Corner rounding end mills

[Alan H.]

Looking to get some corner rounding end mills. Most of my work for these will be on aluminum.

You can get an 8 piece set of HSS 1/16" to 3/8" such as Accusize brand for less than a $100 delivered.

Are they worth having or should I buy individually and step the quality up? Also thought about trying a simple carbide router bit.

 

[JimDawson]

Carbide router bits work great! I use only the finest Harbor Freight bits. $20 for a set of 4. The downside is that they have 1/4 shanks so you can't get too greedy on the cut.

1/2 inch shank router bits are available, and are prefered for heavier work.

http://www.hobby-machinist.com/threads/router-bits-to-cut-aluminum.55296/#post-456649

 

[Billh50]

I have had the cheap sets in the past and they worked just fine even on steel. A couple years agoI gave my set to a friend that is still working and didn't have the money to buy a set.

 

[Cobra]

Because of their specificity to a project, I have just bought singles as I needed.
When you use them, the work best climb milling as opposed to normal end mills being more comfortable with conventional.

 

[FanMan]

When you use them, the work best climb milling as opposed to normal end mills being more comfortable with conventional.

Why is that?

 

[Cobra]

Why is that?

Read the advice on Tom's Techniques site and tried it when I was making the angle plate.

http://www.hobby-machinist.com/threads/angle-plate.49148/

Tried on scrap first. Conventional direction left divots in the surface while the climb milling direction was smooth.
Did the real parts the same way and they came out smooth.
Haven't had a lot of experience machining but in this one case, the advice was good.

Jim

 

[Billh50]

I usually rough to within .005 or so in conventional method then finish in climb milling. That way I don't need to worry about any back lash and table jumping when climb milling.

 

[4GSR]

I have a bunch of them left over from dads shop. I find the larger ones work better if you take cuts from different ares of the cutter soe your not always cutting at the center of the radius of the cutter. Then the last cut would be at the center of the radius where it is near tangent to the edges or the part.

 

[Doubleeboy]

The reason you want to use climb milling with corner rounding endmills is they basically don't cut worth a darn if you try conventional milling. With conventional milling you will swear the cutter is dull or broken, in my experience.

 

[EmilioG]

I only have 3 CR end mills, but they're all quality; Niagara and Melin. Don't use them too often. Only for a few parts that I make on occasion.
They leave a nice professional finish on the parts. See: Tom Griffin using a CR end mill on the lathe. Very cool.
Q: Can CR end mills be hand sharpened? Are the carbide tools worth buying over HSS or cobalt?