Spindle pulley setup?

[Sinij kot]

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.

[BR549]

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

[Sinij kot]

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.

[BR549]

(;-) 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

[Sinij kot]

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!

[BR549]

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

[BR549]

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

[mark4]

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