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View Full Version : Mag rail sear slot....



Skoad
02-24-2006, 11:09 AM
Is there a specific reason why the slot where the sear is, is in a zig-zag cut? It looks like its there to allow a bit of movement, but not too much wiggle....But I can't think of why it would need to wiggle anyway.

Just curious if its really needed or can just a straight, thin slot be there instead.

StygShore
02-24-2006, 11:23 AM
actually... with the zigzag, more material can be cut out, as you are only prividing a guide at the points where the zigzag comes in, rather than providint support all the way down both sides of the channel.


Styg

Skoad
02-24-2006, 11:25 AM
More material to be cut out would only be done if they were trying to save weight and well, if they were trying for that then they would have gutted the sucker ULE style a long time ago :) I *highly* doubt they did it for weight - I mean look at how much weight they saved! Gotta be in the hundredths of an oz. :rolleyes:

And it has to take more time/money to make a zigzag than a straight cut...Just wondering if it actually has a functional purpose for being like that.

Only other thing i can think of is to reduce 'drag' on the sear to just a few points of contact. Really don't see a need for it myself, but maybe thats not the answer.

slade
02-24-2006, 03:20 PM
i was wondering that too. but the sear doesnt need a guide, the ULE rails have that area milled out.

CoolHand
02-25-2006, 12:03 AM
They did it like that to save a tool change.

How do you make a slot that will control a sear that is 1/8" wide, with a 3/16" end mill?

You make the slot zig zagged.

Look at a AM/MM rail, and ask yourself what size end mill could they do every bit of that work with?

That's right, a 3/16" FEM.

It was done that way to make it easier to machine.

Why use a 3/16" instead of a 1/8"?

Because that 3/16" end mill is about 3x stiffer than an 1/8", which means it flexes less, which means it will be harder to break, and will give a slot that is closer to the dimension you are after, AND you can feed it faster. You can see about a 200% gain in productivity by going up that 1/16" in diameter.

Funny how the little things make such big differences in the manufacturing world . . . . . . .

slade
02-25-2006, 12:31 AM
They did it like that to save a tool change.

How do you make a slot that will control a sear that is 1/8" wide, with a 3/16" end mill?

You make the slot zig zagged.

Look at a AM/MM rail, and ask yourself what size end mill could they do every bit of that work with?

That's right, a 3/16" FEM.

It was done that way to make it easier to machine.

Why use a 3/16" instead of a 1/8"?

Because that 3/16" end mill is about 3x stiffer than an 1/8", which means it flexes less, which means it will be harder to break, and will give a slot that is closer to the dimension you are after, AND you can feed it faster. You can see about a 200% gain in productivity by going up that 1/16" in diameter.

Funny how the little things make such big differences in the manufacturing world . . . . . . .
hmm, very smart ryan. i didnt even consider the tooling.

wanna-b-ballin'
02-25-2006, 12:53 AM
thats ingenious. i dont think that would have ever occured to me.