Messages

11

FAQs / Re: Homing and <goto zero> issues

« on: July 12, 2011, 09:20:03 PM »

Homing is not slave if you have separate switches. I somehow had different homing speeds setup once, and it took me a while to figure out what was going on.

I don't feel quite so silly now

If you want to use one home switch with a slaved axis, there's an option in General Config, "Home Slave with Master", which will slave them during homing.

That's useful to know.  I had not seen that option

12

FAQs / Re: Homing and <goto zero> issues

« on: July 10, 2011, 02:41:39 AM »

Ger21
You're right.  I have to take back my last post.  You were right the first time.
Somewhere along the line I reversed the A motor.
When I connected both the X and the A to gearing  I had the horrible grinding during jogging.
I corrected this by getting the motors configured so A was reverse of X and then jogging was fine.
I set up homing negative for both X and A, as you said previously.
I checked motor tuning: My A motor tuning was considerably different from X,
I copied and pasted the X motor tuning settings for steps, speed and acceleration to A and homing is now working smoothly.

So, I assume that Mach 3 will send the same step and Dir commands to the motor and its slave during normal operation  but this is not the case during homing? (i.e. homing is not slaved?)

13

FAQs / Re: Homing and <goto zero> issues

« on: July 09, 2011, 07:46:38 AM »

Finally had time to check out homing.
I have a Y gantry that runs along twin X axes.  The X motors are installed at opposite sides of the gantry, so they need to run in opposite directions in order to move the gantry in the same direction.
I dropped one motor off the rack (so it could turn but not engage) and went through a few homing tests.  I could jog my gantry fine, but in homing the two motors (X and A) were turning in opposite directions.

I've solved my problem by having one motor (the X) home negative and one (the slaved A) home positive.  I don't know whether this is the usual way of dealing with this issue?
Ger21, you pointed me in the right direction, thanks.  Just my particular setup seems to require an alternative approach?

14

Mach Screens / Re: Arrow Keys Jogging doesn't work with a new screen

« on: July 04, 2011, 05:44:08 AM »

I had a similar problem that resolved when I redefined the arrow and pgup/down hotkkeys in config

15

FAQs / Re: Homing and <goto zero> issues

« on: July 04, 2011, 05:41:38 AM »

Thanks Ger21,
That's exactly the feedback I needed.  A is enabled,but in the wrong direction.

Got my router bracket built and installed.  Time to make some dust!

16

FAQs / Re: Homing and <goto zero> issues

« on: July 03, 2011, 05:26:56 AM »

Got the proxies working so now the machine "refs home" nicely in the Z and Y axes, and the X travels to zero but then much grinding ensues.  It's as through the 2 proxies (one either end of the Y-gantry) are confusing Mach 3 and driving the motors in opposite directions (even though one is slaved).  Is this possible?  I thought that the zero sequence allowed for two home switches on a gantry so that the gantry could be squared?

17

FAQs / Re: Homing and <goto zero> issues

« on: June 29, 2011, 02:58:38 AM »

Ger21,
Thank you for your responses.
I have attached the xml file.
Regards
Red

18

FAQs / Re: Homing and <goto zero> issues

« on: June 27, 2011, 09:22:09 PM »

Thanks for the replies and advice.
I downloaded an update of Mach 3, installed it and ran off my old xml file.  The software now zeros after running G code and acts the way I expect.

I'm using proximity switches for home and limts, but have not got them working yet.  I have had a bit of difficulty with the circuit.  I had N/O switches in a parallel circuit, which is fine, but in my application I had them always closed and open on error, which of course does not register in a parallel circuit!  Now I've figured out what was wrong I can get homing working.

1) you "Home" the machine with the Ref All button, not by zeroing the machine while in Machine Coordinates. Even though you are in machine coordinates, you're actually zeroing the current offset, as you can't zero an axis in machine coordinates other than the "Ref" buttons.

This is gold.  Thank you.
I remember somewher that <ref all home> will only work if there are home/limit switches on all axes.  Is this true?

I have tried the <ref> buttons on the diagnostics page.  The Y works fine, but the X results in a horrible grinding that I put down to the 2nd (slaved) X motor turning in the wrong direction.  Is it possible for jogging and cutting to work OK, but not <ref>?

19

FAQs / Homing and <goto zero> issues

« on: June 26, 2011, 06:28:52 AM »

Hi,
Firstly, please forgive me for my ignorance.  I'm pretty new to this and I notice from the level of discussion on the forum that many posters are seasoned hands at CNC.
I'm commissioning a 3x1.2m 3 axis MechMate that I built and things are going fine.  It's able to move correctly in response to G code and the e-stop, feed hold and resume buttons all work. I'm running a PMDX-126 and Gecko 203v's and Mach 3 (2) is installed on a 32 bit gaming (i.e. high specced) PC running 32 bit Windows 7

I'm having problems setting up home are returning to zero. I do not have limit switches and have yet to get my proximity circuit sorted, so I'm slamming into end stops a bit!

1. I set zero for x,y,z with the machine co-ordinates lit.  This should be "table zero", right?
2. I can jog off this zero, switch off machine co-ordinates and re-zero, then regenerate path and and run through g code.  The display shows the work correctly relative to the table and the machine moves correctly in response to the g code.
3. If I <goto zero> at the end of the routine the gantry or car overtravel dramatically, which means I have to be quick hitting <esc> or <reset>.  I have tried debounce values of 500, 1000 and 2000.
4. I cannot subsequently zero any of the axes via the on screen buttons and have to restart the software to be able to do this.

Is there something I'm missing?