Successful Failure, Again!

[Rogue_Machinist]

As some of you have helped me ive been appreciative of the guidance. However got my Long Spade drill finally running, nervously of course, another issue has arisen and its perplexing. I have a DMC DL30 basically a Doosan Clone. Now to the issue. I spoke with Allied as my Feedrate seems to have been too high but easy fix. But not my machine is giving me a SV0436 Soft Thermal "Z" axis. I have to turn the machine off and back on. I was only 1" from finishing the hole. Is there a parameter that could be off or does anyone know if these DMC machines are just garbage

More info is
DMC DL30 Turning Center (HP is either 25 or 30)
FANUC Oi-TD control
And I have coolant through(not 1000psi though)
Spindle load never exceeded 17-20%

 

[Mtndew]

Yeah those drills need a crap ton of Z axis thrust.
Are you able to clear the alarm?
If you're using a super cobalt insert, you could try using a carbide insert to see if that helps.
I know our lathes don't/can't run them at recommended feeds so we back them off quite a bit. I think they cut the feed in half.

 

[Philabuster]

Spade drills require a shit ton of Z axis thrust.

 

[hvnlymachining]

300 psi should be plenty if you can achieve, less might work depending on your chips.

 

[guythatbrews]

To assist the z axis thrust we have advanced the tailstock to push on the back of the drill. It's been a long while ago and I don't remember exactly how we did it, but it worked. Newer lathes may have too many safety interlocks to allow this.

 

[Rogue_Machinist]

Yeah I dont know. This machine has hogged some inconel before no issues. Ive read a few issues that could be like the servo fan is bad or the cable that returns to the PLC is getting a faulty reading. But yeah I got .750 from the bottom of the hole and it faulted again. But yeah I tried to find a carbide insert for this drill and they were out of stock everywhere we looked. Might need to get a hold of Allied and see if I can buy one directly from them.

Ive never had this issue with anything Ive cut EVER. Ok. This is why I drink! I never had gray hair for before working here. LOL

 

[Rogue_Machinist]

Yeah those drills need a crap ton of Z axis thrust.
Are you able to clear the alarm?
If you're using a super cobalt insert, you could try using a carbide insert to see if that helps.
I know our lathes don't/can't run them at recommended feeds so we back them off quite a bit. I think they cut the feed in half.

I have to turn the machine off and back on. Yeah were using the Super Cobalt ones. Even Allied recommended the Carbide as I can turn the RPMs up. So my boss told me to keep running the drill let it error out and restart the machine.

 

[kevin66]

With the exception of our old Mori SL-75 all of our CNC lathes are at max thrust on a spade. As the feed decreases you will run into chip packing in the flutes with stingers and Z will overload also so make sure chips are still flowing out of the hole. Can you watch the Z load meter and reduce feed so your just at 100%? A carbide allied bit would for sure be more productive.

 

[bigjon61]

YG-1 makes a SM point insert that would help with the thrust requirements of that big of a drill. If I remember right, you were drilling 1-1/4?

YG-1: BEST VALUE IN THE WORLD OF CUTTING TOOLS

www.yg1usa.com

 

[Rogue_Machinist]

So I have a plan. And I know its against Allieds Recommendations. But I could write a program to do a peck to break chips and let the Z Axis cool down. A Non retract peck cycle. Say Drill 1/2" or 3/4" then retract 1/4" and then drill more. The drill will never leave the bore. I was watching an old video from my old shop on my phone and our programmer had a peck on them.

 

[Mtndew]

my boss told me to keep running the drill let it error out and restart the machine.

I'd make him do it. If he wants to trip over dollars to save pennies then he can do the shit work.
Can't stand that mentality.

 

[Oddball1616]

Try the peck! I've done that before with Allied spade drills. .250" sounds like a good distance to retract. It might squeal a little.

 

[Ox]

So I have a plan. And I know its against Allieds Recommendations. But I could write a program to do a peck to break chips and let the Z Axis cool down. A Non retract peck cycle. Say Drill 1/2" or 3/4" then retract 1/4" and then drill more. The drill will never leave the bore. I was watching an old video from my old shop on my phone and our programmer had a peck on them.

Well, you are on the right track, but I would not recommend letting the spade in there and dwelling, unless maybe you slow or stop the spindle. Otherwise your tool will be in there chattering.

On deep holes, I have to program in some dwell/cool time as well.
A bad fan could possibly be an issue - but any Fanuc in the last 20 years likely knows when a fan is not turning, so if you are not getting an alarm, it is likely just a fact of heat sinking.


-------------------

Think Snow Eh!
Ox

 

[Rogue_Machinist]

Well, you are on the right track, but I would not recommend letting the spade in there and dwelling, unless maybe you slow or stop the spindle. Otherwise your tool will be in there chattering.

On deep holes, I have to program in some dwell/cool time as well.
A bad fan could possibly be an issue - but any Fanuc in the last 20 years likely knows when a fan is not turning, so if you are not getting an alarm, it is likely just a fact of heat sinking.


-------------------

Think Snow Eh!
Ox

Yeah im getting the SV0436 Softthermal z (OVC) Which means the servo is getting hot. Thinking the slight retract will allow the servo to cool a little. Not 100% sure.

 

[AlfaGTA]

How about more cooling to the “Z” servo drive. Additional blower and some ducting perhaps.
Cheers Ross

 

[Orange Vise]

Z-overload can sometimes be caused by packed chips. The drill tip is riding on a chip rather than the workpiece, and thus not doing any cutting. Like chip recutting, but worse.

I think pecking will help, as long as it's done slowly enough to clear all the chips.

 

[Stirling]

So I have a plan. And I know its against Allieds Recommendations. But I could write a program to do a peck to break chips and let the Z Axis cool down. A Non retract peck cycle. Say Drill 1/2" or 3/4" then retract 1/4" and then drill more. The drill will never leave the bore. I was watching an old video from my old shop on my phone and our programmer had a peck on them.

I use the allies SC geometry with goo d success (small chip) they demand far less feed takes longer but whatever

 

[gbent]

If you have tool grinding capabilities there is a method to cut chip load and feed rate in half successfully. Grind one cutting edge of the drill down by twice the suggested feed rate. On the other cutting edge grind a couple of notches tataling 1/2 the width of the cutting edge. Make sure the notches have appropriate relief. I have never tried it on a drill this small, but have had great success on holes over 4". The narrow width of the chip makes chip management less stressful as well.

 

[Houdini]

I ran a 1.156" YG-1 spade in a Haas MiniMill2, hahaha, all it did is peck, peck, peck......

 

[William Lynn]

I used Allied drills all the time. My Z axis faults were either from feeding too hard or a dull insert. If I was running a proven program and it stalled, a new insert cured it.