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Anybody know how to slow spindle ramp up?

NTM

Cast Iron
Joined
Sep 4, 2009
Location
Mooresville, NC
We have a Mori Seiki with a Fanuc 18i control that pulls enough amps on spindle ramp up to dim the lights. It's a 20/30 HP that gets up to 14K in about one second. It would be fine with me if it took two or three seconds. I have searched this forum and tried to read the books but I haven't found (or understood) what I'm looking for. This has to be a simple adjustment but it is escaping me.
 
Should be a parameter change, did you buy the machine new or used? If new, call your service department, a tech should be able to walk you through it on the phone.
 
Yes, should be a spindle Accel/Decel setting. Might effect tapping though if you plan on tapping with it.

Yeah I figure it's an accel/decel setting and I figure it probably would effect rigid tapping. I'd probably have to set it back for tapping jobs but we don't do many of those and I could stick those on a different machine. My problem is I can't figure out what that setting is so I was wondering if someone else had done this before. The only spindle amp I've ever worked on was much older, this one appears to be completely digital with parameters set through digital settings, meaning no pots etc. I can't figure it out. As it is we're looking at a lot of little brownouts everyday and I wouldn't really care if it took a couple seconds to spool up.
 
I haven't changed the main spindle ramps to date, but I have changed similar stuff.

This should simply be a param in the control - not the drive.

If you just start scrolling down through the params, you should find it.
The params are grouped together in applications, and are fairly well labeled.

Without scrolling through it myself - I wouldn't know which one that you would need.

Also - I highly doubt that it would effect tapping - other than slowing it down a smidge.
On the 18i - I'm sure that it is RIGID tapping.
???


--------------------------

Think Snow Eh!
Ox
 
I haven't changed the main spindle ramps to date, but I have changed similar stuff.

This should simply be a param in the control - not the drive.

If you just start scrolling down through the params, you should find it.
The params are grouped together in applications, and are fairly well labeled.

Without scrolling through it myself - I wouldn't know which one that you would need.

Also - I highly doubt that it would effect tapping - other than slowing it down a smidge.
On the 18i - I'm sure that it is RIGID tapping.
???


--------------------------

Think Snow Eh!
Ox


Yeah I went through a bunch of them and experimented with some changes but go nowhere with it. For example 4030 and 4082 (accel/decel time) sounded promising but nadda. There is a spindle tuning screen with "prop.gain" "int.gain" "loop gain" "time const" but I don't know what any of that means or if it would do anything and figured I should ask around for somebody who has done this or risk breaking something. I figured reducing acceleration on a spindle has got to be a fairly common tweak?
 
Post a picture of your drive. In that era machine it could have an S type drive which has the accel/decel parameters set on the drive, not the control.

8vR2uOv.jpg
 
That's an Alpha series drive so it should be parameter 4082 accel/decel time constant. What is the original value and what values did you try?

Another thing to try would be to set 4028 to 1 and 4029 to 80-100 and test that. That is similar to the soft start function, but unlike the soft start function it does not require an input from the ladder program.

Kind of rare for folks to look to slow down the accel/decel, usually they want it faster. :)
 
None of those params are labeled at all on mine.

There is a separate manual for the Alpha spindle drive parameters. Typically not provided with a machine since the builder has already figured out the appropriate values and loaded them. Google will find you a .pdf copy though with this as a search term...Fanuc B-65160E/02.
 
Instead of changing it, and putting it back for rigid tap jobs, why not just call up a lower rpm, and add a dwell. Repeat to step up to whatever rpm you're looking to go to. Cumbersome...I understand but might be functional enough for your needs.
 
That will help, but it's not nearly as "easy" on the drives (demand) as a slower ramp.
What you end up with is it being in a hurry to git to 8000, then sit and wait, and then a hurry to git to 16K.


---------------------

Think Snow Eh!
Ox
 
There is a separate manual for the Alpha spindle drive parameters. Typically not provided with a machine since the builder has already figured out the appropriate values and loaded them. Google will find you a .pdf copy though with this as a search term...Fanuc B-65160E/02.

It's prolly all the same, but that lists up to 16i, but no 18 controls.
???


------------------

Think Snow Eh!
Ox
 
That's an Alpha series drive so it should be parameter 4082 accel/decel time constant. What is the original value and what values did you try?

Another thing to try would be to set 4028 to 1 and 4029 to 80-100 and test that. That is similar to the soft start function, but unlike the soft start function it does not require an input from the ladder program.

Kind of rare for folks to look to slow down the accel/decel, usually they want it faster. :)


Thank you, this did the trick!
 








 
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