around here it is comon to build tube nothers from hole saws like this http://www.wurth.se/Produkter/Produktkatalog/Borr--Gang/Borr/Halsagar-m-tillbehor/Halsagar/Halsag-HSS-Bimetall/?p=2 the page is in swedish but picture is in english
for smal projekts you simply put the hole saw in a drillpress and cut the pipe in what angle you want. for more serial produktion they build a divice just for notching but the pincip is the same as in drillpress. now you alredy built one but if you ar intrested i will get som pictures on foks noth builds.
Hole saws are fine for mild steel tubing and small production use. shell mill cutters are better but more expensive. Drill presses even ones like this is better used for drilling.




In the past I have used about every cutting device under the sun to cope pipe or tubes Torch, chop saws band saws, drill presses, mills, grinders, sanders, iron workers with special die sets, hydraulic presses, Plasma pipe profile machines, EDM wire machines you name it about the only thing I haven't done yet is buy a Laser torch for my pipe profile machine. all of the methods work and will work just fine.
But With the belt sander I built, I can change out the lead roller for a different diameter tube in a matter of a minute and be profiling a different size before a whole saw can be changed out on a drill press.
Also it has the ability to do about any angle you can imagine and multiple profile cuts like for making a 3 or 4 way joint the lead roller can be raised or lowered for off center profiles. to change the belt just raise the arm this allows the belt to become loose just slip it off slip a new one on lower the arm and go to work. It takes mere seconds.
we have 1000s of cuts to make and they all have to fit as tight as possible for a minimal of tig welding then the weldements have to be polished to a mirror finish. Pre cutting the profiles on the pipe profile machine saves time and sanding belts. This set up can keep about 5 welders supplied with rubes. But the company is thinking about buying as many as 10 more tig machines 5 for field installations and 5 more for the shop Or out sourcing a lot of the straight runs to China, we have over 5000 meters of 4 rail railing to make right now we are concentrating on the stair rails . Or I may be building more machines LOL