More 3d stuff - unattended etching.

[karbomusic]

It's not that I feel this is that much of a time saver or breakthrough but it certainly gave me yet another excuse to combine DIY 3d printing with DIY electronics with the majority of the fun being the engineering  although I will certainly try it out and use it. Thusly, I present the PCB Etchomatic below. Since the Arduino is programmable I have full control over the 'swish factor'...

As seen in Blender when I modeled it.



A quick test before formally building it out - translation, quick cobbled test right after the parts printed to see if what I dreamed up in 3d space worked. There is some more work to be done before it is 'solid and final' after a trip to the hardware store... Just some very simple code driving the servo for the quick test....

[mth5044]

Dude 


Dude

[Kipper4]

Sweet

[J0K3RX]

[J0K3RX]

Honey, phone the neighbors... them boards ain't gonna rock themselves!

[Jdansti]

Cool!  Are the motors model aircraft servos?

[R.G.]

Something very like that, but with a lower center of gravity     appeared in the ARRL's manual from back in the 1970s. They didn't use a servo, just a dumb timer motor with a wheel on its shaft and a pin on the wheel.

The actual rocker was a board with a dowel under it to rock on and a lever arm going up from the board. The motor had a link to the top of the lever arm. When set up right, the board rocked on the dowel, but could never get tilted enough to spill..

I wonder whether one could use plastic paint cans and those paint shaker setups like Home Depot has?

[karbomusic]

That makes me wanna puke just watching it. 

[karbomusic]

Cool!  Are the motors model aircraft servos?

Pretty much, nowadays they are robot servos too since that's a big DIY craze right now but yea basically the same thing. Basically one of these...

http://www.amazon.com/gp/product/B0006O3WVE/

[Jdansti]

Cool!  Are the motors model aircraft servos?

Pretty much, nowadays they are robot servos too since that's a big DIY craze right now but yea basically the same thing. Basically one of these...

http://www.amazon.com/gp/product/B0006O3WVE/

Thanks. Here are a couple versions I've seen used in labs.

[karbomusic]

Something very like that, but with a lower center of gravity     appeared in the ARRL's manual from back in the 1970s. They didn't use a servo, just a dumb timer motor with a wheel on its shaft and a pin on the wheel.

The actual rocker was a board with a dowel under it to rock on and a lever arm going up from the board. The motor had a link to the top of the lever arm. When set up right, the board rocked on the dowel, but could never get tilted enough to spill..

Nice, I think the key for this one might be using as little etchant as possible to do the job which would allow more violent wave motion crashing across the board. Much more and it's just going to sit there deep in the etchant only wiggling back and forth (like the video). I can program the servo degrees and speed enough that I only have to worry about splashing it out. However, it was an engineering time passer that will probably decrease the etching time some and save me a few trips to the garage every five minutes to do exactly the same thing.


Edit: Not sure if anyone noticed but the pivot is very similar to a wah enclosure, that seemed to be the least work for the servo to do aka a seesaw. I agree on the center of gravity, my first 3d model had it with the pivot point much lower than the platform which was obviously going to be a recipe for disaster.

I wonder whether one could use plastic paint cans and those paint shaker setups like Home Depot has?

"I can etch your board in 30 seconds" with one of those hehe. More seriously, I can etch a 1/16", 1 ounce pour 2"x3" board in less that four minutes using a sponge and just wiping, that's the fastest method I've ever used but it requires me to be there and it's a little messy. I still use that method about half the time but this should be a fun exercise to etch while I do something else. There are servo type motors that agitate which I also considered but will be some other pondering project down the road. Maybe it needs to be a little squeegee that wipes the board every 15 seconds lol.

[karbomusic]

Thanks. Here are a couple versions I've seen used in labs.

I can see why the one has 'Pro' written on it, nice piece of gear there.  I just got home from the hardware store - I got a nice piece of clear plexi to bolt on to the top plus some tread tape and screws to mount etc. I'll post the actual finished version when done.

One caveat - etchant seems to find any piece of metal within 5 feet so I'm sure I'll have to remove this contraption right after etching or anything that is metal is going to rust pretty quickly.

[J0K3RX]

What about maybe just a side to side motion or a circular side to side motion instead of tipping?

[karbomusic]

What about maybe just a side to side motion or a circular side to side motion instead of tipping?

I'd imagine there are lots of possibilities - thinking of ^that I can about see in my head how it would probably work well, just speed up the servo so that there is some inertia and a sudden enough of a stop (when reversing direction) to overcome the liquid wanting to follow the bottom of the container. Maybe better if the container itself had a 1mm high pattern on the bottom to stir things up a bit. Might have to be the deluxe model. 

A few refinements while I was away (it's Windex and a piece of PCB - the Windex is for ease of testing and visibility)...

- Added a 8"x5" plexiglass platform that bolts on.
- Added friction tape on top aka the stuff you put on steps.
- Attached a standoff sideways on the bottom of the top platform and used a more permanent and stiffer wire to connect the servo to the platform.
- I have a small cover printing for the Arduino board which I'll attach to the assembly on the opposite side of the servo. Once complete all that is needed is to plug a USB phone charger or similar in to it and off she goes.
- Reprogramed the behavior now it swings 55 degrees end to end and twice as fast which should provide a little more 'wash' - I can go much more violent or swing much further but this is a starting point - don't want to turn it into a toaster.   

I also like J0K3RX's idea.

And in the interest of DIY, here is the incredibly simple code that is the driver for the servo:

Code Select Expand



#include <Servo.h>

Servo pcbServo; 
     
int pos;

void setup()
{
  pcbServo.attach(9);  // attach the servo on pin 9
}

void loop()
{
  for(pos = 65; pos <= 120; pos += 1) // move from 65 degrees to 120 degrees
  {                                   
    pcbServo.write(pos);               
    delay(75);                       // wait 75ms per degree - this sets the speed of the wave                     
  }
 
  delay(1000);                       // pause at 120 degress for 1 second
 
  for(pos = 120; pos>=65; pos-=1)    // move from 120 degrees back to 65 degrees
  {                               
    pcbServo.write(pos);               
    delay(75);                       
  }
 
   delay(1000);                      // pause at 65 degress for 1 second
}


[Jdansti]

Very high techish looking!  Will you be doing a side by side test with a board on the machine and another sitting stationary on the bench?

[karbomusic]

Very high techish looking!  Will you be doing a side by side test with a board on the machine and another sitting stationary on the bench?

Probably at some point. I have a couple I need to etch now but not enough time to set up a proper test. I should however still get a feel for it based on how long I'm used to it taking. I noticed she's drawing less than 30 ma if my meter is correct, that's better than I expected.

[karbomusic]

Closing the loop on this project with a video of it's first job. Etched two PCBs in appx 17 min/ 30 sec and it allows me to see progress without having to pick it up or similar - I think I'm going to permanently install a couple ultra-bright white leads underneath too. I can live with that.

[karbomusic]

Well... I thought I was done then whipped up a little controller app. If connected to a computer they sync up and I can start, stop, nudge left/right as well as get real-time feedback as to the position etc....

App Screenshot:



Videos:

LED for backlighting still to come.

[plexi12000]

    DANG......!  i wish i was this smart!!!!!!