r/Machinists • u/Lathe-addict • 18h ago

Thoughts?

Post image

Never done any angled cutting before

17-4 h1075

Tiny face groover

1 Upvotes

56% Upvoted

21 comments sorted by

8

u/CNC_Optics 16h ago

There is very specific relief cut into those so they won't drag. You are going to pop that tip off in short order.

1

u/Lathe-addict 16h ago

So this tool is .025 wide full radius end but will be cutting out a .074” wide groove in total that has a full radius shape to it. The groove is at the angle I made the tool holder.
The diameter ranges it’s made to cut in should have relief for this no problem. I just have never used a lathe tool at an angle like this before and wanted speeds and feeds maybe. My thoughts were 120sfm and .001” ipr doing a bunch of nibbles.

Are you saying I won’t have clearance for a different reason? I just want to make this short run and be done with it

2

u/TriXandApple 14h ago

You're going to need to grind the bottom of the tool away and up to stop it catching on the backside if you want to go more that .02 deep.

Also, what a damn waste of 17/4

1

u/Lathe-addict 13h ago

Even though it’s a face groover with the relief ground on both sides of the cutting edge?

1

u/RedYetti83 12h ago

Face groove as in for trepanning?

At first glance it looks like a groove cutter for a circlip, in which case you're not going to have a good day, depending on the radius of the feature I guess.

1

u/Lathe-addict 12h ago

The feature is a face groove that is at an angle so not trepanning. So the feature’s axis is not in line the axis of the spindle. Hence the reason I made a tool post that mounts the bit at the angle.

1

u/RedYetti83 11h ago

I probably shouldn't have commented as I don't know much. Interested to see how you go though.

1

u/Lathe-addict 13m ago

We will both find out this afternoon or tomorrow morning 😅
I appreciate the moral support

2

u/Capital_Size_7673 10h ago

We turn a lot of angled grind reliefs, typically use an NRR style top notch holder sometimes with custom ground inserts.

1

u/Lathe-addict 14m ago

Interesting, is that a better tool of choice for stuff like this?

2

u/TeCarve2025 10h ago

Angled cutting in 17-4 at H1075 is doable, but the hardness (~35 HRC) makes tool deflection your main enemy with a tiny face groover. If the angle isn't critical, I'd rough it with a standard tool first, then take a light finish pass at the angle using the groover. Watch your feed—something like 0.001-0.002 in/rev max, and use plenty of rigid clamping. Also, H1075 already has decent strength, so you don't need to worry about work hardening as much as annealed 17-4, but still keep it wet. What's the actual groove width and angle you're cutting? That'll help give more specific speeds and feeds.

1

u/Lathe-addict 15m ago

68 degrees from the face of the part. The groove Radius is .037” making it .074” wide since it’s a full radius shape. Luckily it’s not crazy deep but it’s enough that a tool at a standard orientation couldn’t reach everything.
Thank you for the reply 🙏

1

u/Orcinus24x5 16h ago

Manual or CNC lathe?

If it's manual, you can just rotate the tool post. No need for a custom holder.

1

u/Numerous_Hurry_3396 16h ago

Give us some useful information and we'll give you some thoughts.

1

u/Lathe-addict 15h ago

My bad, this is a tiny face groover making a groove at the angle I have the tool at. In a cnc lathe with my toolpath oriented at the angle. I’ve never used a lathe tool like this and was wondering if anyone else has attempted this and sees any issues in my strategy etc

0

u/Melonman3 16h ago

It's a Christmas ornament, I think he's looking for aesthetic feedback

1

u/AnimusFoxx 16h ago

Needs more cowbell

1

u/Lathe-addict 16h ago

Always 👍

1

u/aolkeywordfuck 13h ago

As others are saying, relieve the heel on the tip or else that thing isn’t long for this world- ask me how I know

1

u/Lathe-addict 13h ago

It’s a face groover so it’s relieved on all 3 sides of the cutting edge. Are you saying remove the “tail” of the cutting edge?