[roundman]

Hi everyone. My question is which method is better and why?

1. Material TI 5
2.using Iscar 1 inch dia insert drill drill aprox 2 inches deep.

This is where I question using the emill and spinning the chuck to rough the ID Bore verses a 5/8 inch shank boring bar.

Do it this way.

3. Use a 1/2 inch emill to rough out the id to within .005 per side of finish dia which I will say is 1.250 dia.

OR this way.

3. After Iscar drill and then rough bore the ID using a boring bar 5/8 shank or largest possible size boring bar. It requires several small passes inside on the bottom of the bore to do this.

We have to use the boring bar to finish the ID anyway.

Feedback is appreciated.

[double a-ron]

I gather that you want to use the end mill because it has a flat bottom and the bore your machining does as well. What does the bottom of the hole look like after the indexable drill is finished? I use a normal 135 deg. drill for all my drilling and can quickly machine a flat bottom because of the point left by the drill bit. I think where your running into trouble is using "the largest size boring bar available". The bigger the bar the the less clearance you have for finishing that bottom. I've done what your talking about only because either I ran out of tool holders for the job and had a live vdi available, or tool to tool clearance problems didn't allow me to have something sticking out that far in z when it was out that far in X. Like a long boring bar in a tool block. I have never done it because it's faster or cheaper. That iscar end mill is what, $90 to $100? The insert is at most $13? The main spindle has 20hp and 150 lb/ft of tq and the live tool spindle is a paltry 7hp an 130 IN/LB. If you can get the job done faster and cheaper with the end mill than the boring bar, you know something I don't.

P.S., I gave up on iscars milling line. Too much money. $90 for a .5" finishred? They're cool, but not that cool. MSC's new ACCUPRO line is of the same quality at a fraction of the cost. I'm sure your Iscar rep will say different, mine did. You'll never get me away from their turning line though. I use their HELI-TURN WNMX insert for roughing and that is one mean insert. Same with their DO-GRIP, that thing is like a Swiss army knife.

[roundman]

:violin::violin:
My new shop boss thinks it is great which I disagreed with. ahe was a former colllegue and now he is running the shop. The iscar tool was actually a Inserted drill and it leaves a edgy bottom. So he wanted to use a endmill to do it and I have been told to do as he says and so I did. The biggest problem besides the obvious of which I agree boring with the right tool is better. When I mention using the largest Boring bar to do this I do mean I would use one which cleared or use the next smallere size to do this. The issue which made it very bad was he progrsmmed it to within .005 total material to take out. It actually oversized the largest size of bore because it cleaned up only if I could cut it and actually measure where I was dimension wise but to clean the bore up I oversized the bore when I cleaned up. I knew it would be close yet I hoped I would be just below tolerance. I think using a emill does have its place "once in a Blue moon" or something like that. I am running mills now so I am not having to deal with when things go wrong it makes the shop boss (he is not the owner) look bad. I did everything he told me to do and so who gets the blame if you guessed me you are right. Thankyou for the tooling insight as I am learning good things like that everyday. I want to gain better programming skills and increase in pay it a trade that I love. My body does not like it however which may push me to other options. I am 53 and I think doing something less physically demanding may be good for my health. Wish me good luck Amigo. Roundman

[roundman]

Have you seen the new Machinists Calculator? It has the whole nine yards supposedly and the formulas are already set up. It is about $70.00.