New Rigid Tapping Question

[RJS100]

I ran tests in wax and finally tapped quite a few holes in 1061 aluminum without any issues. Today I did a test run tapping M5 threads into 1018 cold rolled steel.

The holes are .6 deep + the drill tip and the tap runs .010 short of the bottom or .590" deep.
I tapped these first to a depth of .300 and then to the full depth.
I ran the tap at an actual speed of 640 rpm.

The process looked fine when it tapped to .300" deep, but when it tapped to .600" deep on the second attempt, I think there was resistance some pulling the tap from the hole. Please see attached images and here is the Fusion 360 test file: https://www.dropbox.com/scl/fi/c51q68nc ... o8git&dl=0


Please let me know what adjustments may be needed.

Best... Richard

[tblough]

I suggest you do your testing using Intercon before adding Fusion into the mix. Post a new report so we can see your tapping setup. Initial guesses are it's either chips packing in the flutes, or the index pulse is not registering correctly and you are splitting the lead when re-entering the hole.

[RJS100]

Thanks for your quick response, Tom. Here is the latest report. I tapped 30 deep holes in aluminum yesterday and tapped them at 50% depth followed by the full depth without issue, so I think the index pulse is working.

Here is the tap I am using: https://www.suncoasttools.com/crm/ItemP ... er=YG1TOOL


I did my original testing with Intercon, then started using Fusion, but I could go back to Intercon.

Thanks... Richard

[tblough]

If you are peck tapping without problems in aluminium, then my guess is chip packing in steel. Add more pecks, change to a different tap (geometry, coating, manufacturer), use a different tapping fluid.

[RJS100]

Perfect! I tapped this with the equivalent of a pecking cycle of .250" and everything worked awesome. The threads are just a thing of beauty! For some reason the post does not support the tapping/pecking cycle, so I just created three tapping cycles with increasingly deeper depths. ALL GOOD!

I am getting ready to start my first project with 1018 steel. I tested speeds and feeds for a 1/4" end mill as well as 2-inch 4 flute face mill. These worked out very well even with somewhat aggressive feed/speeds.

For some reason, my 1/4" HSS spotting drill and my 3/8" 4 flute carbide chamfer mill had more vibration than I would have expected. I am using the GWizard Speeds and Feeds calculator to get a starting point, but something is not right. The suggested speed for a 1/4-inch spot drill is 1200 rpm and 1.9 ipm @ .040 deep. For the chamfer mill they suggested 2300 rpm and 3.4 ipm with a .020 chamfer. I need to play with these a bit. My instinct says they rpm is too slow. It is strange that the chamfer mill with a larger diameter, has a faster suggested speed than the 1/4-inch spot drill.

Thanks for your help on this one... Really excited to tap some threads.

Richard

[suntravel]

I would use thread forming with a tool like this:

https://www.suncoasttools.com/crm/ItemP ... er=YG1TOOL

For forming M5 drill with 4.6mm.

Mild steel is perfect for forming, and no chip problem while forming.

Uwe

[cnckeith]

I would use thread forming with a tool like this:

https://www.suncoasttools.com/crm/ItemP ... er=YG1TOOL

For forming M5 drill with 4.6mm.

Mild steel is perfect for forming, and no chip problem while forming.

Uwe

forming creates stronger threads as well!

five axis thread making anyone?

[RJS100]

Thanks. I just bought a handful of those combo taps, so I think I will use the pecking strategy for now. Thanks for the tip on the forming taps. I will certainly keep them in mind for the future. I plan on mostly working with aluminum and some mild steel here and there.

For now, I am going to play with the spotting and chamfer mil a bit more to minimize the vibration I was seeing.

Thanks... Richard

[suntravel]

Cool, interpolating X and Z according to the tilt of the head.
Is this rigid tapping?

I am doing something similar with angular live tooling on the mill turn machines, but there only with a compression holder.

But if your team is making the second spindle Independent, my live tooling is with servo and 1:1 encoder....

... hardware is second spindle rigid tapping ready, just waiting for the small software update.

I am ready to test this weekend

If this is done, I will rebuild the mounting to rotate it around the Y axis, have two unused axes anyway

Uwe

[suntravel]

Thanks. I just bought a handful of those combo taps, so I think I will use the pecking strategy for now. Thanks for the tip on the forming taps. I will certainly keep them in mind for the future. I plan on mostly working with aluminum and some mild steel here and there.

For now, I am going to play with the spotting and chamfer mil a bit more to minimize the vibration I was seeing.

Thanks... Richard

In serial production we have a live time in mild steel of+30000 threads with forming.

So, for hobby you will not get it worn out, maybe kill it with a crash.

For alu avoid TIN coatings.

Uwe