noobie question re tools

[boatmadman]

Is it worthwhile spending extra pennies on carbide end mills?

Ian

[bogstandard]

Ian,

I use carbide for almost everything.

They do have their advantages like staying sharp for a lot longer and being able to take larger cuts. Plus sometimes it is the only way you can machine some materials with any degree of success.

The main disadvantages are that they can very easily get damaged, usually cost a lot more initially, and really, they do need some sort of coolant on them if you are going to take advantage of the higher cut rates.

To prevent tip damage, as I find that just dropping them means they get a one way ticket to the recycle box, whenever you are undoing them from their holder, you need a catching cloth underneath. HSS will bounce, tungsten just chips or breaks.

If you are fairly new to machining, I personally would stick with HSS for the time being, as you can easily damage a cutter by being used incorrectly, unless you have a specific job in mind or want to have a couple in stock, say 6mm and 12mm, just in case you need something with a little more 'punch'.

They are not the be all and end all that everyone thinks they should be, but they do come very close to it.


John

[Darren]

Agree with John Ian,
carbide is nice to use but easily damaged and ruined. You don't even need to drop one to kill it 

[boatmadman]

Thanks for that fella's.

Next question:

When using an end mill on a face, am I right in thinking the width of cut should be less than half the diameter of the tool? And, the feed should be such that the uncut work is fed into the rotation of the tool?

2 questions I know, but I like value for money

Ian

[sbwhart]

Question 2

Yes you've got that correct Ian

Stew

[Darren]

When using an end mill on a face, am I right in thinking the width of cut should be less than half the diameter of the tool?

Well, that all depends, a smaller mill will thank you for only using half the dia of the cutter. A large mill probably wouldn't care less if you used the whole dia.
But you might also like to consider depth of cut, feed rate and rpm, these will all make a difference.

Just take it easy, to begin with and get a feel for how happy your machine sounds. It will let you know if it objects.  

Just don't dive in with big cuts or something will break, probably the cutter if you are lucky.

[boatmadman]

Again, thanks for the advice.

I am itching to make some swarf, but I aint starting until I am happier about what to do and how to do it.

I have used a mill before, a loooong time ago, but a big industrial version that could chomp off like nobody's business. And, if it broke I didnt have to pay to fix it.

But, now this is MY mill, bought with MY money, so easy does it!

Ian