Create a joint_T for rotatable models.

**Since:** 2.1

## Parameters

`shaft_r`

: The shaft radius of the joint_T.`shaft_h`

: The height of the shaft.`t_leng`

: The length of the T part.`thickness`

: The thicnkess of the ring.`spacing`

: The spacing between the shaft and the ring. Default to`0.5`

.`center`

:`false`

(default) for z ranges from 0 to`shaft_h`

.`true`

for z ranges from`-shaft_h / 2`

to`shaft_h / 2`

.

## Examples

```
include <part/joint_T.scad>;
$fn = 48;
joint_T(
shaft_r = 2,
shaft_h = 15,
t_leng = 15,
thickness = 2,
spacing = 0.5
);
```