80% finishing problems - need advice

[AreWeNotMen?]

I'm having a heck of a time "milling" my 80% on my drill press - and yes, I know, that's my first problem - but that's all I have so let's move along.

I drilled all the small holes and larger alternate holes to get ready for the milling. I made some progress, but destroyed the carbide end-mill! I tried looking for tips but I'm guessing my "speed and feed" rates are way wrong.

Constructive advice is appreciated!

Pics of my ignorant mess are included for your amusement....

[kcstott]

Ok one: Do not use carbide in a drill press. High speed steel will work much better

Two: Do not use four flutes on aluminum, two flutes possibly three.

Three: I see no indication of any kind of cutting oil??? WD40 is your friend.

Four: It looks like you were trying to plunge the material out??

I take it you do not have a mill table on your drill press?? and you are holding your fixture by hand and plunging in to your part with the end mill?? bad idea

If that is the case figure out a way to clamp your fixture down as the fixture jumping around you a drill press vise and clamp the vise down.

Outside of that buy a Bridgeport

[AreWeNotMen?]

I'll switch to HSS, and 2-3 flutes. (tutorials showed carbide, 4-flute...oh well)

Was using WD40 - will have a helper spray while I cut.

Those are the drill holes...I was milling laterally.

I was clamping guides to the table to slide laterally, and had top guard to prohibit and inadvertent upward movement. I did go get a mill vise but it was simply too huge for my dinky press.

And...what speed for milling?

[kcstott]

In a mill that endmill would need to be turning atleast 1800 RPM. I can't say on a drill press. Now are you conventional cutting or climb cutting??


feed depth I'd try to keep it at .100" tops for a drill press. maybe even less.

Don't be afraid to flood the pocket with wd40 keep your chips clear too.

[AreWeNotMen?]

My speed choices are 3100, 2340, 1720, 1100, and 620 - so should I run 2340 than?

And, I don't know what "climb cutting" is....

[kcstott]

I'd try 1720 and see how it feels.

as for climb cutting. ok look at your endmill when it's in the press it turning clockwise. If you feed your part from left to right and the endmill is cutting the surface that is away from you. you will notice the end mill is trying to "climb" up the part. feed it the opposite way and that is conventional cutting.



what you want to do is cut is in the conventional technique

[AreWeNotMen?]

Ah, okay - I was doing the conventional method...and will try 1720.

have to wait until tomorrow to get the proper end-mill...I will report back.

Thank you - I appreciate your help! And HFD if you're a dad!

[kcstott]

Yep you to buddy I'm the proud father of a beautiful six year old girl that is the love of my life

[Sunday]

Ok one: Do not use carbide in a drill press. High speed steel will work much better

Two: Do not use four flutes on aluminum, two flutes possibly three.

Three: I see no indication of any kind of cutting oil??? WD40 is your friend.

Four: It looks like you were trying to plunge the material out??

I take it you do not have a mill table on your drill press?? and you are holding your fixture by hand and plunging in to your part with the end mill?? bad idea

If that is the case figure out a way to clamp your fixture down as the fixture jumping around you a drill press vise and clamp the vise down.

Outside of that buy a Bridgeport

This and use lube.

[AreWeNotMen?]

Yep you to buddy I'm the proud father of a beautiful six year old girl that is the love of my life

very cool...

I am a father of four - 28, 27, 27, and 25 - and yeah, they're adults, but there still my "babies"!

[M1NM]

Trying to figure out how aluminum did that to the cutter. Is that a broken drill bit in the hole about in the center of the pocket?

[kcstott]

Trying to figure out how aluminum did that to the cutter. Is that a broken drill bit in the hole about in the center of the pocket?

Good eyes that sure is.

There would be the cause of the problem

But FYI any cutter that can't clear the chips with break. I seen a guy break a 1" endmill in plexiglass. Once the flute clog up you may as well be trying to push a steel rod sideways through the material.

[AreWeNotMen?]

Gaaaaah!

Funny, in a sad way, that my cellphone cam sees better than my eyes!

So I did notice that yesterday before seeing it noticed here, removed it and thought "what the heck, I have one end-mill left...let's make a firearm for Father's Day". It was slow work for me on the drill press, but it turned out okay. I have one more to do, and am ordering the proper HHS mills today before starting that one.

Thanks much to all.

[kcstott]

if you go get some pipe wrap tape and line the profile of your jig it will off set the cutter a little bit. then on the final pass it will allow you to remove the tape and take a clean up cut.

Carbide is fine for aluminum not the best choice but will work. Its the drill press that can kill a carbide end mill although we found what killed yours

[edgerly779]

That broken drill bit has to come out. Cannot finish with it in there. You need an xy table