Armor Plate

[Go Navy]

Need some help on speeds and feeds for MIL-A-46100 49 rc Steel Armor plate. Using a solid carbide 1/2" end mill must go 24" and slot must finish .400 so far everything we have tried has failed. We don't have any other option than to machine this slot just hoping someone else is working with this material. Currently running 100 sfpm and .002 per tooth chipload.

 

Thanks for all the help

Al

[randy]

i think im missing something here .500 e/m finish

at .400

[Gary]

Do you have any bull nose cutters? I would take it down to depth with them or a small insert style cutter then go back in and clean out the corners with a flat tool. Are you using coolant?

[Go Navy]

Sorry thats .400 deep. Still early! We are flooding with cimstar/qualstar coolant with a 15 to 1 ratio with water. We just changed to a bullnose cutter with .o6 rad. crossing our fingers.

 

Thanks for the tip

Al

[within a thou]

I agree with using the smaller cutter too and running your slot as a closed countour and splitting the width of the cut you are taking in half and if thats still not enough using multipass until ya get it in there.

[within a thou]

Also is your cutter snapping burning out or fretting addressing this issue should point ya in the direction of what steps to take to correct this. If you are worried about cycle time with a smaller cutter

[Go Navy]

cycle times are not all that important just have to getrdun. Cutters are cutting great then just snapping at .200 depth of cut. I started out with .075 doc but then the cutters would wear before finishing the slot. I am currently at .125 doc 100 sfpm and .002 chipload seems to be working ok at the moment. I will change to a smaller cutter if I have anymore problems.

 

Thanks again for everyones help

Al

[Roger Peterson]

try the tslot.dll chook using full depth of cut and small stepover (.040" to .080" to start?). I see your slot is .400" deep but how wide?

 

 

HTH

[iowajim62]

Go Navy,

How about program for like 4 of the same cutter and let each one cut so much and then change tools as needed. ?

[Matthew Hajicek - Singularity]

Have you tried doing it as a ramp-contour?

[Go Navy]

Our slot is .500 wide and we can start off the part and end off the part. Have 2 completed now with 4 to go.. LOL

 

Thanks again

Al

[Chris Rizzo]

sounds like your on it now. but another idea, set a small taper value in your stepdown to avoid side-loading a smaller tool at deeper depths, and then make a finish opeation with a 7/16" or something to clean up the walls.

[Quickmike]

I would try the trichoidal milling on it and see how it does. I haven't used it much myself but from what I've read here on the forum this sounds like exactly the type of situation it is intended for.

[Ed@Elite]

Another thing you should do is stop flooding the tool with coolant and switch to an air blast, perferably a light air/oil mist like a Acculube system.

Flooding the carbide when cutting steel, especially hardened steel, is not a good thing to do. It actually fractures the carbide.

Also are you using coated carbide?

[Bruce Caulley]

Plunge. 0.1" stepover, air only, Tialn coated.

[Matthew]

I would try Quickmike's route with the trochoidal pocketing routine. You can set it up to take .005"-.010" (or whatever works best for you) passes using the side of the cutter and it will nibble away at your slot.

[Roger Peterson]

you guys really need to check out the tslot.dll chook. It is made for situations just like this and will peel mill the slot and then make finish passes.

 

HTH

[Go Navy]

Roger

 

I have a tslot2.dll in my chooks but no tslot.dll and when I try to run it I get a unknown file error. I would like to learn more about it could you point me in the right directions to locate it? Finally finished all of these parts but I'm sure there will be more to come.

 

Thanks everyone for their help

Al