# Power Transfer

## Overview

On this page we will go over the pros and cons of a few types of transfer,

* [Gears](#gears)
* [Chains](#chains)
* [Timing Belts](#timing-belts)
* [Round Belts](#round-belts)

Look at [Idlers](#idlers),

and talk about [Gear Ratios](#gear-ratios).

## A Warning for handlers

{% hint style="danger" %}
It goes without saying. Don't put your fingers in when these things move. 

Failure to follow may result in loss of body parts, blood, and pain.
{% endhint %}

## Types of transfer

### Gears

{% hint style="info" %}
Note that gears change the direction of motion
{% endhint %}

{% hint style="success" %}
Precise transfer
{% endhint %}

{% hint style="success" %}
Can be easily self designed for 3d printing ([Fusion 360 tutorial](https://www.youtube.com/watch?v=B8A_11o7QZ0))
{% endhint %}

{% hint style="warning" %}
Need to be meshed with precision
{% endhint %}

![https://grabcad.com/library/15-tooth-18-tooth-gears-meshing](https://2759048249-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-McUrjiqzDSh8JGRCdzp%2F-Mcfg_lbas-34HTTrC-e%2F-McgB7i2MLwNLqM3mdjW%2Fgears%202.gif?alt=media\&token=a0eaf999-8cba-4039-8e27-5554ba6eeaa3)

### Chains

{% hint style="success" %}
Long distances
{% endhint %}

{% hint style="success" %}
Chain length can be adjusted
{% endhint %}

{% hint style="warning" %}
Imprecise transfer; A sprocket can rotate a bit without its counterpart
{% endhint %}

{% hint style="danger" %}
Will skip under heavy loads; Frequent cause of shudder 
{% endhint %}

![https://in.pinterest.com/pin/651473902321724083/](https://2759048249-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-McUrjiqzDSh8JGRCdzp%2F-Mcfg_lbas-34HTTrC-e%2F-McgEvAAmZK7PkkSFgYp%2Fchain.gif?alt=media\&token=299bba96-d405-4312-8190-dc0d4a145870)

### Timing Belts

{% hint style="success" %}
Long distances
{% endhint %}

{% hint style="success" %}
Silent
{% endhint %}

{% hint style="success" %}
Precise transfer
{% endhint %}

{% hint style="warning" %}
Come only in specific sizes
{% endhint %}

![https://grabcad.com/library/timing-gear-set-1](https://2759048249-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-McUrjiqzDSh8JGRCdzp%2F-Mcfg_lbas-34HTTrC-e%2F-McgLK5NSjGCOZAZLv-B%2Ftiming%20belt.gif?alt=media\&token=9e455ac1-798b-4803-930b-f0e1de361fdb)

### Round Belts

{% hint style="success" %}
Long distances
{% endhint %}

{% hint style="success" %}
Distance does not need to be precise
{% endhint %}

{% hint style="success" %}
Pulley angle does not need to be the same
{% endhint %}

{% hint style="warning" %}
Imprecise transfer; Will slip easily
{% endhint %}

![https://www.gobilda.com/3405-series-round-belt-5mm-cord-diameter-95mm-circumference/](https://2759048249-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-McUrjiqzDSh8JGRCdzp%2F-Mcfg_lbas-34HTTrC-e%2F-McgLNl5Jl7RNewO5N1U%2Fround%20belt.jpg?alt=media\&token=186cf352-9214-4084-9f27-4d99007e5483)

## Idlers

Idlers are used to shift chains and belts.They are often used to tension the system (take up slack) or guide it (get around obstacles).

They can be used both inside or outside the chain/belt.

Best when freely rotating (has a bearing) and using the appropriate sprocket/pulley.

![https://www.quora.com/What-is-idler-pulley-and-how-it-is-linked-with-belt-drive](https://2759048249-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-McUrjiqzDSh8JGRCdzp%2F-Mdj-yrofmQmZ0CWPPmi%2F-Mdj9q1mHrUFnd71NAz_%2Fimage.png?alt=media\&token=0ebf22e1-560f-4b01-8765-0a83769be0f3)

![https://www.gobilda.com/3414-series-5mm-htd-pitch-set-screw-pinion-timing-belt-pulley-8mm-rex-bore-24-tooth/](https://2759048249-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-McUrjiqzDSh8JGRCdzp%2F-MdnpqYQA9564Z_kXGqQ%2F-Mds1yjZ8Cj4IUGjU_Q_%2FProduct%20Insight%20Idler.png?alt=media\&token=2a6248c3-8143-4fdd-a9b4-7f0c8840410d)

## Gear Ratios

Also applies to gears, sprockets, and pulleys.

> Driver gear rotations : Driven gear rotations

{% hint style="info" %}
As a rule of thumb, less speed equals more torque (power)

The opposite is also true; more speed equals less torque, which means it gets easier to jam/skip/slip.
{% endhint %}

Here are a few examples

{% tabs %}
{% tab title="3:1" %}
15-tooth driver gear and 45-tooth driven gear.

It will take 3 rotations of the driver gear to equal 1 rotation of the driven gear, therefore, the gear ratio is 3:1
{% endtab %}

{% tab title="1:1" %}
40-tooth driver gear and 40-tooth driven gear

It will take 1 rotation of the driver gear to equal 1 rotation of the driven gear, therefore, the gear ratio is 1:1
{% endtab %}

{% tab title="2:5" %}
25-tooth driver gear and 10-tooth driven gear

It will take 2 rotations of the driver gear to equal 5 rotations of the driven gear, therefore, the gear ratio is 2:5
{% endtab %}
{% endtabs %}