Messages

11

General Mach Discussion / Is it Backlash...still?

« on: September 20, 2014, 04:20:01 PM »

Hey there, not sure if this is a mach question, so may not belong here, but in an effort to knock out some terribly wacky backlash (X-axis) I replaced gibs, lead screws, even one motor. Figured I'd do it on the Y and Z while I was at it, on my Sherline 2000.
It looked like I got out as much backlash as is possible on that machine but if you'll view the attached photo, you'll see where the arrow annotation is, there's this scalloped look to the cut. I tested with Kiran's wizard for cutting a circle.
Anyway, I'm wondering what's causing this. Is it motor tuning? Too tight a gib? Smoothstepper setting?
Any ideas would be appreciated. -Keith

12

SmoothStepper USB / Re: USB S.S. Driver Accumulation Errors?

« on: July 02, 2014, 08:06:47 AM »

Turns out, all of my problems are Window based; not SS's. I was told I needn't optimize Windows (the way I did with the parallel port using Mach3. I did some turning off of Windows behind the scenes stuff and SS is running all day without a hiccup.-Keith

13

General Mach Discussion / Re: Mach3 Sherline Rotary Magic Number

« on: June 24, 2014, 08:00:43 AM »

Oh and that was a typo (A01) I meant G01 A0 as opposed to a G0 A0.

14

General Mach Discussion / Re: Mach3 Sherline Rotary Magic Number

« on: June 24, 2014, 07:59:07 AM »

Thanks Rich. Took all your advice and since there's some wiggle room adjustment of where the worm gear 'sits', I very slightly loosened the bolts that allow for that and very slowly rotated in both directions so it could find it's own place to sit without any lash and low and behold, I'm in action. Works beautifully.
You've been a great help. Thanks, Keith

15

General Mach Discussion / Re: Mach3 Sherline Rotary Magic Number

« on: June 23, 2014, 10:21:59 AM »

That was right on, Rich. And thanks again. Used the calibrate and indeed it changed steps per to 160.
Now I'm just having to find a reasonable velocity and acceleration. When I use the 'tab' for the MPG mode and set the jog rate for 100% and use hotkeys to move, all is well at some good velocities. But when I do an A0 move or an A01 move, I get a clunk when it starts out; worse at different velocities and accelerations. Might just be a mechanical thing since I refurbished the rotary recently. But still it's odd that it happens only in the manual screen for moves.
But anyway, thanks for all your correspondence. -Keith

16

General Mach Discussion / Re: Mach3 Sherline Rotary Magic Number

« on: June 22, 2014, 06:02:52 PM »

Thanks Rich. I'll try that tomorrow.
However, that axis calibration intrigues me. So when the program asks: "how much to move", what unit are they asking for (in other words, knowing what you do about my setup, what part of the equation are they referring to?
Thanks for all your help. I'll get there.
160 does seem to be a very familiar number I used in the past.
-Keith

17

General Mach Discussion / Re: Mach3 Sherline Rotary Magic Number

« on: June 22, 2014, 11:25:34 AM »

So now with a little fiddling, at 28,800 steps per, G01 A.5 goes to 90 degrees, A1 goes to 180, A1.5 goes to 270, and A2 brings me to 360. Weird.
And A0 brings me back exactly to 0. How strange.-Keith

18

General Mach Discussion / Re: Mach3 Sherline Rotary Magic Number

« on: June 22, 2014, 09:34:26 AM »

Okay and thanks Rich. Well here's an example of what I get which is of course way off but if I type in G01 A.05 (that's point zero five) the table moves a bit more than 5 degrees.
Does this hint to where I've gone wrong? Again, I have the steps per at 28800 (half stepping mode, also box checked in ports and pins for Sherline half pulse mode)
-Keith

19

General Mach Discussion / Re: Mach3 Sherline Rotary Magic Number

« on: June 22, 2014, 08:49:32 AM »

Thanks so much Rich. It looks like (since I'm half stepping) that my steps per=28800 is correct from what you wrote.
And so if I entered G01 A80, I should get 1 degree movement.
However, many years ago I set this up so that if I typed G01 A90, it would go to 90 degrees (from 0 degrees) and don't recall why it worked.
I do have the box checked in Mach for angular on the A-Axis I'm using.
Let me ask you, do you know do I have to do anything special with my Smoothstepper configuration that might have changed things since back when, I was using the parallel port to get the above results.
Thanks again, Keith

20

General Mach Discussion / Mach3 Sherline Rotary Magic Number

« on: June 21, 2014, 04:04:53 PM »

I haven't used my Sherline Rotary Table in some time and since did a lot of re-installed. And I know this topic has been covered before but from what I read and apply, I can't get my rotary table to move in degrees properly.
I understand that the worm gear is a 72 turns to get 360 degrees of movement on the table top.
I believe it's doing half stepping, so 400 steps per stepper revolution (.9 degree per half step).
I don't think the velocity and acceleration numbers effect the ability to input degrees and get the table to move to the inputted degree.
I'm just forgetting the magic number in 'steps per' in motor tuning that I had and that worked before.
I'm coming up with the number 28800 but that doesn't work correctly.
So if anybody has that number that allows to put in a G01 A5 and the table goes to 5 degrees from zero, I'd appreciate it very much.
Thanks, Keith