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Author Topic: Different use of Mach3 (dispensing)  (Read 16527 times)

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Re: Different use of Mach3 (dispensing)
« Reply #10 on: April 15, 2009, 03:50:02 AM »
Hi George,
  Great machine!
   This may be a dumb question, but does your machine "find" the
object to dome with the cross hair laser light seen in the video?
  It appeared that you laid the second tray on the spoil board
without aligning it or fastening it to a pre-measured spot. How does this work?
  Thanks,
  Glenn

The set of icons are vertical &horizontal align. I move the tray to happen this.
1) the first icon to be in the center of my tip.
2) the aray of the icon be aligned with laser lines


Re: Different use of Mach3 (dispensing)
« Reply #11 on: April 15, 2009, 04:22:30 AM »
George,
What did you end up using for precisely dispensing the resin?

Great work, i love to see machines controlled by mach3 that are not lathes and mills.

Regards
Fernando

Hi rFernando!
I design and machining this small press head and I connect it with a an air piston 20mm.




The last 2 months the machine has to make about 200.000 times the "down/open ---- up/close" move (since I have to make a very small labels).
It works fine !
Sorry for my terrible English.
George!
Re: Different use of Mach3 (dispensing)
« Reply #12 on: September 04, 2009, 11:10:47 AM »
Congratulations on your machine!

I´m new to this and my project is to do exatcly what you did, a resin dispenser for domes !!!!! It´s great for me to see what you did.

One question (or at least the first one):
One thing I still didn´t figure out is how to control the amount of resin dispensed where the trace is narrow. For example, let´s say I need to dispense resin over a text done using a script font. There are parts where the line is very thin and other parts where it´s wider, so where it´s thin I need to dispense very little resin, or to move faster so the same amount is dispensed along a longe line.

How do you tell Mach to do this?
How do I do this starting from the text graphic??

Thanks a lot in advance!!!




Roman
Re: Different use of Mach3 (dispensing)
« Reply #13 on: September 04, 2009, 01:48:14 PM »
Easiest may be constant flowrate, variable feed - programming the line in segments, or writing either a subroutine or a macro to control feedrate progressively.

Great work on a very interesting and productive machine, well done :)

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Re: Different use of Mach3 (dispensing)
« Reply #14 on: September 05, 2009, 04:52:30 AM »
Just a thought Roman but if the dispensing piston was thread driven (rather than air operated) then this could be operated by a stepper motor controlled by another (possibly the A axis) axis of the machine. This should enable full Mach control of the volume at any point of the work.

Tweakie.
KEEP SAFE !
Re: Different use of Mach3 (dispensing)
« Reply #15 on: September 05, 2009, 09:27:22 AM »
Yes, I did think about it. I know there are two ways to do this. Either to change the resin dispensing rate using another axis for the dispenser or to keep that fixed and change the nozzle speed so the same amount of resin is dispensed in a longer (or shorter) line.

If I use the variable dispensing rate, this would be the 3rd axis since besides this there is no Z. At a constant dispensing rate the dispenser on-off is not an axis. Is this correct??

I need to be able to start with a graphic image of what I want to dispense resin on. The idea is not to write the Gcode.
I wonder if this can be done with LazyCAM or not. If not, what should I use instead?
« Last Edit: September 05, 2009, 09:45:41 AM by Romanr9999 »
Re: Different use of Mach3 (dispensing)
« Reply #16 on: September 05, 2009, 04:45:16 PM »
Well, a peristaltic pump comes to mind, coupled to a stepper - the rollers go around and squeeze the resin through a rubber pipe. If the resin is the type to set solid in the clockwork, fear not, just replace the length of rubber pipe. You'll get very accurate pumping which can be done continuously rather than having to withdraw a piston between shots. There's also the potential for two pumps, one for resin, one for hardener, if it's a two-part glue, forced out through a disposable static mixer nozzle. Interested? :D

the lack of inertia on the pump axis (makr it as Z if you wish, I'd probably call it a spindle) means that acceleration could be very high, and you could easily program in ramp-up and ramp-down rates to suit your application, even putting in a slight suck-back to shut off flow more cleanly. There's a lot of flexibility here, potentially, but I doubt CAM applications have this in mind, so I'd think of hand-coding as the way forward.
Re: Different use of Mach3 (dispensing)
« Reply #17 on: September 06, 2009, 08:48:33 PM »
Can´t we think this like if it were an engraving machine using a v-shaped tool where the Z axis depth makes the line wider or narrower???
Re: Different use of Mach3 (dispensing)
« Reply #18 on: September 07, 2009, 02:33:29 AM »
Similar train of thought - In this case using Z as the control for pumping, but you'd have to get the (fixed) Z value to translate to a continuous pumping motion. My reasoning for using the spindle control is that it's already set up to handle this sort of motion and can be easily ordered to spin (or pump) at a fixed or variable rate.
Re: Different use of Mach3 (dispensing)
« Reply #19 on: September 07, 2009, 07:10:20 AM »
I see your point, although I doubt any CAM package would vary spindle based on the with of the line in a graphic. The people who will be using this has no coding capabilities (Am I asking way too much?? :) )