Tube coping

[dredd]

I am practicing welding tubes and would like options for ways to cope the tubes. i have a knee mill and have been using bimetal hole saws. Is there a cleaner way to do it. I can file/ dremel the tubes but since it is practice, I would rather skip the manuel prep practice.
Chuck

 

[Rbeckett]

There are inexpensive coping jigs available from HF and several other vendors. They use the metal hole saws and are fully adjustable and start around 60 bucks. Pro-tools, and JD Squared offer higher end coping jigs that are suited for production type shops. The price is a bit higher though. Google "Joint Jigger" and you will see the lesser expensive tools. I have worn three or four from HF completely out over the years, but they are inexpensive and do an excellent job for fabbing tube chassis and tube structures.

Bob

 

[DaveD]

Poke around on the Internet. You can actually get decent copes just by cutting the tube at an angle with your favorite chop saw, etc.

 

[8ntsane]

Poke around on the Internet. You can actually get decent copes just by cutting the tube at an angle with your favorite chop saw, etc.

Fully agree with the chop saw. Combine that with a hand grinder and your all set. If your working with thin wall 4130 the hand grinder will do the whole job. In th 25 yrs building race car chassis, the chop saw, and hand grinder was used 90 percent of the time.

 

[Starlight Tools]

I had the JD2 Notchmaster, http://www.jd2.com/ It worked great, although there were times when I could not get the angles I wanted, often my projects consist of pencil point angles, IE the sailboat stands etc. There is a reacharound kit for the Notchmaster and better mandrels here http://www.swagoffroad.com/Metal-Fabrication-Tools-_c_7.html

I have also set up a boring bar holder for the QCTP on the lathe to use the mandrels and have done some coping work using that set up, it allowed me to get the tighter angles, like 30 degrees on the bike rool bar I made for a friends recumbant bike.

Much of my coping has been on Sch 40 pipe and took awhile with the cut off saw and angle grinder to get a good fit, when it was possible to do quicker with the notchmaster.

Walter

 

[Scorpion]

If you're gonna do a mess of one size, use a roughing end mill with your mill. I used to notch hundreds of 2 1/4 x 3/8 wall DOM on a 15 or so degree angle in a day just about every week for three years and the best method I found was a roughing shell mill (essentially a super large roughing end mill). You can't plunge cut but you come in from the side. I could do 50 percent of the notch per pass. I got the idea when I started eyeballing a heavy duty notching machine called the Godzilla which worked that way by design.

A high speed steel end mill won't be cheap but the notches will be perfect and the mill will last for a long time if you get your feed right. Probably much cheaper than a hole saw over time. The mill with a rough cutter is more versatile too and you can do some crazy notches. I notch everything with the mill now and I end up with tighter joints and more accurate tube work as a result. Maybe not cost effective if your doing tube work for hire though. Notches I do now are strictly for me so the trade off is well worth it.

 

[Bradman]

Some time ago I had to cope a bunch of tubing. I think it was 1 1/4 inch OD. I just used a 1 1/4 inch end mill in my Bridgeport. I was going to try and use a fly cutter but the end mill worked great.

 

[Charley Davidson]

This is what we use at work, we build lots of hand rail. I'm gonna try and build the multi coper someday

 

[Smudgemo]

How heavy is the tube's sidewall? All of these methods are fine, but if you are doing thin-wall for bicycles, then a plain old hole saw works very well if you doctor it up by grinding off the hooked teeth to flats. You can see what I mean here: http://www.flickr.com/photos/61735055@N03/7088545373/

Paragon Machine Works makes very nice aluminum blocks, and I simply hold them in a tilting or rotating vise as needed to make my angle. You can get nearly any size you need, and it never takes more than a few swipes with a file to clean things up. Plus it's a lot cheaper than a large end mill.

-Ryan