Easy way to cope tubing

Here is a short article I wrote on the different ways to notch or "cope" tubing including the chopsaw method you described:


There may come a time when you need to notch a piece of tubing or pipe. Most will use this knowlege towards the installation of a roll bar or cage in their car. Here are three methods that I use to do some notching:

The first is the chop saw method, and it requires no notcher at all. It does require a little practice, and it is the method that is most like art. What you do is set the chop saw vise at a 45 degree angle, and cut the corner of the tube off, flip it 180 degrees, and cut the other corner off. You end up with two notches that require a little massaging with a file or disc sander to be a perfect notch.

With the chop saw vise set at 45 degrees, the piece of tube is set in the vise and clamped in place:


The corner of the tube is cut off and you now have one half of a notch:



The tube is now flipped 180 degrees. If you are making a straight 90 degree notch, you will position the tube exactly like the first cut, if it is an angle cut, you will set the tube in a little further in the vise so you are cutting off more of the tube. This is where the art part of it comes in as it takes a while before you know how much to cut off for angle cuts:


Here is the tube before deburring:


And here is the tube after deburring with a disc sander:


Just in case you think you cannot make accurate notches with this method, here is the notch and a piece of tube that it will weld to showing no gap at all. This is the method I use the most including chrome moly TIG welded cages:



The next method is by using a common hole saw tube notcher that several vendors sell. This one is made by Dale Wilch, and has been used thousands of times. I do not use a drill press as I have found that most of them do not have a slow enough low speed, and you end up tying up the drill press. I mount the notcher on the corner of a sturdy table and I power it with a variable speed 1/2" drill:

Here is the notcher and the drill used to power it:


The tube is held in place with a horse shoe shaped piece of strap, and will accomodate tobe sizes from 3/4"-2". It will also notch square tubing:


For straight 90 degree cuts, the tube is set to zero with the adjustable tube holder:


Any angle from 0-50 degrees can be cut by adjusting the tube holder:


The drill is turned on and the holesaw and the arbor that holds it are fed into the tube slowly until the notch is made. You want to notch the tube with the same size hole saw that the tube will weld to, in this case a 2" hole saw was used. A little cutting fluid will prolong hole saw life:


You end up with a nice notch that will need a little tune up:


This notcher works extremely well and the variable speed drill lets you control the feed and speed. The only modification I made to mine was to replace the bronze bushings where the arbor rides with needle bearings as the bronze bushings will only last a few dozen notches:


The last method is a version of the hole saw notcher except that I chucked up the arbor and hole saw in chuck of my lathe, and the tube holder is mounted to the carriage of the lathe. This allows me to use the power of the lathe motor, and more angles than the 0-50 degree range of
the notcher.

The feed on the lathe is used to feed the tube into the spinning hole saw:


Angled notches are done by moving the tool post holder, this one is set at 22 degrees:

 

Great information, thanks everybody. I can use it to build a roll-cage, myself!

 

cool, thanks guys, really good info to know.

 

Great info. I had an experienced cage builder show me the chop saw method when we were putting the cage in my corvette. Boy was I glad he showed us that trick!

 

Bump for a great thread!

 

I had found a copy of an application called TubingMiter.exe off a motorcycle fabrication site. It takes all of its measurements in millimeters. You specify mitered tube diameter, it's wall thickness, the other tube diameter, and the angle. Then you print the page and use it to lay out your cut.

I thought that it was cool, that is until I found this thread. You guys kick ass!


I attached a pdf of an example output.

 

thanks for the little trick,I hope to use it really soon

 

Neat trick! Missed this thread awhile back, gonna have to try it out!

 

he is usually on the HAMB "naysayers" group (grin), if people in doubt about "hints" they should try it and prove it wrong. Just like in repair field, there are mechanics and parts changers, also the group that should not have tools!!!!!!!!!!!!!!!!!!

Enjoy!!

 

Damn Kids!!!!, I waste tubing but you can also use a hole saw on a piece of tubing about 2" or so longer and use the pilot to guide saw and if real good can figure out measurements and get 2 good cuts with one hole drilled.

 

When doing angled miter joints, one thing that REALLY helps is to cut the desired angle on the end of the tube FIRST. That way both notches are the same depth. If you are using a hole saw, this isn't AS important, but when laying notches out by hand, it is much easier to visualize the cut needed.

I teach (and do) it in 3 steps:

First, determine the axis of the joint (fancy way of saying which direction the notch needs to run on the tube) and cut the desired angle. A simple way to figure the angle is to lay the tube in place with a square cut end and measure how much "gap" is on the long side of the joint. (See drawing). Just make sure to leave enough extra tube on your initial (square) cut for angle and notch.

Second, mark depth of notch. This varies depending on what size tube you are notching ON TO. For equal size tubes, I use 1/2 diameter - 1/8". This will leave a little material at the tips of the notch so it won't vaporize when you weld around it. If you REALLY want to know how to calculate the notch depth for any combination of tube sizes, Google "arc sagitta" and learn the geometry. Once you've figured out how deep the notch needs to be, mark that depth on the tube along the center line of the notch axis.

Third, draw the notch profile right on the tube. Keep in mind that we need a ROUND shape, so if what you drew looks like this: \_/ .... wipe it off and try again. What you should have is a "smiley face" (see second drawing). Once you have the shape correct as you are looking at it, turn the tube 90 degrees and you will see the straight line you need to cut to get the notch shape. This method works no matter what the miter angle is.

I do all my notching with a suicide wheel in a Bosch angle grinder. It is the fastest, most versitile tool for the job...and I've tried them all over the years.

 

Good tech. thanks

 

Great stuff Thanks for sharing

 

Thank you gentelmen your timing is perfict I am doing this today and had no idea how.
I was going to buy some hole saws and wing it.
Again thank's for sharing. Viva La HAMB.

 

Made my first cope tonight for my lakester. Using my bandsaw took me a couple tries and 10 minutes to find the swet spot. I now think I can knock these out in less than 5 minutes a pop. only 4 dozen more to go!

 

Thanks for bringing this up again. I need to try it out with the bandsaw I bought a couple of weeks ago.

 

HO Ho,,,sweet tip,great gift,before one thinks it crap and voice ,you think they would try first,,,,,love it

 

Hole saws burn out much to fast and punchs are not really the way to go.I did this drawing a few years back to make it simple.
This my KISS sheet for you all.

 

Ive done that for years with a chop saw. I have a coping saw that collects dust.

 

You ain't kiddin! And thanks, I am looking foward to my next tubing project.