6061-T6 ID Turning and drilling. Dim’s like to open and close.

[Gas-station Jon]

Hey guys, I work for a company called OPW. We make the gas nozzles. And breakaways you see on the hose above your head at the pump. We started using an alternate material when aluminum with short. The OD turning did fine but drilling ID boring is a nightmare. The chips don’t wanna break and there seems to be a lot of heat coming from the material as we try to cut it. We did get it to stabilize, but at the cost of half the parts we normally make. The problem We are still having is when we finish the ID diameters they tend to fluctuates. I have added more than one finish pass, both at different cut depths,(tired).005,.010,.015,.020. Tired PCD, coated, uncoated, stainless grade, But still (depending on the bars, it changes by the bar sometimes) . We can get 10, 20, 30 parts, then the ID will go big or small. We can flip the finishing insert and it goes back to size for another 10, 20, 30 parts. Any ideas would be greatly appreciated. Thanks

 

[Finegrain]

More details PLZ. What inserts, what type of drill, etc.

I turn 6061 a fair bit, and IME unless something really goes sideways, it's very stable. Last job was a 1.753" bore 4.75" deep, +/-.001". Once the machine is warmed up and the tools are set, it's pretty straightforward. Material was Kaiser, but also was happy with Hydro.

Regards.

Mike

 

[rklopp]

Could this be a built-up edge problem? The effective cutter size changes as the BUE comes or goes. What does the tool tip look like under magnification?

 

[rcs60]

rani corp sells diamond tipped inserts with laser engraved chip breakers they are very stable and go a long way in cutting. I did one run of parts that equaled about 8000 feet of material turned on one corner depth of cuts are not large but the finish was very good this was on 6262t9 material

 

[Gas-station Jon]

More details PLZ. What inserts, what type of drill, etc.

I turn 6061 a fair bit, and IME unless something really goes sideways, it's very stable. Last job was a 1.753" bore 4.75" deep, +/-.001". Once the machine is warmed up and the tools are set, it's pretty straightforward. Material was Kaiser, but also was happy with Hydro.

Regards.

Hey guys, I work for a company called OPW. We make the gas nozzles. And breakaways you see on the hose above your head at the pump. We started using an alternate material when aluminum with short. The OD turning did fine but drilling ID boring is a nightmare. The chips don’t wanna break and there seems to be a lot of heat coming from the material as we try to cut it. We did get it to stabilize, but at the cost of half the parts we normally make. The problem We are still having is when we finish the ID diameters they tend to fluctuates. I have added more than one finish pass, both at different cut depths,(tired).005,.010,.015,.020. Tired PCD, coated, uncoated, stainless grade, But still (depending on the bars, it changes by the bar sometimes) . We can get 10, 20, 30 parts, then the ID will go big or small. We can flip the finishing insert and it goes back to size for another 10, 20, 30 parts. Any ideas would be greatly appreciated. Thanks

Mike

Hey Mike, Thanks for replying. So, we are using a 0.937 Seco drill, Inserts SCGX070308-MP , DS2050 (https://www.secotools.com/article/p_03134314) / SPGX0703-MC , DS4050.(https://www.secotools.com/article/p_03134321) 35 Degree bore for finishing the seat down in the ID Sandvik VCGX 11 03 04-AL H10.(https://www.sandvik.coromant.com/en-us/product-details?c=VCGX 11 03 04-AL H10 ) We rough the seat with a 55 degree DCGT11T304-FN2 WNN10 from Walter(https://www.walter-tools.com/en-us/search/pages/default.aspx/product/dcgt11t304-fn2 wnn10). Then a 80 degree( https://www.sandvik.coromant.com/en-us/product-details?c=CCGX 09 T3 08-AL H10)that roughs the linear bore leading up to the seat( the 35 finish that as well on the way out.) Rpm we tried up to 4500, right now, we are at 3000 using constant. Feeds for roughing were with the 6262-T6 (original material) were at .024 per rev. now at around .010. and finish was at .008 now down to .003. The drill chips when we started would come out like ribbon candy. So, put pauses in it. for the most part it breaks the chip into a manageable size. Drill runs at 3000rpm and feeds at .006. 6262 we ran 4500 and fed .015

 

[Gas-station Jon]

Hey guys, I work for a company called OPW. We make the gas nozzles. And breakaways you see on the hose above your head at the pump. We started using an alternate material when aluminum with short. The OD turning did fine but drilling ID boring is a nightmare. The chips don’t wanna break and there seems to be a lot of heat coming from the material as we try to cut it. We did get it to stabilize, but at the cost of half the parts we normally make. The problem We are still having is when we finish the ID diameters they tend to fluctuates. I have added more than one finish pass, both at different cut depths,(tired).005,.010,.015,.020. Tired PCD, coated, uncoated, stainless grade, But still (depending on the bars, it changes by the bar sometimes) . We can get 10, 20, 30 parts, then the ID will go big or small. We can flip the finishing insert and it goes back to size for another 10, 20, 30 parts. Any ideas would be greatly appreciated. Thanks

We are going to look at the insert today under the microscope to see the edge wear.

 

[Gas-station Jon]

Mike

Hey Mike, Thanks for replying. So, we are using a 0.937 Seco drill, Inserts SCGX070308-MP , DS2050 (https://www.secotools.com/article/p_03134314) / SPGX0703-MC , DS4050.(https://www.secotools.com/article/p_03134321) 35 Degree bore for finishing the seat down in the ID Sandvik VCGX 11 03 04-AL H10.(https://www.sandvik.coromant.com/en-us/product-details?c=VCGX 11 03 04-AL H10 ) We rough the seat with a 55 degree DCGT11T304-FN2 WNN10 from Walter(https://www.walter-tools.com/en-us/search/pages/default.aspx/product/dcgt11t304-fn2 wnn10). Then a 80 degree( https://www.sandvik.coromant.com/en-us/product-details?c=CCGX 09 T3 08-AL H10)that roughs the linear bore leading up to the seat( the 35 finish that as well on the way out.) Rpm we tried up to 4500, right now, we are at 3000 using constant. Feeds for roughing were with the 6262-T6 (original material) were at .024 per rev. now at around .010. and finish was at .008 now down to .003. The drill chips when we started would come out like ribbon candy. So, put pauses in it. for the most part it breaks the chip into a manageable size. Drill runs at 3000rpm and feeds at .006. 6262 we ran 4500 and fed .015

 

[Gas-station Jon]

When we run 6262-T6 it runs great. 6061-T6 has double the iron, no lead and 1/3 of the silica in it

 

[Finegrain]

Thanks for the details. I didn't look at all the inserts in detail, but the Walter DCGT at least looks good. I use uncoated, positive, very sharp inserts for 6061.

OK, you mentioned heat. How is the coolant?

If coolant is fine (thru-tool hopefully), then the heat is likely from knotted up swarf down in the bore. I spent a good amount of time programming extra steps to ensure no bird's nest left in the bore between operations.

You may not realize you have packed-up swarf in the bore, since the affected tool (the finisher cutting off-size e.g.) will often pull the swarf ball out as it exits, but not before the pile-up made heat and BUE.

I also find that insert drills sometimes won't break a chip. One job was a mix of Kaiser and Hydro. The Kaiser was ribbons every time, the Hydro was nice broken chips. I now use a chip-break cycle, so if it ribbons, at least the ribbons are short.

HTH, and regards.

Mike

 

[Gas-station Jon]

Right now we are using Ashburn 7090 Semi synthetic, 18% to 20% for the 6061 seems to help, but it's peeled the inside of the machines. We put in a chip break on the drill, as well, to mange the chips. I currently trying to get Blaser coolant to test.

 

[BT Fabrication]

sure sounds like it is a coolant problem or an insert problem. is it straight drilling cycle or is there chip breaking in the program?

i would be changing the insert drill to something with a sharper edge, id be guessing the cutting angle is what is creating all the heat in the part, creating a bue and changing the hole diameter. softer aluminum will be a pain with a drill that works better in harder materials like stainless for that design/angle of edge cut.

 

[Gas-station Jon]

 

[Gas-station Jon]

The chip break is in the program

 

[Gas-station Jon]

 

[wmpy]

Is it possible that your finishing tool is hitting accumulated chips in the bottom of the hole and moving the insert in the pocket? It was your comment about indexing the insert and having the parts go back to size that made me think this could be the problem. I wonder if instead of indexing the insert, you just took it out and put it back in with the same corner, then would the size go back? If you think this might be a concern, take a look at the insert pocket to see if it looks damaged. You can try to fit your smallest feeler gage between the pocket and insert to check if there's any wiggle room. Sometimes, a low rpm coolant flush of the hole before the finish pass can help get rid of any problematic chips.

 

[Gas-station Jon]

10-4, I'll give it a try when we run it again, I mentioned it to our research machining engineer in Ohio. He asked about the clamping pressure and the drilling, residual stress maybe, the clamp is maxed out. Right now we have 6262 in and it's cutting like butter. But we do have 3000 ft of the 6061 left. When the parts come out of the parts catcher, their isn't any chips in the part. I'm thinking of going with carbide boring bars as well. Right now we have always using HSS. But we never had an issue with the 6262.

 

[BT Fabrication]

10-4, I'll give it a try when we run it again, I mentioned it to our research machining engineer in Ohio. He asked about the clamping pressure and the drilling, residual stress maybe, the clamp is maxed out. Right now we have 6262 in and it's cutting like butter. But we do have 3000 ft of the 6061 left. When the parts come out of the parts catcher, their isn't any chips in the part. I'm thinking of going with carbide boring bars as well. Right now we have always using HSS. But we never had an issue with the 6262.

that insert 100% doesn't look good, and its pretty messed up at the leading edge radius. definitely looks like material is sticking to it. have you tried a boring bar with a CCGT insert?
https://www.walter-tools.com/en-us/search/pages/default.aspx/product/ccgt09t304-mn2 wnn10
these have worked well for me in a boring bar. changes the turning forces to push in instead of pushing towards the id bore.