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
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