I used an MMC setup for years, I now use the D-3 but the checkering head and guide setup is very similar. Because the electric tool is guided by the previous line you cut, if this line wavers the next one will waver even worse, and so on...I use the carbide hand tools[push version] to straighten out any wavy lines before making the next one. After it is fully spaced it is usually smooth sailing after that. I make 2 passes each way, and then finish up the outlines and go over the entire pattern with the hand tools, Using a short"pull" tool in the corners.
