[BobWarfield]

Terry, I'm liking the pull stud and drawbar force possibilities.

A couple other things to think about. First, not sure if you're torquing the ER collet chuck nut, but they have torque specs too and they're higher than a lot of folks think:

Getting the Best Performance from ER Collet Chucks « CNCCookbook CNC Blog CNCCookbook CNC Blog

Second, the runout can vary depending on how the cutter is "clocked" in the toolholder. On tapers with drive dogs, you have two positions to insert the cutter. One will have a lower runout. If all is well, it may not be much lower, but there will be a difference.

It does sound like runout from some source is plaguing you. Think of runout as being additive to the chipload. If you're already at the limit, it can push you over and break the cutter. The numbers you measured seemed kind of high.

Last thought is there sure are a lot of places for a chip or burr on an ER collet chuck to hide and mess up the runout.

Cheers,

BW

[Terry G]

Thanks BW for the info.

I completely agree with the ER collet issues and that runout is definitely additive. I use a proper ER collet wrench and pretty much crank down on it. Never had a tool slip so far. I'll check the torques. Would be interesting to see what I am torquing them too.

I am pushing the tools close or at their limits. Since we manufacture a lot of similar parts using the same tools from the same materials, we have figured out what works well for us.

Yes, there are two positions the tool holder can go into the spindle. I'm not sure if the machine keeps track of that when it is changing tools. Never paid attention to it. If it does, I can check each tool holder for the best runout and mark it being sure to install it into the spindle the same way each time.

As far as the ER collets, I am measuring this runout without the tool or collet installed. I have spent a lot of time inspecting the spindle and toolholders for chips and burrs and I am confident this is not the cause.

Once I can measure proper runout on the toolholder collet seat, then I can start looking at the tools themselves and how the collets are working. But that should be the easy part! (hopefully)

Thanks for the link!

[Rocko1]

I would suggest you look at a couple things that changed, It is the cutter. I bet the fact is that the manufacturer changed something or you really didnt order the exact same cutter. I would check with the manufacturer directly and verify. Also sometimes they have mfg defects, lol. Also maybe your previous invincible tool broke due to either your haas have some kind of servo movement issue that it didnt have before. I would test this by programming and milling 2 different circle diameters both a pocket and a male island of of two different diameters. Then see if they are perfectly round.

[metalmansteve]

Sometimes things just remain a mystery. I was running Duramill variable flute end mills with great success....hundreds of nickel parts roughed with a single end mill consistently. All of a sudden their tools snapped off on the first or second part. Duramill reps came in and couldn't explain it. I switched to SGS zcarbs and Niagra's and they run almost as good as the original Duramills. I would experiment with different cutters...most dealers will offer test tools for free. 1/8" tools are cheap anyways. MA Ford makes some good aluminum cutters...good luck.

[Terry G]

Yes the cutter changed being that it was different. I purchase most of my tools from our local distributor. The tools had the same manufacturer part number on them (they keep track of all my purchases so we looked it up).

Tool could have been defective as well since I broke two of them in a row. I put a cheap SGS double sided cutter, and it hasn't broke yet. Just doesn't sound right, and leaves a small burr. These don't have the high helix, so I think they are a little stronger than the high performance aluminum cutters.

I think the fact that I am measuring up to .0015" of runout inside the collet seat of my tool holder is something I need to work out first.

As soon as this has been figured out, and my tool holders are running true, then I will definitely go back to the high performance aluminum cutter I used before and see how they work. These typically leave no burr and cut very quite.

Thanks!

[Terry G]

I purchased a couple new pull studs from my local distributor. Checked the runout of a toolholder inside the collet seat which measured close to .002". Replaced the pull stud and measured again with the same results.

So the pull stud did not change anything. My original pull studs look to be in great shape with no wear marks or anything like that.

Haas tech called me and we went over a few more things to try before they come over. All of which checked out (one of them was the new pull studs).

Yesterday I set up for a new job, purchased a brand new 1/4" Iscar 3flt EM and collet. This part has .375" walls that are finished with the 1/4" EM, as well as soft jaws which were cut with the same 1/4" EM.

First thing I noticed with with this job is that there was significant amount of tool deflection. I typically leave .010" stock for my finish pass. Though now, I am having to run two finish passes, and slow the feed down about 20%. And there is still a little deflection at the bottom of the part.

I can take multiple depth finish passes which I do on some parts, but this part has never needed it.

The finish looks nice with no chatter marks. So could a loose tool holder cause deflection and still leave a nice finish?

I usually keep a few pieces of each job I run to look back on. I checked these same pieces which were ran about a year ago, and the edge finish just looks nicer. Even on my other parts that I finish with other tool diameters, they all look a little smoother. Keep in mind I am inspecting these with a 10X magnifier loop. To the naked eye they all look really good.

Anyway, at least when Haas comes to inspect the machine they can hopefully find something that will take care of these issues.

As minor as this issue may be, it still bothers me that something has recently changed and I'm having to modify my proven programs to get the results I'm after.

[txcncman]

"...could a loose tool holder cause deflection and still leave a nice finish?"

Yes.

[Terry G]

Thanks!

[txcncman]

The effect of a loose tool holder would be to cancel out harmonic vibrations. I have purposely done this with lathe boring bars.

[Terry G]

Thanks. Just trying to see if this problem continues to point to the possibility that my drawbar pressure is low and the tools are not being secured properly.

This is what Haas suggested I check next, but the tools are very expensive. Even the Haas tech would have to purchase one before he came and did a service inspection on the machine.

But looks like I'll need to get this done and hopefully figure out what the problem is.

[Machineit]

Thanks. Just trying to see if this problem continues to point to the possibility that my drawbar pressure is low and the tools are not being secured properly.

This is what Haas suggested I check next, but the tools are very expensive. Even the Haas tech would have to purchase one before he came and did a service inspection on the machine.

But looks like I'll need to get this done and hopefully figure out what the problem is.

I thought we were talking about an eighth inch endmill? If you drawbar is that loose, shut that machine down before it throws the tool right out of the spindle. It would look cool as a top on your table though.

Mike

[txcncman]

Thanks. Just trying to see if this problem continues to point to the possibility that my drawbar pressure is low and the tools are not being secured properly.

This is what Haas suggested I check next, but the tools are very expensive. Even the Haas tech would have to purchase one before he came and did a service inspection on the machine.

But looks like I'll need to get this done and hopefully figure out what the problem is.

Well, you do not need to do the draw bar pressure test. I know different people have different opinions when it comes to machine maintenance. But to me, $1000 is a drop in the bucket. Look at it another way, how much to you spend per year on maintenance on your $30,000 car? Doesn't it make sense to spend twice that much on a $60,000 machine? If you are not intentionally spending money on maintenance of your equipment, if you do not purposefully have it in your budget, you are a crisis waiting to happen. Just a guess, but it will cost you at least the $1000 to rebuild the drawbar mechanism. You could just go ahead and rebuild it and hope that is the actual problem. You probably have enough hours and tool clamp/unclamp cycles on the machine that it needs rebuilt anyway as part of preventative maintenance. How much is down time and broken tooling costing you now?

[Terry G]

That is a good way to look at it. Though the machine only has 1700 hours of spindle run time on it. This seems pretty low for a rebuild, but I can't be sure.

I agree that spending the necessary money on maintenance is very important. This is why a Haas service tech will be inspecting the machine and repairing anything as needed.

Only reason he hasn't come by yet is because Haas wanted me to check a few more things. They are all about learning your own machine and trying to repair it on your own (within your capabilities of course). They have been very helpful with a few other minor issues I have had and was able to repair very quickly with their phone support.

I can't say if my tool holders are loose, just something Haas says should be checked along with a number of other things I have already done.

I'll have an answer soon (hopefully). I'm sure I'll learn a thing or two as well when the tech starts inspecting the machine. Money well spent in my opinion.

[Terry G]

I thought we were talking about an eighth inch endmill? If you drawbar is that loose, shut that machine down before it throws the tool right out of the spindle. It would look cool as a top on your table though.

Mike

Yes, this is where it all started. Was running a job, everything was going perfect. After a hundred parts or so my 1/8" EM snapped. Purchased two new ones, they both snapped within 1" of feed.

After inspecting the cuts on the parts where the EM snapped, I noticed a large burr (even on the new EMs). This was very unusual since all my cuts in the past have been very clean.

After checking the runout on the tool, it was way out. Then I removed the cutter and checked the collet seat of the toolholder for runout. This was also way out. Checked a few more tool holders and the same thing. Then checked the spindle as Haas recommended, and it was better than .0002" which is within spec.

The drawbar pressure was next on the list of things they said need to be checked. I also changed pull studs with no results.

That's how it ended up from breaking an 1/8" cutter to now!

[haastec]

Thanks. Just trying to see if this problem continues to point to the possibility that my drawbar pressure is low and the tools are not being secured properly.

This is what Haas suggested I check next, but the tools are very expensive. Even the Haas tech would have to purchase one before he came and did a service inspection on the machine.

But looks like I'll need to get this done and hopefully figure out what the problem is.

How comfortable are you at trying to removing the drawbar?
There have been a couple of recent posts here about replacing the drawbar. (Scan the threads or do a search) If you removed the drawbar, you could at least do a visual inspection of the washers to make sure that none are cracked or falling apart.

[Terry G]

I would be OK doing this if I had a detailed procedure. Though I wouldn't really know what to look for.

If there were specs with tolerances on each and every component, I could check them and replace as necessary. I think spending the $300.00 or so for two hours of the Haas techs time would be good to start. I feel they can check out quite a bit in that amount of time with their experience.

But if the drawbar is bad and needs rebuilding, with the proper information this is something I could consider tackling. My machine isn't run every day, so I do get 3 or 4 days down time every so often.

[thebodger]

terryg

I just finished reading through this thread ( rater quickly) so if what I suggest has been mentioned, then disregard this post.
Many years ago (30+) I had a situation on a high speed Trumpf aluminum router, very similar problems as yours. Problem drove me nuts for weeks.
What I finally discovered was the spindle taper (not the collet part) was bell mouthed. When I checked the run-out of the spindle, it was good, about .0002 inch. But the taper, wasn't a taper and the dial indicator wasn't showing this. How I found this distortion was by getting a perfect taper made by our toolroom. Then I used machinist blue (Not layout blue) to check how a known correct taper (the one we made) was contacting the spindle taper. It wasn't very good, it was very distorted. I had a hard time understanding how cutting a soft material could cause this, but it can. This is a cheap quick check you can do , use a good new tool holder a blue the taper. then do the same with a problematic tool holder.

Good luck.

Oh and if it is bell mouthed, there are companies that can touch up (minimum regrind) of the spindle IN THE MACHINE. Don't be too hasty to remove and replace spindle.

Hope this helps.

[Terry G]

Hi thebodger,

This is great info. Thanks. I've been meaning to purchase a new tool holder just to test out runout etc. Something I haven't had a chance to do yet, and kind of figured the Haas tech would have something to check this with as well.

But in the meantime, I'll have to see of our local supplier has some machinist blue, to try this out.

Since I don't have a new machine and taper to compare with, how will I know what is or isn't acceptable?

Thanks again for the great suggestion and taking the time to read the thread!

[thebodger]

TerryG

You will know when you see the transfer of the blue from the spindle taper to the tool holder, or vise versa. So what I'm getting at is, put a very light spread of "blue" on the spindle taper, I mean light! Then carefully clamp up a good new tool holder (try not to bump it against the taper as you insert). Clamp tool, then release.
What your looking for is a complete transfer of "blue" from spindle to toolholder.
Look for high or low spots, if you follow me.
If your Haas guy is at all "on the ball" so to speak, he will know this procedure.

[Terry G]

Got it. So you are expecting to see a full even transfer, which makes sense.

I've heard great things of this tech, he is actually familiar with my exact machine as well since he used to service it at the shop I purchased it from.

Thanks again.