Messages

281

General Mach Discussion / Re: Breakout Boards

« on: November 18, 2007, 05:25:11 AM »

Hi,
  yes I use passive breakout boards.
and good quality shielded data cable(twisted pairs)
be sure to only ground the cable at one end. Not sure why, but
its  apparantly good  practice?
    Tony

282

General Mach Discussion / Re: Breakout Boards

« on: November 17, 2007, 05:00:39 PM »

hi,
 for my two-pence worth, I would not use a break out board,and thats nothing to do with cost cutting.
firstly, practically all stepper/servo drives have optoisolation built in.so it is purely to safeguard against bunging
more than 5 volt back down the port by mistake.Treat your port with respect!
 Alternativly use a pci card,best to use them +5volt common though (as a laptop) taken from a spare usb port.
Secondly,if the optoisolater or its wiring isnt quite right,that can be a bitch to trace,giving you mis-steps, and
hours of fun! Some drivers,aparantly dont like being fed through secondary opto's.
Just my opinion!
   Tony
   

283

General Mach Discussion / Re: high count servo encoders

« on: October 28, 2007, 06:07:07 AM »

Hood,
  USB smoothstepper board? whats that all about then?
   cheers
    Tony

284

General Mach Discussion / high count servo encoders

« on: October 28, 2007, 02:26:51 AM »

Guys,
  for my next project I want to retrofit a bridgeport mill,max feedrates on rapid will be about 3-4mpm
I am using 500 watt servo's with 2048 count encoders ( 8193 pulses to deal with)
I would like to use gecko 340's with 10 x dividers. My problem is going to be lost steps on direction
changes.I figure if I use exact stop rather than CV that will go some way to helping.
  I appreciate that I could use a higher kernal speed,but for the sake of reliability with the computer I'm
using I dont want to go above 45khz.
  What I really need to do is make mach3 pause for 1/4  second between direction changes especially rapids
Is this possible? I have bought Mach so can I get into the code somehow and do this?
I really dont want to have to put a G4 between every move,as a toolmaker I do alot of programing
and that would be very tiring!
  cheers
      Tony

285

General Mach Discussion / Re: glass scales and servo's

« on: October 14, 2007, 10:25:30 PM »

dennis,
 I was hoping for a more constructive reply,
 perhaps you could quantify yours as your obviously an expert on the subject.
   Tony

286

General Mach Discussion / glass scales and servo's

« on: October 13, 2007, 12:02:58 PM »

hi,
  I would like to fit linear encoders onto my smalll ballscrewed servoed
miller. I have already got motor encoders and gecko 340's.
I was wondering could a piece of electronics be designed that would instantly sence
a movement pulse streem and switch from the rotary encoders to linear for positional accuracy?
then once the pulse stream stops switches (maybe 1/4 sec pause)back to the rotary motor mounted encoders
to stop them from hunting.Even though I only have .002" backlash I think the machine
will burn its servo's out sharpish without this type of system. I would think it might be possible to do this
in hardware rather than delving into Mach.
  Any thoughts?
   Tony

287

Mach Screens / try this screen set

« on: September 22, 2007, 07:56:03 AM »

Guys,
  I have been working on this screenset for a couple of months now,its for a four axis mill
and gives you everything you need on the mainscreen.
try it out and let me know what you think.
  Tony

288

General Mach Discussion / Re: New Computer w/ no parallel port

« on: September 13, 2007, 04:36:27 PM »

I always use a PCI card on a mach machine, as I figure if I accidently do something silly
with the wiring then it will most likely only blow the pci card and not the mother board.
plus a pci card from ebay is a fraction of the price of an opto isolated breakout board.
tony

289

General Mach Discussion / Re: How to use Mach3 outputs?

« on: September 10, 2007, 04:38:53 PM »

hi,
  dont know if its any use but I use the m07 comand (I only use flood coolant)
to operate a Quill lock. obviously you have to manually put that code in if your using a cam package.
 tony

290

General Mach Discussion / Re: gecko g340

« on: September 04, 2007, 02:30:12 PM »

Cheers Brian,
  that confirms what I thought,I bought some new BEC 260's off ebay for a steal,
but they really require 150 ma @5volt a little bit to much for the gecko's.

  While Im here ,what would haooen if I put 12 volt into the encoders (there rated 5-24)?
would that increase the A B voltage or do all encoders output a standard voltage?
  thanks again
       Tony