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Author Topic: Spindle pulley setup?  (Read 10243 times)

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Offline Hood

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Re: Spindle pulley setup?
« Reply #10 on: April 20, 2011, 05:06:54 PM »
Put a ratio in the spindle pulley setup and your spindle speed DRO will reflect the reduction when you change the pulley number.
Hood
Re: Spindle pulley setup?
« Reply #11 on: April 21, 2011, 09:59:53 AM »
Robin I was afraid that my comment may get misunderstood.  You see on my mill I have the 2J varispeed head, when I switch between high and low gears the top of the head shaft where the sensor is connected is rotating 9 times faster than the spindle itself.  In high gear the index reads 1:1, so there is no issue.  My understanding was that index pulse must be generated once per rev, in my case I get 9 pulses per rev in low gear.
Last night I decided to take apart the head to see where I can tap-in to always get 1:1 index pulse in either gear.  It looks like if I make a really long version of the plug I made for the top of the head I can get to the the spindle shaft directly.  I'm a little concerned with high speed and balancing, this new plug needs to stick out from the spindle tube about 8" to reach the top; at 5000 rpm that might be a problem.  I'll probably just have to try it.

Offline BR549

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Re: Spindle pulley setup?
« Reply #12 on: April 23, 2011, 09:53:25 AM »
IF you do as Hood suggested it will work fine. The ratio settings was put there for bridgeport applications where the top side of the gearbox remains at motor speeds all the time.

(;-) TP
Re: Spindle pulley setup?
« Reply #13 on: April 24, 2011, 11:37:30 AM »
I don't want to hijack this post but i have a question about spindle pulley setup as well. I am using a dremel tool or later a trim router as my spindle motor. as i understand it as this is direct drive the pulley should just be 1 correct?

 and then do i set the min/max as the min max of the motor?? I guess i need to figure out what the min speed the motor will run at is?? i think the max is around 30,000 rpm
Re: Spindle pulley setup?
« Reply #14 on: April 24, 2011, 01:56:19 PM »
I'm getting very frustrated with this spindle setup.
So as I mentioned I have a varispeed head with high and low range.  I set the varispeed dial on high and let Vfd slow it down for me.
I have pulley 1 set up for 500 to 6100 rpm with ratio 1.  Pulley 2 set up for 50 to 499 rpm with ratio  9.
I have done auto spindle calibration for both pulleys.  The problem is with pulley 2.  Mach controls it same exactl way as pulley 1 but in the lower range.  Meaning that control ratio displayed in the tuning wizard is 1 for 499 rpms, but the motor is turning at same speed as it would in pulley 1 for 500 rpms.  Also, there is a grayed out box which says index piles per rev and it shows 1 for either pulley.  I think this needs to read 9 pulses per rev in my case but I don't think there is a way for me to change this.
All I can seem to be able to change is the pulley set up, but changing the ratio there just changes the displayed rpm without affecting the motor control.

This is why I originally thought of needing the true once per rev index in any gear to make things work, but now I'm not even sure that will solve problem.  I'll try that after I finish this post.

Another issue I have is with pulley 1 rpm being off.  I would expect that after completing the auto spindle calibration the new curve for the pulley would be used, but the rpm stays incorrect.  I tried save settings and restart of Mach but nothing works.

What am I doing wrong???
Re: Spindle pulley setup?
« Reply #15 on: April 24, 2011, 02:43:50 PM »
I forgot to mention that VFD is running on MODBus, I now wonder if this is the problem.  I don't know how MODBus works exactly but If it gets 0 to 100% speed signal digitally everything should still work, including spindle calibration.

Offline BR549

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Re: Spindle pulley setup?
« Reply #16 on: April 24, 2011, 06:23:25 PM »
Only tune the spindle for the pulley that runs at 1:1.  That sets the speed for the motor to run from slow to fastest rpm. Do not addd the ratio leave it at 1

Then just set the pulley for the low gear AND add the ratio of 9 to that pulley only.

(;-) TP
Re: Spindle pulley setup?
« Reply #17 on: April 24, 2011, 08:39:30 PM »
BR549, thanks for the explanation, tha does make sense.  I actually discovered what you are talking about only calibrating the 1:1 pulley.  Whan I went back to redo my pulley 1  noticed that it had a curve from pulley 2 calibration.

I did as you say, calibrated pulley 1 and used ration 9 for pulley 2, but no luck.  The motor turns at the same speed for both pulleys, only the RPM DRO changes.  For exapmle if I set speed to 500, pulley 1 works fine.  Go to settings and change pulley number to 2, the RPM DRO now reads 1/9 of 500 but the motor still turns at the same speed as it did for 500, so my actual RPM is about 55.  I would expect the motor speed to be 100% for pulley 2 if the top of the range is at 500rpm.

I wonder if this has something to do with MODBus.  I'm using the Chinese drive plug in (Huanyang VFD).  Info about the drive http://www.machsupport.com/forum/index.php/topic,14182.0.html

Offline BR549

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Re: Spindle pulley setup?
« Reply #18 on: April 24, 2011, 09:10:11 PM »
The motor itself WILL turn at the same rpm range (;-) The gearbox is what slows down the spindle when in low range.

OR are you saying that you cannot vari the motor speed at all ?

(;-) TP
Re: Spindle pulley setup?
« Reply #19 on: April 24, 2011, 10:53:29 PM »
this all sounds good .. for pulley based machines..  what do we do when we have vari-disk drives???  what is the magic?