Since these two saws are my top two choices (considering price and features), I’ll continue with my comparison of them even though the R4512 isn’t available on craigslist right now. I'm sure one will come up soon. I realize there are a million different options and I know everyone has opinions about which brands to get. But I’m limiting this discussion to these two machines for the moment. (By the way, if you are ever searching for Ridgid products on Craigslist, don’t waste your time spelling it correctly. It is almost universally misspelled as “Rigid.”)
I think both of these saws are solid but of course both have their trade-offs. Both have table-mounted trunnions. (“Trunnion” is such a cool, medieval sounding word!) I’ve read lots of strong opinions about how table-mounted trunnions make it difficult to align the blade. I understand that and had an experience a few years ago where I had to return a saw because I couldn’t get the blade aligned. That said, both of these saws are supposed to have features that make it possible to align the blade, so that shouldn’t be an issue. Here is what Fine Woodworking said about it: “As on most contractor’s saws, the trunnions are mounted to the underside of the table, but this saw also has a simple cam and lever built into the rear trunnion.” In the other review referenced below, the person wrote that the left slot on the table was aligned to the blade to .001” over the length of the blade out of the box, which is closer than I’ll ever need. Both machines have a mobile base. Both seem heavy and powerful enough to handle the kind of stuff I plan to do.
I’ve read lots of good things about the 3650. It seems like a workhorse. The one I looked at today was ok, but it has been poorly maintained to say the least. There is another 3650 on craigslist that I will probably go see soon. The 3650 has a cast iron table and cast iron wings. It has a splitter but not a riving knife. The fence seems to be almost to the quality level of after-market fences. The R4512 has a cast iron top but stamped metal wings. There are lots of people who aren’t able to get past this. Cast iron wings would obviously be better, but of all the ripping you do on a table saw, I’ll bet 90% of it happens within 10 or 12 inches of the saw blade, and that area is cast iron on both saws. The only major downside to the stamped wings would be if they got bent out of shape somehow. On the positive side, the R4512 apparently has a really good riving knife. Also, the motor is enclosed, which helps with dust collection and noise suppression – two things that are very important to me in my small, basement shop.
There has been a lot written about the 3650, but almost nothing about the R4512 that I have been able to find. You would think that because it is a major offering from Home Depot, the major woodworking magazines would have done a write up. If I buy one, I’ll definitely write about it. I have to say that right now I’m leaning toward the R4512 because of the riving knife and dust collection. If all things are equal (or even roughly similar), those are two of my most important considerations. If anyone has an R4512, please let me know how it is working for you. Likewise with the 3650.
Here is a review of the 3650 on FineWoodworking.com:
Sometimes the best thing about the review is the comments that it generates. http://www.finewoodworking.com/ToolGuide/ToolGuideProduct.aspx?id=5709
Here is another review of the 3650: http://benchmark.20m.com/reviews/RidgidTS3650/RidgidTS3650Review.html
Here are some Lumberjocks reviews of the R4511, the model that the 4512 replaces. The 4511 had a granite top: http://lumberjocks.com/reviews/product/837