Tip - when scanning your tracing, put a ruler on the scanning bed if it is important that the SWx sketch is the exact same size as the tracing (usually is, but I don't know your application). When scale fidelity is important, what we have done in the past is start by sketching a line on top of the image of the ruler, adding a dim to find out how long the line is is, and the % difference between the length of the sketch line and the corresponding marks on the ruler gives us the exact scale factor for adjusting the inserted sketch image. Kinda obvious, but you need to be thinking of it at the time you scan (hence the tip) Ed
BTW - you asked about splines. Splines are easy as long as you don't overthink them. Try using as few spline points as possible to get the shape. You will need to experiment a little to gain the intuition required for this. Though you can drag tangency vectors for any of the spline points, try hard not to do that on anything except for the beginning and end of the splines. If you do the tangency vector or magnitude for middle spline points you can kink up the spline because of some behind-the-scenes breaking of the curve - notice that, once you mess around with tangency handles a little you get a 'relax' spline box in the Property manager for the spline? Clicking it will unkink that internal breaking, but the spline will move from what you drew (however, it will be smoother) Avoid all that mess by making as relaxed a spline as possible form the get-go. the only time I adjust spline vectors on internal points is when I have a precise point where I know the middle fo a spline must be horizontal or vertical - in those cases, the potential reapir work is worth it. Depending on your shape, you might be better off with a few(underline FEW) splines instead of just one. Again, experience will tell you as this is a case-by-case thing. For fine-tuning the location of spline points, I use the XY in the property manager, setting my spin box values to .001" (or whatever is appropriate to the scale of the job). There are also other tricks - splitting viewports (one macro, one micro) or simplyholding down CTRL while dragging a node to turn off inferencing. one guy even wrote a macro. For me, the PM is the most repeatedly expedient. Definately turn on inflection points for the spline if you know why it matters and it is important not to have an inflection point. Curvature comb is also handy, but I will let others comment on that.