MACH NOT ROUTING RIGHT

[ronhess]

I have a problem routing my project in the center of my material, some of the project is on the material and part is totally off the material. When i do a reference all in machine coordinates it works perfectly, then i switch to work coordinates jog to where i want work 0,0 bring down the z axis to touch the material and zero the x,y and z axis, then do a regen toolpath. When i hit cycle start there is loud binding sound x and z move to where they are suppose to move but y axis lags behind. When i went into the settings tab and ran the set steps per unit test the x and z responded correct, but when i did the y axis i entered to move one inch it moved only a quater inch and that loud binding noise was there. When i use the arrow keys on the keyboard all axis move smoothly. What the heck is going on?

RON HESS

[ostie01]

When moving the Y axis with arrows, does it go the correct distance.

Is the X and Z mechanism are the same than the Y axis, if they are, they should have the same setting for steps per inch.

Also verify for accel of the Y axis.

Do you have one power supply for all axis, if yes, just check if it can output enough current to run all 3 axis at the same time.

Jeff

[Hood]

You may also have a slow jog set so that when using the arrow keys it is not going at full rapid speed. This will give you a false sense of all axis running fine at full speed when actually they are not.
Hood

[rrc1962]

Sounds like the velocity, accel or both are set too high.  The Binding noise sounds like motor stall.   I can set my velocity and accel very high (1200 and 100), and it will jog fine at those settings, but a rapid G00 move in either X or Y will stall the motors.  If I lower the velocity to 800, it runs all day long with no problems.

What is the belt reduction on the pinion?   What is your velocity and accel set at? 

 

[ronhess]

Thanks for responding guys. My machine is a 2'x3' homemade mdf router table with three Vextra PK266-02A stepper motors and stepperworlds FET-3 hi torque controller.  I have a  10TPI half inch acme screw on all three axis. The steps per setting is 4000 for all three axis, this was calculated in the following manner 400steps per rev x 10 tpi = 4000. This was verified during the settings tab test for steps per for each axis. The velocity and acceleration is set as the following:
                                                                     axis  velocity   acceleration       step/pulse      dir/pulse
                                                                       X      22           10                     5                5
                                                                       Y      12            3                     5                 5
                                                                       Z      12            5                      5                5
The slow jog was set at 10% but i used the shift key when i said the motors was running smoothly at fast jog. When i jog the axis around they do move the correct distances. Also the FET-3 has the x and y on one power source and the z on its own source. I have tried for hours adjusting the settings on the Y axis and can't get rid of that binding sound even at a setting of velocity= 5 acceleration=1. The noise comes in play at the first three inches of the table and again at the last three inches of travel, in the center of the table runs nice and quiet. This has been going on for some time now and i can't get any support from the manufactuers. I read on differant forums about people who built router tables with stepper motors smaller than mine. I would like to get this system operating correctly so i could prove to my wife its not a piece of junk and would like to start another build. I was considering a gecko g540 with kelings 381's but i want to find rep. that has a phone that i can speak to for support. Does anyone know one?

RON HESS

[rrc1962]

I would bet the problem is the Stepperworld drive.  Those are OK for experimenting but not much good for driving a real machine.  They may have a better product now, but I tried their stuff about 8 years ago and couldn't get anywhere with it.  If I recall, the drives were not constant current and required power resistors.  It could also be something binding on the Y axis, but based on your V and A numbers, I'd bet on the drive system as I recall about the same results with an Ebay/StepperWorld drive.

We use the G540 and NEMA23 425oz/in motors on a 4x8 gantry plasma/router.  It will rapid at 800IPM with an accel of 100 without losing steps.  We've also used the Keling 381 when we run short on 425's with the same results.

[Graham Waterworth]

It sounds as if the lead screw nut is not in the centre of the support mountings and locking up at the ends of the travel

Graham

[Tweakie.CNC]

Ron,

I agree with Graham on this one, from what you have described it sounds to me like you have a tight or binding lead screw or linear slide. I would suggest checking the alignment etc. to get everything running free without any tight spots.

Tweakie.

[ronhess]

Thanks again guys for responding. I took the stepper motor off the y axis and the screw spins freely without the motor attached. I seen on another post someone asked how to adjust these homemade delrin anti-backlash nuts. Nobody responded, i wonder why? I wanted to attach a picture of this nut and my machine on this reply, but can't find a area to do this in this quik reply.

RON HESS

[Hood]

I wanted to attach a picture of this nut and my machine on this reply, but can't find a area to do this in this quik reply.

RON HESS

Use the full reply page (using reply button on a post) and then use the additional options you will see below the text box.

Hood