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Slotting 1045

FARFLE

Plastic
Joined
Nov 20, 2019
Location
Redmond
Heya all! I have a project I am working on with the Fadal 4020. Shortening and cutting lightening slots in these 1045 steel gear blanks.

2019-11-20_06-32-34 by Jackson Edwards

The problem I am having is short tool life on the end mill I am cutting these slots with. I am getting roughly 60 parts per tool (600 slots) after swapping feeds, speeds, ramp angles and even a few different kinds of tools,

The best combination I have found is:

.3125 Maritool variable 4fl TiAlN for tool steel w .02 radius

Running Mobil soluble oil 100 at a fairly high concentration.

340sfm 4200rpm 7IPM .0004ipt (seems light, but breaks if I lower spindle speed, and breaks if I increase feed rate)

4° profile ramp, this does roughly five zigzags to the bottom. Slot is .340" deep, about 1.2xD

6ipm 14 thou radial finish pass, as the ramping cut leaves a bit to be desired.

Things I have tried:

A straight plunge to 100% depth and slot works some of the time, but depending on coolant stream angle, it will chip load and fail randomly.

Plunge to 1/2 depth and slot works ok, but The tip .150 wears and fails faster than the ramping pass does.

I pulled an end mill after ~50 parts and you can see the degradation on the cutting edges on the bottom edges, as well as the sides about ~.130" up the flute.


2019-11-20_06-55-36 by Jackson Edwards



2019-11-20_06-55-48 by Jackson Edwards

Thanks!
 
Be careful holding multiple parts like that in a vice. Really not a good idea, eventually you will get 2 slightly different size parts and the small one will go flying taking god knows what with it. Could loose a tool? Part? Spindle? Maybe your head after the part passes though those rinky dink fadal doors (I have a 4020 too lol).

In terms of cutter life id be tempted to try a faster feed and lower ramp depth if you need too. Not sure if you will gain much. 600 slots dont seem too bad.
 
600 slots doesn't sound bad, but I would think you should be able to go quite a bit faster. I would be ramping at about 15-20% cutter diameter and feeding about .002ipt. How is the runout of the cutter? Can you get away with machining dry with an air blast?
 
Be careful holding multiple parts like that in a vice. Really not a good idea, eventually you will get 2 slightly different size parts and the small one will go flying taking god knows what with it. Could loose a tool? Part? Spindle? Maybe your head after the part passes though those rinky dink fadal doors (I have a 4020 too lol).

In terms of cutter life id be tempted to try a faster feed and lower ramp depth if you need too. Not sure if you will gain much. 600 slots dont seem too bad.



Luckily these are precision ground, and should be a consistent OD, But I do have my guy watching out to see if one tightens up before the other does. I'll give a faster shallower ramp a shot and see what I get.


The Fadal isn'tset up for air blast at the moment, But the facing op is done dry and works amazingly with a fast adaptive on a 7fl mill.


I'll try snagging a carbide drill and bashing out a series of holes, I am wondering if the super interrupted cut would be better than continuous plunging.
 
Looks like you have a common suggestion going through the responses.

Drills drill better then Endmills.

Looks like you can get two, maybe three holes in each of those slots.

Drilling would remove alot of material quickly.

With less to remove the endmill lasts longer, less chips to recut.
Ramping an endmill has alot of tool engagement, lots of heat with poor chip evacuation.

A nice Cobalt Stub Drill will make short work of the holes. With much of the material hogged out you should be able to bring up the feed by a good amount.

It's one of those add an operation and save time and tool things.
 
Is this an ongoing job? A few changes in tooling and processing methods would help greatly. Slotting this material should be no problem. Drill an entry hole. Speeds and feeds should be 400 sfm and.0012 ipt. Run dry.
 








 
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