Hello Guest it is March 29, 2024, 02:30:22 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - Jeff_Birt

1021
General Mach Discussion / Re: Hooking up limits!
« on: January 31, 2008, 09:14:04 AM »
Quote
The limits im using are Normally open and normally closed with a ground.

How are your limits wired normally open AND normally closed?

It is best to have limit switches wired normally closed. This way when the switch is 'not pressed' you will have a complete electrical circuit. If you feed your switches with common (ground) then in this normal, 'not pressed' state, would provide a 'low' input to the computer. When the switch 'is pressed' the circuit will be open, there will be no electrical connection, and the input pin on your computer will go 'high' signifying the switch has been pressed. Wired this way your limit switch inputs on the computer will need to be set to active high.

The reason for wiring your switches normally closed is that it provides a basic level of supervision of the circuit. If a wire is cut or pulled loose the circuit will be open, just like it the limit was pressed, and your machine will stop before any harm is done.

1022
Very cool. Can you give us an idea on trace width? Also, how are you handling regesteringn the baord when doing two sided PCBs?

1023
Brains Development / Re: mysterious brain
« on: January 30, 2008, 04:57:59 PM »
Try running both ModBus inputs stright through (no operation) to some UserLEDs (or something similar). See if each input value is transferred properly to the output. If so then the problem has to lie in how Brains are ANDing the two inputs. You could also try passing each input through a 'no operation' and then inverting them.

1024
Brains Development / Re: mysterious brain
« on: January 30, 2008, 04:45:38 PM »
Hmm....indeed, it seems the top inverter should be on (green) as well. What type of data is in these ModBus registers? Judgin by the value showing "0.0000" it is not a boolean type. Could the value in the register be smaller than 0.0000? Or perhaps it is beign read as a -0.0000. Yes it can happen, if the register is supposed to be a signed short and somehow gets the msb set you will have a negitive zero, which when cast to a boolean might be a 1. (I don't know how Brains handle type casting).

1025
Brains Development / Re: mysterious brain
« on: January 30, 2008, 04:21:34 PM »
Given the title of this thread I was expecting it to be about Brian  ;), who indeed does have a mysterious brain. (Only putting in 100 hours a week, come on who needs sleep  ;D)

As for the actual question, it just looks like two ModBus registers that are inverted and then anded together to turn on 'Stop File'.

1026
It's a Bridgeport Discovery 308 VMC. I've been working on it in my spare time for another department here on campus. This board is an interface to split the two stock limit/home switches into three separate signals. One switch by itself is -Lim, the other by itself is Home, both together is +Lim. 

http://www.machsupport.com/forum/index.php/topic,3328.0.html


1028
I've made small circuit board on my Dyna 2400 before converting it to Mach3 control but this is the first after the conversion. The board was designed in Eagle (http://www.cadsoftusa.com/) which is a very nice program with a free limited version. The G-Code was generated with http://groups.yahoo.com/group/pcb-gcode/, which works great and has a Mach3 profile. It took a few tries cutting wax to get the settings down but it turned out pretty good. BTW, I ordered the routing and drill bits from http://precisebits.com/ who seem to be really nice folks. Now I just need to fix up my layout some.

The board is 2.8" x 2.5" and the traces are quite large at 0.016". It's an adapter board for another Mach conversion :)

Jeff

1029
Have you run a driver test on your new PC? Start there and see if you get a good driver test (flat line, no big spikes).

1030
General Mach Discussion / Idea for Z-tooling offset calibration
« on: January 02, 2008, 03:08:13 PM »
I've seen various threads relating to various form of 'touch' blocks to zero the tool to during tool changes. While looking through the latest Enco sles catalog today I noticed this: http://www.use-enco.com/CGI/INPDFF?PMPAGE=366&PMITEM=RP308-0391, left side of page the Fowler depth setter. It takes two AAA batteries and lights up when the tool touches it. Makes me wonder if it could be modified to drive an input in Mach3, at less than $50 it would be a good solution for mills where manual tool changes are the norm as it would sort of semi-automate the process (with the right tool change macro or course).