The light source isn’t that much of an issue the problem is that you are projecting on a curved surface (even tho you are projecting a line at the time) and at an angle.
Basically photolithographic printers can have the same issues as you have with projectors where the image can be skewed or morphed so if you are printing say a square you might not get 4 90 degree corners or perfectly straight lines, the size of the print can also vary depending on the distance between the projector and the drum if it’s not exactly the same as the printer thinks it is the size will change and it varies it would cause perspective shift skewing.
With ink jet alignment errors would maintain the shape and size but the shape might not be aligned perfectly to the page so your errors would only be positional or rotational with photolithography you have perspective and projection transformation errors.
Photolithography printers for engineering/architecture have builtin auto alignment to correct for this.
While the errors even for most home printers are very small if you print something like a gear it’s enough to cause wobbling and fit issues.
That said for wood gears if you cut them by hand I would imagine the tolerance errors from cutting would be worse than from printing unless you are very skilled.
Basically photolithographic printers can have the same issues as you have with projectors where the image can be skewed or morphed so if you are printing say a square you might not get 4 90 degree corners or perfectly straight lines, the size of the print can also vary depending on the distance between the projector and the drum if it’s not exactly the same as the printer thinks it is the size will change and it varies it would cause perspective shift skewing.
With ink jet alignment errors would maintain the shape and size but the shape might not be aligned perfectly to the page so your errors would only be positional or rotational with photolithography you have perspective and projection transformation errors.
Photolithography printers for engineering/architecture have builtin auto alignment to correct for this.
While the errors even for most home printers are very small if you print something like a gear it’s enough to cause wobbling and fit issues.
That said for wood gears if you cut them by hand I would imagine the tolerance errors from cutting would be worse than from printing unless you are very skilled.