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I need to make a single piece (therefore automation not necessary). The PVC pipe in question is approximately 490mm long and has a 20mm diameter. I would like to cut four 60° arcs, the location of the cuts along the circumference of the cross section must be within a ±20° tolerance and the cuts must be within a 70° ± 10° tolerance. Cuts cannot extend beyond the corners, if the cut goes to far then the entire hole must become larger too. The width of the cuts (measurement on the long axis of the pipe) can be of any length longer than 3mm. How would I cut out the arcs and what tools would I need? I have provided diagrams below. Thanks in advance.

(I stretched the diameter of the pipe in the diagrams 10x both to make them easier on the eyes and to provide space for annotating)

Valid XHTML Valid XHTML Note: I am unexperienced in this sort of thing but I am sure that there is a better solution than using a handheld grinder and hoping for the best so I am asking.

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  • $\begingroup$ How many times do you need to do this? To what precision? Manually or automatically? What are the requirements for the corners? e.g., Can saw-cuts extend beyond the corners. Please edit the details into your question. $\endgroup$
    – Transistor
    Jul 8 at 7:59
  • $\begingroup$ Both answers still work after your edits. $\endgroup$
    – Solar Mike
    Jul 8 at 10:25
  • $\begingroup$ What tolerance analysis have you done? For example, must these slots be aligned to each other to within X degrees, or each aligned to a different external reference? $\endgroup$ Jul 8 at 14:28
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    $\begingroup$ Tip: "must be as accurate as possible" is not an engineering specification. Specify tolerance using numbers and units. $\endgroup$
    – Transistor
    Jul 8 at 14:55
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Put a hex-head plug in each end so you have a flat.

enter image description here

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  • $\begingroup$ Originally, the cutout required a parallel rip. The idea was to use the flats for a table saw or router table. But the sketch has changed. $\endgroup$
    – Phil Sweet
    Jul 8 at 20:58
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Use a pillar drill and a rotating vice which has graduations on it.

Drill a hole at 0 degrees then rotate for hole at 60 degrees. Repeat for other holes then join with saw cuts, dremel etc.

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  • $\begingroup$ Thank you for the response. It gave me valuable knowledge which I will certainly use in future projects. (I also appreciate the update that both your answer and Phil Sweet's answer still work after the updates) $\endgroup$
    – Danner
    Jul 8 at 11:11

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