Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: dresda on February 15, 2011, 09:41:49 PM
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Bridgeport style mill with high/low with reverse back gear.
I set pulley#1 25-550rpm and ticked the reverse box, set pulley #2 560-3800 If pulley#2 in selected in the config, spindle pulleys It says that way all the time as can be seen in settings screen.
When I change from high to low do I have to go into the config, spindle pulleys and change it to #1?
If I am in pulley #2 and in MDI I select s200m03 it doesn't change from #2 to #1 in settings screen, so if I change gear it still thinks it's #2 and goes backwards.
Ray.
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I should say I'm using a VFD and DSPMC.
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Hi,
FYI - apparently the pulley reverse is broken in 3.43.22 (current lock down).
There was a bug in the spindle pulley reverse stuff that has been the subject of a thread on the Yahoo Mach list for the last couple of days. A new development version was just released today that is supposed to fix it (3.43.30).
Dave
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If I tick the reverse in the box it does reverse, I just want to know if I have to go into the config, spindle pulleys screen every time to change it from #1 to #2?
Ray.
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You can change the currently selected pulley by changing the Spindle pulley DRO - in the stock 1024 screen set that DRO is on the diagnostics page. That avoids the need to go into the mach menus to change the selected pulley.
Dave
If I tick the reverse in the box it does reverse, I just want to know if I have to go into the config, spindle pulleys screen every time to change it from #1 to #2?
Ray.
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Hi Dave, You mean the settings screen right? That's OK, so Is that what i have to do when I change gear? I thought by setting the speed ranges it would then know what range..
Ray.
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You could alter your spindlespeed.m1s macro to look at your commanded speed and set the pulley DRO accordingly.
Hood
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How does it normally work, I thought if you programmed your S command to the Pulley #setting it would it would change the # in the box in settings screen from 1 to 2, mine doesn't change.
Ray.
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OK, I guess I have to go into the setting screen to select pulley #1 or 2 every time I want to change gears, I just thought by selecting the speed range assigned to each pulley it would shift from 1 to 2 even though I still have to manually change gears.
ray.
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dresda, I had exact same question about gear change until I found your post. My conclusion is, better not forget to change gears when running a program.
I had another question, do you have a spindle index sensor on your mill?
I added a spindle sensor to the top of my BP series 1 quick change tube and I think I'm realizing that I can't run it from there for the low gear because the index signal is actually read as 9 times faster than the actual spindle speed.
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Put a ratio in the spindle pulley setup and your spindle speed DRO will reflect the reduction when you change the pulley number.
Hood
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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.
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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
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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
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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???
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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.
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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
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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 (http://www.machsupport.com/forum/index.php/topic,14182.0.html)
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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
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this all sounds good .. for pulley based machines.. what do we do when we have vari-disk drives??? what is the magic?
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The motor itself WILL turn at the same rpm range (;-) The gearbox is what slows down the spindle when in low range.
BR549, as I said in my example the motor runs at the same speed weather I request 500rpm in pulley 1 or 2. When in pulley 2, the motor needs to run 9 times faster o get 500 rpm at spindle. Isn't that true?
amontgom, we ARE talking about varidrive.
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NO that is NOT true. The motor will always run at the speed Range you set up lets say you set your VFD so your motor will run from 500 to 6000 rpm when runing in high range. The spindle will also run 500 -6000 rpm.
NOW when you switch to low gear the "motor" will still run in the 500- 6000 rpm range BUT the gearbox (low range at 9:1) slows the spindle down to a range of 55 -666 rpm.
The ratio setting is a divisor that takes the Motor rpm and divides it by 9 as well so your indicted rpm will read correct. AND the reverse dir check box will allow the Low range to run in the correct direction as the gearbox reverses the direction due to the gears.
(;-) TP
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BR549, ok at least I know what to expect now.
This also brings up another issue. How do I program tapping cycles? I guess I have to multiply tapping rpms by 9 if I'm in low gear. Mach would then use actual rpm to set the feed? I think this means I have to be in in/rev mode and not in/min.
Thanks.
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(;-) NO Mach will turn the spindle at teh correct speed. Set your Pulley2 to run 55 - 666 rpm Mach will do all the conversion for you.
When you switch to pulley 2 mach will use those settings to correct the spindle rpm and the motor will still run correctly.
Switch gears then change pulley settings that is all you do. Mach will do the rest.
I use a macro that I put in the Gcode at tool change times so IF I need to switch gears the macro will apply the correct pulley# to match the speed range required
(;-) TP
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Just went and read the "Bible" by Peter Smith about G84 tapping cycle. Looks like it gets programmed in distance/minute and the distance/revolution is more for lathe. My programing software (SolidCam) doesn't have an easy provision to combat this issue. Meaning that there is no way to set up pulley and speed ranges to make calculations accordingly. The G84 cycle calculates the feed automatically based on TPI and speed without a way to overwrite it.
Sounds like what I have to do in my program is multiply the speed and TPI by 9 to get the proper feed. This way I can still get the gcode generated automatically without having to manually edit it for speed or feed.
Just tried programing it as I described and I seem to be getting proper feed.
I'll give this a try and report how it works.
Thank you for the help!
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I normally use Feed/ Rev in tapping cycles. Much easier to keep track of.
Just a note the SYNC Spindle function is broken in MILL. If you use it the G84 cycle will go nuts.
Just a thought, (;-) TP
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The beauty of using Feed/Rev is it takes no math to do it.
If I were tapping a 1/2 X20 hole you would simply
G95
G84 X0 Y0 Z-1 F[1/20]
G80
G94
(;-) TP
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hello my 2 cents for what it is worth i had the same problem on a bridgeport so i set up 3 buttons on the program screen spindle high m3 spindle low m4 and spindle stop m5 set pully 1 to 510-4200 rpm ratio 3 and pully 2 60-500 rpm ratio 3 . the s commands work mach goes forward or reverse as needed and changes pulleys. the pulley ratio on a bridgeport is 3 to 1 weather you are using cones or adapting to pulleys note when i checked the reverse on number two pulley it ran the wrong way this must be the bug however when unchecked and run the way i describe it functioned perfectly
good day