Tower at first it was tough figuring out the angle and how to position the ishi stick. Once I somewhat got it down I was able to drive flakes WAY past centerline without any problem. I just have to watch out trying to go as fast as Jackcrafty does it on Youtube because I don't abrade like I should. I find that I can get a longer flake when I push in with the ishi stick and hit instead of just placing it on top of the delta. I'm sure that I'm just breaking the surface and Jack can probably add much more than what I know. If I go chip this afternoon I'll try to give an example on how it work for this newbie.