One head big size embroidery machines with open frames offer several advantages over smaller machines or machines with closed frames. Here are some of the main advantages:

1. Larger Embroidery Area: One head big size embroidery machines offer a larger embroidery area, which allows you to create larger designs without having to split them into smaller sections.

2. Versatility: With a larger embroidery area, you can create a wider range of designs, including larger logos, motifs, or images. This makes the machine more versatile and suitable for a variety of embroidery projects.
   

3. Easy to Load and Unload: With an open frame, the embroidery machine is easier to load and unload. You can simply place the fabric on the frame without having to slide it into a closed hoop or frame.

4. Faster Stitching: One head big size embroidery machines can stitch faster than smaller machines, which means you can complete larger projects more quickly.

5. Higher Precision: With a larger embroidery area, the machine can achieve higher precision in stitching. This allows for more complex designs and better quality finished products.

6. Ease of Use: One head big size embroidery machines with open frames are typically easier to use than closed frame machines. The open frame provides better visibility of the fabric, making it easier to align and adjust the design.

Overall, one head big size embroidery machines with open frames are a versatile and efficient tool for creating larger embroidery projects. They offer a larger embroidery area, greater precision, and faster stitching, making them a popular choice among professional embroiderers and hobbyists alike.