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  1. #1
    Join Date
    Jul 2005
    Posts
    194

    EndMill Holder pulled out of TTS

    I'm assuming I just got in a hurry and didn't tighten the drawbar enough, but I was doing a long full width cut with a HSS 1/4 4 flute endmill (3.45 IPM at 1200rpm) and it started cutting deeper and deeper. After investigating, I found that the TTS holder had pulled out of the TTS/R8 adapter.

    Luckily I didn't mess anything up. What did I do incorrectly? How tight do you tighten the drawbar?

  2. #2
    Join Date
    Feb 2006
    Posts
    7063

    Re: EndMill Holder pulled out of TTS

    It must have been REALLY loose to pull out with only a 1/4" tool. To properly retain a TTS toolholder under worst-case conditions the drawbar should be tightened to at least 25 ft-lbs. My power drawbars torque the drawbar to 30 ft-lbs using a DC motor and high-ration gearbox, and I've never once experienced pull-out, even when making the most aggressive cuts with 1/2" endmills at up to 150 IPM.

    Regards,
    Ray L.

  3. #3
    Join Date
    Jul 2005
    Posts
    194

    Re: EndMill Holder pulled out of TTS

    It was pretty snugged down. I've been doing manual machining for the past 15 years and have a pretty good habit of snugging things down. Anything else it might be?

  4. #4
    Join Date
    Feb 2006
    Posts
    7063

    Re: EndMill Holder pulled out of TTS

    Quote Originally Posted by KSky View Post
    It was pretty snugged down. I've been doing manual machining for the past 15 years and have a pretty good habit of snugging things down. Anything else it might be?
    Not really. It is important for the collet bore and TTS shank to be clean and dry, and it helps to put a VERY thin coat of anti-sieze on the collet taper. But, at 25 ft-lbs, there is NO way a 1/4" tool will EVER pull-out, unless the collet, tool shank, spindle bore, or drawbar is significantly damaged.

    Regards,
    Ray L.

  5. #5
    Join Date
    Jun 2008
    Posts
    1082

    Re: EndMill Holder pulled out of TTS

    Did the cut sound OK? I've had tool holders pull out when the cut was producing a lot of vibration.

    Also, another thing to consider is that torque doesn't necessarily translate to holding force. An example: say you left a spindle with a draw-bar attached to a collet outside for a few years and the two pieces rusted together. It would take a LOT of torque to turn THAT draw-bar. 25 ft. lbs. probably wouldn't translate into any additional holding force. That's an extreme, but it's just an example to show that this fact is not debatable (as has occurred many times on this forum).

    Are the threads of the TTS collet or draw-bar buggered up in any way?

  6. #6
    Join Date
    Mar 2009
    Posts
    1863

    Re: EndMill Holder pulled out of TTS

    I've had mine pull out too, but only when I'm trying to haul a$$ thru a chunk of steel with a 1/2 inch 4 flute cutter.

    If I'm cutting aluminum with a 3/4, I have had the cutter pull out too. But that only happens when I'm getting really aggressive. Last time I had that end mill pull down, I hit the hard steel stop at the bottom and messed up the corners on my cutter. OOPS.

    After that, I made a plunge ruff routine and only left .015 on the parts for finishing. All went well after that.
    You can buy GOOD PARTS or you can buy CHEAP PARTS, but you can't buy GOOD CHEAP PARTS.

  7. #7
    Join Date
    Jul 2005
    Posts
    194

    Re: EndMill Holder pulled out of TTS

    It's fairly new TTS tooling, but the end mill was pretty old. It does have a chipped tooth now, I assumed it happened when it started cutting too deep, but perhaps it did so another time and I didn't notice, thus causing vibration and the pulling out? I had done several cuts before and with a new end mill, several cuts after and no problem.

    While I am on the subject, I am cutting out a rectangular piece of 1/4 plate that's 5x7", taking two cuts of .13. Would you just take one cut of .26, or would you use a bigger endmill with multiple/single cuts.

    When I was doing stuff like this on my Bridgeport I would cut up to 1 1/2 times the cutter deep in one pass.

  8. #8
    Join Date
    Jun 2014
    Posts
    1777

    Re: EndMill Holder pulled out of TTS

    Personally, I only get pullout if I have a cutter that is chattering, this can be on any size cutter as well.
    mike sr

  9. #9
    Join Date
    Apr 2013
    Posts
    99

    Re: EndMill Holder pulled out of TTS

    Tormach has a paper on the web site about tool pull out.
    You need to have some lube on the r8 collet in the right places so it properly compresses.

    I had some pull out problems early on and a little lune fixed it

  10. #10
    Join Date
    Jun 2014
    Posts
    1777

    Re: EndMill Holder pulled out of TTS

    This fixed 95 percent of the pullout issues I had.

    I had pullout the other day with a 3/8 long cutter that put its calling card on one of the vise jaws!
    I find it amazing that the cutter never seems to pull out of the holder or er collet, it seem to always pull out of the r8 collet setup.There was a fellow that posted a cure for it on another forum, he basically turned the shank of the toolholder on a very slight taper, this was sometime back so I dont know how it worked out for him over time. In my case, if the cutter isnt chattering during a cut, I wont get pullout.
    mike sr

  11. #11
    Join Date
    Dec 2012
    Posts
    194

    Re: EndMill Holder pulled out of TTS

    even when making the most aggressive cuts with 1/2" endmills at up to 150 IPM.
    Ray L.
    What milling machine are you using?

  12. #12
    Join Date
    Jul 2005
    Posts
    194

    Re: EndMill Holder pulled out of TTS

    tormach 1100 Series 3. I have all of 4 hours of runtime on it. Years and years on the manual Bridgeport.

  13. #13
    Join Date
    Feb 2006
    Posts
    7063

    Re: EndMill Holder pulled out of TTS

    Quote Originally Posted by LRF View Post
    Ray L.
    What milling machine are you using?
    A Novakon Torus Pro. But what does that have to do with the topic at hand? TTS is TTS, and works the same on any machine.

    Regards,
    Ray L.

  14. #14
    Join Date
    Dec 2012
    Posts
    194

    Re: EndMill Holder pulled out of TTS

    Sorry...was only curious what machine you were using

  15. #15
    Join Date
    Nov 2006
    Posts
    134

    Re: EndMill Holder pulled out of TTS

    I believe that the particular dynamics of the PCNC1100 do in fact contribute to the pullout problems that I have experienced with TTS on my tormach mill. It is quite possible that the machine dynamics of a different design, such as the Torus Pro, would not experience chatter conditions in the same manner as the PCNC does. My pullout problems are significantly reduced (nearly eliminated) when I change out my power drawbar springs for a solid bushing, for example. I believe you are using a screwthread-tensioned drawbar arrangement on your machine, is that correct Ray?

    In any case, I don't believe you can accurately state that TTS works the same on any machine, at least as regards this issue of chatter-induced TTS toolholder pullout, using a typical R8-collet TTS setup.

  16. #16
    Join Date
    Feb 2006
    Posts
    7063

    Re: EndMill Holder pulled out of TTS

    Quote Originally Posted by bobeson View Post
    I believe that the particular dynamics of the PCNC1100 do in fact contribute to the pullout problems that I have experienced with TTS on my tormach mill. It is quite possible that the machine dynamics of a different design, such as the Torus Pro, would not experience chatter conditions in the same manner as the PCNC does. My pullout problems are significantly reduced (nearly eliminated) when I change out my power drawbar springs for a solid bushing, for example. I believe you are using a screwthread-tensioned drawbar arrangement on your machine, is that correct Ray?

    In any case, I don't believe you can accurately state that TTS works the same on any machine, at least as regards this issue of chatter-induced TTS toolholder pullout, using a typical R8-collet TTS setup.
    The OP is not using a power drawbar at all, so his environment is much closer to mine than to yours - we are both tightening a drawbar, with no Belleville springs. Mine has never slipped, even under conditions of pretty significant chatter.

    Regards,
    Ray L.

  17. #17
    Join Date
    Jun 2004
    Posts
    6618

    Re: EndMill Holder pulled out of TTS

    I did get a long tool to slip in my old smaller Torus that used no springs. I used a butterfly impact and had the air regulated down. That coupled with dirty tools (not cleaned that week) contributed to the pull out.
    By simply cleaning the tools and adding oil to the taper, that eliminated the issue. However, from then on for that op, I used more air pressure.

    I had the same op pull out yesterday on the new Pulsar. It does have springs and uses a lever draw bar. This time the tools were clean. I adjusted the LDB tighter and that eliminated the pull out.
    Adjusting feeds and speeds would probably have achieved the same results.
    Lee

  18. #18
    Join Date
    Nov 2006
    Posts
    134

    Re: EndMill Holder pulled out of TTS

    Quote Originally Posted by SCzEngrgGroup View Post
    The OP is not using a power drawbar at all, so his environment is much closer to mine than to yours - we are both tightening a drawbar, with no Belleville springs. Mine has never slipped, even under conditions of pretty significant chatter.
    I think I did a poor job of expressing myself regarding the effects of machine design and drawbar style on chatter-related pullout. You are correct, the OP and yourself have more similarity between your drawbar configurations than my default Tormach spring-loaded power drawbar does. However, the overall machine construction and configuration of any TTS-equipped machine (including work clamping, etc.) will affect how frequently TTS holders will pull out during chatter conditions. I used my spring-loaded vs. screw-tightened drawbar configuration difference anecdote as a poorly-executed illustration of the effects of differing machine configurations affecting TTS pullout. My question about your setup was motivated more by curiosity and was somewhat tangential, and not intended to support my main point by inference, although it does read that way in hindsight.

    I am speaking of this because I spent quite a bit of time attempting to characterize and understand the conditions that were causing pullout on my machine. I came to realize it was all a function of the dynamic loading of the toolholder interacting with the machine's motion and drawbar tension. I can easily see how you might never experience TTS pullout with your machine, setup and tooling, whereas various Tormach (or other mill) owners may experience it relatively often if they are doing deep profiling cuts in steel with a standard end mill, for one example. (My worst case example, btw).

    For the OP, I would recommend checking your gib adjustments for all three ways, and also your lubrication effectiveness across all of the ways. I have had problems crop up with pullout when my gibs are too loose or when inadequate way lubrication is causing extra chatter. Also, make sure that your spindle is trammed well. This is easy enough to check, but not particularly easy to correct if you are out of tram. Since you mention slotting and not profiling as being the operation that causes your pullout, I would check the tram first, in fact. You should be checking and adjusting your gibs fairly regularly anyhow, so do this too if you haven't recently.
    Good luck! I know how frustrating it can be to wrestle with this problem.

  19. #19
    Join Date
    Feb 2006
    Posts
    7063

    Re: EndMill Holder pulled out of TTS

    Quote Originally Posted by bobeson View Post
    I think I did a poor job of expressing myself regarding the effects of machine design and drawbar style on chatter-related pullout. You are correct, the OP and yourself have more similarity between your drawbar configurations than my default Tormach spring-loaded power drawbar does. However, the overall machine construction and configuration of any TTS-equipped machine (including work clamping, etc.) will affect how frequently TTS holders will pull out during chatter conditions. I used my spring-loaded vs. screw-tightened drawbar configuration difference anecdote as a poorly-executed illustration of the effects of differing machine configurations affecting TTS pullout. My question about your setup was motivated more by curiosity and was somewhat tangential, and not intended to support my main point by inference, although it does read that way in hindsight.

    I am speaking of this because I spent quite a bit of time attempting to characterize and understand the conditions that were causing pullout on my machine. I came to realize it was all a function of the dynamic loading of the toolholder interacting with the machine's motion and drawbar tension. I can easily see how you might never experience TTS pullout with your machine, setup and tooling, whereas various Tormach (or other mill) owners may experience it relatively often if they are doing deep profiling cuts in steel with a standard end mill, for one example. (My worst case example, btw).

    For the OP, I would recommend checking your gib adjustments for all three ways, and also your lubrication effectiveness across all of the ways. I have had problems crop up with pullout when my gibs are too loose or when inadequate way lubrication is causing extra chatter. Also, make sure that your spindle is trammed well. This is easy enough to check, but not particularly easy to correct if you are out of tram. Since you mention slotting and not profiling as being the operation that causes your pullout, I would check the tram first, in fact. You should be checking and adjusting your gibs fairly regularly anyhow, so do this too if you haven't recently.
    Good luck! I know how frustrating it can be to wrestle with this problem.
    Personally, pullout under chatter would not really concern me too much since, pretty much by definition, if you're getting significant chatter, you're operating outside any proper operating area for the combination of machine, toolholder, tool, and workpiece. Chatter is the result of exceeding the rigidity of the machine and/or toolholder and/or tool and/or workpiece support.. It is brutal on the tools, creates lousy surface finish, and poor dimension. So, you simply shouldn't ever be operating there.

    Regards,
    Ray L.

  20. #20
    Join Date
    Mar 2009
    Posts
    1863

    Re: EndMill Holder pulled out of TTS

    I don't get chatter on my machine. I didn't get it at the beginning. I have run machines long enough that I pretty much know what will work and what won't. I used to get a little chatter when I was cutting steel, but since I don't cut steel any more, I don't get chatter.

    When cutting aluminum I have learned ways to cut that will allow heavy cutting with no chatter or pull out.
    You can buy GOOD PARTS or you can buy CHEAP PARTS, but you can't buy GOOD CHEAP PARTS.

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