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Taps Breaking in Speedio WTF?

Nerdlinger

Stainless
Joined
Aug 10, 2013
Location
Chicago, IL
Thank you for reading this! Let me start by saying we have done this op with these tools running at these parameters for decades and have never had this problem before.

Today we broke one tap, then another didn't break but we got a spindle sync error (Brother tap recovery was sexy, by the way), then broke two more.:mad5:

Material is 1/2" square annealed 4140.

F drill followed up by special 5/16-12 three flute tap all the way through.

S300.

I am using an ER32 tap collet and torquing it down to 100 lb. ft. with a torque wrench.

I checked the collet and holder - everything looks good.

Checked spindle runout - dead nuts on.

Checked the F drill (hole) - dead nuts on.

Even though we have been running at S300 for years the mfg recommended S495. No dice...broke after two pieces.

We used to run this on a Haas with a different fixture that did not support that parts as close to the tapped hole as the new fixture does on the Speedio and we have run this job a couple times on the Speedio to the tune of 3,000 parts with no problems, so I doubt it is fixturing.

When I have time I am going to try running the job the old way in the Haas to see if it has something to do with taps (we ARE using a new batch of taps so I guess it could just be a mistake on their part but does that actually happen? It kind of sucks because it's a special-order tap.)

I doubt the Speedio forgot how to tap but is it maybe too much load for the spindle and therefor loosing its sync with the Z axis? I got that alarm once but the other times the tap just broke...it's kind of hard to follow the load meter because it happens so fast and it spikes when it reverses so I can't tell what's what, but is 5/16-12 in steel maybe too much for it? It is an S700 15kRPM model...but then again we made thousands of parts before with no problems....maybe this batch of material is different but I would think it would have to be VERY different to not be tappable.

Any ideas before I put it back in the Haas?

I'm considering thread milling it to get away from having to order the special taps in the future but have only done that in a tool room setting. Do thread mills last longer than taps in production? It might have to be single point since 12 is a course pitch for a 5/16 hole.

Any help would be appreciated!!:bowdown:

IMG_7862.jpg
 
Bad batch of material?


Maybe...the first 800 pieces from this batch of material were fine then started breaking taps with what we think was a new batch of these special order taps. So the timing lines up closer to the new batch of taps than it does the new batch of material. I'm just leery of blaming the tap guy, but maybe I'm begin too naive.
 
Maybe...the first 800 pieces from this batch of material were fine then started breaking taps with what we think was a new batch of these special order taps. So the timing lines up closer to the new batch of taps than it does the new batch of material. I'm just leery of blaming the tap guy, but maybe I'm begin too naive.

can you try tapping one by hand. Usually a bad tap won't "Feel" right.
 
Well I would at least get the taps up on an optical comparator and see if there are any obvious form issues.

Do the holes that are tapped gage properly?

Are you pegging the spindle load meter when you loose sync? Do you have any taps from the last batch? Look at spindle loads for new and old.

Material diagnosis can be a bit complicated. Do you have another lot you can switch to for awhile and then switch back? Can you check hardness? Not unheard of for sections of a lot to be funky.
 
Well I would at least get the taps up on an optical comparator and see if there are any obvious form issues.

Do the holes that are tapped gage properly?

Are you pegging the spindle load meter when you loose sync? Do you have any taps from the last batch? Look at spindle loads for new and old.

Material diagnosis can be a bit complicated. Do you have another lot you can switch to for awhile and then switch back? Can you check hardness? Not unheard of for sections of a lot to be funky.

Good idea(s)! I put it up on the comparator and everything looks normal (pitch, angle, etc.) The tapped holes do gage properly. Unfortunately we don't have any taps from the last batch so there's nothing to currently compare to. Hardness is in the usual high "teens" HRC.
 
How's that work?? I like sexy things.


Since it knows the machine stopped during a tapping cycle it first prompts you to confirm the tapping conditions (i.e. return height, pitch, etc.) then once you hit "okay" it prompts you to hit "RELSE" plus "F". Once you do that it reverses it back to the return height at a low RPM. Maybe other machines do this too, but I liked it.
 
Since it knows the machine stopped during a tapping cycle it first prompts you to confirm the tapping conditions (i.e. return height, pitch, etc.) then once you hit "okay" it prompts you to hit "RELSE" plus "F". Once you do that it reverses it back to the return height at a low RPM. Maybe other machines do this too, but I liked it.

I do not know of any. (Wish my mills had that!)
My Hurco has an "Interrupt" button, and while IT'S GREAT, (think Tony the Tiger) it does not work with Taps or Keyway cutters.
An ex employee proved that on a couple occasions.:rolleyes5:

Doug.
 
Another thing to try is to optimize the Tapping Time Constant. There is an Mcode for up to 600 RPM, 600-1200 RPM etc... The machines are modal with M250 which is optimized for 6000 RPM. M241 is for up to 600 RPM, M242 for 600-1200 etc... in 10% of 6000 rpm increments. Just put the M241 on the line before your G77 tap code. Then M250 after the G80 to go back to standard setting. The NC programming manual describes this in the Mcode section. I know you have successfully tapped these before without using this, but it may help to improve performance, speed, tool life etc. once you have this sorted.
 
I do not know of any. (Wish my mills had that!)
My Hurco has an "Interrupt" button, and while IT'S GREAT, (think Tony the Tiger) it does not work with Taps or Keyway cutters.
An ex employee proved that on a couple occasions.:rolleyes5:

Doug.

I remember HAAS releasing this feature a few years back.

video
 
They're talking about stalling the spindle, not stopping it on purpose.
It's really there in case you have a power outage or Estop during tapping. I've only stalled a tap doing a larger NPT. In this instance it helped too. All rare occurrences.
 








 
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