Using End Mill For Side Milling

[HBilly1022]

I'm new to milling and just getting some hours in with the new mill. I've squared up a block and my el cheapo vise that came with the mill and things were looking good until a few hrs ago. I finished using a 3/4" end mill to face 4 sides of a 1 1/2" thick mild steel block that was 3" wide and 6" long and figured I would use the end mill to side mill the ends of the block, rather than try to stand it on end and get it square to the other surfaces. Started out ok but I noticed it was getting harder to cut so I stopped and checked the cutter. The bottom sides of the cutter that were below the DOC were still very sharp but the sides of the cutter that were doing the work were dull. I started taking 0.005" deep cuts and backed off to 0.002" as I progressed but dull is dull and it was obviously not getting better so I stopped.

Is this the wrong way to go about side milling and if so what is the right way?

 

[GK1918]

Thats what it looks like 'dull & duller". If something you are doing time to time, I would
buy a roughing end mill then finish with a new end mill. We get into this a lot and thats
why we have a shaper. The reason, there are no suppliers around here for end mills, so
if in the middle of a job & break or dull one, thats time waiting for UPS, and the old story
everybody wants something yesterday. Such a shame, if this was in the 1950s I could
walk & get anything right here, the famous Lincoln twist drill mfg. end mills gear cutters
you name it, now there's low cost housing there now...... I'm now ranting again wife says
I'm whining again?
sam

 

[TommyD]

Sounds like a cheap end mill. Buy a good name brand or, as suggested a rougher but buy GOOD quality cutters. They may cost more initially but will make up for it in how long you are able to use it.

Do you know the difference between conventional and climb milling? With those depth of cuts it sounds like climb milling.

 

[Billh50]

Some of the cheap endmills are not sharpened right and will not last. I always buy name brands for endmills. I was taught to conventional mill on a manual mill, unless I am only taking a skim cut. The reason I was told this is because if for some reason the table jumps the endmill will grab the part and pull it right out of the vice and also gouge the part. I have seen this happen many times through the years.

 

[Karl_T]

+1 What everybody said about sharp cutters.

Cutting on the side REALLY benefits from a rigid setup. A good vice and clamping the axis not in use help. Now, your mill is the limiting factor. The DOC that you can best remove at once will need to be found by trial and error. I can take .100 deep by 0.025 wide at a time on my Excello. The Supermax will easily do .25 deep by 0.025 wide on the side. Years ago, my clapped out bridgeport really struggled with this cut. Using a ruffer and then a skin cut with a new end mill was about the only way to get er done.

 

[planeflyer21]

All good advice!

What's your experience with knives? Same concept. I used to think that a knife is a knife is a knife, and hooboy were people stupid for paying $_____ for one. Then I had a nice pocket knife that I used daily and didn't need to sharpen one blade for years, after having some that needed constant sharpening with great effort. Hhmmm...

 

[Bob Korves]

Scale and corrosion on the work will prematurely dull the cutter. I usually run a flap disc over rough skinned material with an angle grinder before putting it in the vise. Don't know if that was an issue for what you were doing...

 

[mmcmdl]

End mills are made to " cut " and not " rub " material off . Same as a drill . With proper speeds and feeds they'll live a longer life . A rougher " corn cob " end mill will chew material off like there's no tomorrow providing you have the proper set up . As stated above , conventional cut when roughing , climb when finishing . Better finish without the " hairs " .

 

[Metal]

Also depending on your speed you could have been heating up and hardening the steel, the end might have been cutting, but the sides could also have been rubbing and warming things up which would explain why they dulled out.

 

[HBilly1022]

Thanks for all the replies, a wealth of info here. Looks like I need to get a roughing cutter and stop using these cheap end mills for side milling.

Scale and corrosion on the work will prematurely dull the cutter. I usually run a flap disc over rough skinned material with an angle grinder before putting it in the vise. Don't know if that was an issue for what you were doing...

Were you in my shop watching what I was doing, lol. That is exactly what I did. I have a bunch of mild steel I get from the scrap steel yard and that is what I use for just about all of my projects. The piece I was playing with / learning was indeed covered in mill scale, rust and generally in rough shape. Next time I will take a grinder to it before it goes into the mill vise or lathe.

Sounds like a cheap end mill. Buy a good name brand or, as suggested a rougher but buy GOOD quality cutters. They may cost more initially but will make up for it in how long you are able to use it.

Do you know the difference between conventional and climb milling? With those depth of cuts it sounds like climb milling.

Not sure about the climb cut. Is it the same as using a router in woodworking? When cutting along the edge of a work piece, a climb cut would be moving the cutter towards me, if the work piece is on the left side of the cutter (or in the case of milling machine, moving the table to the left with the cutter being on the backside of the work piece). Is that right and if so, should I be using a conventional or climb cut when doing edges?