Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: GEORGETOUBALIS on April 10, 2009, 05:33:32 AM

Title: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS on April 10, 2009, 05:33:32 AM
I finally finish the doming machine project.

http://www.youtube.com/watch?v=z5_H_WVbz98

The machine.
Parker linear motion tables 406 &404 series
Drives 750 OEM
Motors nema 34

All from ebay.!

Title: Re: Different use of Mach3 (dispensing)
Post by: Overloaded on April 10, 2009, 07:25:57 AM
Very nice George.
Well done !
RC
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS on April 10, 2009, 08:07:44 AM
thanxs RC!

The 406 parker linear motion table hold all the mass of X and Z axis (about 70lb)
has 20mm lead and high feed rates is not a problem.
The X has lead 5mm and high fees rates is a problem.
If I change the frequency to 35000 or more my motors does not sound very well and I have noticeable vibration.
With 5mm lead the parker says that the maximum speed of screw can be 50 rps. but I can't catch that speed.
Any way may be I will change the 404 parker linear motion table with one that has 15mm or 20mm leed.
George!
Title: Re: Different use of Mach3 (dispensing)
Post by: Overloaded on April 10, 2009, 08:21:56 AM
George,
 Have you looked into the Smooth Stepper ?
It will produce a MUCH faster and cleaner pulse stream.
I have one but have not used it yet but hear nothing but good news about them.
RC
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS on April 10, 2009, 08:51:06 AM
RC
The parker OEM 750 are very good drives with impressive characteristics and 3-4 times more expensive than Smooth Stepper
 plus they can handle 75VDC 6-7Amp That means speed and power.
http://www.arcetri.astro.it/irlab/doc/OEM750%20User%20Guide.pdf
I think that I push them to hard. Or my PC is slow (3.2 Ghz with XP).
Or maybe the power supply is small (75VDC 10A) maybe I need 20A.
the 3 drives is configured to give 6.8A/drive.
George.

Title: Re: Different use of Mach3 (dispensing)
Post by: Tweakie.CNC on April 10, 2009, 09:20:55 AM
Fascinating doming machine you have there George.

Tweakie.
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS on April 10, 2009, 09:26:30 AM
thanxs Tweakie!
Title: Re: Different use of Mach3 (dispensing)
Post by: Petergough on April 14, 2009, 04:52:20 PM
Hi George,
I think you are correct,
power supply needs upsizing,
2 jobs I have done to date,
found best to oversize by 10-20% of
the max current per drive x number of drives,
we have 4x 6 amp motors, power supply is 30 amp,
this help when braking heavy loads as power ploughed back in
on deceleration has somewhere to be absorbed,
some good info on the Gecko site.
Great machine/idea
regards
peter
Title: Re: Different use of Mach3 (dispensing)
Post by: fer_mayrl on April 14, 2009, 08:49:14 PM
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
Title: Re: Different use of Mach3 (dispensing)
Post by: Glenn on April 14, 2009, 09:38:26 PM
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
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS 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

(http://img4.imageshack.us/img4/3330/0101110110.th.jpg) (http://img4.imageshack.us/my.php?image=0101110110.jpg)
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS 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.
(http://img23.imageshack.us/img23/8864/pinchvalvehead.th.jpg) (http://img23.imageshack.us/my.php?image=pinchvalvehead.jpg)
(http://img25.imageshack.us/img25/3462/pinchvalvehead2.th.jpg) (http://img25.imageshack.us/my.php?image=pinchvalvehead2.jpg)
(http://img22.imageshack.us/img22/427/pinchvalve.th.jpg) (http://img22.imageshack.us/my.php?image=pinchvalve.jpg)

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!
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 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
Title: Re: Different use of Mach3 (dispensing)
Post by: BluePinnacle 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 :)
Title: Re: Different use of Mach3 (dispensing)
Post by: Tweakie.CNC 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.
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 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?
Title: Re: Different use of Mach3 (dispensing)
Post by: BluePinnacle 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.
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 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???
Title: Re: Different use of Mach3 (dispensing)
Post by: BluePinnacle 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.
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 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?? :) )
Title: Re: Different use of Mach3 (dispensing)
Post by: BluePinnacle on September 07, 2009, 07:44:30 AM
I'm sure we could dream up a couple of lines of code here, or write a quick macro. What level of complexity to you expect to need?
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on September 07, 2009, 08:14:08 AM
I expect this to be used mostly to dispense the resing along text using scripted fonts.
Another idea I just came accross is having the operator to draw by hand lines or vectors on top of the graphic to be used and having the CAM software to follow this vectors. This would make the paths simpler.

The operators have graphic design skills but no coding capabilities. So I can request them to do some pre processing as long as it is graphic oriented.
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS on September 07, 2009, 08:22:58 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?

Dear Roman 9999
Take a close look to this video.
http://www.youtube.com/watch?v=cXBLt6v4FZY&feature=related
You have to draw the path your self to have these quality of dispensing.
I keep the feed rate stable.... major rule.
 and when I have to fill the more wider parts of the letter I design one more little path only in that area.
(http://img137.imageshack.us/img137/8240/path.th.jpg) (http://img137.imageshack.us/i/path.jpg/)

George!



Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on September 07, 2009, 09:18:33 AM
George,
That´s awesome.
What do you use to draw the lines? What software?
I know I can perfectly control the machine with Mach once I have the gcode generated.
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS on September 07, 2009, 10:39:58 AM
George,
That´s awesome.
What do you use to draw the lines? What software?
I know I can perfectly control the machine with Mach once I have the gcode generated.

Adobe Illustrator.
George!
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on September 07, 2009, 02:18:55 PM
What do you use to create the Gcode? LazyCAM?

what profile do you use? Mill?
Title: Re: Different use of Mach3 (dispensing)
Post by: GEORGETOUBALIS on September 07, 2009, 02:34:39 PM
What do you use to create the Gcode? LazyCAM?

what profile do you use? Mill?

Artcam!
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on September 09, 2009, 07:57:32 AM
George,

I tried what you said about drawing lines and it seems to work even with LazyCAM!!!

How do you pump the resin? I thought about using pneumatic cylinders although I´d need a way to stop dispensing to refill the cylinders from time to time.
Title: Re: Different use of Mach3 (dispensing)
Post by: BluePinnacle on September 09, 2009, 09:54:44 AM
One of these is the answer: http://en.wikipedia.org/wiki/Peristaltic_pump

just replace the hose when it is knackered. Not hard to build or buy.
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on June 03, 2010, 01:47:00 PM
George,

I´m finally working on my domes machine and it´s almost done, although I still have some open issues left.

How do you control when to start and stop resin dispensing? Do you need to hand code that or Artcam does the job for you from the drawing??
Title: Re: Different use of Mach3 (dispensing)
Post by: BluePinnacle on June 03, 2010, 03:45:53 PM
I was thinking of using the pump with a stepper motor. Call it axis A,you could program in dispensing rates, suck-back, etc. You could also use parametric code to alter the flowrate along a run, ie ramp up and down.
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on June 03, 2010, 03:53:08 PM
I think I just came accross a neat solution.
My machine besides Mach3 also has a PLC incorporated.
What I´m testing at this very moment is to use the DIR pin of Z axis to control when to start and stop the pumping. I use the signal transitions from on to off and viceversa to start and stop the pump.
The pulses are generated by the PLC in my case.
My goal is to get something that will not require any hand codding at all. The GCode will come from Lazycam.
Title: Re: Different use of Mach3 (dispensing)
Post by: poppabear on June 05, 2010, 04:02:28 AM
A PLC huh, that is cool.

I would do this then, I would send your Feed Rate across the modbus to your plc and use that value there as an Analog value to vary the dispense rate, the faster you go, the more your analog signal increases......   I would put a Max and Min feed rate limitation so you would have a High and Low end to your analog value.

scott
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on June 05, 2010, 03:22:28 PM
While testing this I run into another problem (yet another one in the hugelist).

I connected the motor driver PULSE and DIRECTION signals to PLC outputs and started making some tests.
I keep the DIR signal unchanged and send ON-OFF sequences to the PULSE pin to make the motor turn.

When doing this, first of all, the motor makes loud noises and shakes like somthing is about to brake each time it moves, this happens even if I send a single pulse to the driver. Also, if I send a series of pulses the motor turns a few steps in one direction and then it either misses a couple steps or it turns one or two steps in the opposite direction.(!?!?!?)

Of course the motor&driver works perfectly when it´s directly controlled by M3 through the PC parallel port.

I´m not sure what may be different between the pulses M3 creates and the ones from the PLC.
Title: Re: Different use of Mach3 (dispensing)
Post by: Romanr9999 on June 09, 2010, 09:47:32 AM
I found what was wrong.
The pulses out of the PLC were too wide (too much time) and that´s why the motor was not running smooth.

Now I only need to decide how to control the pump from Mach3.
I thought about using the Z axis direction pin, so when the Z axis go down the pump should start and when the Z axis goes up to stop. It´s like if this was a mill, when the tool goes down it means it´s working on the material.
The problem I also found is if I stop the program for some reason (or if I need to run it step by step), the pump will keep dispensing resin even when the axis are not moving.

Anybody used Mach3 for a laser cutting machine? there should be the same problem there to start and stop the laser beam.
Title: Re: Different use of Mach3 (dispensing)
Post by: Tweakie.CNC on June 09, 2010, 11:48:25 AM
For my laser I use M11P1 to turn the laser on and M10P1 to turn it off. (these commands are added to the existing GCode in place of the Z- and Z+ commands).

I have the same problem with stopping mid line, the laser remains on.

The cure for this is, I think, to add a new, VB, screen 'stop' button which issues the M10P1 and then activates the feed hold function. Something similar could possibly be done for the single step function.

Tweakie.
Title: Re: Different use of Mach3 (dispensing)
Post by: Ya-Nvr-No on June 10, 2010, 11:42:10 AM
Why not just use a canned drilling cycle and by varying the drill depth (Z Axis) it would dispense varied amounts based on depth of Z. Doesn't it just fill a plunger of some type? Has some interesting applications.
Title: Re: Different use of Mach3 (dispensing)
Post by: CHINAFSYY on June 21, 2010, 10:21:44 AM
Very nice George.
Well done !