-51 degrees F. in North Pole, Alaska

Do you want to know what it is like....Well it is very cold.
Today, there will be no outdoor activities. Just stay inside and stay warm.
Make sure you have communications with the outside world and the heater stays on.
It is days like this that I wish we lived in a condo. Living where there are no neighbors and where we have all this privacy is not an asset at -51F.
So far the water hasn't frozen and the septic line is still working.

Offset Pipe Bending Opinion

It seems almost impossible that for 60 years electricians have been given the wrong information for bending offsets in conduit. The multiplying factors are not correct and using the cosecant of an angle as a multiplier to find the distance between bends is incorrect. Someone has been pulling the shade down on electricians and no one bothered to check the information for over 60 years, that I know of, and I have read a lot of information on this. I am convinced that someone years ago was so desperate to sell EMT and benders that they over-simplified the bending math to convince users that bending offsets is simple, easy and fast. Or someone has been fooling the labor market by deliberately publishing the wrong information to make pipe bending more labor intensive. Anyway, the bottom line is my research into the mathematics of bending offsets has revealed an almost flagrant ignorance of the facts. I shudder to think of the erroneous offset tables now being so widely accepted that they are now attached to hand bender handles, and the person responsible is bragging about this in one of his books that has sold over two million copies.
The article at http://www.electrician.com/electa1/offset.html
explains my findings.

More on the Offset Bend math and calculator

I updated the offset calculator and article again. I was curious about finding if the method to find the distance between bends by multiplying the height of the offset by the cosecant of the angle was correct. This is where those multipliers of 6 for 10 degrees, 2.6 for 22.5 degrees, 2.0 for 30 degrees, 1.4 for 45 degrees, and 1.2 for 60 degrees come from. This method is an approximation and is not mathematically correct. For most offsets of up to 45 degrees, there is little difference in using this method or using the correct mathematical calculation. However, again for steep angles and large pipe these multipliers will give you errors that require recutting the pipe and/or altering the bend angles. I have placed the correct calculation in the offset calculator and added a conversion for decimal to the nearest 16th of an inch in fractions.
I purchased Jack Benfield's Benfield Conduit Bending Manual from Amazon.com. I read in this book that has sold over 2 million copies that there is no need to use complex trigonometry and that the tables and methods in this book can be used for any size pipe. I differ with Jack on this because I have used his famous zip tables in the field for large rigid pipe and had nothing but curse words for whoever invented these inaccurate tables. Jack Benfield wrote the book based on his experiences starting back in the 1930's. Perhaps from the 1930's to the 1960's using precise mathematical calculations was a bit of a task. However, today, with a desktop computer in every job shack, I think the time has come to quit being simple and inaccurate. Jack's book is, in my opinion, outdated. Today's electricians are computer literate. The IBEW apprenticeship school in Fairbanks, Alaska even has a computer lab to teach journeymen and apprentices how to use a computer. I believe that using computers for bending pipe has come of age.

Even more on the Mathematics of the Offset Bend

I have again revised the article and calculator in the mathematics of the offset bend, and did some bends to verify the calculator. I also added a calculation for the straight pipe length that is the straight piece of pipe between the two offset bends. Oh yes, many a time, I have made the first bend to steep only to find that I couldn’t make the second bend. Then I would have to take degrees out of the first bend and wrestle the pipe around trying to get the correct offset height. Anyway, the offset calculations appear to be more accurate than the Tables supplied with various benders.

More on the Mathematics of the Offset Bend

I again revised, revised and revised again the article on the offset bend shrinkage math. It has become an algorithm unto itself now and no longer bears resemblance to the real world. The math checks out, but I wonder how a field verification test will hold out. I should go get a 555 Greenlee bender and at least try it out, but it is 20 below zero and I am not going to do it in the house. There are also so many field variables such as the type of bender and the wear and tear on the shoes. Does the pipe stretch or does it compress or do all pipes have the same malleability? Then there is the case of the oiled shoe. My partner and I had a problem with 3 inch pipe flattening using a one shot Enterpac at Pump Station 7 in about 1981. The hydraulic fluid kept leaking and the shoe got oiled. It was years later that I learned that an oily shoe will cause the pipe to flatten. I learned that a shoe properly treated with vinegar is better.

I do think that the new electricians should make the big move to laptops. If the infantry soldiers can fight a war with them, perhaps electricians can do a better job of wiring. It is fact that almost every job shack in Alaska now has a computer with an Internet connection. Many as-builds are now required in Auto Cad format. So why not!

Mathematics of the Offset Bend Article Updated

I received a call about the Mathematics of the Offset bend Article that I wrote a few years ago. So I reread the article and decided it should be revised. I added 5 pages and a downloadable spreadsheet calculator. I wrote the article because the shrinkage multiplier zip guides that so many electricians use never worked for me. Usually when I used this guide to precut rigid pipe the pipe came out short and had to be put in the dog pile. I always thought it was me, but now I know the zip guide is just that, a guide and is not precise. The offset JavaScript calculator in the article on page 6 that determines and applies the gain from the arc of the bends is mathematically more correct, but needs further verification in the field. It is almost unbelievable how much math is involved in the calculation of shrinkage. In the field, most of us do not do these calculations. Most of us develop our own techniques for the situation at hand and the bender(s) at hand and make them work. I have seen one electrician use a back hoe to bend rigid pipe for underground installions. He placed the pipe in soft dirt and applied pressure using the back of the bucket and did a fine job of it. This method is not recommended and is illegal by Code, but it seemed to work just fine at the time.

I also added more Code to the alaskavirtaultour.com index page. Talk about CSS ad DHTML that page is full of it. It isn't a page at all but a computer program. It combines JavaScript with CSS to produce effects never achievable with standard HTML. The page is only viewable using Internet Explorer version 5 and above.

Bye, bye Netscape

For years I have tried to keep web pages compatible with the Netscape Browser. This was an immense task requiring many hours of work and requiring that the advanced features of Microsoft’s Internet Explorer be forsaken for the sake of compatibility. In the 90’s Netscape was the leading browser, but then Microsoft came along with Internet Explorer and now 98 per cent of the visitors to electrician.com use Microsoft’s Internet Explorer version 5 or above. I have tried Firefox, Mozilla, and Opera and they all have compatibility problems. I no longer am going to even try to stay compatible! My pages are designed to work in IE 5.0 or better and that is all there is to it. Additionally, my multimedia pages at alaskavirtualtour.com are being designed for speeds of 150k or higher and for screen sizes of 1024 by 768 or 1280 by 1024 at 32 bits. 60 per cent of the visitors have these resolutions.

During the last several weeks I have become totally committed to developing the code for the multimedia site alaskavirtualtour.com. About 70 per cent of the code took me about 300 hours to write, and much of the work was done in all night sessions. I borrowed, begged and stole the other 30 per cent. Now I suppose any number of web page designers will borrow all that I have done. There is no way to hide the JavaScript code that I know of. You can jumble it, or make it difficult to find, but it is always there somewhere, and a persistent designer with enough savy can always find it. For you new comers just right click in any page and select source and you can see the source code for that page. Don’t ever under estimate the value of the right mouse click!

My multimedia talents have been honed some more for what comes later – developing multimedia training courses for the Internet. In 1996 I purchased a Sony VX 1000 for $3500 with the intent of making digital training videos. This camera was about 8 years ahead of computers, memory, hard drives, connection speed, and software. I made movies alright, but I had to buy a $1800 Seagate 9.5 gigabyte hard drive and a $1000 capture card that only connected using the VHS cables while the Sony’s digital firewire was not useable. It took 5 hours to render a 5 minute film! And the hard drive had to be partitioned into 2 Gigabyte partitions because Windows 95 could not access more than that. Today all that has changed. Multimedia is here and the Internet, computers, and software are ready!