I just planked up some apple logs and to avoid too much loss due to warping, I planked them thick; 2 inches. It will take a long time to dry but I don't need it urgently. You say that your log is dry; been drying for years. How many years? I normally plank wood at 1.5 inches thick and leave them to dry (in a shed kept at 40-50% relative humidity) for 2 years or more. It may be that your log is not as dry as you would like and so cutting to 15mm thick may result in significant warping as it finishes drying. My advice would be to cut to 35 to 40 mm thick then see if it is dry enough then rip in to two planks ready for thicknessing to 15mm.
Using a chainsaw will, at best, waste a lot of material; the kerf is thick and cutting a straight plank with a hand held chainsaw is an art form!
Using a table saw, as has been said, would be difficult and dangerous. At best you could ruin your log and table saw, at worst you could be badly hurt as well.
Using a band saw is the standard method for hobbyists for good reasons; it works and is safe if done correctly.
Using a hand ripsaw is safe but hard work and requires a bit of skill.
Making a sled for your bandsaw is a safe method but is not really necessary if you don't need/want waney edges.
The method I use is to make a roughly flat side by planning off a centimetre or so of bark and sap wood using an electric hand planer. I then run that over my planer thicknesser to make it properly flat. I then use the bandsaw to slice off a flat side at 90 degrees to the first flat face. You can use a sled or a rip-fence to guide you or do it by hand. (As long as your first flat face is wide enough, and you don't push too hard then the log should not roll.) The new flat face is never perfectly flat so I run that over the planer thicknesser. I then use that new flat face to square the first flat face using the fence on the planer thicknesser. I now have two flat faces at 90 degrees. I then take a 1.5 inch slice off the log using the band saw (using the rip-fence). However, remember to calculate where your cuts will be relative to the pith. If the cut is square enough I can take another slice and so on. (If the newly created face is not very square/flat, I take a few shavings off using the planer thicknesser, remembering to square the two cut surfaces. Please be careful with the last slice on the bandsaw as the curve of the log may mean the lower part of the bandsaw blade is exposed and you don't want to trim the ends off your fingers; use a hand held push block which has a good gripping surface.
It sounds like a lot of work.... and it is, but it is very satisfying cutting your own planks from your own logs and even more so if you cut down the tree yourself
Two tips; use a sharp bandsaw blade with 3 or 4 tpi and coat the ends of the planks with wax sealer to help prevent splitting. (You can also use paint.)
I have so far used this technique with Yew, Laburnum, Cherry, Eucalyptus, Willow, Ash, Linden, Pear, Hawthorn and most recently Apple.
PS Eucalyptus is a pain in the @#% and warps and twists like crazy; good for making propeller blades, maybe.
Anyway, have fun, be patient and stay safe. Good luck.
