# Milling Of Small Parts



## EmilioG (May 19, 2015)

I've done some milling on a BP, but very little.  I need to mill off a small section of round 1018 1/2" stock.
Only 1/4" deep (half) and 1/2" length leaving a small "notch".   Do I set the depth stop on the mill (no dro)
and make several passes?  What about the length of cut (sideways cut)?  Thanks


----------



## Ed ke6bnl (May 19, 2015)

I am no machinest but I like to touch off on the top of the round stock and zero the table and raise the table .500 in small passes.


----------



## chips&more (May 19, 2015)

A sketch or blue print would really help. Sorry, at least for me, the description you have is leaving too much to the imagination.


----------



## JimDawson (May 19, 2015)

On a BP, I normally lock the quill and use the knee to move the work into the tool.  Zero off of the top of the work.

I would use a 0.25, 2 flute, end mill, and do it in 3 passes, of 0.125, 0.120, and 0.005 for a clean up.  About 600 RPM, and use some oil.


----------



## EmilioG (May 19, 2015)

Should I blue the part with Dykem so I can see how far I need to go?


----------



## kingmt01 (May 19, 2015)

I don't really understand what you are saying ether but I'd think measuring as you cut would be the best bet. It would also depend on how exact you need to be.


----------



## Tony Wells (May 19, 2015)

No need as long as you trust the dials, or indicator if you have one you can stick on the knee. I'm a little more crude I guess. I would run the quill stop nuts up to a point where the end mill and spindle nose clear the workpiece and however you are holding it. Holding a little pressure on a 1/2" end mill, or a mechanics grade Jo block between the moving collar and the stop nuts, I would simply crank the table up until I saw, hear, and or felt the end mill (running) touch off. Now you know that when you remove the 1/2" spacer, the stop nuts are very, very close to 0.500 from the finished depth of cut. 

Now depending on the end mill, and how fussy I needed to be, and how well I had ahold of it, I might drop it the whole 1/2" and run across it. If I thought I could get by with the results, I'd use a 1/2" end mill to do it too. Quick and dirty, but at times that's all that is needed, and gets the job done quicker. If you need closely controlled sizing, this is NOT the way to do it. Just an option.


----------



## EmilioG (May 19, 2015)

This is one of the parts that was made for me
There are two versions of the same part; 3/4" square and 1/2" square.   1018 steel


----------



## kingmt01 (May 19, 2015)

So how close does this have to be? I usually hog out as much as I can as fast as I can with my machine leaving .02"ish on the sides then start working a little more careful.


----------



## EmilioG (May 19, 2015)

This mates to another part and both have to be rounded on the ends.  So -.0000  +.0010


----------



## JimDawson (May 19, 2015)

I think the dials would suffice for that accuracy.  ''Trust but Verify''  with your mic.  Since you posted a picture and I can see what you are doing, I would use a 1/2 inch, 4 flute end mill, about 400 RPM, full depth of cut (- 0.010 for a clean up), and about a 0.200 step over.

Just grind the radius on the end unless it requires a lot of accuracy.


----------



## EmilioG (May 20, 2015)

Thank you all.  I'll try a corner rounding end mill at another time on a rotab. for the radius.
I'll posy a photo of the completed project soon.


----------



## EmilioG (May 20, 2015)

Can you drill holes with a center cutting end mill?


----------



## T Bredehoft (May 20, 2015)

Yes, you can make holes with a center cutting end mill, but expect them to go oversize.


----------



## JimDawson (May 20, 2015)

EmilioG said:


> Can you drill holes with a center cutting end mill?





T Bredehoft said:


> Yes, you can make holes with a center cutting end mill, but expect them to go oversize.



I normally avoid drilling holes with an end mill where possible.  It's better to at least drill a pilot hole then plunge with the end mill.  As Tom says, the end mill will walk around a bit.  The primary reason I would use an end mill to drill a hole is to move a hole over or straighten out a miss drilled hole.


----------



## Ulma Doctor (May 21, 2015)

in addition to Jim's excellent advise.
i sometimes will use an endmill smaller than the intended size on purpose, then clean the bore up with a reamer or correct size drill.
i'll use this process when removing broken bolts in soft substrates like aluminum


----------



## EmilioG (May 21, 2015)

Yes, that is sound advice.  I've seen where a machinist drilled a pilot hole /through, then used an end mill to open it up then used
a tap to get a nice clean straight tapped hole.


----------



## Paul in OKC (May 23, 2015)

If done on a BP, I would use a 1/2" endmill and take one pass and leave about.01 for a finish pass (for depth). From end of part take half diameter of cutter and step over. 5-600 rpm, use oil or spray bottle with coolant.


----------



## chips&more (May 23, 2015)

EmilioG said:


> Can you drill holes with a center cutting end mill?


You can get or make “drill point end mills” that do a much better job of preforming a plunge cut…Good Luck, Dave.


----------



## EmilioG (May 23, 2015)

Thank you. I won't be doing any drilling with an end mill.  But I did see that Guhring has a new end mill called
the Diver, that claims to do it all, ramping, drilling, plunging etc...


----------



## sgisler (May 24, 2015)

Wow, just saw the vid. Wicked


Stan,
Sent from my iPhone using Tapatalk


----------



## Pontiac Freak (May 26, 2015)

That Guhring bit looks expensive!


----------



## sgisler (May 26, 2015)

That's what I figured. Haven't been able to find a supplier yet. Poked around on the net a couple times looking for a supplier in N America. If I could find one, I would be veeeery tempted to try it!


Stan,
Sent from my iPhone using Tapatalk


----------



## EmilioG (May 26, 2015)

Contact Bill Gaudette at Guhring USA in CT or try Prober Inc. NJ.


----------



## sgisler (May 26, 2015)

Will do! Thanks! 
Should have known to check here first!!


Stan,
Sent from my iPhone using Tapatalk


----------



## EmilioG (May 28, 2015)

So now, for the actual cut with the end mill, which direction do I start? side to side or front to back?
Which side does the end mill have to be on?


----------



## Paul in OKC (May 28, 2015)

Going to assume you will hang the part out of the vise just enough to machine this step. With part in right side of the vise, start with the endmill closest to you and feed away. Again about half the diameter of the endmill for cut width. Go across and come back. Move over and finish. This is 'conventional' cutting. If you want a good finish on the vertical edge, leave about .005, and after making the second pass, move over the last but and feed back to front. This is 'climb' cutting. Climb cutting will give you a better finish on verticle surfaces, but you need to be careful. On manual machines you can't take too much of a cut or it will grab. Five to ten thou is good. Use oil, or a spray bottle with some coolant. Hope that helps.


----------



## EmilioG (May 29, 2015)

Thank you.  I'll post photos when I'm finished with all the parts.
The End Mills are new and I have a couple of carbide end mills, one was a free sample.
I know carbide isn't appropriate for this.  I will use a solid, rigid set up. Lock the quill and table, except for the 
Y axis.  I'm using a 1/4" end mill for the 1/2" steel parts and a 1/2" end mill for 3/4" parts.
I will have to use the mills dials for all the cuts, no DRO.


----------

