Small oops.

[vlmarshall]

Hey Zee, here's one you haven't done yet. While making a pass around the footplates for my Cracker locomotives, I had an endmill pull out of it's collet.
I just happened to be pointing a camera at the thing, and captured 37 seconds of vid before I dove for the stop button. This is why I use a scrap plate as a fixture between my parts and the mill table. ;D
[ame]http://www.youtube.com/watch?v=uP2smwtsDJo[/ame]

I heard the cut getting ugly, and kept dropping the feedrate, but I was trying to hold the camera steady, and not really paying attention to what was going on.
Once the tool swung the corner and started cutting full-width, things went to crap in a hurry.

 

[rake60]

Nice tutorial vlmarshall!

When you hear the sound of a WW2 Fighter going down it's never
a good thing!

Rick

 

[zeeprogrammer]

Hey Zee, here's one you haven't done yet.

An assumption!

This is why I use a scrap plate as a fixture between my parts and the mill table.

I can provide you with additional reasons.
I've got two holes in my table. The upside is that they're a constant reminder that I'll do it again. Upside? :big:

You're obviously okay (well...physically ). I hope the equipment is okay. Any damage to the part?

 

[vlmarshall]

Haha, well, it turns out I killed the part anyway. I wasn't paying attention while setting my zero point, the profile is off by the cutter diameter in both X and Y.
So, here's my first part in the HMEM scrap pile! ;D

 

[Foozer]

Haha, well, it turns out I killed the part anyway. I wasn't paying attention while setting my zero point, the profile is off by the cutter diameter in both X and Y.
So, here's my first part in the HMEM scrap pile! ;D

That sounds oh so familiar, that's right i forgot to account for the edge finder diameter. Me, four parts scrapped till one became passable

 

[Maryak]

Vern,

Glad no serious damage to you or the mill. ;D

As one of our Prime Ministers said. "Life was not meant to be easy."

Best Regards
Bob

 

[tel]

The climb-milling didn't help either. Probably the cause of the pull out.

 

[vlmarshall]

The climb-milling didn't help either. Probably the cause of the pull out.

I know...but it's a habit! oh:

Actually, after the fact, I remembered a bit of a mushy feeling while tightening the "drawbar". (It's a litte Sherline, the Drawbar's just a bolt), I should have checked it out better.

Too many distractions while machining at home, sometimes. ;D

 

[vlmarshall]

Glad no serious damage to you or the mill. ;D

Nah, no damage, just an inch-long section where it cut through the stock in one pass. Since I was climbing, the endmill,( and the mill, for that matter ;D ), deflected away from the part's finish line.

 

[steamboatmodel]

I was always told to never climb mill on a manual mill. Its something I always have to consciously remember as I programed/operated CNC where climb milling is the norm.
Regards,
Gerald.

 

[vlmarshall]

I was always told to never climb mill on a manual mill. Its something I always have to consciously remember as I programed/operated CNC where climb milling is the norm.
Regards,
Gerald.

Exactly! I'm spoiled by CNC all day long at work, and all evening at home.

 

[rake60]

Here I go again suggesting the breaking of my own rules....

Climb milling is potentially dangerous!
As has already been stated here in CNC operations climb milling
is the method of choice. After seeing the finishes produced by that
in the CNC machine I was running at work I was hooked on the idea.
EVERY roughing cut I take on my home mill is conventional milling.
I leave .015" then take a "pre-finish" cut of .007" in a climb milling
operation. It's going to dig in a bit. it might actually take .010"
The final finish cut will take whats left. The finish is clean and there
is no polishing required.

Please Note!
The gibs are adjusted tight.
The spindle speed is high and
the feed is half what it is for a roughing cut.

Rick

 

[steamboatmodel]

Here I go again suggesting the breaking of my own rules....

Climb milling is potentially dangerous!
As has already been stated here in CNC operations climb milling
is the method of choice. After seeing the finishes produced by that
in the CNC machine I was running at work I was hooked on the idea.
EVERY roughing cut I take on my home mill is conventional milling.
I leave .015" then take a "pre-finish" cut of .007" in a climb milling
operation. It's going to dig in a bit. it might actually take .010"
The final finish cut will take whats left. The finish is clean and there
is no polishing required.

Please Note!
The gibs are adjusted tight.
The spindle speed is high and
the feed is half what it is for a roughing cut.

Rick

The only other sugestion I can add is to make dang sure the part is held very solid and the mill is tight in its holder. Its not fun having ether shift when milling, and with climb milling they will want too.
Regards,
Gerald.