<p>Your lead screw nut advances 8&nbsp;mm every complete rotation of 200 full steps, so a single full step would change the height by 8/200 = 0.04&nbsp;mm. This implies you need to set the layer height a multiple of 0.04&nbsp;mm.</p>

<p>The gear ratio of 4:1 (a reduction) is required to get to your desired 0.01&nbsp;mm layer height, but that is a very uncommon and a too small layer height to use.</p>

CC BY-SA 4.0
2020-05-31T22:36:45.717Z
2020-05-31T22:36:45.717Z
0scar
<p>My calibration at my printer is okay. When I try to move 10&nbsp;mm, it's exactly 10&nbsp;mm.</p>

<p>But I want to know what is my precision for Z-axis.</p>

<p>(<em>not posting the link of the product maybe it's not okay for the platform</em>)</p>

<p><strong>Spec for leadscrew:</strong></p>

<ul>
<li>Lead screw diameter: 8&nbsp;mm</li>
<li>Screw pitch: 2&nbsp;mm</li>
<li>Lead of thread: 8&nbsp;mm</li>
</ul>

<p><a href="https://i.sstatic.net/jwenH.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/jwenH.png" alt="calculator page"></a></p>

<p>My question; is my gear ratio 4:1 or 1:4? It's giving different results.</p>

CC BY-SA 4.0
2020-05-31T22:29:03.973Z
[This answer](/a/10597/) gives insight in leadscrews.
0scar
CC BY-SA 4.0
2020-06-01T03:11:14.253Z
In my experience, with decent stepper drivers (e.g. A4988), sticking to full steps for Z axis does not seem to be important (doesn't seem to make any difference to print quality).
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2020-06-01T03:14:48.987Z
My question is not just for 3D printers, I'm thinking about modifying to high precision CNC :) Thanks in advance
ahmetertem
CC BY-SA 4.0
2020-06-02T11:08:17.193Z
In short: It's 1:1, and your "pitch" for that calculator is 8 mm. Pitch and lead are frequently confused.
towe
<calibration><lead-screw>
Calculating gear ratio for leadscrew
ahmetertem
# Calculating gear ratio for leadscrew

(Asked by: username_0 on 2020-05-31)

My calibration at my printer is okay. When I try to move 10 mm, it's exactly 10 mm.

But I want to know what is my precision for Z-axis.

(*not posting the link of the product maybe it's not okay for the platform*)

**Spec for leadscrew:**

* Lead screw diameter: 8 mm
* Screw pitch: 2 mm
* Lead of thread: 8 mm

[![calculator page](https://i.sstatic.net/jwenH.png)](https://i.sstatic.net/jwenH.png)

My question; is my gear ratio 4:1 or 1:4? It's giving different results.

**Tags:** calibration, lead-screw
> **Comments:**
> **username_1**: [This answer](/a/10597/) gives insight in leadscrews.  
> **username_2**: In my experience, with decent stepper drivers (e.g. A4988), sticking to full steps for Z axis does not seem to be important (doesn't seem to make any difference to print quality).  
> **username_0**: My question is not just for 3D printers, I'm thinking about modifying to high precision CNC :) Thanks in advance  
> **username_3**: In short: It's 1:1, and your "pitch" for that calculator is 8 mm. Pitch and lead are frequently confused.  

---

## 1 answers

### Answer by username_1 on 2020-05-31. Score: 1 | Accepted answer

Your lead screw nut advances 8 mm every complete rotation of 200 full steps, so a single full step would change the height by 8/200 = 0.04 mm. This implies you need to set the layer height a multiple of 0.04 mm.

The gear ratio of 4:1 (a reduction) is required to get to your desired 0.01 mm layer height, but that is a very uncommon and a too small layer height to use.


---

