A Z-Plus question

How tight should the movement of a Z-plus be? I apologise ahead of time for this verbose post.

Before I installed it I could not rotate the stepper/threaded shaft with my fingers. When I received the unit I could move the router mounting assembly down by placing the Z-Plus unit on the deck and pressing down on the aforesaid assembly with a real lot of force. I could not however do the reverse. I thought this was unusual as I had seen a number of videos where people have a knob whereby they can easily manually move their router up and down. And even instances where people complain the the z axis falls when powered down. Neither of these two have not used the Z-Plus though.

On installing the Z-Plus and powering up it all seemed to be working OK so I figured all was normal with the ‘stiff Z’

In recent times I have been looking more closely at the situation and noticed that if I use the piece of paper trick for zeroing I can bring the mill down in 0.1mm steps until the paper binds. Now by backing off again by 0.1mm the paper is still held firmly, meaning the Z is not retracting by the full 0.1mm. I have confirmed this with a dial gauge that the retraction is less than 0.1mm, in fact it is less than half this. But it only happens in the first 0.1mm retraction, further steps are all normal. The stepper also sounds different for this first step than other movements. My thinking is that the stepper is loosing steps on this first upward movement.

So my question again is how stiff should a Z-Plus be?

I have an HDZ 3.2. The ballscrew is similar but different. With the HDZ I can move the carriage up and down but the ballscrew is hard to get a grip on and I can get it to move about a 1/4 to half turn before I have to regrip before I can move it again. The ballscrew is quite slick because of the grease/oil applied to the ballscrew.

So the HDZ is quite stiff and hard to move but glides very nicely during operation/jogging.

Makes me wonder if there are adjustments available on the Z-Plus. The advertising talks of a “custom made anti-backlash nut” but I can’t find anything regarding adjustments. I too have the Z-Plus so I will watch this thread with interest.


Steve would you kindly for a test do the ‘paper zeroing’ trick on yours.

Thanks Guy.

The ZPlus uses a leadscrew, so is much less efficient in this regard to a ball screw. also it does not transmit power in the reverse direction of transmission like a ball screw when it comes to linear motion and would not recommend forcing plate movement. Instead turning the lead screw or stepper motor to move the plate up and down or jogging when under power.


This is could be backlash, which is common for leadscrews and where the anti-backlash nut comes in. My first inclination is the nut has unintentional wear due to the forceful moving of the plate or at least became unadjusted. I’d recommend contacting Carbide3D support to determine next procedures for the Z-plus.


I just did the ‘paper test’ on my Z-Plus. Not that it matters, but are you using an older version of Carbide Motion? Mine (Build 513) does .025mm, .25mm and 1mm steps. I don’t have a .1mm step so I can’t simulate your situation precisely.

Anyways…I was still able to replicate your issue (to an extent) using .025mm steps, which are 4x smaller than a .1mm step. I bring it down one .025mm step at a time until the paper binds. But I have to bring it up TWO .025 steps to release the paper. It’s very repeatable. I did it several times, moving the X and Y a little bit each time in case I was “denting” the wasteboard. So it seems there is “some” backlash in mine (~.025mm?), but less than yours. Hope that helps. If you need more experiments, let me know…


Thanks Steve that’s interesting. I’m not using CM but a Masso controller and can step in 1.0, 0.1 and 0.01 (mm) steps although the latter is very fine and I rarely use it. I might just lurk with this a little longer and see if another chimes in with additional information. Thanks and cheers

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