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Cant Break A Chip Help!!

If you mean an air blast instead of 460 psi coolant, I think don't bother. The mass of the coolant at 460 psi will far outweigh air blast, even if you could get 460 psi air.

Ramping down with a macro isn't too bad. Just figure out the incremental x associated with the incremental z. For 30*, if z = .003 then x = .003 X 1.732 X 2 for diameter. or 3.464*z. Or you can just pull off straight in x and reposition.

For x retract at 30*, with Z1 being the Z destination for the desired DOC.

#1 = -.003 (initial cutting depth variable)
WHILE[#1 GT [-Z1]]DO1
G1 Z[#1] U[.003*3.464]F.003
W.004 U[-.004*3.464]F.012 (incremental retract)
W-.004 U[.004*3.464](incremental reposition)
#1=#1-.003 (decrement Z for next cut)
END1
G1 Z[-Z1], F.003 (to insure you get to Z1 regardless of how the peck increment works out)

Then proceed with the Z feed to the bottom, starting with -Z1-.003. It might be less confusing to increment x to the depth of cut and back figure z. If you use trig in the macro to figure the movement of the axis not being decremented or incremented, you'll have a macro that automatically figures the related axis when you tweak the numbers.

How are you handling the bottom of the hole? In other words, are you using a drill with a point, just driving it as deep as you can, or an indexable drill? Just curious. The flat bottom always adds a bit of excitement.
We are knocking out the bottom with a U drill. Had to enable to dragging to eliminate the excitement in the bottom of the bore. The bar and inserts didn't care for that too much before eliminating the drag.
 
Definitely try a smaller radius insert. Also consider having a roughing and finishing boring bar.

Are you boring on the main or the sub spindle? On the 2600SY, you can use subspindle thru-bore coolant. It does a very good job of keeping chips out of your part. Often I turn off main coolant completely and just use thru-bore coolant when doing ID work on the sub because it does such a good job of flushing chips away.

Also, is the design of the part set in stone? Can you suggest a re-design so this becomes two parts? Whoever is paying for these parts would save a LOT of money if this is possible.
 
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Definitely try a smaller radius insert. Also consider having a roughing and finishing boring bar.

Are you boring on the main or the sub spindle? On the 2600SY, you can use subspindle thru-bore coolant. It does a very good job of keeping chips out of your part. Often I turn off main coolant completely and just use thru-bore coolant when doing ID work on the sub because it does such a good job of flushing chips away.

Also, is the design of the part set in stone? Can you suggest a re-design so this becomes two parts? Whoever is paying for these parts would save a LOT of money if this is possible.
That is interesting using the sub. Never would have thought to use that. Love the idea.

Not sure if there is any budging on the design. The OD has a +/-.0005 tolerance and a 16ra finish. I would have to do I secondary finishing OP on the OD after the two parts are mated.

I am a little nervous that I may have under quoted these if you think we could reduce the cost further if there were two separate pieces!!!
 
You might have under quoted. Seems like you didn't anticipate that this part was going to be annoying for chip control.
 
We had a bit of a breakthrough yesterday. We used the same Mits insert with a feed of .004 ipr, 400 sfm, .025 DOC, pecking at .01. There are little to no chips left in the bore after roughing. Finishing at the same parameters, but lowered the feed to .003. That feed leaves .375-.500 tight curled chips. Majority of those chips are washed away as well. There are not enough left in the bore to create a birds nest inside to give us fits.

We have a sharper insert that we are going to try, but I hesitate to mess up a good thing.

We certainly appreciate all of the feedback and tips that have been thrown at us. This is an amazing collection of knowledge on this forum!!
 
Also, is the design of the part set in stone? Can you suggest a re-design so this becomes two parts? Whoever is paying for these parts would save a LOT of money if this is possible.

Making that part two pieces would be a waste of time, firstly you'll have to come up with a way of joining them.
Making 2 parts is going to take longer irregardless of the chip issues.

Plus your going to use more material, which over 10k+ is not going to be insigificant.

My assumption is there will always be some chip issue with a part like this, no matter how hard you try to fix the problem.
 
Making 2 parts is going to take longer irregardless of the chip issues
I'm sorry to be so blunt but this is wrong.

Making this a two-part assembly (either by threading on an end cap or bolting it on) would be much faster and overall less expensive.

The extra material involved would be irrelevant compared to the savings in machine time, labor, and tooling.

Overall it's a moot point because the OP said that the customer's requirements wouldn't allow this to be a two part design, but that doesn't change the fact that making this out of two parts would be much faster and less expensive.
 
I'm sorry to be so blunt but this is wrong.

Making this a two-part assembly (either by threading on an end cap or bolting it on) would be much faster and overall less expensive.

The extra material involved would be irrelevant compared to the savings in machine time, labor, and tooling.

Overall it's a moot point because the OP said that the customer's requirements wouldn't allow this to be a two part design, but that doesn't change the fact that making this out of two parts would be much faster and less expensive.

Making it out of two parts to fix a minor problem is bizarre thinking.

How long do you think it's going to take to thread 10k+ parts together? Not trivial, and we don't even know it's function. Maybe it's a nogo.

Maybe get some more experience before you let the crazy out (being blunt)
 
rough drill the back hole and bore as a first extra op to allow chips to exit at rear.
 








 
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