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What we Learn from this Picture?

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oskar

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#1
The attached picture indicates a cut using an endmill and it says it should not have been done this way but I don’t understand why. Picture is taken from https://toolingaround.ca/lms.php

The text on the picture also says “..for some cuts, it is appropriate…” What are these appropriate cuts?

Thank you
Nicolas
 

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tq60

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#2
We would have placed material sideways flat and cleaned up the end.

Far easier to insure square cut.

Using end when making pockets etc.

Sent from my SAMSUNG-SM-G930A using Tapatalk
 

T Bredehoft

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#3
.for some cuts, it is appropriate…” What are these appropriate cuts?
If the piece were horizontal in the vice, the top surface could be cut as shown. The more of the work secured in the vice, the safer, more secure the piece is. As shown in the picture, the leverage from the cut could move the work.
 

markba633csi

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#4
Nothing really wrong although the piece may shift and the work proceeds slower than using the side of the cutter (or using a flycutter instead)
Mark
 

RJSakowski

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#5
It all depends upon the tools at hand. If the workpiece were on the order of 2" square, it would take an extra long end mill to side mill the end. Even if the machinist had an end mill with 2" flutes, it would be prone to chatter. Facing may be the only option available.

I would cut all four long faces first. I would take pains to square up the stock. The fixed jaw of the vise would need to be vertical. The direction of cut would be along y, with shallow depth of cut. A small width of cut will keep most of the cutting force in the y direction and minimize having the workpiece pull free.

If there is concern about the ability to square in the x direction, once the facing operation was complete, the workpiece could be rotated 90º which will place a squared edge on the floor of the vise. Repeat the facing process and you would have a squared end. Flip the workpiece over and face the opposite end to dimension.
 

JimDawson

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#6
Looks like a lot of stick out on the workpiece, not well supported, but other than that it's OK. I spent about 6 hours cutting like that yesterday. Then for one of the parts I laid it down and used the side of the endmill.
 

benmychree

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#7
Both the part and the angle plate are very poorly secured and could easily move under cutting forces. The angle plate is only clamped down at one end, best would be if holes or slots were made near the center of its base to match the T slot spacing on the table. Standing the part upright on the face of the plate with only one clamp is asking for trouble, with movement of the part likely. As others have said, laying the part down on the table or holding it horizontal in a vise and cutting with the fluted of the end mill would be best.
 

oskar

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#8
My thanks to all.
 

BaronJ

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#9
Hi Oskar, Guys,

The difference between an "end mill" and a "slot drill" Is that a slot drill is designed to cut on its sides and make slots, where as an end mill usually is able to be plunged into a surface. However today the differences are not worth bothering about since they are often used interchangeably and both tools capable of doing both jobs.

In the old days slot drills often had two straight flutes and couldn't plunge.
 

markba633csi

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#10
You will find both plunge cutting and non-plunge cutting end mills; I have both types and sometimes have to take a close look to tell them apart
m
 

BaronJ

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#11
Hi Mark, Guys,

The trick to telling which cutter is a plungeable cutter, is to look at the sharp end, and if one cutting edge extends beyond the center line then it is what is called center cutting and can be plunged into the work like an ordinary drill. Most modern slot drills are of the center cutting type.
 
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