Milling Bits

[justme]

All,

Curious what options (if any) and/or recommendations for being able to sharpen milling bits.  Was handed a carbide milling bit - 12.68 mm - that has some damage (it was making it's way to the garbage).  Curious to see if there is a means to sharpen.

Attached is a picture - while this may be a candidate for the circular file, was thinking it's a opportunity to work with another material and type of bit.

Thanks!

[RichColvin]

I bet the new diamond wheels are a good bet.

[Ken S]

Many years ago, a member posted a question asking if drill bits could be sharpened with the Tormek. Jeff Farris, the moderator, replied, "not yet".
So, to your question about milling cutters, "not yet" (and maybe never, but who knows?".

Looking at the photo, I would suggest the circular file (English idiom for discard it). If money is no object for the person making the request, I suspect it could be resharpened.Even then, it would not conform to the original size.

Ken

[Ken S]

I agree with Rich, however, I think a new bit is a much more cost effective bet.

Ken

[justme]

Rich,

Yes indeed - with your post, pinged the local dealer on the wheels + the MB-100.  Problem: TS-740 only has enough space for 2 more wheels.  <grin>

Thanks!

[Ken S]

A second TS-740 should solve your problem, perhaps with a second T8. This cutter is turning into a very pricey sharpening job. 

Ken

[justme]

Wasn't sure - thought it worth asking.  If circular file is best solution - so be it.  May still try to 'play' with it a bit.  Biggest issue is likely just getting to a 'perfectly flush' end, eg: constant/consistent rotation of the bit while moving side-to-side vs. changing diameter of the stone.  The most interesting issue is likely the facets on the flutes, but with the MB-100 and the diamond wheels - may be possible.

Which raises another interesting point: How does one true the stone for use with the MB-100?  <runs and hides> 

[Ken S]

Interesting question. I have pondered ways to true the side of the grinding wheel. I posted a photo quite a while back reconfiguring a usb and the torlock jig, I don't remember exactly how it worked, only that it involvol using only one leg in the usb sleeve.

Although the new multi base is designed for the new diamond wheels with an accurate diamond side grit, I am certain that wheels are slready spinning planning how to adapt it to other uses and wheels.
I think we should at least try it in its intended role.

Ken

[RickKrung]

Wasn't sure - thought it worth asking.  If circular file is best solution - so be it.  May still try to 'play' with it a bit.  Biggest issue is likely just getting to a 'perfectly flush' end, eg: constant/consistent rotation of the bit while moving side-to-side vs. changing diameter of the stone.  The most interesting issue is likely the facets on the flutes, but with the MB-100 and the diamond wheels - may be possible.

Which raises another interesting point: How does one true the stone for use with the MB-100?  <runs and hides> 

I think the answer is a clear and emphatic "No".  That milling cutter appears to be carbide, based on how it has fractured.  That complicates things beyond what is already a non-starter.  It may be true that once it was not possible to sharpen drill bits on a Tormek, but now it is.  I do not think there will be a jig anytime soon for sharpening milling cutters.  There are precise angles (planar and rotational) and distances that must be maintained.  The machines designed and built for this task are far more complex and precision than the Tormek.  The manual set up of the flutes of a drill in the Tormek drill jig are far too crude for attempting to sharpen such a milling cutter. 

It can be sharpened, by a qualified sharpening shop, with the proper grinding machine tools.  Don't know where you are located, but finding such a shop usually requires proximity to a major metropolitan area.  When I lived in Portland, OR, I had several similar bits sharpened, and like Ken said, they don't conform to the original specs (dimensions), which by itself is not a problem, one just has to keep in mind what you are working with. 



Rick

[Ken S]

When I was a student, I worked for the electric company as a meter reader. I literally walked the entire town every month. Almost all the meters were outside. I particularly enjoyed one inside meter. It was in a furniture reninishing shop. Each month I would enjoy talking with the owner for a few minutes. He was an older man with a wealth of knowledge and experience; true wisdom. He was a consummate craftsman. One month he was grumbling about "the damn women who buy an old chair at a yard sale for fifty cents and expect me to fix it for a quarter".

While we all like to save money, I think expecting a cheap repair job stems from ignorance rather than mean spiritedness. While a basic chisel or kitchen knife can be adequately sharpened with an inexpensive oilstone by a somewhat skilled person, a more professional result requires more skill and, most probably, a larger investment in equipment. The equipment required to properly sharpen a milling cutter would requie substantial investment and training. Most people are clueless about this. Hence the need for tradesmen to educate their customers.

Ken

[justme]

Both fair points.  For me, this is both enjoyable and educational.  Learning what the Tormek can (and cannot) do is interesting.  The tangents - such as sharpening of a milling bit - is equally interesting.  For curiosity, I've been researching what and how milling bits are sharpened.  Rather interesting set of tools and knowledge.

While I won't suggest trying to convert a gazelle into a giraffe - with the advent of the diamond wheels, the philosophical delta becomes the machinist level accuracy of adjustment (at a high level).  Due to my insatiable curiosity on this topic, have spent some hours researching (for my own education) on everything involved.  Found some interesting videos from "this old tony" on this topic.  Particularly interesting.

Greatly appreciate the feedback and information on this.