Please forgive my ignorance but I cant see for the life of me how you get the cuts in the blackwood with the setup of your sledge as it is in the photo I can see how it would make an angled cut across the wood but not on the face of the wood the configuration of the sledge seems wrong to me for the cuts you say you made unless I have mist something which is more than likely the case the old grey matter dont seem to work as fast as it once did LOL