Problem- servos faulting out

[djtoolz]

dxf files created in bobcad v.22, toolpath and g-code created in deskcnc (can't get bobcad post processor for deskcnc to work yet) but anyway 2 different programs generated the same way. program 1 is a pocket w/ islands, program 2 is just a pocket. Program 1 will fault out the servos as soon as the machine starts to move. i've slowed the feed rate from 20 ipm to 8 ipm . Program 2 ran without a problem at 15 ipm. According to the paperwork that came with my mill package a 20 pitch screw and globe motors should be able to run 50 ipm. Any ideas on this one.

[imserv]

50 inches per minute is the max that the Globe motors can go at 30 vdc The motor voltage is dependant on the line voltage to the controller power supply. It does not mean that your machine can go that fast.

Many things can prevent your machine from traveling this fast. Things such as too tight of gib adjustment, lack of lubrication on the slides or lead screw, too tight of adjustment on the anti-backlash nuts, etc.

You probably need to derate the max steps per second when the machine is rapiding to accomodate a lower line voltage. This is covered in some detail on the IMService user forum.

Have you tried to write a simple g-code program to test the machine? that way you can easily detect what is causing faults and eliminate any problems that may be associated with the Bobcad, files or the pocketing complexities.

Fred Smith - IMService

[djtoolz]

why is it I can jog all 3 axis @ 30 ipm with no servo faults. This does not make sense to me that the gibbs or anti-backlash is out of adjustment. also why should I have to pay more money to access your support forum when I've already spent over $2300.00 with you and still have not gotten a working system. I was under the impression that my purchasing a system and not a kit would mean that I would receive for my hard earned money an out of the box operational machine, not 3 years worth of headaches and disappointment

[imserv]

You can probably jog each axis individually at 30 ipm, but not all three at once. Also jogging is usually set to a speed slower than a G00 rapid speed, for operation safety. You most likely have some motion that needs more power than the system is designed to deliver. We intentionally provide less power than the drivers or the motors can deliver to insure that the Sherlines do not prematurely wear from over zealous adjustment of gibs and backlash. This is seen as a servo fault when the commanded motion requires more power than that available.

We provided free support to all DeskCNC users for over 5 years. That support is still available on our public forums. Most questions that customers have are answered there.

IMService customers were given free access to the new user forum for 6 months to 2 years. The subscription cost is primarily to cover the on-going costs of software and site maintenance.

Fred Smith - IMService
http://www.imsrv.com

[greasetattoo]

I am having the same problem..
My servos keep faulting out.

It worked fine before I upgraded my Sherline mill with new leadscrews.
I have Kerk Motion precision KerKote treated leadscrews.
The screws are 4 tpi (.250) dual start threads.
I came up with 225 IPM.
84000 Speed Max. Velocity.
The machine was way to fassst. (servos faulted)


I am using a IMservice controller with the globe motors.

Here are my settings I am using now. (servos still fault)
Acceleration 1250000
Acceleration scale 10
Max. Vel. 25000
Start Vel. 2500

What should I do?
Help!

[greasetattoo]

I might have fixed it!

I loosened my Z backlash and gave it some new oil.
Seems to be working now.

Maybe, got a little binding going on.
Let's hope it's gone!

[wmgeorge]

Originally Posted by imserv 50 inches per minute is the max that the Globe motors can go at 30 vdc The motor voltage is dependant on the line voltage to the controller power supply. It does not mean that your machine can go that fast You can probably jog each axis individually at 30 ipm, but not all three at once. Fred Smith - IMService http://www.imsrv.com

Fred, This is interesting as you just told me over on your "private forum" that the IM Service factory built 12 x 24 inch router table and control box power supply would do 350 IPM? Just wondering, is there a difference now?

[imserv]

This thread was about machines with 20 threads per inch, like the Sherline and Taig. On those applications the max ipm is 50, and our system design speed is around 45. On our CNC routers with .1 to .5 inch per turn threads, the max speed is proportionally faster, 100-500, with design speeds of 90-350 ipm.
Fred Smith - IMService
http://www.imsrv.com

[wmgeorge]

Interesting. I just went out and checked my new 12 x 24 x 4 inch IM Service router purchased from you, and All the lead screws are 10 TPI, including the "Z". This is checking with my Starett thread gauge.

So this means for every turn of your 2.8:1 geared belt drive output, the the linear motion would be .1 of an inch?
I hope I'm following this, and your motor speed max is about 2800 rpm.

[imserv]

No, you are not even close ( that's a joke ) . Measure how far the different leadscrews actually move when you turn the manual handles one full revolution. The output shaft from the motor/belt reducer remains fixed at 1000 rpm max. The distance moved per revolutoin is determined by the leadscrews, which are different on different machines, even on different axes on the same machine.

Maximum speed is calculated by multiplying max rpm times distance traveled per revolution

20 pitch = .05 inch pre rev
Max speed of 1000 rpm *.05 = 50 ipm

10 pitch = .1 inch per rev
max speed of 1000 rpm * .1 = 100 ipm

.2 inch per rev * 1000 rpm = 200 ipm ( our 12 x 12 router w/ hi-speed option, which we conservatively derate to 175 ipm specification)

.5 inch per rev * 1000 rpm = 500 ipm ( our 12 x 24 router, which we derate to 350 ipm, to maintain CNC control to tolerances that are about 10% of the accuracy of the machine)


Fred Smith - IMService
http://www.imsrv.com

[wmgeorge]

Well with the latest controller software/firmware update (12-19-08) the machine is a lot speedier. It sings as it runs!

My machine will (more than likely) never be set to run the rated 350 ipm, as my personal view for a 12 x 24 (inch) router it would lead to a lot of un-necessary wear and tear.
I am very happy to be VCarving at 100 ipm, I'd rather have nice accurate cuts on my work. BG

[greasetattoo]

What is the firmware/software update?
Is that for the IM service controller?

How do you update it?
If so..
Let me know.

thanks,
Greasetattoo