I bought an old Atlas 10F machine that was supposed to be a good deal but turned out not so good of a deal after all. It was supposed to have all the accessories and a lot more junk to go along. I was really busy when the guy brought it by and didn't have time to go through the boxes. Months later I had some time so I decided to set the machine up in my new room that I built for my machine shop. It cleaned up nicely and I mounted it to a large machine table that I built just for this machine. Now let me get this straight right now........I am no stretch of the smallest bit of imagination 'a machinist' of any sort, just a wannabe machinist at best. After I got the machine set up I decided to chuck up a piece of stock and try my hand at making a few chips. This is when I found out about change gears. When I started to turn the stock it I could tell right away that the carriage feed was way to fast because when it was cutting the stock it was leaving lines, like threads as it was cutting. I could manual feed it and it was leaving a smoother finish but still rough. I did a little reading that led me to looking at the gear setup and possibly changing the gears to slow it down some. The machine came with what was supposed to be a complete set but looking at the gear charts I see that the gears I have are no way near enough gears to put together any of the setups on the gear charts I have looked at in the threading manual I downloaded yesterday. I've been on e-bay all morning looking around for some deals but didn't see much at what I would be willing to pay. The thing I'm wondering is, on the threading charts they list gears like 48F, 64F, 64B, 24, 56B for instance. What does the letter after the tooth number mean, are they a different gear all together than the gears that just have the tooth number like 64 or 64A? The way this thing is set up is like nothing I have seen in any of the thread cutting charts. It almost seems like the feed is turning about the same speed as the spindle. I put it in back gear to try and slow it down a little and it did slow it down but it's still the same ratio between the feed and the spindle speed.....too fast on the feed. I've got like a million questions to ask about this machine and figured this was as good a question as any to start off with.