First off I am new to 3d printers, I bought a CTC some time back and it came with a sd cad that already had some sample prints on it so I tried one and it printed fine so I put the sd in my computer and deleted all of the samples then I put some different one that were STL files on it and when I plug it in to the printer it will say that there is no files on the sd.

Check and see if you happened to slide the lock switch on the SD by accident when inserting it into the card reader.

Also you might want to re- format the SD card again and try and load files to it again.

Renecww3 has the answer for you. You need to use software to slice the 3d model (stl) file into g code and then save it to a sd card format file… If you are new to printing I would use a pc so you can try different settings before producing sd card files.

you can’t directly print a .stl file, you need slicing software like makerbot desktop to create .x3g files. those files the printer will recognize and print. cheers

That’s what it was thank you so much : )