I agree with Debossman, it's illegal to make copies of the DVDs, even if you own them. they don't care why you want to make copies of it, and making a copy of it for your own purposes is really no different than making a copy of it to sell. I mean, why don't you just go to a movie file sharing site and download the illegal copies from there?
I don't know much about your DVD burner that you are using. Is it hooked up to your computer? If so, have you considered buying a DVD recorder (you know, one that plays and burns DVDs on your TV? I don't know if that will work for you or not. See if you can record your DVD onto VHS tape. You will lose some quality in your copy, but it sounds like you aren't too concerned with that. If you get it onto VHS, then playing it back on VHS and redubbing it onto a new blank DVD should be easy with a DVD recorder.
I don't know much about your DVD burner that you are using. Is it hooked up to your computer? If so, have you considered buying a DVD recorder (you know, one that plays and burns DVDs on your TV? I don't know if that will work for you or not. See if you can record your DVD onto VHS tape. You will lose some quality in your copy, but it sounds like you aren't too concerned with that. If you get it onto VHS, then playing it back on VHS and redubbing it onto a new blank DVD should be easy with a DVD recorder.