USING THE Model3 tube Bender$ HOW TO construct a motorcycle frame:
My bendtech SE software by 2020 Software solutions was sold to me in early 2000's by Cris. Obselete now. WHen you use the software you shoot at targets like a gun, measure a "thing" you want to copy bend to bend, take a protractor and measure the bends and check them against your results. It generates Distances, Rotation, and Degrees of bend.
"distances which you mark on the tube" You slide the tube into the bender and locate at each mark for each bend, read the rotation off the protractor clamped to the end of the tube (which in this case is incremental with a reset at each bend) then bend to the degrees called for on the bender shoe plus spring-back of tube, Release, advance to next mark, do it all over again.. I have to keep a bend sheet to keep track of where I am.
The software is user calibrated for a mandrel shoe, in the normal MC frame here I use mostly a 4.5 CLR (centerline radius) shoe. It normally calculates for this and hits it pretty well.. most of the time. IF the nose clamp is not tight, the tube will slip in the shoe as it bends, messing it all up.. unpredictable.
One of the cool features is you can check a "reverse" bends box and it will.. do it all in reverse order.. having a long uptube sweep hit the bender, of the floor is a good reason to do this.. I used my bender in the vertical mode for years, now it is laid back down and rotates clockwise parallel to the floor. (easier to swap out dies)
Preparing to WELD: just like paint, the end result is in the preparation, fish mouthing tube in the shape of the connecting joining tube, making tight accurrate joints to weld, on real thick tube, you bevel the ends to get a deep penetration and build the Vee up with good weld. They make some great new tools, which I don't have, one is a pin template you wrap around the tube, slide the pins up to the ajoining tube, set them, then index it upon the tube to fishmouth, mark and transfer the pattern, cut and weld joint.
Welding, I prefer Tig when I can see.. I suggest tig or oxygen acetylene cause it is more flexible, less brittle, less slag in the weld. I learned to tig from a Alaskan Pipe welder on a buzz box.. REAL HOT, you use the filler rod, dipping in the puddle to cool the puddle and run like hell.. because I learned this method I have a hell of a time welding thin stuff.. I want to press the go-amps pedal and run like hell.. OLD habits, and old dogs I guess. I try to use a new self taught method these days.. Doo Doo Dah.. dip dip, heat puddle, dip dip, heat puddle, feather pedal, keep it wet.. Like Jim Spradley "Henrob Jim" (henrob, Dillon 2000 gas torch) said.. it is all about the puddle, the wet spot. No reason to worry about the whole weld, just the lil spot you are on and molten, as you complete that puddle there, move on.
Disclaimer, I am not the best, do not know it all.. This is just how I do it. If you have something to teach me, I am willing to listen. If you want to call names and argue, I don't have time. I grew up in a neighborhood populated by Sociopaths and psychopaths, proving one of them out to be a bragging liar is just dangerous as they follow a vendetta of revenge. I moved on and away. No matter what, i am going to have fun.