Newbie- First Tooling Question

[Phishaholic]

I’m getting ready to purchase a new PCNC and I’m trying to decide on what initial tooling to get. I have a manual grizzly with a little tooling. I guess my question is. If I could only get 6 endmillls or other cutting bits which one should I get to start off with? I mainly work in Aluminum and most part I make would fit in a 5" cube. Tool life and surface finish are important; I know that my cutting strategy will affect the finished part and tool life. Any thoughts, ideas, or experiences would be appreciated.

Larry O

[HMB3000]

I would recomend that you buy the cheapest tools you can find...just make sure they are center cutting (for plunging into work)...after you run the machine for a while then buy some insert tooling...but start with the cheap stuff as a learning curve will claim a few endmill in the begining...another sudjestion of a cheap way to learn is to bolt down a piece of wood and put a pencil in a drill chuck set your Z depth to -.002...it is real cheap

[instructor37]

Originally Posted by Phishaholic I’m getting ready to purchase a new PCNC and I’m trying to decide on what initial tooling to get. I have a manual grizzly with a little tooling. I guess my question is. If I could only get 6 endmillls or other cutting bits which one should I get to start off with? I mainly work in Aluminum and most part I make would fit in a 5" cube. Tool life and surface finish are important; I know that my cutting strategy will affect the finished part and tool life. Any thoughts, ideas, or experiences would be appreciated. Larry O

larry-
Please don't be offended, but your question seems out of proportion. You are getting ready to drop 10-20K on a mill and you are asking a question that would be appropriate for a guy buying his first mini mill from Harbor Freight. In fact, the size and material you are working is more appropriate for that size machine. Usually when a guy steps up from a Grizzly size machine its because he has maxed out its capacities already and would have a pretty good idea what tooling he needs to move up.

[zephyr9900]

Larry, for 90% of my work I use Atrax carbide endmills from Enco. Carbide is much stiffer than HSS which means less cutter deflection and a better surface finish in general. Atrax are American-made cutters and much better quality than the cheaper Asian bits and not that much more expensive.

With the carbide bits you need to use the ER collet-style holders because carbide bits don't have setscrew flats, and will walk right out of a setscrew-type endmill holder. I only use the setscrew holders for occasional-use HSS bits I already had.

I use flat endmills in 3/8, 1/4, 1/8 and 1/16 diameter and ball-ends in 1/4 and 1/8 for most of my work, the latter for 3D contouring. I have used bits down to .020" in the Proxxon spindle so far.

For that matter, I don't use the 3/8" bit all that much. With manual machining I would always use the largest bit I could to minimize the handle cranking to clear out material, but with CNC it is trivial to set the stepover distance to match the bit and let the machine do the work. The 1/4" bits, flat and ball, get probably 75% of my use.

Best regards,

Randy

[Phishaholic]

Instructor37
I'm not offened by your answer. I guess A better question would be. What bits and cutters see the most spindle time on your machines?

I'm getting this machine because of its capabilities and cost. I have an idea for a product used in the bomb disposal community and would make 100 plus units that have compound curves that would take too much time for me to make in a timely manner on my grizzly. I have a full time job that kind of gets in the way.

Larry O

[MichaelHenry]

I like end mills from Lakeshore Carbide and Mari-Tool. Give them (or your own preferred vendor) a call and ask them to make some recommendations.

Mike

[justgary]

Wow. Someone is not having a good day. And typing at the top of his lungs, too!

Anyway, I agree with Randy and highspeedmazak on the tooling, but I grind flats on my carbide mills and use the set screw holders. The TTS tool holders do save you a lot of time. I don't use 1/2" very often at all. More because I have it in a HSS set than that I need it (except for when I need the length).

I am discovering that I like corner radius mills the best, because you get the flat bottom like an endmill plus the rounded edge like a ball mill. The cut loading is not nearly as high as with the square corner, and you don't have to change tools as often if you choose wisely. They do cost more than a flat end mill, but not more than a flat plus a ball mill.

Regards,

- Just Gary

[HMB3000]

Originally Posted by Phishaholic ... If I could only get 6 endmillls or other cutting bits which one should I get to start off with? be appreciated. Larry O

Larry my thought of buying the cheapest stuff you can find... is based on your request for first order...Don't waste your money on any good tools as you will snap a $50 end mill as fast as a $10 end mill...spend as little as you can right now...in a few weeks of playing around with the machine then buy some good stuff....in other word every one makes mistakes with a new machine and I don't care who's machine it is...I have crashed just about every machine made in the last 30 years learning a new controller...You should have seen what I did to Rolls-Royce on a 25' dia. propeller for an aircaft carrier...it was not a good day to ask for a raise...Thank God for weilding and filling...but after that day I knew the controller and what not to do...and I still worked for them a couple of years untill I was bored

[David Bord]

Originally Posted by zephyr9900 Larry, for 90% of my work I use Atrax carbide endmills from Enco. Carbide is much stiffer than HSS which means less cutter deflection and a better surface finish in general. Atrax are American-made cutters and much better quality than the cheaper Asian bits and not that much more expensive. With the carbide bits you need to use the ER collet-style holders because carbide bits don't have setscrew flats, and will walk right out of a setscrew-type endmill holder. I only use the setscrew holders for occasional-use HSS bits I already had. I use flat endmills in 3/8, 1/4, 1/8 and 1/16 diameter and ball-ends in 1/4 and 1/8 for most of my work, the latter for 3D contouring. I have used bits down to .020" in the Proxxon spindle so far. For that matter, I don't use the 3/8" bit all that much. With manual machining I would always use the largest bit I could to minimize the handle cranking to clear out material, but with CNC it is trivial to set the stepover distance to match the bit and let the machine do the work. The 1/4" bits, flat and ball, get probably 75% of my use. Best regards, Randy

Randy, I thought the same thing, and then asked Greg at Tormach. He said it would pull the tool out of the R8 collet before it would move from the setscrew with a carbide bit and no flat.

I have been using carbide with the set screw holds since... and have had very good luck! I have had the tool holder pulled out on a 1/2 inch bit and the set screw didnt budge with a carbide bit.

David

[300sniper]

for aluminum, i have been using mostly 3 flute carbide endmills in 1/4", 3/8" and 1/2". for removing material fast, i absolutely love the 1/2" at 4500 rpm, around 30 ipm and .1-.125 depth of cut. it throws a fat rooster tail of chips behind it and leaves a great finish.

before i started using the 3 flute endmills for aluminum, i was using 2 flute carbide atrax from enco. they work great and are much cheaper than the 3 flutes. if i was learning cnc (i still am), i would start with the atrax and buy a bunch when they are on sale. you will most likely chip if not break a few when you are learning.

definatly include enough funds in you machine budget for the full tts set. in my opinion it is a must have.

[zephyr9900]

Originally Posted by David Bord I have been using carbide with the set screw holds since... and have had very good luck!

I will try a setscrew holder again with one of my carbide endmills, David. And maybe a longer-arm Allen wrench. I was not happy about the endmill creeping out the last time I tried but will trust your report!

Originally Posted by 300sniper for aluminum, i have been using mostly 3 flute carbide endmills

My 1/4" ball-end is a 3-flute and I really like it, 300sniper. I hadn't thought of trying 3-flutes for flat machining though. Next time I need to restock I'll try a couple.

Randy

[David Bord]

Originally Posted by zephyr9900 I will try a setscrew holder again with one of my carbide endmills, David. And maybe a longer-arm Allen wrench. I was not happy about the endmill creeping out the last time I tried but will trust your report! Randy

Cool, I slide the holder in the mill to hold it and just give it a good tightening. Let us know how it works out. The only thing I use the ER holders for are .125 and smaller. Mostly cause they are pricey