How to make my drill bits last longer

Is a cutting fluid being used? Is the drill being regularly sharpened? Is a spotting drill used before the twist drill?


So are using cutting fluid but the robot makes it a mist so we have a lot of extra fluid being used. We have only been sharpening them once they start to wonder. And there is no starting hole, step bits, or spotting drilling going on the robot just grabs the 16mm bit, turns on the lube mist, and drills (which makes a "lovely" squealing sound on the metal).
 
Is the coating thick enough to make a difference when drilling?
IMO, any thickness will cause wear. Hard coated anodizing is much worse but even decorative anodizing is abrasive.
I usually make it a practice to strip anodizing from a surface before machining. When I do machine an anodized surface, I try to work it so the tool makes contact on exit. Anodizing is brittle and will shatter.
The oxide coating on HR steel os also hard on tooling. I will band saw out of necessity but before subjecting an expensive milling cutter to it, I will remove the oxide coating.
 
Try using a Guhring HSCO drill bit they are carbide drill and last for ever also they are sharpen by laser, i've had great success with them.
DSC_0143.JPGDSC_0148.JPG
 
What kind of robot is doing this drilling? You mentioned the bits only work for about 2 weeks, how many holes are drilled in 2 weeks? Roughly how long does the robot take to drill each hole?

Unfortunately, if you are plunging and using mist, the coolant is never going to get to the cutting face where it is needed. It will just be spraying onto the chips that are already in the drills flutes. To get the lubricant where it is needed, it needs to either retract or you need through spindle coolant.

When you sharpen them, how is that being done? If they are just sharpened by hand and aren't done well, that will contribute to the drill walking while it cuts.

I have found cast aluminum to be particularly gummy and prone to packing into the drill when I am drilling. With something like extruded 6061, I can usually get to 2 or 3x diameter with the drill before the chips stop escaping before it retracts. With cast, it tends to get stuck almost immediately and gets knocked loose from the drill bit once it goes back in after the retract.

There are some things you could try which might help. I am not sure how practical they will be for your application, but nonetheless:
1. Try to peck drill instead of through drilling. This will let it clear the chips and get some lubricant to the cutting surface.
2. If the robot can do it, try using an end mill to interpolate the circle instead of drill.
3. You could drill a little bit under the diameter needed then switch to a boring head and bore it. It will be straighter, rounder, and you won't need to worry about the drill walking.
4. Make sure you are using the right drill bits. This sounds like an industrial application, so weigh the cost of better gear against the time it takes to drill the holes, sharpen, change out the bits, replace them, etc.
5. Make sure you are using a proper lubricant for the drill. When I drill cast, WD40 does a much better job than any of the oils I have tried. Something specifically for aluminum might make sense for your application.
6. Make sure feeds and speeds are on. If it is squeeling and the hole is all chattery, the drill bit is going to wear out faster. Ideally there should be no squeeling. If your RPMs are too high and feed to slow, the bit will wear out faster.

It is hard to give really good specific answers without knowing a lot more details, but just using torque to force a drill bit through is really the worst case scenario.
 
I have had 9/16" last over years on very day use. We sharpen drill bit down to 1/8" and 9/16" we would down 1/2" of flute
Dave
 
What kind of robot is doing this drilling? You mentioned the bits only work for about 2 weeks, how many holes are drilled in 2 weeks? Roughly how long does the robot take to drill each hole?

Unfortunately, if you are plunging and using mist, the coolant is never going to get to the cutting face where it is needed. It will just be spraying onto the chips that are already in the drills flutes. To get the lubricant where it is needed, it needs to either retract or you need through spindle coolant.

When you sharpen them, how is that being done? If they are just sharpened by hand and aren't done well, that will contribute to the drill walking while it cuts.

I have found cast aluminum to be particularly gummy and prone to packing into the drill when I am drilling. With something like extruded 6061, I can usually get to 2 or 3x diameter with the drill before the chips stop escaping before it retracts. With cast, it tends to get stuck almost immediately and gets knocked loose from the drill bit once it goes back in after the retract.

There are some things you could try which might help. I am not sure how practical they will be for your application, but nonetheless:
1. Try to peck drill instead of through drilling. This will let it clear the chips and get some lubricant to the cutting surface.
2. If the robot can do it, try using an end mill to interpolate the circle instead of drill.
3. You could drill a little bit under the diameter needed then switch to a boring head and bore it. It will be straighter, rounder, and you won't need to worry about the drill walking.
4. Make sure you are using the right drill bits. This sounds like an industrial application, so weigh the cost of better gear against the time it takes to drill the holes, sharpen, change out the bits, replace them, etc.
5. Make sure you are using a proper lubricant for the drill. When I drill cast, WD40 does a much better job than any of the oils I have tried. Something specifically for aluminum might make sense for your application.
6. Make sure feeds and speeds are on. If it is squeeling and the hole is all chattery, the drill bit is going to wear out faster. Ideally there should be no squeeling. If your RPMs are too high and feed to slow, the bit will wear out faster.

It is hard to give really good specific answers without knowing a lot more details, but just using torque to force a drill bit through is really the worst case scenario.


We are using a Fanuc M10iA robot that has a drill mount. I'm not to sure how they sharpen them but I think we send it back to our drill supplier and they sharpen them for us. And it takes roughly 4-5 min to get each hole done.
I'll see if I can change the code a bit so the robot sprays some lubricant, then start drill for 30 seconds, stop drill, spray lubricant, then repeat until the hole is done and see that makes a difference. And I'll have to ask about the boring bit, we might be able to switch the bit to a 15.75mm or a 15.5mm then bore the rest of the diameter.

Thank you for the tips, I'll keep you posted on what works and doesn't. If any of you have any other suggestions that would be great.

Steven Hansen
 
"I'll see if I can change the code a bit so the robot sprays some lubricant, then start drill for 30 seconds, stop drill, spray lubricant, then repeat until the hole is done and see that makes a difference. And I'll have to ask about the boring bit, we might be able to switch the bit to a 15.75mm or a 15.5mm then bore the rest of the diameter."
I think that will make a big improvement- the squealing is telling you something is not quite right- pay attention to that
Mark
 
Back
Top