#  Combine Chambers 

 



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  expand\_more  

 
  

 

Now that we have the basic chamber, we will repeat it to create row of 11 chambers using the **Linear Pattern** feature. Since we need to pattern the entire chamber, we use **Bodies to Pattern** (instead of Features) and click on the chamber that we made. \[[Video: Patterning chambers in a row](http://www.youtube.com/watch?v=RFOFkYr9RGI)\]

 ![image177](/sites/g/files/omnuum4601/files/2024-11/image177.png)

 

Now we select the direction to pattern the chamber. Under **Direction 1**, select an edge to determine the direction of patterning. You can use any edge parallel to the actuator main axis.

 ![image178](/sites/g/files/omnuum4601/files/2024-11/image178.png)

 

Set the distance to 10mm (8mm chamber thickness + 2mm spacer) and the pattern # to 11.

 ![image179](/sites/g/files/omnuum4601/files/2024-11/image179.png)

 

This gives us 11 separate solid bodies, which could be annoying later, so we merge them into a single solid body using the **Combine** feature.

 ![image180](/sites/g/files/omnuum4601/files/2024-11/image180.png)

 

**Combine** is usually not available in the default toolbar. In the top dropdown menu, go to Insert > Features and click on **Combine.** If the option is not there, you will have to click on “Customize Menu” and manually add it – and add the **Split** feature as well, for later.

 ![image181_crop](/sites/g/files/omnuum4601/files/2024-11/image181_crop.png)

 

In **Combine,** use the **Add** operation type to add all the chamber bodies together. Under **Bodies to Combine**, select all the chambers.

 ![image182](/sites/g/files/omnuum4601/files/2024-11/image182.png)

 

 ![image183](/sites/g/files/omnuum4601/files/2024-11/image183.png)

 

Next, we need to thicken the two ends of the actuator so that they don’t bulge out like the other sidewalls. To do this, use **Extruded Boss/Base** twice, to add 2mm extra thickness to each end wall. \[[Video: Thicken actuator ends](http://www.youtube.com/watch?v=PIOWXDN7Qd4)\]

 ![image186_1](/sites/g/files/omnuum4601/files/2024-11/image186_1.png)

 

 ![image187_1](/sites/g/files/omnuum4601/files/2024-11/image187_1.png)

 

Now we cut the 2x2 mm central air channel. \[[Video: Cutting central air channel](http://www.youtube.com/watch?v=VMrEqa264ZI)\] To ensure that it is centered along the axis, we first need to create some **reference geometry**: a point that we can use to draw a centered rectangle later.

 ![image189_1](/sites/g/files/omnuum4601/files/2024-11/image189_1.png)

 

In the **Point** sidebar, select the “Center of Face” option, then click on the bottom face of the actuator (not inside a chamber). A dot should appear at the center.

 ![image190](/sites/g/files/omnuum4601/files/2024-11/image190.png)

 

Now we use **Extruded Cut** to create the central channel. On the bottom face of the actuator, draw a rectangle using the reference point we just created as its center, and having its edge coincide with the inner face of one of the end chambers.

 ![image191_1](/sites/g/files/omnuum4601/files/2024-11/image191_1.png)

 

 ![image192](/sites/g/files/omnuum4601/files/2024-11/image192.png)

 

Use **Smart Dimension** to make the rectangle 2mm wide, then exit the sketch and make the **Extruded Cut** 2mm deep.

 ![image193](/sites/g/files/omnuum4601/files/2024-11/image193.png)

 

The main body of the actuator is now complete, but [in the next step we will add some extra features to aid fabrication](/book/pneunets-add-bonding-features).



 

##  Bibliography 

Ilievski et al. (2011) [Soft robotics for chemists.](/publications/soft-robotics-chemists)

Mosadegh et al. (2013) [Pneumatic Networks for Soft Robotics that Actuate Rapidly.](/publications/pneumatic-networks-soft-robotics-actuate-rapidly)

Ogura et al. (2009) [Micro pneumatic curling actuator: Nematode actuator.](/publications/micro-pneumatic-curling-actuator-nematode-actuator)

Polygerinos et al. (2013) [Towards a soft pneumatic glove for hand rehabilitation.](/publications/towards-soft-pneumatic-glove-hand-rehabilitation)

Shepherd et al. (2011) [Multigait soft robot.](/publications/multigait-soft-robot-0)

Sun et al. (2013) [Characterization of silicone rubber based soft pneumatic actuators.](/publications/characterization-silicone-rubber-based-soft-pneumatic-actuators)



 

##  Contributors 

Panagiotis Polygerinos

Bobak Mosadegh

Alexandre Campo