Endmills

[tracksntreadslou]

Heres a good question for all you machinests ..Where do you buy your endmills ?...I am looking for a good site that sells new inexpensive fair to good quality endmills..I have been cutting mostly aluminum and been using Niagra HSS Double end for the 3/16 and smaller cutters ..these are costing me over $20 a peice and i know my local supplyer isnt marking them up that much ..Is it recommended that I use 2 0r 4 flute and should i use carbide ... will that give much more extended Life ?..Lately I have been cutting thicker aluminum .37 thick and like to use a 1/8 toolbit on acount of radiaus..i am hoping to find longer shanks as well ..Should I add another 1/2 toolbit thickness for releif in my CAM programing when cutting out thicker parts ?
What Brands do you guys like to use ?
anyway thanks for any advice from you guys

[ihbuilder]

http://www.maritool.com/Cutting-Tools-End-Mills-Finishers-Square-End-3-Flute-High-Helix-Double-End-3-Flute/c78_79_80_201_336/index.html

Lou , here you can do better then that in carbide . when getting EM's for cutting alum. get them specifically for cutting aluminum

here's his site http://www.maritool.com/

[9W Monighan]

I look on ebay for mills first. Lot a good deals on them if it's what your looking for. I like the solid carbide rougher finisher type mills. I get them from MSC supply.

[Espeefan]

Lou, I'm not a real machinist, but I have been really happy with the end mills I've been getting from McMaster-Carr. I just get the high speed steel, nitride coated end mills, and so far I haven't dulled any out cutting aluminum. I'm sure they aren't the cheapest, but it's rare that I need to buy a replacement, unless I do something stupid, like run it into my vise.

In my limited experiences, I'd recommend using two flute end mills for aluminum, although I personally run four flute without issues. I don't run CNC though, and I'm sure my feed rates are much less then yours. What really makes a difference is running some kind of cutting oil, even if you simply apply it with a squeeze bottle, which is what I like to do. I save about .010" for a finishing pass, and I either take that in two passes, at .005" each, with smaller diameter end mills, or take it in one pass with the larger diameter end mills.

Your mileage my vary, and like I said, I'm not an expert. Just a guy who is basically figuring this out on his own.

What is your issue with your end mills? Are you clogging them up, or dulling them out? I've been running the same end mills since I started machining parts, which has been about 2.5 years now. My cut quality still looks great. Even on the end mills I use all of the time.

[tracksntreadslou]

Thanks to everyone for the good advice ..I think this Thread will be helpfull to others that are getting into machining Manual or CNC ..
looking at some of the prices it looks like I will do much better and going to give the carbide a go..
Nathan You must be doing something right ..Good on ya with keeping those bits sharp ..So far I have dulled about a half dozen..I guess finding that sweet spot by manual milling is a bit easyer ..more feel to it..If i remember i only broke 1 when I had my 3 in 1 manual mill .When I first started cnc I broke some experimenting with feed speed ..Really important to keep the chips clear when sloting as well
I am using WD 40 and rapid tap for cutting oil and that seems to be working ok ..Is there something out there thats better recommended for alumminum ?...
The material I have been cutting I find at the recycle depot for about $2 a pound ..I have noticed thats there has been some that dont cut well and gum up..need lots of lubricant and slower speeds .. One thing is for sure is i am having alot of fun with this CNC thing .

[Espeefan]

Lou, I agree that you can better feel what the cutter is doing with an all manual mill. I honestly don't know much about calculating the feeds, speeds, and depth of cut. I just do what feels, sounds, and looks right. I am sure it's much more difficult to figure out all of that with a CNC machine.

I wonder if the quality of your aluminum is to blame. The stuff that gums up much faster and seems to act less forgiving is probably a cheaper grade. I've only ever purchased T-6061, and I'm sure it helps to develop a feel for one grade and type of material.

I've had really good results using Rigid Nuclear thread cutting oil on aluminum. I'll run a bead of oil ahead of the end mill, from a squeeze bottle, every two or three passes. I also do my best to remove the chips so that they don't get dragged back into the end mill on a second pass. Harder to do with a CNC mill, unless you can have a constant supply of pressurized air to blow the chips away. For my small operation, I've been using a blast of air from the compressed 'duster' air cans. Alternatively, I could use a portable air tank, with a blow off nozzle, filled from the compressor in the garage, which would probably be cheaper in the long run. Anything is better then nothing though. I should buy a small airbrush compressor someday.

[Madda]

I've been using on my cnc these: http://www.shop-apt.co.uk/carbide-end-mills.html I only cut aluminium and their uncoated carbide bits are quite nice.
ctctools.biz endmills are cheap and also do the job.

[grumpygrady]

lol I use harbor freight or ebay endmills and just go slow and they are all still sharp but I don't use any smaller than 3/8ths right now with 1/2 the largest and finish the corners with a rattail file or a dremal bit lol spell check may or may not be right lol

2 flute for aluminum and 4 for brass or steel in a cummins mini mill but I don't use it as much as you fellows do I am sure , as for cutting oil I use transmission fluid and it work ok anyway no mills are getting gummed up
hope that this helps a little

[pugs]

The gummy aluminum is probably Chinese stuff if it is marked as 6061-T6. It is just softer and sticks to tools, leaves bad finish. I specify US made aluminum when I order material after several bad experiences with the cheap stuff.

In alum I don't like 4 flute endmill, stick with 3 or 2 as that gives you more chip clearance for the aggressive cuts you can take. High helix mills designed for aluminum work really well. Lately I've been using OSG blizzard brand 3 flute, have used alot of CGS 2000 series 2 flute in the past. They aren't the cheapest but they seem to run longer and faster for me which means cheaper per part.

For taps I only use form taps in alum, so much nicer.

If you plug up a mill with aluminum, or lolipop it as I call it, get yourself some Lye drain cleaner (Red Devil) and a small container. put the endmill in some water into the container and sprinkle some lye in. It will start getting hot and bubbling while it eats away at the aluminum. really bad plugs may not completely dissolve away but usually good enough to be able to pop it off carefully. Do in well ventilated area as the vapors coming off are hydrogen. It will turn the endmill black but it leaves the edges sharp yet. Usually let it sit till it stops bubbling which can be 15 mins or more depending on how much lye you put in.

[tracksntreadslou]

Thank you very much Madda ..I have never used carbide bits as most were too pricey ..Now that I am finding better connections and getting better at this cnc thing I am going to start using them..Jezz some of them are half the price as the HSS

I've been using on my cnc these: http://www.shop-apt.co.uk/carbide-end-mills.html I only cut aluminium and their uncoated carbide bits are quite nice.
ctctools.biz endmills are cheap and also do the job.
Thanks GG..Been shopping around on ebay and some much better buys there for sure ..Definatley going to try the tranny oil as well..Have you heard of this new coolant thats mixed with air ..supposed to be very userfreindly..no oders
Anyway thanks for everyones input

lol I use harbor freight or ebay endmills and just go slow and they are all still sharp but I don't use any smaller than 3/8ths right now with 1/2 the largest and finish the corners with a rattail file or a dremal bit lol spell check may or may not be right lol

2 flute for aluminum and 4 for brass or steel in a cummins mini mill but I don't use it as much as you fellows do I am sure , as for cutting oil I use transmission fluid and it work ok anyway no mills are getting gummed up
hope that this helps a little

Thanks Pugs ..Now there is some great adivice ..I and going to dig a few of the older bits out and clean them up.....a few times i just used a small exacto knife and chipped them off ..doesnt last long as there seems to be a filum of aluminum thats left behind the more stuff sticks to .thanks for your good tips

The gummy aluminum is probably Chinese stuff if it is marked as 6061-T6. It is just softer and sticks to tools, leaves bad finish. I specify US made aluminum when I order material after several bad experiences with the cheap stuff.

In alum I don't like 4 flute endmill, stick with 3 or 2 as that gives you more chip clearance for the aggressive cuts you can take. High helix mills designed for aluminum work really well. Lately I've been using OSG blizzard brand 3 flute, have used alot of CGS 2000 series 2 flute in the past. They aren't the cheapest but they seem to run longer and faster for me which means cheaper per part.

For taps I only use form taps in alum, so much nicer.

If you plug up a mill with aluminum, or lolipop it as I call it, get yourself some Lye drain cleaner (Red Devil) and a small container. put the endmill in some water into the container and sprinkle some lye in. It will start getting hot and bubbling while it eats away at the aluminum. really bad plugs may not completely dissolve away but usually good enough to be able to pop it off carefully. Do in well ventilated area as the vapors coming off are hydrogen. It will turn the endmill black but it leaves the edges sharp yet. Usually let it sit till it stops bubbling which can be 15 mins or more depending on how much lye you put in.

Thanks Nathan ..Taking a while but i think im getting the hang of it..Alot of times I can start the program ..Some will be fairly long a few hours ...spray a good dose of WD 40 and walk away ..I can come back every 10-15 minutes sweep away the chips and lube it up again ..Other times I have to be there to sweepout chips every pass and really babysit..I can tell with the softer aluminum will form a small lip on the top cutting edge so usually will slow the feed speed and that will usually help ..You can tell sometimes when a chip will get sttuck to the toolbit as the sound will change ..another good shot of lube .I am running my spindle speed at the second highest speed of around 6400 rpm..the highest speed available is 10800 rpm .. now that im bit more confident after stalling the motor a few times and breaking a few bits :( i may experiment with that faster spindle speed ....from what i have read the faster the better with aluminum ..wish I had a spindle motor with more balls
I guessing I speed up the spindle I will have less torque

Lou, I agree that you can better feel what the cutter is doing with an all manual mill. I honestly don't know much about calculating the feeds, speeds, and depth of cut. I just do what feels, sounds, and looks right. I am sure it's much more difficult to figure out all of that with a CNC machine.

I wonder if the quality of your aluminum is to blame. The stuff that gums up much faster and seems to act less forgiving is probably a cheaper grade. I've only ever purchased T-6061, and I'm sure it helps to develop a feel for one grade and type of material.

I've had really good results using Rigid Nuclear thread cutting oil on aluminum. I'll run a bead of oil ahead of the end mill, from a squeeze bottle, every two or three passes. I also do my best to remove the chips so that they don't get dragged back into the end mill on a second pass. Harder to do with a CNC mill, unless you can have a constant supply of pressurized air to blow the chips away. For my small operation, I've been using a blast of air from the compressed 'duster' air cans. Alternatively, I could use a portable air tank, with a blow off nozzle, filled from the compressor in the garage, which would probably be cheaper in the long run. Anything is better then nothing though. I should buy a small airbrush compressor someday.

[grumpygrady]

[ I should buy a small airbrush compressor someday. ]


if you need a compressor check with your family or neighbors and friends for a older nebulizer , they make great air for airbrush

they can be found at yard sells for under five dollars

[DADSGARAGE]

Heres a good question for all you machinests ..Where do you buy your endmills ?...I am looking for a good site that sells new inexpensive fair to good quality endmills..I have been cutting mostly aluminum and been using Niagra HSS Double end for the 3/16 and smaller cutters ..these are costing me over $20 a peice and i know my local supplyer isnt marking them up that much ..Is it recommended that I use 2 0r 4 flute and should i use carbide ... will that give much more extended Life ?..Lately I have been cutting thicker aluminum .37 thick and like to use a 1/8 toolbit on acount of radiaus..i am hoping to find longer shanks as well ..Should I add another 1/2 toolbit thickness for releif in my CAM programing when cutting out thicker parts ?
What Brands do you guys like to use ?
anyway thanks for any advice from you guys

Here is a place to find some tooling.....

http://www.kbctools.com/can/main.cfm

[motocrawler]

I get my end mills from two places in the lower mainland. I find busybee tools has good endmills at good prices and Thomas skinner has the real nice high end bits. I would invest in a nice set of carbide endmills (2 flute for Al) and it should last you a very long time. Also remember that you can always send you current dull bits in to get sharpened, if you do send them in make sure you measure them when they come back to accommodate for any changes due to the grinding and sharpening. All CNC equipment will have a offset function for this.