548,466 active members*
2,537 visitors online*
Register for free
Login
IndustryArena Forum > MetalWorking Machines > Okuma > Spindle acceleration/deceleration
Results 1 to 11 of 11
  1. #1
    Registered
    Join Date
    Nov 2016
    Posts
    18

    Spindle acceleration/deceleration

    Good morning,


    We have another new to us 2012 OKUMA LT2000EX Serial #163297 machine.


    The main spindle is not the "standard" or the same size as the other 2 machines that we have. It is 68mm through the draw tube, the other ones are 2".


    The max speed on the main is 5,000 rpm, 6,000 on the sub.





    The problem is that it takes a very long time to accelerate up to speed. It's so bad that I have taken CSS out of some tools because it is "waiting" for the spindle to get to speed between roughing passes. During the cutoff process when the spindles are synced it takes forever to start and stop. That's only with a 2" dia bar!





    I wrote a simple program to just sync the spindles and accelerate up to a speed and back to stop. (below)


    When the spindles are synced together at 2,500 rpm it takes 22 seconds to get up to speed and back to zero. @ 4,500 rpm it takes 56 seconds! The other machines @ 4,500 rpm it takes 26 seconds!




    Now this problem isn't just during the transfer when they are synced together. But it is only on the main spindle. The sub spindle is the standard 2" dia. and accelerated and decelerates just like our other machines.

    The only suggestion tech support has suggested is the Work weight setting must be set to heavy. But the work weight parameter is set to no chuck on all the machines except for one. Which is our LB3000IIEX with 3" spindles. It's set to 10" (main) 6" (sub). But even this machine is within 1-2 seconds of the other machines running the test program.

    This is adding a considerable amount of cycle time!




    Any ideas what is going on here???


    G13
    G140 (MAIN SPINDLE)
    G144 G136 M109 M76
    (SPINDLE SYNC TIME TEST)
    G50 S5000
    P200

    P201 G97 S1500 M3

    M185 M247 (CHK ROT I'LOCK OFF, OPP SPDL ROTATION I'LOCK OFF)

    M249 (OPEN SUB)
    M151

    G04 F.5
    M248 (CLOSE SUB)
    M84
    G4 F.5 (SUB PULL)
    M83
    G97 S4500 M3
    G97 S4500 M5
    M150
    P990

    G14
    G141 (SUB SPINDLE)
    G144 G136 M109
    G50 S5000
    P200

    P201 G97 S1500 M4

    G140
    P990
    M2
    %









  2. #2
    Member
    Join Date
    Jun 2015
    Posts
    3524

    Re: Spindle acceleration/deceleration

    hy what options do you have at " workweight (main spindle ) " ? i understood that now it is at " no chuck ", but what else is there ? okuma dealer is the one that can enable them; is ok if okuma dealer recomanded setting change, but is not ok if options are not enabled; they should enable that even if machine was delivered without a chuck

    Now this problem isn't just during the transfer when they are synced together. But it is only on the main spindle
    to be sure that you check only main spindle, use M150+G140; if it works in M150, then begin to investigate also 151

    Which is our LB3000IIEX with 3" spindles.
    you mean 3" spindle bore ?

    i have acceleration times for 3000series, normal and big bore; i will share them and test program as reference

    besides workweight, there is at least other spindle acc parameter; i will look for it a bit later / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  3. #3
    Registered
    Join Date
    Nov 2016
    Posts
    18

    Re: Spindle acceleration/deceleration

    Quote Originally Posted by deadlykitten View Post
    hy what options do you have at " workweight (main spindle ) " ? i understood that now it is at " no chuck ", but what else is there ? okuma dealer is the one that can enable them; is ok if okuma dealer recomanded setting change, but is not ok if options are not enabled; they should enable that even if machine was delivered without a chuck

    There are just settings for 3 different settings for the main and sub.
    Main is No chuck, 8" or 10"
    Sub is No chuck 6" or 8"



    to be sure that you check only main spindle, use M150+G140; if it works in M150, then begin to investigate also 151
    I was running the program in (M150) mode and there was very similar rough turning operations on the main and sub spindles.
    With CSS turned on both spindles. The main spindle was just finishing roughing the part, while on the sub it roughed turned, finish turned, drilled 2" deep, C'bore .30 deep and then tapped a M16-1.5 hole 1.5 deep before the main was done! That is nutz!


    Isolated just one spindle at a time 0-5,000-0
    Main 14 seconds
    sub 6 seconds


    you mean 3" spindle bore ? Yes that's correct

    i have acceleration times for 3000series, normal and big bore; i will share them and test program as reference

    besides workweight, there is at least other spindle acc parameter; i will look for it a bit later / kindly They asked me to check for several other pages but they were not there.
    hmmm

  4. #4
    Member
    Join Date
    Jun 2015
    Posts
    3524

    Re: Spindle acceleration/deceleration

    There are just settings for 3 different settings for the main and sub.Main is No chuck, 8" or 10"
    Sub is No chuck 6" or 8"
    hy there may be more or less options; normally, 1st is the standard chuck for that spindle, and futher options are for bigger chucks

    he only suggestion tech support has suggested is the Work weight setting must be set to heavy
    heavy setting is enabled :
    ... on standard spindles with heavier than standard chuck
    ... on big bore spindles

    The max speed on the main is 5,000 rpm, 6,000 on the sub

    I was running the program in (M150) mode and there was very similar rough turning operations on the main and sub spindles.With CSS turned on both spindles.
    you should take out from equation the 2nd spindle, because it seems to be smaller & faster, and this is normal

    you should compare the 1st spindle to a similar spindle from other machine; if i get it right, you have problems with the big bore, and you also have 2 more lathes with normal 1st spindle; i don't have times for 2000series, but for 3000, the difference between normal and big bore is <0.4seconds @ 2500rpm; i don't know if this applies proportionally to the 2000 ?!

    also, when you compare spindles for 2000 series, there are 3 variants for main spindle ( standard, high power, big bore ) and 1 variant for the sub spindle

    what i try to say, is that you need a real reference, and stop comparing to the subspindle and/or sync more, or whatvere else; i would look into spindle diagram, and search for a similar machine, with same chuck ... but as you describe it, it seems to be slowed down for whatever reason

    little list :
    ... work weight : if heavy is missing, then try the latest option : for example, if now is [ no chuck ], then simply switch to [ 8 ] or better to [ 10 ]
    ... machine user para spindle \ page 5 \ spindle power peek cut : change it, cycle power, check for difference
    ... machine sys para spindle : torque limit to be 100%
    ... parameter SPINDLE ACCEL SET; possible not to find it, because it is optional

    if you need a reference program for acceleration time :
    Code:
    G50 S2000
    G04 F1.5
    M331
    V1=VDIN[1000]
    G97 S2000 M3 M42
    G04 F1.5
    M331
    V1=VDIN[1000]-V1
    M05
    
    
    FWRITC D.TXT;A
    PUT V1
    WRITE C
    
    
    M02


    please be aware, there may be something related to your power source : High power source inductance of input power supply results in longer acceleration/deceleration time of the spindle. Also, operating with a high-inductance power supply can trigger the protection circuit in the DC power supply unit. Rated output is guaranteed under normal rated voltage. Fluctuation in input voltage can result in rated output not being met, even if the fluctuation is within the allowable voltage range / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  5. #5
    Registered
    Join Date
    Apr 2009
    Posts
    1168

    Re: Spindle acceleration/deceleration

    Have you check your torque limit value for the spindle? It should be in the "machine system parameters (spindle)" area. Maybe it has been turned down from 100%. What you describe is very unusual and not normal by any means.

    Another thing to check is orientation sync speed. Perform an M151 with the spindles stopped and 1 chuck open. It should complete quickly...say under 2 seconds. If it doesn't then we may have something going on there that's slowing the sync.

    If I'm understanding you correctly, when accelerating/decelerating without sync, The main goes slowly and the sub goes normally, correct?

    Best regards,
    Experience is what you get just after you needed it.

  6. #6
    Registered
    Join Date
    Nov 2016
    Posts
    18

    Re: Spindle acceleration/deceleration

    Yes, I checked this. All the machines are set at 100% for the torque limit value.

    With the sub spindle open, M151 less than 2 seconds.

    That's correct, even without the spindles synced together the main spindle takes twice as long to accelerate and decelerate than the sub.

    I understand what Deadlykitten is saying about comparing machines with like features. But even our LB3000 with the big bore is within a second of the LT2000 machines with the 2" bores.
    Something isn't set right on this machine or has gotten changed to suit who had it before us.

  7. #7
    Registered
    Join Date
    Nov 2016
    Posts
    18

    Re: Spindle acceleration/deceleration

    I changed the main and the sub to the largest chuck that was available and it added 5 seconds to the cycle.

  8. #8
    Member
    Join Date
    Jun 2015
    Posts
    3524

    Re: Spindle acceleration/deceleration

    hy zufan, check the power suply; it appears a few times inside manuals as a warning, and leads to increased acc/dec time

    there is a faulty situation during which the spindle still works, but slower

    I understand what Deadlykitten is saying about comparing machines with like features. But even our LB3000 with the big bore is within a second of the LT2000 machines with the 2" bores.
    in such a case, sorry ignore my advice / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  9. #9
    Registered
    Join Date
    Apr 2009
    Posts
    1168

    Re: Spindle acceleration/deceleration

    Ok, I think that you should check the current draw on all 3 phases going to the motor and compare readings. My suspicion is that you have a motor problem. If familiar, you could meg the motor to check the windings. If it's pulling on only 1 then it will be much slower and weaker.

    Does the motor seem weak when cutting?

    If the motor checks out, then you would need to contact Okuma and have them use their SPIN-V software to make adjustments to the spindles.

    If the motor doesn't check out, check by the bottom of the spindle for the labyrinth vent. Occasionally these got clogged and caused the coolant to not drain properly and back up into the integrated spindle causing the motor to short the windings. Be careful though if you have someone try to repair it. Our dealer wanted almost 2x the cost due to wanting to order parts that weren't needed. Armature was scored but perfectly functional, just needed cleaning. Windings were toasted.

    Best regards,

    PS> more details on the pictured mustang please! ;-) Need for speed?!
    Experience is what you get just after you needed it.

  10. #10
    Registered
    Join Date
    Nov 2016
    Posts
    18

    Re: Spindle acceleration/deceleration

    Thanks! I'll pass this info on to our maintenance team.
    I've only ran a few jobs through the machine. Nothing that was really pushing the load. Now the part that I have setup in one of the other machines would be a good test, if they would get the high pressure hooked up. It's a radiator hose extension and I'm drilling a Ø1.375 hole 5.5" deep.

    2011 45th Anniversary Shelby GT350 Super charged with 600+hp
    We went to church with a older couple and he passed away less than a year after he had it built. He was only able to drive it once or twice. Being a 6 speed she couldn't drive it. So she let me take it to the car shows for her. Incredible car! She sold both of them in the last couple years :'(

  11. #11
    Member
    Join Date
    Jun 2015
    Posts
    3524

    Re: Spindle acceleration/deceleration

    if they would get the high pressure hooked up. It's a radiator hose extension and I'm drilling a Ø1.375 hole 5.5" deep
    hy i have reached 6" without high pressure, with a similar drill, using custom peking
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

Similar Threads

  1. Acceleration deceleration for spindle
    By gyzoli in forum Fanuc
    Replies: 1
    Last Post: 07-09-2019, 12:39 PM
  2. dx-32 Spindle Acceleration/Deceleration Problem
    By cybermachineman in forum Bridgeport / Hardinge Mills
    Replies: 4
    Last Post: 05-22-2011, 07:01 AM
  3. Replies: 11
    Last Post: 01-20-2011, 01:49 AM
  4. slow acceleration/deceleration fanuc OM
    By brann in forum Fanuc
    Replies: 5
    Last Post: 09-11-2009, 05:05 AM
  5. acceleration/deceleration of masses
    By Pat2000 in forum Mechanical Calculations/Engineering Design
    Replies: 5
    Last Post: 11-07-2005, 12:51 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •