Sacrfice tooling life to save on repairs

[Dalego]

Out of curiosity, how many are running 20% less on feed and speed in order to give spindle and bearings longer life? Where I work, we do long setups for a few parts instead of long runs of parts. Example is we may setup for 30 mins to run a 5 min cycle and then on to the next part/setup. We run a VF 10 if that helps. We got it used recently. No idea on what the previous owners did for maintenance. Did not bother looking it over or replacing parts before running. So now the spindle broke. We believe the fingers that hold the retention pin broke but wont know for sure until sometime next week. So now I have been told to run at 20% less speed to avoid the wear on the spindle, raise the tooling on each pass high enough so if the fingers ever let loos again it wont grab the holder thus extending toolpath and time. Now at 20% reduction we would be paying full price for half a tool I think. To me it makes no sense pissing money away on tooling to avoid doing maintenance as needed. We are a busy little shop but we should be able to plan for down time for preventative repairs. I am very irritated about this and am looking to see what others think or do with their machine. Thanks for letting me rant a bit.

 

[mhajicek]

Babying it until you can get it repaired, sure. After it's fixed, never. Calculate the extra cost, in time and tooling, over the MTBF of the spindle.

 

[coyoinu]

new from the factory, a haas spindle is rated for 4000 hrs at max speed.

 

[Milland]

new from the factory, a haas spindle is rated for 4000 hrs at max speed.

That seems low, do you have a reference for where that rated life came from?

 

[thesidetalker]

Out of curiosity, how many are running 20% less on feed and speed in order to give spindle and bearings longer life? Where I work, we do long setups for a few parts instead of long runs of parts. Example is we may setup for 30 mins to run a 5 min cycle and then on to the next part/setup. We run a VF 10 if that helps. We got it used recently. No idea on what the previous owners did for maintenance. Did not bother looking it over or replacing parts before running. So now the spindle broke. We believe the fingers that hold the retention pin broke but wont know for sure until sometime next week. So now I have been told to run at 20% less speed to avoid the wear on the spindle, raise the tooling on each pass high enough so if the fingers ever let loos again it wont grab the holder thus extending toolpath and time. Now at 20% reduction we would be paying full price for half a tool I think. To me it makes no sense pissing money away on tooling to avoid doing maintenance as needed. We are a busy little shop but we should be able to plan for down time for preventative repairs. I am very irritated about this and am looking to see what others think or do with their machine. Thanks for letting me rant a bit.

This whole post is filled with WTF? lol where to even start.

Care to share any details of the actual things that matter? How did the spindle just "break?"

Of course it will break from crashing in to vises and such. It just isn't going to wind up dead one day from running at 100% of 'normal' parameters, instead of 80% of 'normal'. That's a load of shit.



You have to raise the tooling high enough so if the "fingers" ever let loose again, it wont grab the holder? What on earth are you talking about?





Sounds like somebody is crashing things and wont fess up.

Out of curiosity, how many are running 20% less on feed and speed in order to give spindle and bearings longer life?

Nobody.

20% less than what? This is ridiculous. 20% less than max spindle speed I could understand, but 20% feed? what is "normal" feed?

 

[Dalego]

We had been drilling holes in a run of parts and all was fine. The other morning the holder came out of the spindle after a number of cycles. The machine is not being serviced until sometime next week when parts show up. So far it is being assumed that the hydraulic fingers that hold the retention pin broke but we will not know for sure until it gets taken apart. As for the 20% less - 20% slower per manufacturer recommended speed and feed. For this particular tool it is 1862 RPM and 19.8 IMP that will both need to be reduced 20%. After the holder and tooling fell out of the spindle the retention knob hit inside the spindle creating more damage. Nobody crashed the machine. So that is why we have been instructed to raise the spindle higher on toolpaths.

Drilling holes. Spindle moved upwards to continue to next hole. Tooling and holder came out of spindle. I usually rapid 1 inch above material to next feature (hole) Operator was able to hit the E-stop but not soon enough and the inside of the spindle took damage as well as the tooling left in the hole. Haas service dept is where I am getting the finger broke information from.

 

[coyoinu]

That seems low, do you have a reference for where that rated life came from?

overheard it from Gene himself during a Tuesday engineering meeting at the Oxnard factory. "2 shifts a day for a year"

 

[CarbideBob]

"1862 RPM and 19.8 IMP"
Where do these numbers come from?
Please do not tell me some catalog or website. These are just starting guidelines and often written by clerks that have never run a machine.
20 percent off both? Is the tool life worse or might it be better?
Google Taylor tool life curve.

The big loss is production time which means paying employees more hours and money for the same number of parts shipped.
20% slower is a lot nicer on spindle bearings but I do not see how it helps the retention mechanism when drilling.
Chip jam/evac and retract speed problems?
Bob

 

[Dalego]

Numbers are not from a website or catalog. These are close to manufacturer recommended parameters and what we found works best for the material we use. We have been running these parts and programs for a very long time at these speeds. I am not the one making the call to slow things down. I would rather fix the spindle and carry on unless we determine something else has caused the breakage once we do the repairs. I am just curious as to how common it is to run at slower speeds in other shops. Other than the being easier on the bearings I see no benefit from slowing down. Just like any other moving part, I would think there is a number of hours before the parts need to be replace to avoid unwanted down time. So going slower really gains nothing IMO. Maybe I am wrong and that is why I made this thread. To see if slowing down is the way to go. My problem is tooling life is lost as well as the cycle times.

The machine broke. Was not crashed. I see no need to make these changes unless we find a logical reason to do so. Then again it may just be my drive to get things done in an efficient amount of time and adding cost to things that we cannot charge for is just......bleh

 

[gustafson]

Please run slowly and save your machines so people can get a good deal on the used market

And everyone else can divide up the work you used to do.



If a machine needs to be babied to get the job done, then you need a better machine or to do the job differently

 

[Dalego]

Forget I even asked. I wanted some questions answered not to be ridiculed. What a waste of time today here.

 

[Milland]

Unless this is a very unusual machine (or a HSK), Haas do not use fingers for pull stud retention, they use an outer sleeve with through holes for ~1/4" bearing balls which are captured by geometry within the spindle that force the balls into the area under the stud head taper.

If you've had the holder come out, there's a very good chance there's broken belleville washers in the spring stack, which weakens the retaining ability of the drawbar. This isn't just a performance issue, it's a safety problem if the holder and tool are ejected again.

The machine really should be checked with a drawbar dynamometer, and if found low, the drawbar serviced/replaced. Running "slow" is a very poor substitute for repair.

 

[thesidetalker]

Forget I even asked. I wanted some questions answered not to be ridiculed. What a waste of time today here.

As you should be. Your post was bad, and you should feel bad.

You gotta provide more information if you expect any kind of a response that isn't smart-ass.

No details at all. All we got is: "I drill this same hole a lot. This time the tool just fell out of the spindle. Why? If I go 20% slower will that save my machine from next time?"

This is asinine. You still can't even say what material it is. What tool it is. What holder. No information about the setup. You say you don't know if the fingers are broken or not and apparently can't even look up into the empty spindle taper to see? No pictures of nothing.


LOL "the tool just fell out! I was doing everything correct but the machine just fell apart by itself. honest."

Then to suggest changing rapid heights higher will save the spindle taper next time, because the tool randomly dropping out of the spindle is a regular occurrence? This way the spindle taper will clear the tool that regularly gets stuck in the workpiece? LOL.

 

[CarbideBob]

.... Haas do not use fingers for pull stud retention, they use an outer sleeve with through holes for ~1/4" bearing balls which are captured by geometry within the spindle that force the balls into the area under the stud head taper.

But the OP says fingers for this and we must assume he knows tool retention types in his own machine.

 

[Milland]

But the OP says fingers for this and we must assume he knows tool retention types in his own machine.

Maybe he should pull his fingers out?

[That was for the Brit members..]

 

[Dalego]

As you should be. Your post was bad, and you should feel bad.

You gotta provide more information if you expect any kind of a response that isn't smart-ass.

No details at all. All we got is: "I drill this same hole a lot. This time the tool just fell out of the spindle. Why? If I go 20% slower will that save my machine from next time?"

This is asinine. You still can't even say what material it is. What tool it is. What holder. No information about the setup. You say you don't know if the fingers are broken or not and apparently can't even look up into the empty spindle taper to see? No pictures of nothing.


LOL "the tool just fell out! I was doing everything correct but the machine just fell apart by itself. honest."

Then to suggest changing rapid heights higher will save the spindle taper next time, because the tool randomly dropping out of the spindle is a regular occurrence? This way the spindle taper will clear the tool that regularly gets stuck in the workpiece? LOL.

I feel bad as I thought this was a discussion forum. Not a bitch a guy out and ridicule without asking questions forum. Did I see a need to divulge all the unrequested information you complain about? Nope. Did I think it mattered? Nope. I had a lot of respect for this site. If I ever revisit the page again I will be sure to get you what leg I was standing on and shoe size too so you don't bitch about not knowing without asking. That is IF I ever need advice from a group of smug assholes.

 

[Big B]

I feel bad as I thought this was a discussion forum. Not a bitch a guy out and ridicule without asking questions forum. Did I see a need to divulge all the unrequested information you complain about? Nope. Did I think it mattered? Nope. I had a lot of respect for this site. If I ever revisit the page again I will be sure to get you what leg I was standing on and shoe size too so you don't bitch about not knowing without asking. That is IF I ever need advice from a group of smug assholes.

There's a wealth of information available here if you know how to ask but being a jerk won't help at all. Answer the questions that are asked and you will get good answers. Tell everyone that they are a bunch of assholes and it won't get you far. Good luck with the repair crew. Hopefully your machine won't be junk by the time they get there.

 

[mhajicek]

From what you've said, you do not have a spindle problem, you have a drawbar problem. Your spindle is fine.

Drilling forces are mostly axial up into the spindle taper, so reducing feeds and speeds will likely not help at all. You need to get your drawbar mechanism fixed ASAP.

 

[Djstorm100]

overheard it from Gene himself during a Tuesday engineering meeting at the Oxnard factory. "2 shifts a day for a year"

What about the meeting where Gene decided to switch to Galvanneal waycovers.

"Galvanneal is not a problem"

Now they offer stainless at a up charge.

 

[Garwood]

new from the factory, a haas spindle is rated for 4000 hrs at max speed.

Even as a Haas-disliker I find that number low. I have never heard a number thrown out for any spindle before, just know that I've owned many machines with 20 times those hours at max RPM and still going strong.