Welding of a frame from a shaped pipe. How to assemble it correctly and make potholders so that the diagonals are even

  • Mar 04, 2021
Welding of a frame from a shaped pipe. How to assemble it correctly and make potholders so that the diagonals are even

Friends, I welcome everyone to our channel dedicated to all self-taught beginners in manual arc welding and locksmith.

Let's take a look at an important topic for beginners - how to properly make potholders when setting diagonals, if we are welding a frame from shaped pipes.

Welding of a frame from a shaped pipe. How to assemble it correctly and make potholders so that the diagonals are even

Today at work I welded a frame from a 40 x 40 mm profile pipe. Its thickness is 1.5 mm, it will be a blank for the rear wall of the Kamaz trailer.

First of all, we cut the blanks to the desired size and make cuts at 45 degrees. The more accurate we make these cuts, the easier it will be to assemble the frame itself and the more accurate the initial diagonals will be, even without fitting.

We laid out the blanks in a frame and now we measure the length, width, and diagonals. There are two options for the development of events, the diagonal is immediately good, within 2 mm. And the second option, the discrepancy is 2-5 mm. We put the potholders in the inner corners of the frame. So the design will be like on hinges, it will be easy to fit the required even diagonals.

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Before tacking, measure the diagonals at the outer corners. And now the very essence.

If the diagonals are different, within 2-5 mm, then we put the potholders in the inner corners at a smaller diagonal, now I will explain why this is so.

For example, I took the constructor from my son. All of us, Soviet children, had such a designer! I just saw this in a toy store and could not resist buying it.

First, a little theory. Here we have two parts at right angles to each other. We put a potholder in the inner corner of these parts. The potholder begins to cool down and begins to pull these parts to itself. And we get an angle not right, but a little less-less than 90 degrees. Based on this, we go further.

Here is a frame whose diagonals are a little uneven, for example, I made the structure straight so with a big difference, so that it was clearer for you. We put potholders where the diagonals are smaller and see what happens.

These tacks begin to pull the workpieces onto themselves and the overall structure is aligned. The frame is straightened - the diagonals tend to the same value. Often, you don't need to hammer anything down anymore.

Consider the second option, when, after assembly, before tacking, the diagonal is excellent - the difference is within 1-2 mm.

If, in a frame with initially flat diagonals, we also put the potholders diagonally. See what happens then.

Diagonal potholders begin to pull on two parts and we get a frame with different diagonals. It's just that the tacks of the second diagonal will not be able to compensate for the tightening force of the first tacks, this has been noticed for a long time in welding work. What is the right way then? Look.

We make potholders clockwise or counterclockwise. But there is also a little trick here. As mentioned earlier, the second tack does not fully compensate for the first. So we make the first potholder a little smaller, the second a little fatter. The third is smaller, the fourth is fatter. In this sequence, everything will turn out fine.

Now we will make a couple of tacks at the outer corners. The order is also clockwise or counterclockwise.

Now our frame is ready for welding, its diagonals are correctly and evenly aligned.