Do a search for "telar toba" and you will get many hits on spanish language websites (telar = loom in spanish)
Beautiful weaving and very good looking looms. Use the "translate" feature on your web browser to get a clue.
edited to add:
I highly recommend this site:
Includes a tutorial on weaving on the toba sash loom with details of the construction that shows everything you need to see to make your own loom.
It's in Spanish so get your spanish/english dictionary out.
The tutorial is a picture file so you can't copy and paste the text into a translator, you would have to type it all in.