Messages

1421

General Mach Discussion / Re: G81 weirdness, newbie

« on: August 31, 2007, 08:57:30 AM »

Hi Guys:

 Actually, both are wrong. In the first program the move
N118 X-.5762 Y-1.5873 should have a g1 in it. This is because the G80 cancels the canned cycel, but it also cancels all modal motion commands, so the line
doesnt have a modal movement type. IT needs to have G1 reinstantiated.

 The second example, trys to change the Z of a canned cycle, that too cannot be done while in the cycle. The Z can only change when
entering a canned cycle. Ill list to see if I can change this bnehaviour, the G80 cancellation of all modal is a holdover from EMC's interpreter,
but I see in the code where I once changed it, then changed it back, so I suspect there are unknown problems in other areas when I just reinstantiate the
last motion prior to a canned cycle. But Ill see what I can do.

Art
 

1422

General Mach Discussion / Re: MAXNC10CL and MACH3 issues

« on: August 24, 2007, 10:02:09 AM »

Hi:

 Here are the Max files I have... The FTP is not online, but shoudl be soon. I cant seem to find a xml for the maxcl.. though I know Ive seen one,
Ill keep looking..

Art

1423

General Mach Discussion / Re: Accurate homing

« on: August 21, 2007, 03:03:32 PM »

Hi:

  Just to kick in.. ( Thanks brett fro steering me to this post..)

  Estop and limit events shoudl not be prevalent on any system, BUT, if for whatever reason they are..

Estop is just that, an emergnecy, all power shoudl be cut, ( which woudl release brakes on a bug system, thats truly safe..). Mach3 keeps track of all pulses at all times. The DRO's are always accurate as to the pulses put out. Doesnt matter what you do. Postion is lost only when a motor cant keep up. If using servo's, the Rogers baord makes it pretty much infalible. Brian has demonstrated at shows with grabbing the axis and stopping it, thus causing an estop, when the rest is pressed, the DRO's go to the actual motor position, and no homing in necessary. That having been said, Homing shoudl never be risky, it shoudl be accurate. Mine is accurate to .01mm's. If yours isnt, then you need better switches.

   Now it IS possible to home to an index using macro's. All it takes is a "move to index " macro. A very slow move that stops when an input sees a pulse woudl do. Slow, but do-able, Ive never bothered as my homing always seems so accurate I woudlnt gain from the complexity. KISS is always a good idea if you can do it IMO.

  When hitting stop, many steppers will lose position due to abrupt stopping. Many servo's will not. Alot depends on the system.

>>they know how many pusles move the axis how far. BUT if the computer puts out a pulse which the motor misses - for what ever reason, then the DRO IS NO LONGER ACCURATE. As an alternative - if you press E-Stop - and the computer instantly ceases putting out pulses - yet the momentum of your system carries the motor over a few steps (4.8 to the thousanth of an inch on mine) then the DRO (which registers to 1/10th of a thousanth) can no longer be accurat

  Both true statements. BUT , and this is where the theory breaks, it is just as likely for a system to miss a step pulse as an encoder pulse. Both are similar in nature, and both happen. Since nothing, ( truly nothing ) can see the missing encoder pulse, no system, closed or open loop, servo or stepper, is immune to lost pulses. Whiel its true that in true closed loop only 1 weak link exists, any chain is only as strong as its weakest link, so closed loop is questionably better. The true ( and to my mind only )  advantage to a closed loop system with fuill encoder feedback, is that Estops, and sudden stop button presses will not lose position. That having been said, that situation shoudl be a rare one. And homing will cure that in a properly setup system.  I may make some changes soon in the stop system, but Estop will always be a problem.. and should be. :-)

Art

1424

General Mach Discussion / Re: Deckel Mach Retrofit

« on: August 13, 2007, 09:56:20 PM »

Very nice machine. Looks like quite a challenge, but will be one cool tool when done..

Art

1425

G-Code, CAD, and CAM discussions / Re: doing a mirror cut

« on: July 22, 2007, 10:45:55 AM »

Just one quick note here. With IJ code, the X and Y muct be scaled the same, so if you use -1 in the X, then you must use -1 in the Y as well. Shoudl work then..

Art

1426

Share Your GCode / Re: GCode Sharing

« on: July 21, 2007, 03:57:40 PM »

Hi Bill:

 It was  a sharp pointed engraving bit..
.032 I think..

Art

1427

General Mach Discussion / Re: OEMLed 111

« on: July 16, 2007, 04:40:18 PM »

William:

  Great!. Glad to hear you made it over the learning curve. Its a fairly steep one, but now that your there, I suspect
youll be able to do lots of weird and wonderfull things with the program. Have fun..

Art

1428

General Mach Discussion / Re: Bad Driver Test

« on: July 16, 2007, 08:34:27 AM »

Now thats funny..

Art

1429

LazyCam (Beta) / Re: LazyCam 2.02

« on: July 13, 2007, 01:52:30 PM »

Chip:

 I had a tolerance set too severe in some offsetting, so redownload the updater.. may or may not fix your current trouble..

Art

1430

General Mach Discussion / Re: Update post from Art

« on: July 13, 2007, 01:35:44 PM »

Hi:

 If your velocity slider is maxed out, then going up in kernal speed will allow higher tuning. If it isnt, then its unlikely to help. Try widening the pulse time in the motor tuning. It sometimes helps if the
opto's in your system are a bit slow..

Art