Happy Labor Day everyone!
Material like 316 SS cat B; have high surface finish call-outs and can not break chips over a chip breaking insert. have used various manufacturers with differing results. Still need an op stop due to large bird’s nest. What have you come up with for a fix or work around?
Thanks in advance,
Frank
Have you tried contacting your tool sales rep. They have a very good knowledge of their products how to make things happen. If you don’t have a representative you can just call them. I called Kennametal Walter Sandvik and they’ve all been more than happy to share their wisdom of their tool knowledge with me.
I am not at the level where I can call them. I am new to the shop and new to cutting these materials. I am asking for my own education. My boss is sharp and has been in this a long time, the requirements of surface finish are what keeps us from getting the chip to break. ie, cant use the aggressive feeds and speeds to get the material to hit the right inserts and break off. I have a work around that I think would be huge for the industry, so I am tipping my toes in the waters to see what others may have come up with for fixing this issue. Thank you for the feedback!
Respectfully,
Frank
Please be advised at any of the above-mentioned tool manufacturers they talk to people with any level of experience from zero on. So feel confident that if you called Kennasametal and ask him questions about what tool to get to do whatever operation with they would be happy to assist you!
Thanks Travis!
I appreciate the feedback.
I will assume you are having issues running this part on a lathe, in the past I had created a macro that changed feedrates in linear paths specific to a distance… example G1 Z12.000 F.010 was used to turn a lenth 12" long. Inserting a macro that asked 1 variable (how many instances) and a 2nd variable for the second feed rate would yield a variable feed rate that did not stop during the machining process, just briefly changed the feed rate and then resumed original feedrate. Example the G1 Z12.000 F.010 could have 240 instances of linear feed rate about .048" long with .002" F.004. such that the sum would equal the 12.000 original length. This yielded a surface finish that had no dwell marks and the chips would break and fall into the chip pan. Using a custom macro in our Fanuc controller, we could play with feed rates and # of instances and gain an optimum finish and chip breakage. We were running 316L stainless, turning 1/4" dia. stock to .0625 dia x 12" long, then turned a tear drop in the very center of part about .375 in length and then we turned another 12" length down to .0625" and then parted it off. One VNMG cutting tool and ISCAR part off, no birds nest. This was back in the late eighties.
Stephen!
Wow, wow, wow! I had come up with something similar. I looked at using my turn tool like a groover, how long of a dwell at a given diameter to get 1.25 X circumference. Then move a tool nose radius. Make this a W move and loop it for the given Z length. So macro that with your return to Z start and next X diameter. And just keep looping these two til you get to finish diameter. Then run a spring pass. Since it was getting threaded, no issues with relief marks. But on this next job there is no way to hide it so I added a third loop which only moves W 0.010 so the witness marks would not be discernable to the naked eye. What is your thinking on this? Thanks for responding!
Respectfully,
Frank
Is your tool on center? Is it a negative or postive tool? You dont say what you surface footage or feed rates are. Stephen’s example is great, but the amount of tool, and chip breakers on the market you should be able to break a chip and get good finish. Thats why a tool rep is a good resource. You might be running too slow and not getting enough heat in the insert to get the flow required to break a chip.
Thanks!
We are running neutral inserts on a swiss; yes, it is on center. Surface footage is 400. And we have an .011 feedrate. He has talked to one rep about this issue. Solved most of the problem BUT not all of it.
Respectfully,
Frank
Hello everyone!
Hope ya’ll are staying safe; may all of you and yours have some terrific Holidays! So, this time we are dealing with 6061 aluminum. I am programming this (new shop, new opportunities!!), 3 flute kennametal #609 drill 9.92 mm. S5000
#545 = 0.000 ( variable for cut )
WHILE #545 GT -1.550 DO1 ( LOOP )
G1 Z#545 F0.010 ( DRILL DEPTH )
G4 U.030 ( DWELL 2 BREAK CHIPS )
#545 = #545 - 0.0125
END1
CHIPS COME OUT LIKE CONFETTI
Thanks for your attention and response!!
Have you tried a peck instead of a dwell?
All the peck did was give massive stringers and rats nests. That was why I posted the code. The dwell breaks the chip when the rotation runs out of material. This is the fix for the rats nest. Figured I would share…
Thanks for the update.