your ideas on a pipe profiling machine

[D-man]

Thats perfect steve!!!

thats exactly the sort of thing i need but without all the bells and whistles! lol but where to start..

Where can i find a cheap chuck? rotary head?

[m_c]

I'd almost suggest some kind of custom rotary head.

A rotary table seems like overkill for machining plastic, but is probably the easier option.

I'd think a more basic axle with clamping head, driven by either a gear reduction stepper or double belt reduction would provide enough torque/accuracy, and be far quicker at spinning the pipe.

The clamping head/chuck could be a challenge, as you can't really put too much pressure onto PVC pipe. Perhaps some sort of metal plug for each pipe size bolted to the rotary head to support the inside of the pipe and prevent it collapsing in, then jaws which clamp down onto the outside. The big issue is covering the range of pipe sizes, while not making it too hard to swap between sizes.
Perhaps have the centre plug held on with a centre bolt, then jaws, or even a big pipe clamp to clamp the pipe onto the centre plug.

[D-man]

I see what your saying M_C

the only way time the cut will be verticle is when the router is at the top of the pipe. but when the pipe rotates when the side of the hole is put back into position it will be on an angle.. correct see diagram.

where as if i have an extra axis the router bit will stay vertical all the way around the hole

Does this make sense?