Volodymyr

Parallelogram problem

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I am telling you' Anvil, we are talking two different languages.

Read my post above more slowly.

You are missing something.

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I dont think so. Im agreeing with the gent you commented on who does his tapers square_octagon_round., and suggested you try drawing out a piece of one inch his way, then your way, and see which is faster. Its a good learning experience.

 

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On 7/20/2019 at 2:20 AM, anvil said:

this will answer your question. Start with a length of 1" round. 

No it will not because we are not discussing round.

Obviously round is first squared then tapered.

Striker's claim is that square must be rounded to be tapered.

NOTHING COULD BE FARTHER FROM THE TRUTH.

SQUARE IS DRAWN OUT SQUARE.

ROUND IS SQUARED THEN DRAWN OUT THEN RE-ROUNDED (and in fact should go 4 sided to 8 sided to 16 sided to round).

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actually, either way works, square or round, doesnt matter. Its just that one way may be a bit more efficient than another.  ;)

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Actually tapering round round promotes interior crackin as material is torqued around the center axis in shear rather than being compressed as when working square.  This is generally not so much a problem using mild steel; but was very much so using real wrought iron and can be a problem using higher carbon/higher alloy steels today.

This is why the older books suggest making round square to taper and a few even have photo micrographs of the cracking  when that wasn't done.

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On 8/30/2019 at 1:14 PM, arftist said:

SQUARE IS DRAWN OUT SQUARE.

well, here's a pic of a long ago day. I was just where you are in your beliefs, or at least I was questioning what I'd been taught and read about as well. And that is that tapering square-octogon-round was the most efficient way. Over time I saw that when I forged a taper on say half square, forging it square worked! Pretty much 5/8" too. And I rarely worked larger stock.

Along came this job, subbed from some friends in Denver that had literally thousands of these to do for a restoration. I did 50 or a hundred or so. This pic is delivery day in my Willys pu. I still have the pu.

the job was as described above. I took it for the learning, not the money. But I did make money__  ;)  The lesson was to gain massive experience drawing out large stock by doing enough repetition in a short amount of time to get my answer to this question.

You can bet that I tried and cried experimenting with every possible way I could think of!

I got my answer. Your conclusions may differ.  ;)

square, octagon, round.

There is actually a physical reason for this. Take it as you will. It's what I was taught and makes sense.

1: steel follows the path of least resistance.

2: when tapering square, there is less resistance sideways, not in length.

3: forging on the diamond, or on narrow flats has less resistance in length. Thus it's more efficient. I'm not equipped to argue physics, just throwing out what I was taught.

Also, at least for me, I have far more control keeping a nice smooth taper. Especially on long tapers.

 

20190901_111013.jpg

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Anvil, that is a pile of round bar.

Everyone agrees, round to square then back to round. 

This discussion however, is about square bar. 

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Also for things like fence pickets they probably won't have problems with a bit of internal cracking. I was doing a load bearing item with the possibility of failure causing injury or fatality I would be very careful how I did things!

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On 9/5/2019 at 6:14 AM, arftist said:

Anvil, that is a pile of round bar

I need to make this clear, It doesnt matter what the cross section I start with is, square or round, especially with heavy stock. For me, heavy stock is 1" and larger. Lol, some daze heavy stock is anything over 5/8".  :)

For square bar forged and tapered to either square or round

And

For round bar forged and tapered to either square or round:

If im forging square bar i forge it octogon, round, octogon, square, octogon, whatever the final cross section is.

Visa versa if i start with round.

Another benefit for this is that the octogon step is a danged fine transition between the opposite cross sections and just happens naturally when tapering in this manner if you leave a little octogon section between the square(round) and the round(square) at the beginning of the taper. Assuming you are going from one to the other.

Hope this helps and clarifies any misunderstanding you may have.

For what its worth, im not here to tell you how you or your teachers or anyone else ought to do anything. Im here to present just how I do it,, and give my reasons why. ;)

However, if you were working in my shop, it would be a different story. I do know which technique is more efficient, and im not one to pay for that lost time. However, I never have a problem, if you are working for me, to pay for your learning time even if learning something new takes more time than what you are familier with. I call that a win win situation. At the very least you would have experience with two techniques to do the same function and be able to make up your mind as to which you will use.  

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