Originally Posted by
OkumaWiz
The Okuma is the best that I've seen in the industry for synced rotation ... They definitely did their homework on this one
hello mr Wizard i am glad to hear such news; a normal spindle do not react at rpms <40-50, thus a minimal rpm is required. Also there is not so much torque until circa500rpm. If both spindles can accelerate in sync, then there should be an improved motion controller for small rpms. Maybe something similar to the special function for " spindle extreme low speed cutting " ?
Originally Posted by
OkumaWiz
It also checks to make sure that at least one chuck is open when syncing to avoid "twisting" the part during sync
well, if it syncs so good, then it should definetly do it with both chucks closed. A spindle accelerates at circa175% load, at least for some 3000 models, and maybe, when both chucks are clamped, the acceleration time is greater, so to reduce required acceleration load ... so to avoid breaking the neck
Originally Posted by
OkumaWiz
Your chuck has clearance in it in order to operate. As it clamps, the tolerances are taken up and the part moves slightly in Z. This shows up as motor load as the axis sees the motion. This occurs even on a dead length collet chuck. That is why after clamping, you may want to back off slightly with a W axis to avoid pinching the cuttoff tool when the load is released. Use the load meter to determine how far to back off. Move in W+ until the load decreases to zero and then starts to climb again to about 20%. Then record the amount W moved. Put a G91G94 W.00xx F50 in your program to accomplish this after clamping. It will make your groove tool last MUCH longer
it is possible to code entirely that behaviour, so to avoid the manual setting time :
Code:
W @ approach position
torque skip until contact
record W position and check if position is good (*3)
clamp 2nd chuck
G29 PZ=15 (*1)
G04 F0.3
G29 PZ=10
G04 F0.3
G29 PZ=5
G04 F0.3
G29 PZ=0
G04 F0.3
G22 PZ=20 Z=small_positive_value F+15*5 G94 D G91 (*2)
record W position and check if position is good (*3)
NOEX G90
cut
(
*1 starting to reduce W load
sequential reduction should deliver smoother behaviour
maybe is not needed to reduce until 0 load, but it is needed
to reduce under the reversal-spike load, which also depends
on feed
*2 that code will output 15mm/min; such a smaller feed is needed, because
also the travel is short, and it should be executed slow, smoooth
*3 stats for nerds :) if implemented right, it will save the day
)
Originally Posted by
deadlykitten
don't worry, you may use the torque functions to protect your machine
someone crashed his machine during a transfer; his code was ok, only that it hit into a case that does not frequently occur
part was still into the 2nd spindle when the transfer started, and the crash required service intervention, bla-bla-bla
so, to avoid this :
... use the torque skip function not only from a small clearance ( c ) in front of the 1st chuck, but from a greater clearance ( c+part_length )
... use load monitor, at least during W approach ( so to monitor entire travel )
... check if 2nd spindle is empty ( torque limit, load monitor ) before begining the transfer sequence / kindly