Eating up TiN cated HSS endmills need helP!

I did not take the time to read every reply, Maybe some one allready pointed a few things out ... here is my thoughts.

Your chips indicate too much heat. Too fast of rpm, no coolant etc etc. I think both...
And I have machine those chinese quick change base plates for friends and customers before. They had the same problem you are having. Some of the ones I have seen were very hard. Usually i can mill them with no issue using carbide, but I had 2 that I had to grind before. They were very hard!
 
It's something I have thought about many times for my self. I dont like more rpm then I need. So on a lathe if the part is real small I may use hss just to keep the rpms lower. On a mill if the cutter is small I might want it to be hss for the same reason. I love my index tooling but I dont care to run my little lathe at 2k if I dont have to ahahaha
 
The statement "2 flute end mills are for aluminum, 4 flute for steel" isn't quite correct, as I use them interchangeably, and for most hobby work, they can be. They are used that way industrially because you can take a much greater cut per flute with 2 flute end mills cutting aluminum, which can fill up a 4 flutes open area, clogging the mill and causing problems. And the cutting speed (for a given cut depth/flute) is twice as fast for a 4 flute (and 3 times as fast for a 6 flute) end mill, so when the chip buildup isn't a problem (cutting steel) you can run at higher feed rates and reduce cycle time. Of course, without a power feed, actually feeding slow enough to use a 2 flute end mill in steel can be a problem. As others have already stated, your cutting speed is way too high. You can just google speed and feed and it will pull up some calculators to get the speed. To get the feed, you will need to know how much cut per flute you want to go, which varies with the size end mill, material you are cutting, and rigidity, but I would probably start with .0015 to .002 for that 5/8 cutter.
 
chuckorlando said:
It's something I have thought about many times for my self. I dont like more rpm then I need. So on a lathe if the part is real small I may use hss just to keep the rpms lower. On a mill if the cutter is small I might want it to be hss for the same reason. I love my index tooling but I dont care to run my little lathe at 2k if I dont have to ahahaha
Click to expand...

A little off topic but: I'm kinda the opposite and should remember that when posting here. I like relatively high speed and carbide. I do have one set of hss bits for the lathe but they are indexable inserts. I don't grind cutters. Tried it, can do it fine, but I'd rather be working on stuff. My little lathe can almost get to 2500 rpm now and with a 6" bed for a 8" swing is plenty rigid for decent sized cuts on small stuff. :)
 
Look up in any tooling catalog for aluminum cutting endmills and 2 flute are the first choice. Can they cut other materials? sure. Can a 4 flute endmill be used on aluminum? Of course. The results may not be the same. Aluminum chips flow best with minimal flutes. A single flute mill also will work well. As far as cutting slots, a center cutting mill can do the job.

The bottom line is we generally try to use what we have on hand. If it works, fine. If it doesn't work, we will buy the right tool anyway.
 
I dont mind the speed. I just want something that works. Ill test out the end mills tomorrow. Wish me luck
 
cjtoombs said:
The statement "2 flute end mills are for aluminum, 4 flute for steel" isn't quite correct, as I use them interchangeably, and for most hobby work, they can be. They are used that way industrially because you can take a much greater cut per flute with 2 flute end mills cutting aluminum, which can fill up a 4 flutes open area, clogging the mill and causing problems. And the cutting speed (for a given cut depth/flute) is twice as fast for a 4 flute (and 3 times as fast for a 6 flute) end mill, so when the chip buildup isn't a problem (cutting steel) you can run at higher feed rates and reduce cycle time. Of course, without a power feed, actually feeding slow enough to use a 2 flute end mill in steel can be a problem. As others have already stated, your cutting speed is way too high. You can just google speed and feed and it will pull up some calculators to get the speed. To get the feed, you will need to know how much cut per flute you want to go, which varies with the size end mill, material you are cutting, and rigidity, but I would probably start with .0015 to .002 for that 5/8 cutter.
Click to expand...

I regularly use a 5 flute end mill for hogging out a 2" diameter hole about 2.5" deep in 6061-T6, and that was after experimenting with several different tools to find one that did the job best. There is alot more to chip clearance than just the number of flutes the endmill has:

-diameter of tool
-clearance around tool
-presence and type of coolant
-tool cutting profile (finish, hogging, etc..)
-chip thickness and how much its broken up during the cut
-how much material you are trying to pump through the tool flutes
-tool material and tendency to stick to aluminum (wrong coating, or low rigidity HSS and therefore increased heat)

In addition, chip clearance may not be your only concern, you may need to consider a stronger and more rigid tool to get the job done, and more flutes equals more strength, and significantly so.

IMO, generalities when it comes to machining are misleading at best and a serious setback for beginners when they try to correlate them with what they run into in their learning process. The day a beginner decides to abandon generalities and start working the problem is the day they become a machinist.
 
One other thing, make sure all your gibs are tight and unused axis are locked (including the quill.)

For the price you pay getting the full set of (basically junk) endmills from China you could get a single Weldon, Niagra, ITW, etc. endmill that would last twice as long as the full set would. Then once it gets dull, send it to the sharpener. Sharpening junk endmills is not worth it.
 
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