Eating up TiN cated HSS endmills need helP!

[Freddy]

You have to keep in mind that two fluts end mills work well in soft materials at high speed like aluminum , for hard materials without heat treatment you should use 4, 6, ... Fluts at low speed , if the metal is hardened carbide is used. In this case , using 3/8 end mill 4 fluts the cut may be 1/4 deep x 3/16 side.

 

[darkzero]

I but a lot of stuff from meritool for my CNC maybe I will give them a go for this.

Curious, if you have & run CNC, how are you determining speeds, feeds, & DOC? It's basically the same with conventional.

 

[stupoty]

i have not used the TIN coated tooling from LMS,
but, if it's anything like the TIN coated stuff from HF, i'd throw it in the garbage and try a USA made endmill or a European made endmill (Germany,Poland,Austria,Switzerland,Sweden,Italy etc all make finer tooling)

i really don't like to use very inexpensive tools and tooling.
for me it does 2 counterproductive things
1, wasting time changing out inferior broken tooling
2, aggravation, after taking the time to do a proper set up fouling a piece of work that is nearly completed because i wanted to save a couple bucks on some cheap tooling.
after i set up, i want to complete the operations until it is necessary to change tooling for other operations.

good tooling can be broken too, i can attest to that.

i do believe that better materials + better tooling = superior work

i have a cheep (read china made) hss tin coated set of end mills and to be fair for the price they have done quite well, i have some other brand cutters e.g. Dormer and they are much better i keep an eye out on ebay for cheep new ones (gotta have a hobby ;-) .

my mill is a rf 25 so its moderatly light, ive been finding 12mm (1/2 inch)and smaller end mills work best for me on steel, i generly spin about 350 - 450 rpm for 12mm on steel.

if i get what feels like excessive vibration i back off cut depth or cutter diamitor a little.

I also find that if my clamping set up is a little flexible that going to a smaller diamitor cutter to try and reduce cutting forces and help reduce any vibration.

Stuart

 

[wrmiller]

All I looked at was the color of your chips. Your spindle speed and/or your feed is way too aggressive. On my smaller mill (PM25) I can easily take .2-.3 DOC with a full width pass, but...

I use a quality endmill, 3/8" or 1/4" rougher for hogging, and go SLOW. When the chips start coming out between silver and a light blue that is aggressive enough for that machine. Then one or two light passes with a regular 4-flute (again, a better quality one) at a slightly higher spindle rpm and I'm done.

As someone said above, I too stopped using the bargain basement cutters because these smaller mills require better cutters and setups than their larger brethren to compensate for the lack of mass and rigidity.

Just my experience.

 

[chuckorlando]

I was just doing some calculations here. With a cs of 400 for carbide you got 400x4/.1875 = or 1600/.1875 = rpm 8533. The same calculation for hss with a cs of 100 is 2133rpm. Those are the bottom numbers for both hss and carbide for cutting speed. So if you do like me and cut that number in half for starters your still in the 1000-4000rpm range

 

[wrmiller]

I was just doing some calculations here. With a cs of 400 for carbide you got 400x4/.1875 = or 1600/.1875 = rpm 8533. The same calculation for hss with a cs of 100 is 2133rpm. Those are the bottom numbers for both hss and carbide for cutting speed. So if you do like me and cut that number in half for starters your still in the 1000-4000rpm range

Yea, wasn't trying to get explicit here as the cutters are different (apples and oranges thing), but you can gauge from the color of your chips. With my carbide cutters I typically start somewhere between 1000 and 1500 rpm and go from there.

I'm kinda old school in that I listen to the machine. It will pretty much tell me when it's happy or not.

 

[chuckorlando]

I agree. They talk to you for sure. I was actually re reading the thread and noticed his rpm seems real low. So I did some math to confirm my suspicion.Granted thats also for softer plain carbon like 1018. I usually do the math then take the recommendation and cut it in half. Work up from there.I cant get 8000rpm if I wanted to so it dont matter in that regard. But I say you need more spindle rpm and less feed possibly and alot more coolant

Yea, wasn't trying to get explicit here as the cutters are different (apples and oranges thing), but you can gauge from the color of your chips. With my carbide cutters I typically start somewhere between 1000 and 1500 rpm and go from there.

I'm kinda old school in that I listen to the machine. It will pretty much tell me when it's happy or not.

 

[Bill C.]

Try a slower speed or a lot coolant. Those chips look burned to me.

You have done the "file test" so it not harden steel. I don't recall ever using coated end-mills.

Hopefully they can help you. Good luck

 

[NightWing]

100 SFM on a 5/8" diameter tool is 612 RPM.

 

[Inflight]

Coolant makes a huge difference.

Try the brown sulphurized cutting oil applied with an acid brush or a cool-mist #77 solution applied with a spray bottle.


Matt