Messages

2651

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gunstocks!!!!!

« on: May 18, 2012, 07:00:37 AM »

Continue perfecting your work as i will need a nice pair of checked grips for my pistol I am doing.
No hurry though......figure a few years before i need them.
RICH

2652

Show"N"Tell ( What you have made with your CNC machine.) / Re: Constructing a Low Profile Tool Height Setter.

« on: May 18, 2012, 06:50:46 AM »

now if you can get that to fit and I can read it, between just two of those lines on that scale

The limit on machine engraving is approx .015" high considering that if you have no spindle run out, can get a tip point
down to .001" radius, and keeping depth at about .001". IE; letter E .003" for the engraved line and spaces between.

Yet it is interesting how they can make reference targets with line widths or spaces  is down in the microns.

Tweakie, rumor has it that YNN can't see the letters on a stop sign at 5 feet so let not your heart be troubled at .5mm.
You may want to bump the size of our pics up a bit for him. 

RICH

2653

Tangent Corner / Re: Can't find Programming Software

« on: May 17, 2012, 08:23:57 PM »

Russ,
Seems like it comes with the drive ....?
The attached may give you a clue on fiding it....
RICH

2654

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gunstocks!!!!!

« on: May 17, 2012, 06:36:25 AM »

Nice work on the gun stocks and thanks for posting. Assume they shoot well also and that you made the the rest also.
RICH

2655

G-Code, CAD, and CAM discussions / Re: Cambam question

« on: May 15, 2012, 06:15:42 AM »

Don't use CamBam's CAD so can't be of much help other than to say if you don't get a response here that you go to the CamBam site
have a look at the videos, manuals, etc and maybe register for the forum and ask there.
RICH

2656

General Mach Discussion / Re: Stepper freeze noise with higher driver kernel speed...

« on: May 14, 2012, 05:11:08 PM »

Not sure what you can't get over but sounds like your motors are skipping when using the 45 khz. So if the sent signal is bad the motor skips / misses steps and can do some wierd things. Could be as simple as that.
RICH   

2657

General Mach Discussion / Re: Stepper freeze noise with higher driver kernel speed...

« on: May 14, 2012, 04:55:42 PM »

As has been stated if the system reponds well at 25 kZ and your satisfied with the velocity and acceleration you have then don't use  a higher kernel speed. The higher kernel may allow use of a higher velocity setting in motor tuning but that is only as good as the rest of the system from the computer to the motor. An example would be using a higher velocity but you have no torque from the motor and it is not reliable. That is bragging rights without common sense. You may find that the 125 ipm is really not reliable over time.
FWIW,
RICH

2658

Tangent Corner / Re: Stepper motor Inductance ?

« on: May 12, 2012, 09:15:46 AM »

Russ,
I don't know how that drive works ie;  remember in a typical ac motor if one lowers the voltage the amps go up ( that's how you burn up motors
since the resistance to the increased current becomes heat and without thermal protection amps go to infinity if the ability is there to do so).

Typicaly for a stepper a low voltage will limit the max rpm possible since the the abillity to energise the motor winding  is diminished. If voltage is ok but amps are low the motor won't work right, since you can't energize the inductive field enough to hold the torque or step it. At very low amps it may not even turn. The lower the inductance of the motor the faster the current gets to the windings. If one increases the amps it works correctly but then as the fields alternate the losses due to inductance becomes heat. Putting fins on the motor would allow for conducting some of the heat away ( maybe 10 degrees or so unless you have forced air cooling / convection like a fan blowing over the fins).

But forget all of the above since don't know how that drive is sensing current or voltage and adjusting accordingly given some designed inductance.
So not sure what affect putting additional external inductance will have on the drive and for that matter how the phases will react to the external inductance.

I would call Parker and talk to one of their tech support guys. Sometimes if you just tell them upfront what your concerns are and that your trying to save some money for the "company" ( btw, some are responsive to hobbiest if they are not busy!) .

Always interesting to find out dumb ( hey hey ....me  not you folks .....) when you get into the expertise of a different discipline. 

RICH

2659

General Mach Discussion / Re: easy motor tuning

« on: May 12, 2012, 08:06:55 AM »

Fred,
Not sure what the manuals say about using the axis calibration. To lazy to have a look at them.

There is a nice axis calculator in the Members Docs which one can use to do caclulations and comes in handy if one wants to compare
different parameters. Here is the link:
http://www.machsupport.com/forum/index.php/topic,16315.msg110286.html#msg110286

I also like to calculate the steps per unit , use that value and then check the axis movement to extremes ie; profile the axis for record keeping.
The profiling is done opticaly but note that i have the tools to do it that way and may be a little wierd........
 
RICH
 

2660

General Mach Discussion / Re: easy motor tuning

« on: May 11, 2012, 09:47:41 AM »

Fred,
Position the axis so you can make a move as long as possible .....a move you can measure. Remove any backlash, you move one way and then a small distance the other way.

You will asked how far to move, lets say 10", the axis will move 10" based on the current steps per unit settings, it will then will ask you how far you
moved....you measure and find it to be 9.950" and that's what you input for the value. The steps per  will be recalculated and you will be asked if you want to change them, you reply ok, if you go to motor tuning you will find that the steps per have been changed. Save settings if you want to keep the revised settings.

You can use the mill screen for the tuning, but, make note of the values and use them in the turn screen.

Once you have the steps per correct then you want to try a a few intermediate steps and see how linear the axis is in movement.
With the steps per unit correct then you want to check for backlash.

RICH