W150CTDproject

all i can say is WOW! for the semi rims id go with a set of the 22's Super single wheels from American Force with the 8-10 lug adapters. i think that would look sick. Great thread and good work!

mullishacrew

thanks!, those rims loook slick, i want to do duallys on the back and yes with the 8-10 lug adpaters and all that good stuff. i think this week im gonna go ahead and make some frame rails after work, and then over the weekend i will slice the frame and install the frame rails, i have another idea in my head to extend the frame for a larger box 10' because i have a old style logger box on there that i can also extend easily, what do you guys think? and i dont loose the 8' bed with the stacks and the cargo box

mullishacrew

here is a little picture i drew up. i think ill have the gusset extend past the cut about 12" both sides and then weld it all up and then either bolt it or drill the plate and weld it to the existing frame. i was just going to put a plate in the inside of the frame but make it so it basically has to be hammerd in. should i do one on the outside of the frame rail? i dont really want to just because i want it to look seamless but what do you guys figure?

W150CTDproject

can always keep the stock rails and put a 10' flatbed

mullishacrew

yeah but mine are rotted where the gas tank is, so im am going to rebuild the whole back half anyway.

W150CTDproject

oooh ok

Alec

The most important attachment is the top and bottom flange. The top flange is under compression, the bottom is under tension, and the center of the web has (almost) no load at all in the middle of the frame.

This isn't the best desription, but it was easy to find. Wikipedia Link

Long tapered welded splices along the top and bottom flange usually give the best results, especially if you are a good welder, which it looks as though you probably are. If you want to get fancy, a sort of finger joint, where the corner of the channel top and bottom are long and pointy, is even better, as the top inch and a half or so of the web takes some of the load, too.

Obviously, you can do a gusset as you described, but you end up having to use a much heavier piece of steel to get the same strength, as the gusset has to be thick enough to transmit the load without a flange at the top and bottom, and long enough so that the stress can be transferred to it from the flanges of the "C" through the web . . .

I hope that some of that made sense, if not, just ignore the armchair engineering, and enjoy the project!

mullishacrew

is this kinda what you mean?

Alec

Yes, but maybe I shouldn't have said finger joint, exactly, because it would be better to have only two "fingers" if the picture you have is "three" fingers. And having a long scarf, or taper, on the top & bottom flange is the most important part.

If you think about the bottom flange as being a bunch of wires, or strings, under tension, and the top being a bunch of rods, under compression, anything that disrupts the consistency of the steel wants to run along the strings/rods as much as possible, not across them. And, holes, etc., should be rounded in the corners with as large a radius as is practical, so there aren't sudden changes in the strength of the piece.


I'm sorry that I don't have a simple drawing program that I know how to use.

Alec

comptz

Is this what you mean?

Alec

If you have enough space, that is fine, but what I was trying to describe is two "v's" that wrap around the top and bottom corner of the channel, so the points of the v's fall on the top and bottom corners, and the web has a single v that is formed by the arms of the two v's meeting in the middle (the same shape that he originally had for the end of the gussets).

Trebor

Alec,
I think the loading characteristics of a beam and a channel are somewhat different because a C channel piece of metal is physically an H beam that is cut in half vertically. While the upper and lower flat portions share some of the same characteristics of the beam more of the vertical load is in fact carried by the vertical section because there is less metal to stretch and load in the top and bottom flanges.

The best frame welding splice method I have seen to date was cutting the top flange and going straight down to the mid point of the frame channel, then cut horizontally traveling a distance half the height if the channel, then from there directly down to the bottom of the frame. This in effect gives more welding surface increasing strength. This is then followed by a plate cut to fit inside the channel.

Alec

Trebor,

I'm not sure that I follow what you are saying about the beam and the channel.

I am not a licensed mechanical engineer, so maybe I've missed something, but as I understand it, loosely speaking, if you take a rectangular solid and load it as a beam, it will be about the same strength as a properly designed wide flange, or H, beam. The stress carried by the web, or vertical section, regardless of the beams shape, is limited by how much the material at the very top and bottom can stretch before they fail -- the material at the topmost and bottommost of a beam must deform for any load to be carried by any other part of the beam (except for shear along the neutral axis at the ends of the beam, but that is a whole different problem), as that is where any stretch or compression must be physically greatest if the beam bends.

If you can avoid it, you do not want a splice that cuts across the top or bottom flange at a right angle, because even if you have a perfect weld, the change in material from piece, to weld, to piece, will encourage cracking if the force is perpendicular to the splice.

But now I am a thread hijacker. I will apologize, and

speed75

I say cut it staight and fish plate outside and box inside

mullishacrew

no no, this is good, i went and talked to a welder and they suggested i do what ALEC said. i agree on the angle of the top and bottom side, more pull strength and more weld area as well. and the V cut as u said, along with the fish plate inside. i like to hear the suggestions so no worrys about highjacking! oh you think i should gring the weld smooth when im done ? or just leave it for that little extra meat?