Lead screw length issue

I’m at the final stages of assembly and i realized my lead screw is toonlong. See attached picture. How long should the lead screw be?

I must have completely missed it in the documentation and cannot find it. Here is the picture of what my assembly looks like:

Do i need to cut it? If so what tools did you guys use to cut lead screw?

Yes, you will need to cut down that screw. I made mine a little shorter than the Z tubes. Technically it can be as short as just a few threads into the nut on the top of the core, when your Z tubes are level with the bottom of the core. Because your Z tubes should never come up past the bottom bearings.

To cut it you could use a cut-off wheel, or hack-saw. Make sure you put the cut end into the Z motor coupler so you don’t bum up the core nut.

+1 What Tim said. It’s actually in the build guide, but I did the same thing, realized I needed to read it more closely when I saw the problem with mine. Easy fix with an angle grinder, cut it a little shorter than the length of my z tubes, then used a sanding disc to kinda make it convex a little (probably not necessary).

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I hope hand hacksaw does the job :confused:

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Lol it will, just less noise and more sweat!

@Les_Bois @Strider_Matic,

So I took a break and I’m back at it again today. In need of one last piece of advise before i start sweating. :slight_smile:

Do i need to disassemble the lead screw from the stepper motor to cut it or can I cut it while it is the assembly? Will the vibrations from hacksaw affect the assembly? Really feeling lazy to disassemble and do it.

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I didn’t remove mine. Made it easier to know where to cut. Idk that I would be able to fit a hacksaw between the rails, though. I’d also be pretty bummed if I ended up bending the z rod. Probably best to remove it. I’ve figured out that building the mpcnc benefits from more plan/prep really. Shouldn’t be much hassle to remove it, though.

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I was worried you’d say that. At least i tried. :joy:

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Yeah I’d undo the coupler. Wouldn’t want to risk stretching it out. Its just two little set screws!:stuck_out_tongue_winking_eye:

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Haha, I say it because I’m basically an ogre and will just bang parts around until they fit unless I make a very conscious effort to do things right. Lol

Got it done guys, i had to buy a disk for $2 from local home depot for my angle grinder. It worked.

Lead screw is in the picture as well, if you can spot it :slight_smile:

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