Coated end mills for hobby shop manual mills

darkzero said:
You should watch all of Stefan's videos. He's actually a pretty knowledgeable guy. Don't let his age fool you (I'm not sure how old he is but he doesn't look old). It was hard for me to overcome his heavy accent at first but I think his English actually pretty good, English is not easy to learn as a second language. I always look forward to his videos.
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In one of Stefan's earlier videos he said he learned English from watching YouTube videos. I think his English is damn good, much better than my German... He even has colloquial English down better than many who were born into it. He is one intelligent, hard working, and clever guy.
 
Good strategy to use roughing end mills first and to use HSS un coated EM. I was given this advice long ago by a very talented machinist.
My first experience with a carbide end mill was a very expensive, 6 flute Guhring 1/2" EM, Firex coated, super cool looking. I chipped a few cutting
edges running it too slow. Good thing it was a free sample from Guhring. I felt bad anyway.

Now, I buy mostly NOS Niagra cutters. HSS and Cobalt.
The bright finish let's me use them on any type of metal and are less expensive. Niagra is now moving away from un coated HSS end mills., so I buy what I can
at reduced prices as they come up., new, never used. I can barely sharpen a large HSS drill!

I use BP mills, so I can spin the smaller carbide cutters fast and
not ruin anymore Carbide EM's. The talent, wisdom and experience here is awesome. As I work more, my respect for talented machinists grows. Especially
the old school methods. Cnc work is something else., I imagine.

Interesting video. Would like to see a similar shoot out using larger EM's.
 
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When you are using a HSS or cobalt end mill and it is becoming dull, and it is the only one you have of that size to finish the job with, it is quite possible to give it a bit more life by carefully stoning the cutting edges and flutes. Try to hold the original angles and to remove the same amount of material from all flutes so they all keep cutting. Leave any chips in the cutting edges as they are. It certainly won't make them like new again, but it can get the job finished... I typically use fine grit square India stones with mineral spirits and/or fine diamond laps (Eze lap.)
 
Bob Korves said:
In one of Stefan's earlier videos he said he learned English from watching YouTube videos. I think his English is damn good, much better than my German... He even has colloquial English down better than many who were born into it. He is one intelligent, hard working, and clever guy.
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No kidding. His commentary and (undeserved) self-deprecation are subtle and nuanced. My favorite phrase of his is "pretty okay". I love how This Old Tony uses it as well as many other Stefan references.

There are few better ways to better understand your own language than to study another one. It forces you to really focus on the various mechanisms of language and why the pieces work together the way they do. Precious few people ever do that with their own language without such a prompt. While it's terribly rusty from about 15 years in storage, I still speak at least survival Japanese. It is a fascinating language, beautifully structured with very few exceptions to the well-defined rules. I consider myself fortunate to have not been in the position of starting with such a disciplined language and then trying to learn English, as unruly as it is. When someone makes a point of really studying English to be truly conversant and effective in communication their thoughts they tend to become more proficient and articulate than the casual lifelong speaker. Even when Stefan stumbles on word selection or pronunciation I still find him far easier to understand than a number of native English speaking YouTube video creators.
 
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I found some TiN coated 2 flute 1/4" shank 1/8" endmills on Ebay yesterday, 4 for $22.50, that's $5.62 each, to add to my collection of small end mills. I have to make some 1/8 slots in Lucite, these should work well.
 
I am asked, when the customer wants to drill their own holes, and have been asked many times; "Do I need a special drill bit to drill stainless steel?" I just tell them you need a good quality drill bit and lubricant. The reason they ask is their experience(s) based on lack of experience are many dull, low quality drill bits. Quality HSS steel cutters have parameters that fit a wide range where speed and feed make the difference, along with lubricant making the difference in how long they last, how many holes, etc. We have many discussions on the use of carbide cutters and the supporting arguments come across as someone making excuses for a prodigal child. Buying anything used leaves one guessing, especially in regards to how it was used, is it dull and so on, but if the deal is good, go for it. There's no experience gained in using a dull cutter with no knowledge in what or how it happened to be dulled. If I start with new I learn; **Don't do that again** if I dull it, or buy this again if I'm still making holes after 100+. Buying new on the other hand should be done to fit the job you have, not the job(s) you may have.

With the full understanding this is a hobby, there's too many charts available showing materials and cutting tools to use for there to be any second guessing. A known quality tool is hard to beat. Coatings on cutting tools (my experience) may improve the cut or assist with chip control, but if there is significant cost involved I'll pass. My experience to date puts coatings in general, into a sales feature category. I prefer to spend on a lubricant suited for the material.
 
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