:D I resized it a little

while this doesnt pertain to the machining parameters, it is definately something that everyone here should have:D

Bump

here is a good link with some info on machining.
http://www.production-machining.com/...es/030202.html

Robert

I just got a mill (well not delivered yet) :D

I have a set of 12 endmills for creating the channels.

Now from what I understand I drill a hole with a drill. Stick me end mill in and start taking off small layers. From the indo above it seems to indicated I can go 1.5* the diameter of the endmill down. So for a 1/8th endmill I can mill 3/8 depth? Seems a lot.

BTW Fixittt the slot mills I mentioned in my "Hi from me" thread, have two cutting blades where as endmills have 4 cutting blades (according to a fitter and turner whos worked for many years as a fitter and turner)

Also Is there such a thing as going too slow? I wouldn't have thought so but I'm going to be cautious and practise a lot.

The data in the tables are for proffesional machines that can handle that, basicaly it's not a problem for tool going that deep if you start from the side because every part of the tool is cutting, the problem is only in machine itself if it can handle to keep the rpm and not vibarate too much, so with powerfull & rigid machine no problem going up to 1.5mm* diameter deep. But remember the suggested rpm for smaller bits, this is the problem if you can't have those high rpm's with good torque, then you must go slower and in smaller depth steps.
Too slow is not a problem at all
Two(three) blade bit are usualy for ment for long chanell milling, and they can all handle drilling (milling in Z direction)
Four or more blades bits can be also used for chanell milling but for going in Z direction the must have front tooth to the center of the bit (I hope you understand what I mean - if not I'll take pics), but primary use for those are face milling going from side to side like you can see on the second acad picture (Parameters for smooth face milling, with end mills)

Oh yeah one more thing, and very importan I might add.
There are three ways you can mill.
http://www2.arnes.si/~mlivak/Cnc/typ...%20milling.GIF


2nd EDIT :D


Surface finish is better with climb milling but the cutting forces are directed unfavourable so this type of milling should only take place on machine that are made to handle those forces.
So for classic machines conventional milling is the right choice.

I think the same direcrion milling is also called climb milling?

Am I reading the graph right?
You would want the tool in 1 to be spinning the opposite direction? 2 is fine and 3 is Symetrical milling?

Well I don't know the correct english word I just translate our description. The way we want to mill on normal machines is No.1. So yes, we move the work piece against the rotation of the tool.
No.2 is the way we can't realy do it properly, without having special machine, and No.3 is ok too, because it's simetrical

The 2 english phrases are
Cline and Climb milling.
#1 in the graph is for manual mills. As the forcesw are not as great on the machine.

#2 is for CNC machines. As they can handel the forces put on the material. Also note that you have to have a very good vise, I have seen parts ripped right out of a vise before.

Almost invariably, the preferred method of milling is climb. This varies for different materials (wax seems to like conventional, steel and aluminum prefer climb), but in general, go with climb-cutting first.

Bob

So let me get this straight to correct the pic.
No1 is cline milling
No2 is climb milling
No3 os symetrical milling.

If that is correct I'm still saying No.1 method is the preffered one at least on classic mill.

Allow me to clarify:
No. 1 is climb cutting
No. 2 is conventional cutting
No. 3 has many different names, depending on who you're talking to. Usually need an explanation so we're both referring to the same thing ... :rolleyes:

Bob

EDIT: I have it bass-ackwards. I was thinking along the lines of cutter movement instead of workpiece feed direction: No.1 is conventional, No.2 is climb. Climb is still preferable for most situations. Sorry about the mix-up. :cry:

Since everyone is going to post their opinion...

Here's a link: RobJack's guide
I think that explains it all.

Picture & post updated.
Btw. from my experience conventional milling is preffered for classic mill. Climb milling gives you better surface but machine shoud be CNC

That's what I had heard. It was also mentioned that Climb milling is much harder on the machine.

its realy easy to understand if you think of Climb milling like this.

The endmill flutes are trying to Climb the part. In turn trying to pull the part closer. More stresses!!!!!! I have tried to climb mill on a bridgport machine, and didnt have the "Slop" out of the table, and it slammed the whole table forward. Manual mills have backlash in them, that is just the way it is. It sounded like a gunshot, and I got "SCHOOLED" on whyit was wrong. Not to mention an ass chewing!

I have no experience on Bridgeport brand machines, all of my experience is on CNC mills. But, in general, I avoided conventional cutting like STD's. Only wax seemed to like it...

Bob

Question for those with experience ....
 

...milling copper:

What is the minimum "fin" thickness you would be comfortable leaving? I realize that this will be somewhat dependent on "fin" height, but if anyone has any guidelines.....:confused:



Bob

utabintarbo

This may sound like a smart a$$ answer, but I beleive that you already know. If you have ever milled copper, or like material you know that very thin walls + high RPM endmills= broken parts

But there are many different ways to achevie the desired wall thickness. Granted you dont want them to be paper thin. But if your wanting to make very thin walls, that is going to increase the machining time alot. You will have to make alot of really shallow passes so you dont break the wall.

Well, I have never had the pleasure of milling copper:rolleyes: . Just aluminum, steel, graphite, and wax. My general tendency is towards safety (lot of "lights-out" milling in my past) where I would take small bites faster rather than have something break.

I have made some pretty thin walls before in the materials I have machined, I'm just looking for a practical minimum wall thickness I can reasonably expect to achieve in copper.

Any ideas on that?:drool:

Bob

bump
 

No ideas?:(

NPT thread specs
 

For those interested (me!) here are the NPT thread specs (along with a few more).

Click me

Maybe someone else can post the european counterpart?

Can anyone make sense of this gibberish?

I'm trying to figure out how much flexing polycarbonate will have, under different thickness, and different pressure.

From:
http://www.bayplastics.co.uk/data%20...20111sheet.htm

Limiting flexural stress

Typical values
90-95

Units
N/mm²

Test method
DIN 53452


BTW: here's an interesting link:
http://www.machinist-materials.com/c...r_plastics.htm

Still searching...

but I found something interesting: the machinist guide to the US Army!

Fundamentals:
http://155.217.58.58/cgi-bin/atdl.dll/tc/9-524/toc.htm

The tables, all the tables, it's all there:
http://155.217.58.58/cgi-bin/atdl.dl...4/Appa.htm#top

If that's not enough... Here' s a page to more links:

http://www.machinist-materials.com/links.htm