| Per Westermark 04/30/12 16:05 Read: 319 times Sweden |
#187275 - Need not be exactly in middle. Responding to: Mahmood Elnasser's previous message |
If you have two position pins in a straigt vertical or horisontal line, then you just flip the board. The CAD program will not care if the two pins are a bit away from the center of the board. So in theory, the two holes could be top-left and bottom-left and after you flip board they are top-right/bottom-right. Just that the CAD program produces data relative to the holes so the machine in that case on one pass do most work to the right of the pins, and after flip have most work to do to the left of the pins.
The issue is that you need to align the pins so that you can flip the board while maintaining exact relative position. With two pins in diagonal corners, you can't flip the board because the board must then have four holes - it will be the two opposite diagonal holes that would be used after board is flipped. No such issue with the two holes in vertical or horisontal line on board. +--------------------+ | | | | | o o | <= not symmetrically placed | | +--------------------+ +--------------------+ | | | o o | <= but still ok after flip | | | | +--------------------+ So as you see from above - having the holes symmetrically just means that you can make maximum size PCB in relation to table size of machine. As long as board is smaller, it doesn't matter if you have an assymetry. Just that by minimizing the longest distance from hole to side of board, you get board better held down. One interesting thing with very narrow traces is that the bit can "push" the trace sideways, if bit isn't sharp enough and movement speed suitable. |
| Topic | Author | Date |
| CNC | Mahmood Elnasser | 04/14/12 10:43 |
| Enjoy :) | Oliver Sedlacek | 04/16/12 04:14 |
| Having fun | Mahmood Elnasser | 04/17/12 13:53 |
| Congratulations | Joseph Hebert | 04/16/12 09:42 |
| We looked at buying one of those | Jez Smith | 04/16/12 14:09 |
| Me Either! | Joseph Hebert | 04/16/12 14:17 |
| We use a variety | Jez Smith | 04/17/12 00:50 |
| do not be lazy,Mr.Smith | Stefan KAnev | 04/17/12 11:28 |
| prototype cost and turnaround | Joseph Hebert | 04/17/12 13:31 |
| I'll find the ads | Erik Malund | 04/17/12 14:14 |
| googled | Erik Malund | 04/17/12 14:22 |
| Ebay deal | Steve M. Taylor | 04/17/12 15:08 |
What about this one then...  | Robert Revens | 04/25/12 12:59 |
| Follow up on prototype board shops | Joseph Hebert | 06/22/12 08:41 |
| international pcb houses | Mahmood Elnasser | 06/22/12 14:13 |
| PCB Houses | Joseph Hebert | 06/22/12 16:55 |
| working out of town | Erik Malund | 04/17/12 07:20 |
| CNC bits | Mahmood Elnasser | 04/25/12 06:37 |
| answering | Joseph Hebert | 04/25/12 11:38 |
| it happens | Mahmood Elnasser | 04/25/12 14:51 |
| what other tools required? | Mahmood Elnasser | 04/25/12 15:00 |
| a new trick zeroing Z axis | Mahmood Elnasser | 04/26/12 12:26 |
| Z ref | Steve M. Taylor | 04/26/12 13:10 |
| Collet type | Mahmood Elnasser | 06/22/12 14:27 |
| Z axis reference | Mahmood Elnasser | 07/02/12 01:40 |
| Vacuum | Per Westermark | 07/02/12 02:35 |
| this sort of thing happens often, from my experience | Richard Erlacher | 05/01/12 07:38 |
| ctrl+A, crtl+C, submit | David Brown | 09/19/12 01:34 |
| tools | Joseph Hebert | 04/26/12 14:11 |
| holding the PCB | Mahmood Elnasser | 04/27/12 00:27 |
| Holding the PCB | Joseph Hebert | 04/27/12 14:06 |
| Carbon steel? | Per Westermark | 04/27/12 20:16 |
| Not tungsten carbide | Joseph Hebert | 04/28/12 16:37 |
| Just carbide is a bit lazy slang for tungsten carbide | Per Westermark | 04/28/12 21:41 |
| If you say so. | Joseph Hebert | 04/28/12 22:30 |
| Plate through holes | Mahmood Elnasser | 04/28/12 11:05 |
| plating holes | Joseph Hebert | 04/28/12 16:46 |
| plated through holes cont. | Joseph Hebert | 04/28/12 22:37 |
| 2 point registration system | Mahmood Elnasser | 04/30/12 14:27 |
| Need not be exactly in middle. | Per Westermark | 04/30/12 16:05 |
| is it that simple? | Mahmood Elnasser | 05/01/12 00:27 |
| 2-pin registration | Joseph Hebert | 04/30/12 23:40 |
| Fine pitch milling | Joseph Hebert | 05/01/12 23:54 |
| Solder Mask | Mahmood Elnasser | 05/02/12 10:28 |
| solder mask and legend | Joseph Hebert | 05/02/12 11:47 |
| too much work | Mahmood Elnasser | 05/02/12 15:54 |
| Much work | Joseph Hebert | 05/06/12 15:50 |
| My CNC | Steve M. Taylor | 05/07/12 06:57 |
| Is That... | Michael Karas | 05/07/12 10:30 |
| which cad did you use? | Mahmood Elnasser | 05/07/12 15:58 |
| Limit Switches | Michael Karas | 05/08/12 00:22 |
| Will do | Mahmood Elnasser | 05/08/12 10:55 |
| Little Plates | Michael Karas | 05/08/12 16:40 |
| MEchanical limit switches | Steve M. Taylor | 05/11/12 12:50 |
| Your project | Joseph Hebert | 05/10/12 06:18 |
| This: | Steve M. Taylor | 05/11/12 12:38 |
| very cool! | Joseph Hebert | 05/11/12 13:29 |
| Funnel | Michael Karas | 05/12/12 12:37 |
| Funnel ! | Steve M. Taylor | 05/13/12 13:04 |
| Lawyer or Solicitor - Not ! ! | Michael Karas | 05/13/12 15:43 |
| RIght | Steve M. Taylor | 05/14/12 12:16 |
| vacuum pick and place tool | David Brown | 09/19/12 01:29 |
| 90 degrees bits | Mahmood Elnasser | 09/14/12 04:22 |
| Z-axis depth control | Joseph Hebert | 09/15/12 22:53 |
| stepper | Mahmood Elnasser | 09/16/12 06:34 |
| z-axis control | Joseph Hebert | 09/16/12 15:37 |
| oiling | Mahmood Elnasser | 09/29/12 14:49 |
| lubrication | Joseph Hebert | 10/01/12 10:41 |
| Lube | Steve M. Taylor | 10/05/12 14:47 |
| ballscrews | Mahmood Elnasser | 10/06/12 00:21 |
| Ballscrews | Steve M. Taylor | 10/06/12 14:00 |
| Sometimes it's useful for controlling dynamics | Richard Erlacher | 10/06/12 14:08 |
| ballscrews & table slides | Joseph Hebert | 10/06/12 15:15 |
LINUXCNC | Mahmood Elnasser | 10/19/12 02:08 |