(Buck, I tried to post to you directly but your fake email address bounced). Hi Buck, First of all, your plan to end up with one diameter at 2.5" round when starting with 2.5" square is a bit ambitious. You might get lucky and end up >2 3/8" but doubt much if you will get 2.5" round. Okay, normally you would use a large spindle gouge or roughing gouge and turn the piece to a cylindar. To make the cylindar as straight as possible, align your tool rest with the lathe ways by sighting over the top of the tool rest and make sure it is parallel to the ways. When the piece is getting to round, run your forefinger against the tool rest while cutting the piece. This acts as a gage to control depth of cut. Get your cut started and sway your body (arms are clamped to your sides). Sounds clumsy but it will work. Now that the piece is round (suggest you do all 4 pieces plus at least one practice piece at the same time), mark the length of the leg. I would make the largest end start at the headstock end so you don't have to cut anything off there. Any drive center mark should be hidden at assembly. At the small end of the leg, set a pair of machinists calipers to your desired diameter plus about 1/16". Use your parting tool and cut a groove down to where the calipers will just slip on. It is safe to do this while the wood is spinning, just pay attention to what you are doing. (If you don't have the calipers, use an open end wrench the proper size, just make the groove wider). You said you have some extra length so turn the small end diameter about 1/2" or so wide - beyond the marked end of the leg. This will give you room to start your tapering cut(s). Starting at the large diameter still remaining down at the foot, start cutting material away toward the smaller diameter. You can still be using your roughing gouge or large shallow spindle gouge. You need to visualize the taper and cut away anything that doesn't belong there. Yep, I know, easy for me to say. The upshot is that you can't cut anything from the headstock end because it is already undersize. When you have some length of taper started, turn your tool rest so it is parallel to the taper. Using your forefinger as before as a guide, cut away excess material. In case you aren't real happy with how things are going, you can use a block plane, placed on top of the piece but skewed at about a 45° angle to also remove material. Don't extend the blade very far until you experience the cut a bit. Oh, by the way, you always want to be cutting from the large end to the small end to keep from chipping out the wood. When you have it about to size, take a piece of 1 x 2 or such and glue a piece of 80 grit sandpaper on one wide side. Move the tool rest out of the way and sand the entire piece, from end to end at one time. Final sand with
120 grit if you are going to paint and a bit finer if you are not. Remeasure for length and use the parting tool to cut most of the way thru the piece. Stop the lathe and finish with a small hand saw. There you have it.Jim in Ohio