30 degree hole in 1/4" 316 SS plate.

[Aukai]

I need to step up my game here for fishing pole holders. The normal angle through the flat plate is 30 degrees for 1.5, or 2" pipe. What is my easiest approach to this with a 9x50 mill, adjustable angle milling table, angle the head? What cutter, carbide annular, or center cutting end mill, straight through hole then angle witch ever over till 30 degrees? The commercially available holders do not meet tough commercial fishing demands, so I do get requests{I did 30 years commercial, and know) big line 180-250# and very tight drags, also hydraulic reels with no drag, this is not play with them fishing.

 

[55fairlane]

How about a picture of what you talking about building

 

[mattthemuppet2]

Tilt the head and annular cutter would be my guess, but an annular cutter that size isn’t going to be cheap. Don’t know if you need carbide tipped, if you go slow and use lots of cutting oil hss should be fine

 

[jwmelvin]

You might think about a fixture to hold the plate at an angle, so you can leave your head trammed and quill locked (feed with knee). It could maybe clamp the plate as it’s squeezed in the vise, or might use separate clamping screws. I don’t think the quill auto feed is up to this, and you want a steady feed rate to avoid work hardening.

 

[Eddyde]

I agree with going the jig/fixture route, especially if it's a part you'll be making often. Could be a set of soft jaws for your vise that have a 30º angled grooves milled into the face, if your vise opens wide enough. Also agree an annular cutter is the way to go for making the holes.

 

[markba633csi]

Water jet

 

[MrWhoopee]

Water jet

I think that may mean something different in Hawaii.

 

[Aukai]

No water jets on this island, I want the 30 degree angle to go through the plate at the same angle as the pipe. The holder below would fail at the pin first, and get a 1/4" SS bolt, then the next failure is the pipe snapping off at the base. Thank you for the responses so far, I do have the annular cutters already.

 

[mksj]

If you plan on making multiple pieces then I would probably make a metal holding fixture for the plate to mount in, cut a recess with a boring head to hold the plate and use the mounting screws into the block to prevent it from turning. Use an annular cutter first to cut down into the fixture, so there is a circular cut down as shown. Mount the plate, using the annular cutter at around 200 RPM, begin the cut until it starts to punch through on the top and then continue with even pressure to get continuous swarf/chips but not to much force to deflect annular cutter due to the asymmetry. The cutting force pushing on one side in and pulling out on the other side should be somewhat even if it is held rigidly in the fixture but the teeth may catch on the outward cutting side. Annular cutters do better when cutting with even pressure on all the cutter tips. If you get a lot of vibration/movement of the cutter, you may need to mount the plate between an upper and lower fixture that bolts together to form a guide for the cutter and prevent wanting to pull out the plate on the outward cutting side. Probably would not us a carbide tip cutter, they have fewer cutting tips and may be more likely to fracture because of the intermittent cutting as opposed to even continuous cutting of a parallel surface to the teeth.

 

[den-den]

Perhaps I am way off track but would you consider cutting the oval with a plasma cutter. I am assuming the plate will be welded to the pipe and don't see why machinist precision is needed here. 316 SS is a pain to machine and is rough on cutters, if machining is not necessary, don't.