One thing is that the Niagara 3/8", 4-flute end mill you linked is a high-quality, well-known part. I am not surprised it cut well for you. I am not familiar at all with the carbide mill brand you linked, but the 1/8", 4-flute is not at all the same thing. The optimal speeds and feeds would be very different from those of the Niagara, not to mention I have no idea about the quality of the end mill, which could be a factor too.
-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
Spindle Speed/Feed Rate Tutorial
- Thread starter briansalomon
- Start date
One thing is that the Niagara 3/8", 4-flute end mill you linked is a high-quality, well-known part. I am not surprised it cut well for you. I am not familiar at all with the carbide mill brand you linked, but the 1/8", 4-flute is not at all the same thing. The optimal speeds and feeds would be very different from those of the Niagara, not to mention I have no idea about the quality of the end mill, which could be a factor too.
Yeah, that high helix angle on the 1/8” one is not a good choice for copper or aluminum. Travers has a good chart of what helix angle is suitable for which materials.
Choose the Right Helix Angle for Machining | Travers Tool Co.
Learn the pros and cons of low helix, high helix and variable helix angles and how they impact your machining and workpiece finish.
solutions.travers.com
I also would not be using 4 flute end mills on non-ferrous materials unless you are taking light radial cuts on the order of 10% diameter or less. The flutes don’t have enough space for the chips if you take too much of a cut, but if you are doing light passes, the increased rigidity of the 4 flute end mill can help reduce deflection on large axial depths of cut.
I bought this one to replace it. https://www.ebay.com/itm/137331690594Yeah, that high helix angle on the 1/8” one is not a good choice for copper or aluminum. Travers has a good chart of what helix angle is suitable for which materials.
Choose the Right Helix Angle for Machining | Travers Tool Co.
Learn the pros and cons of low helix, high helix and variable helix angles and how they impact your machining and workpiece finish.
I also would not be using 4 flute end mills on non-ferrous materials unless you are taking light radial cuts on the order of 10% diameter or less. The flutes don’t have enough space for the chips if you take too much of a cut, but if you are doing light passes, the increased rigidity of the 4 flute end mill can help reduce deflection on large axial depths of cut.
I appreciate all the advice. I think it's saving me a few bucks.
That looks like it should work better.
Here's what I'm using. This is with a 1/8" 2 flute HSS end mill https://drive.google.com/file/d/1ImOMXrhivqyDZBUrOnL9zzpWnkS7RVVy/view?usp=sharing
Thanks; it’s a Foredom clone.
Here's a video of what I'm seeing. I'm running at ~1000 on the 1st pass and am taking ~1/8" and if I had tried to feed at the same rate I'm using at the higher RPM it will stall. When I increase speed to 2400 there's no increase in resistance and the mill seems happier. If I slow the feed down I can take a lot deeper cut. Zooming in will give you a better view.
This with a 'wrong' 4 flute Niagra cutter. My gut feeling is that this cutter is sharper and just better ground than my other cutters.
drive.google.com
This with a 'wrong' 4 flute Niagra cutter. My gut feeling is that this cutter is sharper and just better ground than my other cutters.
PXL_20260605_181039414.TS.mp4
drive.google.com
Attachments
I use one of these.. (and I mostly run cnc's
https://www.ebay.com/itm/1779504419...bV6baD3NaBmiPfJXJ+sNt2ttrU|tkp:Bk9SR-yzppXTZw
https://www.ebay.com/itm/1779504419...bV6baD3NaBmiPfJXJ+sNt2ttrU|tkp:Bk9SR-yzppXTZw
I like that. I can keep it by the mill and I'll know for sure if I'm trying to do something I shouldn't. No phone or calculator required... and the price is right.