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Newbe help
« on: June 12, 2009, 07:45:20 PM »
Hi   Totally new to this stuff.  Doing a conversion on a BP cnc series 1.

 I replaced all steppers and have keling drives with a G 11 BOB from cnc4pc.

 I just fired it up. I have 6 or so red lights on on the BOB. I can jog 2 motors but they will only go in 1 direction. My Y axis is the Z jog button. All the leds on the mach display for inputs are out.

  Any advice?  Doesnt the red lights on the BOB mean there is something wrong??
                Thanks,  Jim

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Re: Newbe help
« Reply #1 on: June 12, 2009, 07:47:27 PM »
Not familiar wit that BOB but would think the LEDs are just showing you the state of the pins. It sounds like you dont have the correct pins asigned in Mach for each axis.
Hood
Re: Newbe help
« Reply #2 on: June 12, 2009, 09:44:43 PM »
 Hi Hood.  Yea I am sure that is the axis problem but what about it only moving one direction even when you change from +  or - on the axis jog button on the screen?

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Re: Newbe help
« Reply #3 on: June 13, 2009, 02:28:45 AM »
That is likely the same problem, ie you have the wrong pin asigned in Mach for the Dir so when you change direction the signal is not being seen by that axis so it continues in the direction it was travelling in.
Hood
Re: Newbe help
« Reply #4 on: June 13, 2009, 02:40:58 PM »
Ok. Started over this morning. I kept changing things yesterday and ended up having everything wrong.

 Reset everything and all motors are running at jog. Yipiee..  I started tuning and I dont know what is wrong again. I have the steps up to 16000.    :o  Yes thats right.that is what it took to get the dro to read correctly.What do I have set wrong??   ???

 the screw is .200 pitch. I have 2 to 1 pulleys. A 24 tooth on the screw and a 12 tooth on the motor.The motors are keling 906 oz steppers.

 I know what I have works but isnt correct.  Thanks a bunch      Jim
« Last Edit: June 13, 2009, 02:42:35 PM by j king »

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Re: Newbe help
« Reply #5 on: June 13, 2009, 04:02:00 PM »
It will depend on what stepping your drives are set to but this is how you work out your steps per unit.
Your stepper motors need 200 steps to do one revolution
Your motors need to turn two revolutions to turn your ballscrew one revolution.
So that means it is 200 x 2 = 400 steps per revolution of the screw.

You need 5 revolutions of the screw to move 1 inch  which is a unit so 5 x 400 = 2000 steps per unit.

However as mentioned at the start your drives will not be full step but likely microstepping and if the chinese variety they will be settable by dip switch so you need to know what it is set to.
 16,000 sounds as if it could well be correct as it would mean your drives are set to 8 microsteps, ie 2,000 x 8 = 16,000 steps per unit.
Hood
Re: Newbe help
« Reply #6 on: June 13, 2009, 05:44:22 PM »
Thanks Hood. Is it ok to leave it here? It will run slower correct? It seems like it is and the . I tried to change dip switches but couldnt get it dialed in. Here is the drive that I am using. It is set at 256 now.             http://www.kelinginc.net/KL-8078.pdf


           Thanks for your help.  Ps. I have never ran or been around a cnc so I am totally ignorant to this stuff.Been machining for 25 years tho..Just want to play!!


                                                            Jim

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Re: Newbe help
« Reply #7 on: June 13, 2009, 05:55:32 PM »
Not really sure what you are meaning, if the dips are set to 256 then you would need 512,000 steps per unit in motor tuning but that would be crazy and you would  only get a few IPM for rapids :D I suspect you may be reading the dip switches wrong and if it is giving you accurate measurements ie when you command a 1 inch move it moves 1 inch then all is good :)

 Not sure what kernel speed you have Mach set to but if you are at 25KHz and finding the 16,000 steps per unit are limiting your rapids then you should be able to increase to 45KHz kernal no problems, most computers/parallel ports can handle that. Also set your pulse widths to 2 or maybe even 3 on the motor tuning page as I think these drives require a slightly wider pulse.

And lastly no worries about being new to CNC, we all were at one time and we are all still learning :)

Hood