Ali Chamferring cutters

[PeterT]

My AliExpress 90-deg chamfering cutters arrived & I must say I'm quite impressed with them. I struggle with the multi-flute cutters, even good quality ones. They seem to be very rpm & feed sensitive. Things go dandy for a while & then in a blink they can develop this harmonic & you get ugly bumpy path syndrome like looks like a ring of fine teeth which is then hard to remedy. On thin metal it can be even worse.

These (I guess you could call them 1-flute) cutters just seem to work with a lot more control. I had to do some very fiddly chamfering for M3 screw heads & I could control the chip right down to the thou. I'm not exactly sure how to sharpen them if you grind the whole body down, or if you can somehow dress the angled through hole which makes the cutting lip itself. They have some mystery coating that's kind of a bronze color, not like the gold TIN (or in some cases gold spray paint I swear LOL).

https://www.aliexpress.com/item/4pc...329.html?spm=a2g0s.9042311.0.0.3da24c4d5zrcg6

 

[PeterT]

And these are the classic muli-tflute. Again AliExpress. They are very well made, better than some others I've bought in the past. But I just dont seem to get along with them as well. If you guys have any tips, let me know. Otherwise they will be reserved for wood butchery.

 

[DPittman]

Peter,

I have had similar experience to yours and really quite like my 90 degree chamfers. I have some cheap multi flute (60 degree I think) cutters and they are horrible on all metal.
I have used a sharpening steel rod to dress the cutting edge on my 90 degree cutters. I just run/file in thru the hole perpendicular to the cutting edge.

Don

 

[PeterT]

Example M3 chamfer bores, 7075 Al

 

[PeterT]

Well, this topic came up on another forum so thought I'd post. Another fellow mentioned there is nothing wrong with multi-fluted cutters if they are of decent quality & used properly. By that he meant rigidly held, relatively slow rpm & controlled down feed. It occurred to me up until now, I mostly used them in my drill press (or drill press action in my mill) & moderate speed. So I gave it a shot in the mill at low rpm & fine down feed, work secured in vise with table locked. Sure enough, much better results. No harmonics so wavy peripheral cut. So I have become friends with them again & even made an MDF toolblock for unwittingly throwing them under the bus.

 

[DPittman]

Well that's good to know. I did find that my horrible quality princess auto ones did perform better at slow speeds, but I still thought the job was awful. Maybe I need to try slower yet. And I was also mostly using them in a hand drill to make matters worse.
Don