How to weld?

[kahnbiraj]

Okay. So I started cutting the links for my frame. And there are basically these two ways to go. One is to cut straight links and weld them at the perpendicular joints. Other is to cut both at a 45 degree angle and weld them. Since I will be following either of these ways all along,Please suggest which one should I chose and why. And yes, I do understand engineering stuffs too.

 

[mckutzy]

...... And yes, I do understand engineering stuffs too.

Butt joints are the easiest in square tube but have open ends that need to be capped. Mitered joints are a little more difficult as then tend to warp when tacking, unless the joint is held fast using a set of clamps, a corner clamp ect. They also need to be cut correctly as to not throw off the overall joint in that it wont be square.

This pretty much depends on the overall design as the forces are taken into account when the frame is designed.

BUT.....
Im kinda confused if you already know..... why are you asking us.... in an engineering point of view or "stuffs" as you put it?

 

[kahnbiraj]

This pretty much depends on the overall design as the forces are taken into account when the frame is designed.

This is exactly what i am talking about. How do I base the selection of joint type based on what forces act on the frame?

And I added the 'engineering' bit so that someone could explain me the engineering on which the selection is based.

 

[mckutzy]

What are you building? start with that... then work into what specifics youll need.

Most of what you going to see here is what people have done, and experiences. Maybe not alot of scientific analyses, but the basic info to get what you want. but depends on what are you building.

 

[chancer]

If you weld them cut straight on perpendicular lines it is not as strong as doing the 45°.

For example on a 90° corner with 1" square pipe you have 4" of weld.

While on the same 1" pipe cut at 45° you get 6" of weld.

Therfore increasing the Strength of the joint by having more actual surface area on the actual Joint.

Aslo in the event of a crash impact at the corner joint with a 45° the energy is dissipated into both pipes as opposed to only 1 pipe using the other method.

So structurally from an engineering stndpoint the 45° is a much better Joint.

They are however more difficult to fabricate and therefore most DIYers do not bother.