Run die grinder on coolant

Hi Guys,

We thread some stainless pipe in our Mazak QT15 CNC lathe. 1/2" and 3/4" NPT threads in stainless 304 pipe. Cut with laydown inserts. I have found that running a wire wheel over the threads takes care of any micro burrs, makes the parts safer to handle, and the thread gauge to thread on nicely.

We currently run a 2" wire wheel on a handheld cordless right angle grinder after the program is done and before we unload the part. I'd like to do the wire wheeling automatically. It isn't a live tooled machine. And it is a turret type. So the only "power" I have is the low pressure coolant that runs through the turret and to the tool holder.

Is there any possibility of the low pressure coolant being capable of running a small off the shelf die grinder? If it wasn't 5:15 on a Friday afternoon, I'd be trying it right now.

Thanks,

-Jim

And with the off-the-shelf die grinder on coolant being probably a stupid idea ... does anyone have a clever idea?

My next stupid clever ideas is a cordless die grinder in the lathe and triggered by coolant expanding a bladder against the trigger.

What I would really like is a donut shaped wire brush with a mandrel. Something like
McMaster-Carr
but with a mandrel and available in size for 1/2" and 3/4" NPT thread.

No chance to run an air die grinder. A water wheel / peleton / rubber vane might give you enough grunt for rotation of a wheel against a spinning part. The coolant pump would need to be a positive displacement type rather than a centrifugal.

Got any high pressure oil available to run a hydraulic motor?

hmm... running a die grinder on coolant..? asking at 5:15 on a Friday... have you had a few already?

or maybe you are trollin' us, and I took the bait... so wait, why can't you just run an air die grinder on air?

Not a drinker...just a long week and was confusing air tools working underwater and air tools working with water in my mind.

I want to mount the tool to the CNC lathe turret and have the CNC operate it. I don't have live tools or air or anything other than coolant to the turret.

kb0thn said:

Not a drinker...just a long week and was confusing air tools working underwater and air tools working with water in my mind.

I want to mount the tool to the CNC lathe turret and have the CNC operate it. I don't have live tools or air or anything other than coolant to the turret.

Click to expand...

No air? That's the usual option. Or electricity. It takes significant power to run a die grinder.

kb0thn said:

Hi Guys,

We thread some stainless pipe in our Mazak QT15 CNC lathe. 1/2" and 3/4" NPT threads in stainless 304 pipe. Cut with laydown inserts. I have found that running a wire wheel over the threads takes care of any micro burrs, makes the parts safer to handle, and the thread gauge to thread on nicely.

We currently run a 2" wire wheel on a handheld cordless right angle grinder after the program is done and before we unload the part. I'd like to do the wire wheeling automatically. It isn't a live tooled machine. And it is a turret type. So the only "power" I have is the low pressure coolant that runs through the turret and to the tool holder.

Is there any possibility of the low pressure coolant being capable of running a small off the shelf die grinder? If it wasn't 5:15 on a Friday afternoon, I'd be trying it right now.

Thanks,

-Jim

Click to expand...

Easy to find out...even on a Sunday...:d
Pneumatic 1/4 in. Air Die Grinder

Looks like $12 to find out.

Id try mounting a 4-6" wire wheel on a shaft fitted in one of your boring bar pockets with a nylok to give friction resistance so it just barely turns.
I'm sure there is a sweet spot with pressure, feed & repeats that wipes the micro burrs

Dont dental powerheads run on high pressure water?

Use an electric die grinder. Use the coolant pressure to trigger an appropriate pressure switch, use that to activate a relay to run the die grinder. You can probably use an m-code, is it? to enable/disable the relay so the grinder doesn't run every time the coolant is turned on, but only when it's needed.

Not a bad idea, cheap to try and all that.

What about mounting the McCarr style donut brush on the turret and rotating the pipe threads inside it?

Coolant could keep the brush clear.

Another possible thing to try: mount a freely turning (on suitable bearing) wire wheel so it can intersect the spinning part at maybe (to be determined) 30 deg angle. Spinning part powers the wheel. Might require two wheels. One angled to the left and one to the right.

Denis

Hydraulic grinders are also used underwater. That should run just fine on coolant, low coolant pressure might mean reduced power....YMMV

Have you considered full profile inserts? Deburr the leading thread with your turning tool and the burrs shouldn't be terrible.

I have seen pneumatic grinders mounted to the turret, with a quick connect fitting mounted such that is plugs into air when the turret indexes to that tool.
Seems like a lot of work, I would pursue a static method like others are suggesting.
How many parts? That dictates how long to spend improving the process.


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If your coolant is clean enough, not a chance unless you filter it, and you have enough pressure it would probably work. Keep in mind the die grinders I am familiar with use the air and oil to lubricate the bearings as well as the vanes.

Here is a block I made to take the guts of my die grinder so I have a "live" tool for my little manual lathe to drill holes. On second thought could you rig a solenoid valve and use air to drive your air grinder? Do you have 2 spare M codes?

I had a machine that controlled a 3 way solenoid valve with an M-code to put air in the coolant stream for milling steel. That would be easy to rig up to drive an air tool.

Air motors typically get their RPM from the gas expansion and that won't be happening with a liquid.

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mjk said:

Id try mounting a 4-6" wire wheel on a shaft fitted in one of your boring bar pockets with a nylok to give friction resistance so it just barely turns.
I'm sure there is a sweet spot with pressure, feed & repeats that wipes the micro burrs

Click to expand...

Awesome! I was having similar thoughts. I'm going to try this.

bigjon61 said:

Have you considered full profile inserts? Deburr the leading thread with your turning tool and the burrs shouldn't be terrible.

Click to expand...

Yes, I am running full profile inserts. SECO 16ER14NPT CP500. It's kind of a problem part. With this SECO insert the tool life is really variable. Sometimes I get one part and sometimes I get 30 parts per corner. At $8 per corner it is really annoying. I have tried CARMEX and got consistently poor (terrible) results. Will hopefully be trying Vargus in near future.

The burrs aren't terrible. There is usually a little string burr, about 1/4 long and a few tho diameter, at the start of the thread. I chamfer before threading. That string burr gets pulled under the ring gauge and stops the gauge from going on. Besides that burr, running the wire wheel over the threads seems to make them mate smoother and have less sharp stuff for handling. The particular part gets handled by the end user. My threads look much nicer than the typical torn nasty threads on most pipe and that makes the assembly nicer for the customer.

kineticmx said:

I have seen pneumatic grinders mounted to the turret, with a quick connect fitting mounted such that is plugs into air when the turret indexes to that tool.
Seems like a lot of work, I would pursue a static method like others are suggesting.
How many parts? That dictates how long to spend improving the process.

Click to expand...

It's a few hundred parts per year. Forever. Goes in a product we make. I typically run about 50 pipes (100 ends) at a go. Getting the part deburred in machine would greatly reduce the cycle time. We gauge the part while it is still in the chuck so we can replace an insert (see above) without scrapping the part. So I would double the throughput on the part and probably save 12 hours per year in front of the machine. We've been making the part for 11 years now. Did the first 7 years on a Rigid pipe threader with sharp threads and the guy running the machine complaining how difficult the work was to make consistent threads. Moved it to the lathe and have beautiful threads but am fighting randomly exploding inserts. Looking at a $$$ threading machine (Oyster), but they are a lot of $$$$$ and the factory samples have tearing and aren't as nice as what we want.

Thanks all!

Cole2534 said:

Air motors typically get their RPM from the gas expansion and that won't be happening with a liquid.

Sent via CNC 88HS

Click to expand...

Internal combustion motors typically get their RPM from gas expansion.

-Doozer