix - z rod pushing well nut out

Mine used to be partially out when I home Z, but it has about half the threads still in there.  You could get longer bed leveling screws and springs but that costs you a little bit of Z height.  Or the Volcano hot end hangs a little deeper.

SD4 w/ RUMBA, E3D Volcano, all bearings, glass bed

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Re: Backlash fix - z rod pushing well nut out

Or go to home depot and get another 5/16-18  threaded rod, cut it to the size you need and install it. You will need a coupler though and there's directions on this site how to remove the old rod. At that point you may as well just upgrade to one of the other smaller rods with a finer thread pitch.

The well nut doesn't fix backlash, it helps with the z-wobble.

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Re: Backlash fix - z rod pushing well nut out

metaldrgn wrote:

The well nut doesn't fix backlash, it helps with the z-wobble.

OH REALLY ???
I am getting tired of misinformation!
But, What would I know wink

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

6

Re: Backlash fix - z rod pushing well nut out

metaldrgn wrote:

The well nut doesn't fix backlash

Yes it will. Wardr pointed this out to me. I tried it one my main unit, then ran back out for another to use on my second printer. It's one of the easiest and cheapest fixes out there. Just try it

Printit Mason and Printit Horizon printers
Multiple SD2s- Bulldog XL, E3D v5/v6/Lite6, Volcano, Hobb Goblin, Titan, .9 motor, Lawsy carriages, direct Y drive, fishing line...the list goes on
Filawinder and Filastruder #1870.....worth every penny!

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Re: Backlash fix - z rod pushing well nut out

wardjr wrote:
metaldrgn wrote:

The well nut doesn't fix backlash, it helps with the z-wobble.

OH REALLY ???
I am getting tired of misinformation!
But, What would I know wink

Enlighten me, how does it?

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Re: Backlash fix - z rod pushing well nut out

Ok I think I see what you are saying. I was talking about the single well nut replacement option. Yes adding one to the existing one would reduce backlash.

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Re: Backlash fix - z rod pushing well nut out

This has been covered so many times but here is one of the originals and even though he runs his upside down offering less cushion it still works.  All backlash is, is the slop between the nut and the threads of the rod.  By adding another nut and a way (spring or Rubber in this case) to press opposite the other nut you effectively eliminate any slop and therefor a change in direction doesn't become lost motion due to slop or play between the threads.  One nut is always bushing up while the other is always pushing down with the bed static in the middle of the two nuts.  Have a read this was just one small discussion on the issue. http://www.soliforum.com/topic/2341/poo … -required/

Now, none of this will help remove Z-wobble which is caused by the Z-rod being bent or out of alignment.  As the bent rod spins it applies lateral forces to the platform and actually causes the bed to wobble.  The only proper solution to this is replace the bent rod.  There have been several successful slop nuts designed and implemented that will reduce or eliminate the Z-wobble but many have negative consequences such as increased backlash.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

10

Re: Backlash fix - z rod pushing well nut out

metaldrgn wrote:

Ok I think I see what you are saying. I was talking about the single well nut replacement option. Yes adding one to the existing one would reduce backlash.

I was not aware of a single replacement option.  This would definitely not help and explains your confusion.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

11

Re: Backlash fix - z rod pushing well nut out

Yes I remember reading about someone who replaced their pressed in nut with a well nut to reduce the z wobble. I hadn't seen anything on adding it as a secondary. Glad we got that cleared up! wink