Rick Finsta
Stainless
- Joined
- Sep 27, 2017
So, I've been running an Ingersoll 2" diameter 3xD inserted drill, that takes the square inserts (inside and outside are the same) to rough holes in 2"x8" aluminum extrusion (6061-T6511). I have been running 2000SFM and 0.011ipt (21.45IPM) for a long time now using flood coolant. Machine is an Okuma bridge mill (560-V) and I am using a standard (not dual contact) 1.5" sidelock holder.
Well, I just hooked up through tool high pressure coolant and have had my first issues with this tool. When the drill gets to the bottom of its travel (0.125" below the stock bottom)I had it chatter when it goes to rapid back up and dig in enough that it lifted the part slightly (a few thousandths). This happened on the same piece of stock twice in a row even after I reset the material, retightened, and then probed the stock back in.
The material is 20" long and sitting between two Orange vises. I double checked the tram prior to trying it a second time and it was good. I stuck some paper shim between the moving jaws and the stock and went back to flood coolant for the last hole. I am using 4140PH shop-made step jaws that grip about 0.780" deep and they must be smooth as OP2 I flip over the part and grip on the final profile.
This is my bread-and-butter part so I need to figure this out.
Is this something that changed when using high pressure through coolant that could be destabilizing this drill with this stickout? Is it the stock extrusion is not square enough and I'll need to use paper shim on this lot?
The plan was always to move to a 2xD drill and dual contact holder for this but I was hoping to space out the new tool purchases (to utilize the TSC) over the next few months to soften the hit on the budget.
Anything I'm not seeing here? I have some drops from previous lots of raw stock that I guess I could compare for squareness. Any other ideas?
I simply cannot afford to have a part lift on this drill - I know it would completely wreck my spindle. Worst case I can go to punching a through hole with a smaller drill and roughing with another tool (helical boring).
Well, I just hooked up through tool high pressure coolant and have had my first issues with this tool. When the drill gets to the bottom of its travel (0.125" below the stock bottom)I had it chatter when it goes to rapid back up and dig in enough that it lifted the part slightly (a few thousandths). This happened on the same piece of stock twice in a row even after I reset the material, retightened, and then probed the stock back in.
The material is 20" long and sitting between two Orange vises. I double checked the tram prior to trying it a second time and it was good. I stuck some paper shim between the moving jaws and the stock and went back to flood coolant for the last hole. I am using 4140PH shop-made step jaws that grip about 0.780" deep and they must be smooth as OP2 I flip over the part and grip on the final profile.
This is my bread-and-butter part so I need to figure this out.
Is this something that changed when using high pressure through coolant that could be destabilizing this drill with this stickout? Is it the stock extrusion is not square enough and I'll need to use paper shim on this lot?
The plan was always to move to a 2xD drill and dual contact holder for this but I was hoping to space out the new tool purchases (to utilize the TSC) over the next few months to soften the hit on the budget.
Anything I'm not seeing here? I have some drops from previous lots of raw stock that I guess I could compare for squareness. Any other ideas?
I simply cannot afford to have a part lift on this drill - I know it would completely wreck my spindle. Worst case I can go to punching a through hole with a smaller drill and roughing with another tool (helical boring).