A router will not be as good as a spindle - much noisier, less accurate and more prone to wear. Far better to get another spindle with a greater capacity. If you machine is quite small, don,t be too put off by the 1/8th collet. I have a spindle and have been using 1/8" down to 0.5mm cutters for years, and I always say "I can make anything" (except money). G.