If you want a good TTF shooter design look at successful TTF shooters here on the forum. Bill HAYS was generous enough to post many TTF Designs here. They are all great designs. (ie Patriot) Or you can keep it simple and fast and get a poly ranger that will shoot flats,tubes OTT or TTF for 25 bucks and kicks arse and is practically indestructible! I guess what I'm saying is Bill Hays worked out the dimensions.The sling has got to be the right size for TTF.
Treefork's Bill Hays suggestion is a good one. The Patriot is a great design and is easily modified for any attachment method you might prefer. Bill has been extremely generous and shared several excellent designs with the forum.
Sure I like Bill's slingshots, they are outstanding, but I don't shoot sideways.
I shoot my slingshot different than the most of you.
I hold my slingshot at an 45deg angle and therefore I make my own to fit my shooting style.
the way you hold your sling has little to do with design, i have made 5 of your eagles now, and have seen the new owners hold in every way except the intended 90*, angle, in truth the way that you hold the frame is mostly in the mind. the frame will do the same thing rotating in all 360*, it is up to the shooter to find and hold at his confort zone, i have Hays gangsta, and 45*, the same with AKM's, CHEPO69's, Bob Fionda's, dankungs, the very cool SPS, in the final analysis its not the frame, its a combination of the ergos/comfort and the shooter. it matters little if its hammer, gansta, natty they can all be shot from just about any angle and be accurate, it all depends on how much time you put into practice.