Roughing mill selection

J

JustaDB

Ultra Member
In a vainglorious attempt at tooling up a mill, I have come up against a wall: How to choose a roughing end mill? After reading a number of articles & still wandering around clueless, I abase myself before the experts.

At this point I'm looking at mild steel for machining material, although that may expand to aluminum at some point.

Looking at solid carbide, 4 flute, 45mm-ish cutting length. My biggest question is diameter. My intention at this point is to use it largely for edge work (as opposed to top, slots, etc). As such, I'm thinking rigidity is key and am leaning towards 16mm or 18mm diameter.

Thoughts? Suggestions?

TIA.
 
DPittman

DPittman

Ultra Member
Premium Member
Biggest I have is 12mm, I think 18mm might be overkill?
However here is a 3/4" one with a good price when the $5 coupon is taken off.

Accusize Industrial Tools 3/4'' Dia by 3/4'' Shk Dia M42 8% Cobalt Tialn Roughing End Mill, 1-5/8'' Flt Length, 3-3/4'' Oal, Coarse Tooth, 1102-0034 https://a.co/d/7rBF6uZ
 
F

Former Member

Guest
Since I've switched to CNC and do not have an automatic tool changer, any endmill I use must be able to finish.

I also have switched to carbide only. Why? ROI it is cheaper in the long run and results in better finishes and faster cuts.

Aluminium, new can of worms, dedicated and designed for Aluminium endmills, YES! Worth the money. Again faster cut, less noise, better chip removal, better finish.

Finally if you can get into flood cooling, can be messy, but the benefits gain oh so worth it.
 
J

JustaDB

Ultra Member
DPittman said:
Biggest I have is 12mm, I think 18mm might be overkill?
However here is a 3/4" one with a good price when the $5 coupon is taken off.

Accusize Industrial Tools 3/4'' Dia by 3/4'' Shk Dia M42 8% Cobalt Tialn Roughing End Mill, 1-5/8'' Flt Length, 3-3/4'' Oal, Coarse Tooth, 1102-0034 https://a.co/d/7rBF6uZ
Click to expand...
Mornin'!

Thx for the link. I see that one is HSS. Is yours, also? Any issues w/ it?

Do you find your 1/2" flexes at all?
 
DPittman

DPittman

Ultra Member
Premium Member
JustaDB said:
Mornin'!

Thx for the link. I see that one is HSS. Is yours, also? Any issues w/ it?

Do you find your 1/2" flexes at all?
Click to expand...
I have not really pushed my machine to it's limits yet as I am still learning so I don't really see any flex in the end mills with what I do. I've actually only done a test run with that particular bit. There are also lots a good carbide choices on Ali Express.
 
M

mbond

Well-Known Member
Premium Member
Every tool flexes to some degree. It can't develop force to apply to the work unless it deflects to _some_ degree. Some elastic deflection is required. If it becomes plastic, then you break your tool. This also applies to your quill, headstock, knee and every part of of every tool that you use. The key is manageable and consistent deflection.

The amount of deflection required to produce any given force is proportional to the size*** of the part, so we all faviour larger parts. But it is always a balance

Note size*** depends a lot on geometry, materials and complex factors, so your millage will vary. I know how unhelpful that is, but unfortunately no one can really give great advise without putting their hands on your setup
 
F

Former Member

Guest
Spending a fair bit of time in front of my mill and lathe, I am always looking for the best, fastest longest life possible on all of my tooling as I now approach it for production and as a one man shop time reduction is money.

Carbide is the way to go since you are starting, start here cost between HS and Carbide is almost the same. One warning don't drop or bang carbide it will chip beyond that start with the calculated feeds and speeds and slowly ramp them up, you know when these are right as the machine will let you know.

The alternative is start down the HS tooling path, invest and ultimately transfer over to carbide (been there done that) at an additional expense.

The unfortunate note is the pay to play (learn) rule applies and you will break a few so start with the one or two you need, learn and expand from there.
 
Susquatch

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
JustaDB said:
At this point I'm looking at mild steel for machining material, although that may expand to aluminum at some point.

Looking at solid carbide, 4 flute, 45mm-ish cutting length. My biggest question is diameter. My intention at this point is to use it largely for edge work (as opposed to top, slots, etc). As such, I'm thinking rigidity is key and am leaning towards 16mm or 18mm diameter.

Thoughts? Suggestions?
Click to expand...

I'm in the same camp as @DPittman @mbond and @YotaBota. I don't push my tooling needlessly.

I think it's important to distinguish between hobby and business use. I really don't care about production rates or overall life. I have broken 3 endmills now but in all 3 cases cuz I was too aggressive - twice with small carbide bits and in the 3rd case because I was deliberately climb milling and got too aggressive with a 1/2 inch HSS endmill, and the backlash bit me.

My advice is to use whatever you want but go slower than you think you need to.

I haven't broken an endmill in the last year. I credit that almost entirely to learning to feel when the bit is happy and not pushing it.

With a 2 inch long endmill, I prefer a bigger diameter - at least 1/2" but 5/8 or even 3/4 would be less likely to break as long as you don't push it.
 
Engmaxx

Engmaxx

(Michael)
DPittman said:
Biggest I have is 12mm, I think 18mm might be overkill?
However here is a 3/4" one with a good price when the $5 coupon is taken off.

Accusize Industrial Tools 3/4'' Dia by 3/4'' Shk Dia M42 8% Cobalt Tialn Roughing End Mill, 1-5/8'' Flt Length, 3-3/4'' Oal, Coarse Tooth, 1102-0034 https://a.co/d/7rBF6uZ
Click to expand...
I have some cast iron to mill soon and this will help out for sure. Ordered. BTW, discount applies to only one end mill: I tried two thinking $10 and then tried going back to order same again but no coupon. One time deal only. Good deal though! Phanks!
 
DPittman

DPittman

Ultra Member
Premium Member
Engmaxx said:
I have some cast iron to mill soon and this will help out for sure. Ordered. BTW, discount applies to only one end mill: I tried two thinking $10 and then tried going back to order same again but no coupon. One time deal only. Good deal though! Phanks!
Click to expand...
It'll be fun hogging out cast iron with that.
 
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