Hi and welcome to the forum
Personally I don't know the DW320, but I do have a DW1751, it's big brother. A few of points about RASs (radial arm saws) - they are excellent for crosscutting, they are reasonable for mitre cutting (more so if you use a jig like the mitre jig
here), but what they are not good at is rip sawing (just a tad fraught). The main thing is to get your machine set-up properly first, and for that you'll need the manual. Try any deWalt sales outlet as DW can still supply some of the parts for the machine. If that doesn't work come back to me and I'll do you a general "how to set-up a DW RAS" tutorial based on experience of having several DW RAS's. Whatever else you do make sure that you set the machine up properly and install the correct type of blade BEFORE attempting to rip on the saw as ripping is one of the most dangerous operations to perform on a RAS and you need to approach it methodically. As a matter of interest there is also an article on reconditioning DW RASs on
Badger Pond, although this is aimed at older American-made DW RASs the general set-up from the article applies to all RASs. I'd also strongly recommend reading the HSE leaflets
"Safe working at woodworking machines" and
"Safe use of manually operated cross cut saws" - they're free and the advice contained therein is good advice.
Regards
Scrit