Re sharpen what????

[THEE THAINZ™]

Ok,

We have an engineer who is also in charge of our continuous improvement program. He came up to me today with a great cost saving idea (face palm coming). He wants to send out spent indexable inserts out and have them reground FACE PALM . He feels that they can be put back to manufacturer spec. I tried to explain to him not possible but he pulled the engineer card and said it was and also a viable solution to reducing tooling costs. So if you could say anything to this guy (to convince him it's a bad idea) what would you say?

[Guest]

So if you could say anything to this guy (to convince him it's a bad idea) what would you say?

Just had to.

 

On s serious note,

1. "Sharpening" of an insert, you're goinig to remove the coating for sure
    
   
2. You're either going to a) Change the IC of the insert or Change the height of your insert. Pick your poison, they are both bad.
    
   
3. You're going to wreck the chip-breaker
   

Those are the best 3/4 arguments against I that I can think of at the moment.

[robk]

We have been doing this for years on round inserts only. Both carbide and ceramic. Obviously stepping down a size after regrind.

[Joe788]

We have been doing this for years on round inserts only. Both carbide and ceramic. Obviously stepping down a size after regrind.

 

^This. I was going to say there are certain type of inserts and certain circumstances where regrinding actually works, but rob beat me to it.

 

And yes, the "engineer" is high if he thinks it's going to be cost effective (or possible) to return a regular DNMG lathe insert back to manufacturers spec. If you guys are a normal shop using normals types of tooling - this engineer's "cost saving" idea could take a few wrong turns and end up being the most expensive tooling decision in your shop's history.

[THEE THAINZ™]

My thoughts on all the above. The insert he took was a Walters High feed insert. If it was a round insert you could go for a specific diameter and adjust for the difference but on anything else to grind them all the same and keep the correct geometry not possible in my mind. These inserts as well as any other insert I use cuts only Titanium (6-4 cast primarily). I push them as hard as my machine or fixtures allow. The one mentioned is on a 2" dia 4 pocket high feed mill. Ran at 173 sfm with .099 cpr and a .05 doc. any more and I would rip the part out of the fixture. Currently I get around 8-12 part per edge or 24-36 minutes of use. Thanks for the confirmation looks like there is one more thing to add to the things to teach an engineer list.

[specv]

Wow, we only do this with our PCD tipped inserts and only because they are 60-90 $ each. also they are in adjustable pockets anyway.

[Newbeeee™]

We have been doing this for years on round inserts only. Both carbide and ceramic. Obviously stepping down a size after regrind.

Every day's a schoolday!

I really wouldn't have thought that this was cost effective.

[jeff]

LOL @ Engineeers!!!

I effin hate engineers.

 

 

Idiots.

[chris m]

Jeff, that hurts me deep inside

 

We used to regrind TNGA 331 inserts to TNGA 332 for years because we ran absolute sh!tloads of them; worked great because they were uncoated flat-top ceramics. In your application may not make sense. I have NEVER experienced a 'reconditioned' tool that worked as well as a new one, regardless of the manufacturer's claims. If you are pushing the tools to the edge, a reconditioned tool may be the recipe for disaster.

 

C

[robk]

Every day's a schoolday!

I really wouldn't have thought that this was cost effective.

From my understanding the cost savings are $2-3 savings per ceramic insert. Not sure about carbide, but when you use $200K+ of tooling per month the savings are significant.

[jeff]

Jeff, that hurts me deep inside

 

We used to regrind TNGA 331 inserts to TNGA 332 for years because we ran absolute sh!tloads of them; worked great because they were uncoated flat-top ceramics. In your application may not make sense. I have NEVER experienced a 'reconditioned' tool that worked as well as a new one, regardless of the manufacturer's claims. If you are pushing the tools to the edge, a reconditioned tool may be the recipe for disaster.

 

C

 

I'm mostly referring to the "booksmart" engi's out there that are fresh out of college and the ink on their diploma isn't even dry yet.

Not the smart ones with actual hands on experience and know what their doing like you lol.

One of my good friends is an engineer, and he likes to always try and 1up me because he thinks I'm just a shop rat that doesn't know jack squat.. very irritating.

[CADCAM3D5AXIS]

^^^^ +1000000000000000000000000000000^^^^^^^^^^^^^^^

[Newbeeee™]

From my understanding the cost savings are $2-3 savings per ceramic insert. Not sure about carbide, but when you use $200K+ of tooling per month the savings are significant.

Thanks Rob.

Wow - we don't even spend what you do a year!

[chris m]

Not the smart ones with actual hands on experience and know what their doing like you lol.

 

Thank you for taking the first step toward repairing my fragile self esteem

[Incogneeto]

Alright I will be happy to grind those for him. Tell him I will need the check in advance. And there is a 60 to 90 day return time on those.(long enough for the check to clear and I relocate)

We ran f-16 landing gear approx.$55,000 per when complete.Would you put a regrind on any part of that??? Ask the engineer if he thinks heat has any effect on todays carbide.

compositions. Or is it cheaper when you have to keep changing them do to failure. Sorry but I would rather just eat it. Don't be too down on engineers I took a few on the floor and let them

dance with a hot chip!! they can learn !!! HE Haw!!! YOUCH!!

[Newbeeee™]

I took a few on the floor and let them

dance with a hot chip!! they can learn !!! HE Haw!!! YOUCH!!

[mikenaturalice]

I can't speak to resharpening, but we used to run some cutter bodies that would use the other edge of a typical 2 edged insert. Something like an apkt, I doubt this is any use to you, but thought I would throw it out there....

[chris m]

Mike, we have some CNMG turning holders that use the 100 degree corner for exactly the same reason

 

C

[P B]

I would suggest to the imagineer to recoup some money by recycling. We get good money for scrap carbide and turn it into sparkling amber liquid and prime beef. (tastes good and gets browny points all round) even the managers enjoy it. But saying that we don't use the quantities that some of you are talking.