Insert V-Bits - Sharp tips

[Mark Bolton]

Been having some issues with insert V bit tips specifically some 60 degree amana inserts we run a bit. We have occasion to run some very small text which requires a true V bit not something like an engraver with a .005 tip. We have all the Amana insert V bits but run a 60 degree insert and a 60 degree solid most often. The insert tips break off like nothing no matter how shallow or how slow you go. This is all in wood, Walnut, Hard Maple, whatever. In very short order (like perhaps 50 small characters (perhaps 1/2" tall) you've got a .005 flat bottom bit because the tip is gone. You can barely see that its gone with magnification but it is in fact gone.

Paying 25 bucks a whack for an insert that loses its tip that fast is not fun.

Any of you using something different?

Im pretty much convinced to stick with solid or brazed tooling and keep sending them out because at least the tip stays pretty much there to a V point until its so dull its just rubbing a fuzzy bottom in the text but when the insert tip is gone youve still got an insert that 98% of the insert has never seen its first wood fiber and its roached.

I have run insanely slow feeds and played around with the speeds but no luck.

[Jim Becker]

While I'm not doing any kind of production, I've not had any issue with these insert cutters and have used the 60º quite a bit in my various faddling...have you by any chance communicated with Amana about the issue you're having?

[Mark Bolton]

What are you running for feeds and rpms on your 60 degree inserts? And what depth of cut?

[Mick Simon]

It may be a runout issue causing the tips to fracture off. I've used the same bit for years without issue. Maybe the body is out of balance.

[Adam Bullington]

Mark,

I've been running the 90 degree and the 60 degree insert cutter very regular since February with multiple production runs of plaques and signs with anywhere from 12 letters to well over 70-200 letters in each plaque. I've only had to change the 90 degree insert one time and that was due to hitting a embedded piece of metal in one of my plaque blanks. From my experience your frustrations should not be happening..especially that fast.. I cut at 250 IPM @ 12000 rpm on my big 90 degree cutter and 18000 rpm on the 60 degree cutter and have a flat depth of .375 on all my plaques done with a v carve toolpath and the width of the font lines determine the depth of cut for each character or each part of each character. As an example: my last white oak production run had approximately 8,475 characters spread over 75 plaques and i used the same cutters on the entire run and will continue to run them for may more jobs.

[Mark Bolton]

Thanks Adam. We never have an issue with the 90 degree or the 45 because there is more meat at the tip. The issue that we are having may not even be obvious unless youre trying to carve extremely small/shallow lettering with either a V Carve or a profile (on) toolpath.

These are so small that they require a true Point on the insert. Of course the extreme tip does basically zero cutting and just rubbing but there still cant be a flat there of any size. When I am talking about the tip breaking off Im talking about an amount that can barely be seen by eye (even though mine are aging) but is clear with a magnifying headset at 4x. When that extremely sharp tip goes away you basically have an amana in-groove engraving tool. An insert V bit with a small flat on the tip (unfortunately it doesnt cut like a ground flat like our in-groove engravers do).

Today I honed the tip of the insert to get a job done but its not something I want to be doing with any regularity.

My gut feeling for these super small/fine jobs is we are going to have to stick with a solid tool like this:

https://www.toolstoday.com/media/cat.../1/5162_3_.jpg

The tip on those gets dull but there is so much meat there its always going to be a true V.

I have tried running the 60 degree insert super slow on these tiny characters and its still an issue.

[Mark Bolton]

I just order some of their 45264 bits. Cheaper than the inserts. We will see.

[Brian Lamb]

Have you tried a standard single lip engraving cutter? Like these:

https://bitsbits.com/index.php?main_...vbb5t7adca0j67

[Peter Christensen]

Can you run the letters with a cutter with a small radius to rough out the letters, then go back over with the insert cutters? They would be taking such a light cut that they may not chip.

[Mike Heidrick]

Try the cmt 3 flute laser v bit.