Long end mills

[PTcutter]

hi I just joined this site but I've been visiting for a while and now I need some advice.

I've just gotten this project handed to me that requires some very long VERY thin end mills. I am running a fadal VMC4020 and I need to know where I can get some 4"x1/8" carbide end mills. and some 4"x1/16" carbide end mills.

any suggestions would be very helpful.

PTcutter

[psychomill]

Are you looking for endmills or saws???

OR

Is it 1/16 and 1/8 endmills, 4.00" long??

[PTcutter]

the second sorry I can see how that could be confusing.

I am searching for a 1/8"dia. and a 1/16" dia. at LEAST 4" long

[psychomill]

Off hand, I don't know anybody who makes carbide ones 4.0 long and keep them in stock. However, I do have endmills like that for some of my parts, but there are custom ground. Check out Destiny Tool and give them a call for you need. They have a good price (and can be coated too) and delivery.

HTH

[PTcutter]

thanks a lot I will check it out

[krustykrab]

What is the job and what are you trying to cut?

Is there draft on the walls? if so, custom grind a cutter to suit the job, otherwise you will pay big bucks for long carbide like that.

Not that it really matters much, but unless you are cutting something like styrofoam, I can't see how a 4" long 1/8 or 1/16 cutter will last or be accurate in any other material.

But I'd like to hear the rest of this story to see how things went. Great learning experience.

[psychomill]

Not that it really matters much, but unless you are cutting something like styrofoam, I can't see how a 4" long 1/8 or 1/16 cutter will last or be accurate in any other material.

Oh, you'd be surprised....

[krustykrab]

Please, surprise me, cause I know that I've still a lot to learn.

I would hope that the Fadal has a speed head on it, because I don't think the 4020's come with anyting more than a 15,000 rpm spindle.

[psychomill]

For most, speed will kill the tool in this case. Not saying that you can't run that tool at those speeds, but it will take more than just a "good cutter". At 4" long, most shops don't have the 'stuff' to make it run that. However, it will work, and the end result for the speed and feed will be well within the range of the Fadal. The most important aspect of this will be the TIR.

[PTcutter]

the job is an aluminium cavaty to be used as a prototype, the walls have a draft but it is so slight there is just enough room to do any work on it. the reason I need the smaller cutters is that there is detail work that has to be done in the bottom of the cavaty. the cavaty is aprox. 2.5" deep if not a little deeper and only 3"x2.5" wide/tall.

As for the cutters lasting, we have 3 or 4 small cutters that we have been using quite often and they have lasted quite a while and they have been sorely abused, as long as we don't take too deep a cut we should be ok. the other problem is that the cutters have to be ball nosed.

and the part about the grinding one to size almost made me choke on laughter. not that it isn't a good idea but the only cutters we have in stock that are more than 3.5" long are 1.5" in diameter! it would be just a little bit of grinding there!

[miljnor]

Psychomill:

i almost never do that kind of work. sooo could you give me an example of using that long and thin of and end mill in alum./steel feeds/speeds you used. and what exactly is neccessary to get that. I would assume some sort of messuring tool to get the TIR very low??? what else???

[krustykrab]

I would have expected you to buy a 3/16 blank, and possible bring it down to the taper size you need. Thus a little more rigid than a straight cutter.

BTW, why not just make a carbon and burn it? Take no time at all...just a guess, not and edm specialist.