Messages

11

General Mach Discussion / accuracy issue

« on: May 12, 2009, 10:23:46 AM »

Hello,
I use A 4th axis to make windings. The motor driver uses 8 pulses per step. Motor has 200 step/rev. And for this axis, 1 unit is 1 turn. So I configured 1600 steps/units (at 1200 units/min)  This is quite fast but OK with 35kHz Kernel.
My problem is that after many turns, the motor 0 position is no longer correct. It shifts about 0.15 turn per 100 turns. (i.e. missing 0.15 * 1600 steps to actually reach the correct position). There is no torque on the motor, so no risk to lose steps - and acceleration is very slow.
So I tried replacin 1600 by 1602.4 (+0.15%). It helps but does not seems to be perfect.
A few month ago, I did not have this problem with the same settings. So I tried with an old copy of the .xml setting file, and still the problem occurs. So probably a hardware issue ?
Also the other axis do not seem to have this problem (with 200 steps/unit)
I use a laptop (X31). And it could also be a cause ? Pulse freq is stable (36137Hz and time in interrupt is around 4usec)

I'm lost. Thanks in advance. Pierre.

12

General Mach Discussion / Re: input value in DRO

« on: May 13, 2008, 04:16:03 AM »

Auto Calculator option
-> YES !, I like it. 

Thanks again.

Pierre.

13

General Mach Discussion / Re: input value in DRO - Nearly solved

« on: May 08, 2008, 06:37:03 AM »

I just found something :
On the thinkpad keyboard (french keyboard), if I deypress a 'shift'+ 'Num/Defil' key, the keys 'J K L, U I O, 7 8 9' are considered like '1 2 3, 4 5 6, 7 8 9' of the numerical keyboard - right part of a 102 keys keyboard (sorry - I don't know the name of this right part of a keyboard in english).  And with these keys, IT WORKS : I can input values in DROs !!!
This solves my problem. But obviously, it would be more convenient to be able to use the usual numeric keys..

If it is not clear, I'll make a picture of the keyboard to show what works and what does not.

Anyway, thanks a lot for help. I really appreciate.

Pierre.

14

General Mach Discussion / Re: input value in DRO

« on: May 08, 2008, 06:12:29 AM »

> in the mean time you may be able to manually set up a new profile, it would mean entering all the settings again manually rather than just cloning a previous profile but I think it would work.

I tried using MachTurn. I take the profile given at the install. No modification at all. I get exactly the same result as for DROs :
For instance, the DRO "Feed : inches/min" is 6.00 by default.
I click on it -> it turns white.
I hit '1'  (need to press shift - key(1) because there is no separate keyboard for numbers on this computer keyboard), the DRO value turns to zero.
If I validate with 'enter', it stays at 0. Otherwise, it turns back to '6.00'.
I tried all keys. Characters yield no DRO change. Numbers, '-', '+', yield '0'. Just depressing 'Alt' also yields '0' but NOT 'ctrl' or 'shift' alone.

There seems to be nothing special in the config of this PC (XP was just installed, not many other soft : office, CAD, antivirus and mach.
Really strange. I'll try to connect an external keyboard when I can. Otherwise, I have no idea.

Pierre.

15

General Mach Discussion / Re: input value in DRO

« on: May 08, 2008, 05:11:20 AM »

>Do you have any custom VB buttons or Brains?
No

>Y axis home button :
it should not be on.
For me, it seems to work. I set X=300 and Y=496, Z=0 for home (the home switches are also limit switches for me). It is more convenient for me to have them in the upper right corner. Therefore this setting.

I still can't input numbers in DRO, even when the machine is not connected to the PC (no limit switch on)

Pierre.

16

General Mach Discussion / Re: input value in DRO

« on: May 07, 2008, 10:30:13 AM »

Thanks again.
My config: Laptop IBM Thinkpad X31 + Windows XP pro
Controller on the parallel port (0x3bc)  - nanotech IMT901 based + 4 axis machine (PF 600C)
The mach3 driver works fine, mouvements are smooth.
I tryed version 2.63; I just reinstalled v1.83. Same result.
The joystick is a USB standard joystick. I use it to jog. (just a little stange thing : when my home buttons are ON, I no longer can jog with the jostick. I first need to move out of the switches using the arrow on the keyboard)
My A axis is a rotary table (4th axis). I just wan't to set the diameter (in the setting screen 'A diameter' DRO), because the feed rate is not correct otherwise when I launch my G-code. Also I need to change the 'tool change location : X, Y, Y' DROs in the same setting screen.

I understood the normal working of the DRO (the 'enter' key needs be pressed to validate). I know exactly how it should work because it does work on my desktop PC. (for some reasons, I now need to use the laptop instead - which I know is not so good a choice)

I already spend hours on the DRO input problem. This is why I talked about a trick to input values another way; I really need to find somethnig. But obviously I would prefer to really solve the issue (very surprising indeed that I seem to be the only one !)

Just another thing : I launched keygrabber once. Don't really know what it does and how. It seems not to appear anymore.

Pierre.

17

General Mach Discussion / Re: input value in DRO

« on: May 07, 2008, 08:23:45 AM »

I disabled the joystick. Still it does not work.

I just noticed that in fact, when I hit something (numbers..) in an initially non zero DRO, and then I hit enter, the DRO turns and stays to zero. It does change. I just cannot input the numbers I want.

Is there another way to set the A diameter and the change tool positions (for instance in the G-Code)?  I imagine it is possible using vb. Maybe I'll have to try that.

Pierre

18

General Mach Discussion / Re: input value in DRO

« on: May 07, 2008, 07:19:14 AM »

Thanks a lot for the support. Here goes the xml file.
Pierre

19

General Mach Discussion / Re: input value in DRO

« on: May 07, 2008, 06:26:54 AM »

OK. I am not in 'machine coordinate' mode so I should be able to alter these DROs. But I can't.
Same for all DRO's.
Actually I can input values, text.. in the MDI line for instance, or in the config menus.
Everything seems to work perfectly, except changing the DROs values.

Pierre.

20

General Mach Discussion / Re: input value in DRO

« on: May 07, 2008, 05:35:20 AM »

I don't understand the question. The DROs values are displayed OK. Only when I try to change them, I can't. I try to change the A rotation diameter, the X,Y Z tool change position (in the setting screen). I don't want to change the DROs of X,Y Z current positions (And this would only change the offset I think - I cannot change anything here either anyway).

Pierre.