giant inflatable robot

Recently, other laboratories have been doing a lot of inflatable manufacturing, and we think it\'s time to write a manual about it.
What is the theme of inflatable better
Is the robot of Ize structures?
This is an advanced view of the manufacturing process.
For us, the first step in building an inflatable model is to design a 3D model using CAD programs such as AutoCAD or Solidworks.
To make the robot more stable, we used the art license and added a third leg.
In addition, the inflatable shape tends to the sphere when inflated, so some allowance must be set aside.
For example, to prevent leg injuries, we point them inside.
With the model at hand, we can use hino (
As an ongoing work download for Mac)
Expand the flat, \"developable\" surface and can be stitched into the original model.
Next, we need to increase the seam allowance by 10mm and arrange the parts to the printable page.
With Illustrator or Inkscape, we can get the DXF output of Rhino and add the seam allowance using \"path offset.
Panels with allowance can be arranged manually to fit the printable page.
This method works well, but can be very tedious for many panels.
As an experiment, we read the output of Rhino and added the seam allowance in a programmed way and nested the parts on paper.
Now, we print out the panel with the seam allowance.
We used a Roland Versacam with 48 beds, but if you tile the panel over multiple pages, any printer will do that.
After printing, you can cut and stick the tiled pages together.
After the panel printing is finished, we need to cut the shape from the fabric.
For small parts, you can cut the paper and fabric in one step, but for larger parts, it is usually easier to cut the paper first.
Use weight to ensure that the paper pattern does not slide on the fabric when cutting.
Use patterns as guides to identify which panels are connected through which seams.
For most robots, we use flat seams.
For large diameter segments (like the belly)
The stress on the fabric is high and attention must be paid to maximizing the joint strength.
For smaller accessories, the strength is not so important, and it is not so simple, it is possible to use easier seams.
To serve the bladder, we need to get into the lumen.
For this, we put a zipper on the back of the robot.
This also provides access to the human driver. . .
Finally, to get into the expansion valve, We reinforced a small hole under the zipper.
Valves are always placed in standardized positions due to historical reasons.
Some cavities, such as fingers, eyes, antennas and buttons, are too small to easily expand by the internal bladder.
For these parts, we just fill the foam inside to support them and simplify the bladder structure.
Fabric envelopes are not breathable so we need an internal bladder to keep the robot inflated.
However, like a resilient Castle, a continuous blower allows the robot to remain inflated without a bladder.
This can also be used to quickly test the inflatable shape before making the bladder.
The polyurethane bladder is super large and elastic, so the fabric envelope bears all the power and thus determines the shape of the robot.
At the same time, the internal bladder accumulates inside and only provides sealing.
This system is like the tubes and tires of your bike wheels.
In general, the bladder should be large enough to avoid stretching.
Because of this, the shape of the bladder can be greatly simplified.
We have made a simple 2D approximation of the robot, which can be easily constructed by hot bonding.
After cutting the polyurethane panel, we assemble each half using a pulse sealer and then attach them around the edges into a large inflatable bag.
After the shape is done, we still have to add nozzles to pump in and out of the air. Stick-on one-
The valve makes this easy and can be bought from the supply store of the kite maker, like this one.
Finally, in order to keep the bladder properly distributed within the fabric envelope, we need to have a connection point at each end.
We use the pulse sealer again to glue a small ring of polyurethane at the end of the arm, leg and head.
Now that everything is done, we just need to plug the bladder in and inflate it.
From the limbs, tie the ring on the bladder to the envelope.
Pass the nozzle through the inflatable hole and evenly distribute the bladder inside the envelope.
The talcum powder helps the bladder slide to the position and sit better.
Start delivering air to the bladder while massaging the robot to eliminate spots where the bladder does not properly fill in the fabric envelope.
If all goes well, you will get a robotic gas bag!