how to mill angles?

[cowanrg]

hello everyone. im trying to get into this hobby, and there is still a lot i dont know.

i was wondering how you could mill an angle on a plate of metal if the milling machine doesnt have a tilting head. for instance, this is what i want to mill (just the faceplate):

http://www.passlabs.com/amplifiers/x3.jpg

but how would you mill the angle on the fins if the mill head (or table) doesnt tilt? im sure its POSSIBLE, but is it very easy? the back doesnt need to have the angle, just the front face with the angle on each side of the fin.

this is the mill i plan to get:

http://images.grizzly.com/grizzlycom...00/G/G3358.jpg

(i can get it locally for around $800) i know its not the best mill out there, but ive been looking around for awhile, and i dont need very high accuracy, the size of the table is the big thing i need. plus, i like that it has a bit of power and weight to it. i can fix the accuracy (or so ive read that you can do that) later on when i get more accustomed to using it.

SO, thats the problem. it may be a simple solution, im not sure. i dont really even need or want to mill that piece, im just wondering if i could, and how could i. im just trying to learn. thanks!

[ViperTX]

Look at sine plates.

[cowanrg]

that looks perfect, thanks! so nothing is impossible, its just gonna cost extra money to get a sine plate if i want to do angles.

[cowanrg]

after looking at that a little bit more, i realized something... how do you attach the sine plate to the table of the mill? the bottom on most of them looks like its just a plate of metal. i have a clamping kit, but how would you actually clamp it to the table? and do you just screw your work-piece into the top of the sine plate?

[HuFlungDung]

A sine plate takes up a fair bit of vertical room. And, for what you are milling there, does it really require high accuracy? A sine plate doesn't do you a heck of a lot of good unless you buy a set of gauge blocks to prop it up with. Of course, you need to know how the trig "sine function" works to make use of the whole thing

I would wonder if you could not buy an angle cutting endmill. That looks like about a 120 degree angle. I know you can get carbide insert endmills with 60, 90 and 120 degree included angles. If those are too expensive for you, there are also high speed endmills with angle grinds available.

[DareBee]

You can clamp it in your vise on an angle.
Instead of using a Sine bar you can figure out the vertical deviation over a known distance and set up with a plunge indicator OR those fin angles probably dont need to be at a perfect set angle just eyeball it on a standard bevel protractor.

[cowanrg]

hum, that sounds about right. its just cosmetic, the angle can be really just about anything. just as long as the right and left sides match, thats all that matters.

[DareBee]

If your bevel protractor is small enough you can set it on the bottom of the vise and rest your workpiece right on the blade. Don't adjust the protractor and do the same to flip the part to the other side.

[mineralman]

I have a very inexpensive solution. Harbor Freight has a 4" tilting vise for $20! It bolts to the mill table.

I normally don't recommend HF stuff, but I bought one thinking for that price I couldn't go wrong. It is excellent! Well made, well finished, more than worth the price.

Larry
New Orleans

[JFettig]

If you running a cnc, just cut it with a ball mill, draft it out and measure or calculate the stepover, I recently cut a 30 degree angle from horisontal with a 3/16" ball mill .020 stepover and a little sanding and it looked awesome.

Jon

[DareBee]

Originally Posted by JFettig If you running a cnc, just cut it with a ball mill, draft it out and measure or calculate the stepover, I recently cut a 30 degree angle from horisontal with a 3/16" ball mill .020 stepover and a little sanding and it looked awesome. Jon

Is a good method but will not work on the part he wants to cut.

[Zoff]

It is the best mill exept it is too much money, see if you can get it for $450.00. Any mill is the best if operator knows how to use it.
Aproach accesible surfaces then position part at an angle to aproach angular surfaces with side or face of end mill. Should take 1 hour max.