I couldn't submit my assignment on time because of printer machine problem so I need to get excuse from profeesor

Can't you just prepare a personal letter with the usual heading (return address, date, professor's name and address) and say that you were unable to submit your assignment on time because it was on your computer, your printer was not working, you could not repair it yourself, you could not find a printer to borrow?

Ask for a written extension and sign your name.

When you write your letter, resist taking a tone in the letter that you deserve the extension. You don't. Simply ask for it honestly and include your problem with the printer as an extenuating circumstance.

Having a printer problem didn't stop you from printing your homework, it just stopped you from printing it at home. There are thousands of printers between your house and your classroom, so getting your homework printed is your responsibility.

I'm just saying, be careful and HONEST in your request. That honesty may just get your extension, even if with a lowered grade.

BTW, if you can write and submit a letter, I assume you will be printing this letter? Make sure your late assignment is attached to the letter you write, or your teacher will know you STILL haven't really even done it.

- that is why I suggested that the line "I could not repair it, I could not borrow a printer" be included.