Tube coping calculator

[matteh99]

ISKI,
If you are doing a bunch of the same making a cutting guide defiantly makes sense.

You could do a combo of the chop saw and printout tubing cope. Get it close with the chop saw and then finish it with the paper template.

Eric

[samsberr]

Mr Gadget:

The chop saw calc. link has an extra(http://) in it...
Thanks for posting.
Great tools.

Here is a nice site for printing out tube coping patterns. If you don't have a notcher this will help you draw the coping cut path.

Tube Coping Calculator

Here is the calculator for a chop saw
Chop saw coping calculator

[Gadget]

Thanks for pointing that out Steve. I have fixed the link now.

[UnfinishedProjects]

Thanks for the calcs. Will sure use them when I get back. I have always used rectangle tubing since it is easy to work with. Once I weld up a tubing bender and practice coping the tube, I think I will forget the square stuff.

[mike77]

Does anyone know what the formulas are to calculate the angles to use a chop saw, or where to find them? The site mentioned doesn't work for me more often than it does. I don't know if it's my browser, computer, or what. So I'd like to have the formulas that I can put into a spreadsheet of my own.

Thanks,
Mike

[matteh99]

If you are doing the same size tubing on both I can get you the formulas. If you want to do different size pipes I can't help you. (right now)

[Gadget]

Try this.

Making perfect pipe Saddle cuts with a bandsaw or chopsaw

[mike77]

Thanks Dan. It's a great explanation of the process, but I don't see any formulas. Did I just miss them?
Matteh99, I'll take whatever I can find. Most of what I would do should be same size pipe but who knows what the next project might bring?
I know this is in a book out there somewhere. I think I read about the method on the Pirate4x4 site and one of the members posted a pic from a book showing some of the info. Unfortunately he didn't mention what book it was and there wasn't enough info there to really work off of.

Mike

[Gadget]

I got this off of the Pirate 4x4 board, thought it might be useful to some of you.

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Re: chop saw tube notching. - Pirate4x4.Com

The chop saw method,if understood , is a science. With known tube size and joint angle, tube can be notched with great accuracy. The notch is achieved by cutting two opposing angles on one end of a piece of tube, to form a point. The cross-section of this cut will be an elliptical cut due to the shape of the tube. Changes in both of the two angled cuts must be made for the intersection angle and the size of the two tubes being joined. The only real limitation is the max angle of the chop saw.

You start with what I call the base angle. This is the angle of both cuts if the joint was 90*. For an example, I am fitting Two tubes together that are both 1.75", at an 90* joint. The base angle, or the angle of both cuts is 28*. These two cuts must meet at a point, and the point must also be centered on the tube.

What if I want an 15* joint with my 1.75" tube???? You must start with your base angle, witch was 28* for 1.75"(remember above), and subtract 15* from one cut, and add 15* to the other cut to form a perfect notch. So now I must make a 13* cut and an 43* cut , with the point centered on the tube. Perfect coped joint, with no grinding.

Remember your base angle will change with the tube being cut and the tube that you are fitting to.

Here are a few examples of base angles...

2.0" to 2.0" tube, base angle of 30*

1.75" to 1.75" tube, base angle of 28*

1.5" to 1.5" tube, base angle of 26*

1.25" to 1.25" tube, base angle of 22.5*

1" to 1" tube, Base angle of 20*

Now to fit different size tubes together

1.75" to 2" tube, base angle of 25*

1.75" to 1.25" tube, base angle of 45*

1.25" to 1.75 tube, base angle of 20*

1" to 2" tube, base angle of 12*

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