Milling Angles

[EmilioG]

I have a small project where I need to cut a few angles, like making a toe clamp.
I've seen YT videos where machinists cut angles using the end of an EM instead of the side.
The cuts don't look very good this way. I'm thinking that using the side of the end mill would leave a better,
flatter finish., but this would necessitate put the work on an angle plate, bolted down, then cutting the angles
with the work upside down.

I don't have a sine plate, sine vise, rotating vise, or tilt table. I do have angle blocks and an angle plate with holes and slots that will fit in a vise.
Q: How are you cutting your angles? I don't want to tilt the mill head. I don't want to ruin the few pieces of O1 tool steel that I have for this project.
The angle cuts are 10°-30° on 1/4" thick stock. In order to use the side of the EM, the work needs to be elevated., which is why I'm thinking that bolting and clamping
to a slotted angle plate should do the trick. The cuts are 3/4" wide, so should I use a large end mill to make the cut in one pass?

 

[RJSakowski]

Personally, I would face mill. If you finsh cut in a single pass with an end mill larger in diameter than your work isw wide, you shoulde have a good finish. I would use an angle vise if the angle isn't critical. If it was, I would use my sine plate, either clamping the work to the plate or mounting a vise on the plate.

But if you want to side mill, you could mount your work in the vise at the desired angle and perpendicular to the vise jaws, you coul mount the cut face parallel to the jaws and tilt the vise to the correct angle, or you could mount the vise at the correct angle to either the x or y axis and work off the side of the vise. It all depends upon the size of the work.

 

[Mitch Alsup]

The end of an end mill can be made to cut a very fine finish if you move the table at a very slow rate.
The sides of an end mill always seem to leave a stippled texture on the finish no matter how slowly one moves the table plunge cutting.
The sides of the end mill may give a nice finish climb milling when moving the table very slowly.

Personally, for a toe clamp, I would not worry about the finish.

 

[EmilioG]

I have limited tooling/work holding options. I don't have a face mill, which won't work for the side milling I'd like to do anyway., correct? I don't have a tilting vise or rotating vise, so my options are limited.
Also, it's not a toe clamp, it's a finger for a finger plate and some angles need the work turned to the side, which is why
my only option would be to use a slotted angle plate in the vise. The finger has bolt holes. My question is the size of the end mill
I should use. Using the side of the EM, an EM in the 7/8" range should work. I have a 6 flute carbide EM that should leave a nice finish.
Maybe I should do a test run on some 1018 scrap. Thanks.

 

[Billh50]

Mill it with the bottom of the end mill and then sand the surface if you want a better finish. But for somethng like a toe clamp I would not bother.

 

[richl]

You can lap it on sand paper to get the desired finish after milling. I do it a lot because it's typically the easiest way...
make sure you have a very good set of endmills. The biggest improvement I made to my milling technique was buying higher end end mills from American, German, japanese manufacturers. Do a search on eBay, you'll find some

Angle plates to work in the vise, this video is by joe p ( a good guy to learn from)

Great way to make some angle plates to work in your vise.
There is a thread on here for adding a piece of round stock to a plate, you can use it in your vise in conjunction with angle plates or a sin gauge to get any desired angle you need. I have some pics of one I made, but they are on my other tablet...

Have fun

 

[EmilioG]

Thanks, I've seen that video. I already own quality end mills; all are Guhring, Niagara, Hanita, etc... All new, sharp. from bright to Ticn, TiAln,
cobalt, carbide....I've only seen CNC machines make nice angle cuts using the center of the cutter.

 

[magu]

Thanks, I've seen that video. I already own quality end mills; all are Guhring, Niagara, Hanita, etc... All new, sharp. from bright to Ticn, TiAln,
cobalt, carbide....I've only seen CNC machines make nice angle cuts using the center of the cutter.

This is almost exclusively because of the control and planning that goes in, the cutter is the same.

Mill it with the bottom of the end mill and then sand the surface if you want a better finish. But for somethng like a toe clamp I would not bother.

Even understanding that it isn't a toe clamp that you're making, this is what I would do.

Maybe I should do a test run on some 1018 scrap. Thanks.

You'd probably be better off milling your O1 "half way" or so, and experimenting with finish there. O1 and 1018 will need to be treated differently me thinks.

 

[EmilioG]

This type of finger, needs to be held at different side angles to make these cuts, hence the slotted angle plate.
The 1018 is just to check work holding ideas.

 

[magu]

The 1018 is just to check work holding ideas.

Gotcha, I thought we were still on surface finish.