What Is The Purpose Of Milling "Dog-Ears" In Jaws??

[Mill&Lathe]

I am new to milling jaws on the milling machines and have been watching guys milling what they call "dog-ears" on the jaws that they mill to hold parts. When I ask them the point of "Dog-ears", they reply that it has to do with locating off the part but somehow while contemplating this, I cannot get it to sink into my mind to fully grasp their purpose of adding dog-ears to newly milled jaws. As I see it, milling jaws without a dog-ear would be be no different than milling dog-ears, but I am sure that I am missing the point and/or purpose of dog-ears.

Can someone please explain breifly (and in total newbie terms) what the purpose and function that "dog-ears" serve when it comes to milling fresh jaws in the mill? I just cannot grasp why they are needed and why they are advantageous compared to not milling them at all.

Thank you!!

[Mill&Lathe]

Anyone?

I am now starting to wonder if maybe my suspicions about the so-called "dog-ears" being useless are true, being that it seems nobody here has any input on them so far.

[RICHARD ZASTROW]

Mill&Lathe, Patience, it's a day off for most.LOL

Maybe you should describe what you mean by "dog ears." It may be a local term. I bet I've been at this longer than you have and I haven't heard of dog ears on milling jaws. I am ASSUMING you refer to milling machine vise jaws.

I've often used end stops on the ends of vise jaws for locating & preventing parts from moving in a vise.

Dick Z

[Delw]

I think what he is refering to is tabs so to speak, were you butt the part up against the "TAB/dogear" for a location so you dont have to find the edge of the part every single time.


first operation stuff direct from flat bar, all you need to do is mill vertical slots in the vice.
for example lets say you have a part that finishes at 6" in length and you saw cut your parts. of coarse they are a tad over 6". you set the part in the vice jaws so you have a little bit on each end(hanging over your grroves) that cuts the finish DIM and you dont have to guess or indicate were the machine will cut.

all the slots should be deeper than the location depth as not to have a burr make the part higher on one side. the same with all corners put a 1/8" wide groover deeper than the location surface. incase your stock again has burrs on it.


Delw

[lancut]

they call this "Solid Stop" in SE Georgia, usually clamp on raised vice jaw.

[Mill&Lathe]

Originally Posted by RICHARD ZASTROW Mill&Lathe, Patience, it's a day off for most.LOL Maybe you should describe what you mean by "dog ears." It may be a local term. I bet I've been at this longer than you have and I haven't heard of dog ears on milling jaws. I am ASSUMING you refer to milling machine vise jaws. I've often used end stops on the ends of vise jaws for locating & preventing parts from moving in a vise. Dick Z

Thanks so much for your reply RICHARD ZASTROW, I appreciate it! I guess the best I can describe these dog-ears that guys are milling is sort of basically like milling jaws as normal to hold a part, but in one of the corners to which the part is pressed up against. there is sort of like a relief which is said to be at least the diameter of the endmill used to mill the jaws. It is basicly like a relief the diameter and distance of the endmill that was used in cutting the jaws. When the jaw cutting is completed, it sort of looks like the shape of a tobacco pipe where the part that the tobacco gets burned would be the endmills relief, and the length of the pipe would be the shape of the jaws that actually hold the part. Please except my apologies if this example makes it more confusing to understand. I just cannot think of a better example right now at the moment.

Originally Posted by Delw I think what he is refering to is tabs so to speak, were you butt the part up against the "TAB/dogear" for a location so you dont have to find the edge of the part every single time. first operation stuff direct from flat bar, all you need to do is mill vertical slots in the vice. for example lets say you have a part that finishes at 6" in length and you saw cut your parts. of coarse they are a tad over 6". you set the part in the vice jaws so you have a little bit on each end(hanging over your grroves) that cuts the finish DIM and you dont have to guess or indicate were the machine will cut. all the slots should be deeper than the location depth as not to have a burr make the part higher on one side. the same with all corners put a 1/8" wide groover deeper than the location surface. incase your stock again has burrs on it. Delw

Thanks for your reply Delw, I really appreciate it!! I think you are understanding what I am trying to explain. But instead of it being for sawed parts, it is actually being used for parts that are already at finish dimension already to size by the lathe dept before reaching our mills. And you are correct the dogears are at a depth lower than the freshly cut jaws to which actually hold the part. So, since it is my assumption that you understand what I am referring to, can you please explain how these dogears are beneficial to parts that arrive to our mills that are already at finished dimension from the previous lathe dept? I see what you mean by needing this for sawed-off parts, but how can this be beneficial for parts that are already to exactly finished dimensions? I am just failing to understand the concept at this time and want very much to understand why the experienced mill guys are cutting these dogears for finished-to-length parts.

And again, THANKS guys for your replies!!!

[mactec54]

Mill&Lathe

Take a photo of what they are doing, I get what you are saying, But you may be right it sounds like a waste of time, & gives the vice jaw less clamping area

[Mill&Lathe]

Originally Posted by mactec54 Mill&Lathe Take a photo of what they are doing, I get what you are saying, But you may be right it sounds like a waste of time, & gives the vice jaw less clamping area

Thanks for your reply mactec54, I really appreciate it!

Gosh, I hope this illustration/diagram below comes out correctly when I post this, but here is basically what it looks like when milled:

|`|________
|__________

The part is usually round and came directly from the lathe dept at finished dimension with chamfers and all. When placed in the newly cut jaws, the part is inserted into the jaws with pressure by hand to press up against the left side of the jaws. As shown above, the dogears just seem to act as a relief, but I cannot figure out why it is needed! Especially since it does consume a bunch of extra time to cut them. I just dont get it and want so badly to understand it!

THANKS!!!

[rowbare]

Looks to me like it provides clearance for the working end mill to keep it from hitting the jaws during some part of the operation.

bob

[mactec54]

Mill&Lathe

Is this for lathe chuck or in a milling vice

[Mill&Lathe]

Originally Posted by mactec54 Mill&Lathe Is this for lathe chuck or in a milling vice

It is round parts that are clamped into a milling vice. Thanks again for your help!

[Mill&Lathe]

Originally Posted by rowbare Looks to me like it provides clearance for the working end mill to keep it from hitting the jaws during some part of the operation. bob

Actually, perhaps that may be a possibility but I dont think there was any need for having any clearance but I could be incorrect. But that would make sense, but again, I dont think there was any clearance issues from what I recall. Thanks for your reply rowbar!

This is eating away at me for sure!