View Full Version : Coping small diameter to side of large diameter cylinder
11-22-2010, 11:17 PM
Ok,building a smoker out of an old compressor tank. Plan is to put the "chimney" of 2" pipe vertically on the top side of the back of the horizontal tank. If that makes sence. If I put it on the top, it would be an easy cope but I want to put it about a quarter the way down the back.
Any layout ideas? I had thought I would hold it in place and run my dividers around to give me a line. I was thinking there has to be a better way.
11-22-2010, 11:25 PM
Might have a thing or two for you to consider to help you with your fitting question. Best regards, Allan
11-22-2010, 11:51 PM
I went to an muffler shop. You can get a few cutoffs about the right diameter for practice fitting. This is one of those where with a flap disc you can make gentle adjustments to a coped tube to test for the angle and look that you want. Tack the tube, take a look, if it isn't what you want cut the tacks and adjust some more. Once you have the look and placement you want, trace the holes and make the cuts.
Here's something I did similar on a smallscale awhile back. This was the second one of these lil guys. The 1st one finally rusted and burned out.
I do like you suggested at first with the dividers after I rough cut the tube at an angle to remove the majority of the waste. With a bit of practice you can do it quickly and easily. It helps if you temporarily tack the high side in place so it doesn't move while you scribe your line.
If you have more than one to do in the same rough location like Sandy's, make a paper template from the 1st tube and then mark and cut the next to match.
11-24-2010, 11:47 PM
Fantastic tips. Those photos are egg-zactly what I'm looking to do. Thank you
12-02-2010, 10:39 PM
I'm actually a software guy (and a wanna be welder...) do you have access to a CAD program and a printer? I wrote a tubenotcher program that can prove pretty handy.
check out the "Create DXF" option on http://www.cobratorch.net/ttn_dxf/
Type in the diameters of the two 'tubes', all the work is done for you... A DXF file is easily imported to a CAD program, where you can plot it out full size on a plotter. Obviously if you are working in smaller stuff, you can just use a regular printer.
12-05-2010, 11:25 PM
zipzit, nice program. I learned all this in fab school but this will come in handy! I also like the ability to send it to autocad.
aevald has the formula I always use. Although I don't use so many points on the half moon as I am usually working with large pipe/tube.
vBulletin® v3.8.7, Copyright ©2000-2013, vBulletin Solutions, Inc.