On Sat, 9 Mar 2019 10:14:09 -0600, you wrote:
Harvey,
? Ok, so after re-reading this again, did you build this from scratch
or from exiting technologies?
Scratch. The PC boards for the processor and display driver and so on
are home made double sided. I did not make the linear rail, bought
that. Camera ditto.
Stepper driver was homemade, another PC board, power supply wasn't.
Basic support stand wasn't homemade. Programming was a special
purpose program, don't think I used an operating system on this one.
however the display driver and such were off the shelf, but my shelf.
Box was repurposed from an old disk drive enclosure (which is where I
got the power supply).
Sounds like a pretty complex project. I
won't be attempting that any time soon. :) But I sure would like to see
a pic of it.
I'll work on getting pictures of it.
My Apache Laminator arrived yesterday and the kit to modify
it the day before, so I am going to get started on that shortly. Your
project listed below is very cool but I don't know that I would ever
need to go that far into drilling my simple projects. I may see about
putting my USB magnifier to good use though as the eyes are getting older...
The techniques I needed to be able to do 10/10 double sided boards
with relatively small vias, and those boards were pretty packed, at
least as far as traces were concerned.
I got tired of not having the top layer match the bottom layer. I
have some ruined boards because of that. Considering the work needed
to make a decent board, well, I wanted to maximize the return on the
effort.
Harvey
Thanks
On 3/8/2019 10:51 AM, Harvey White wrote:
On Fri, 8 Mar 2019 08:25:31 -0600, you wrote
So you use a tv camera now for your
drilling? I have one of those cheap USB cameras that is a magnifier. Is
that what you used?
Actually, no. It's a bit more elaborate than that.
I have a linear rail that has about 6 inches of travel, then machined
a holder that holds the clamp for a proxxon drill. The 12 volt
version works just fine. That is driven by a linear stepper motor
(shaft attached, goes in and out of the motor).
That in turn is driven by an old, but standard design (L297/L298
stepper driver system). There are sensors on the linear rail for
bottom sensing and top sensing.
I found an old Pace desoldering stand, the kind used for a hot air
desolderer. It has a fixed height arm with a rack and pinion stage
for lowering the soldering tool.
Cut a hole in that base and mounted the proxxon upside down so it goes
through the center of the hole. Mounted an old vacuum cleaner nozzle
with a flexible extension so it removes debris from the underside.
On the top slide, I mounted a surveilance TV camera, this one runs on
12 volts too (most run on 24vac, and they're NOT kidding about the VAC
part because there's a small transformer in there that won't tolerate
DC). With an extender, it short focuses enough that I get
magnification. The small monitor is mounted above the camera.
The electronics allow you to home, and set maximum travel. Pressing a
footswitch starts a drill cycle, turns on the drill, moves it to the
up position, then back to a rest position.
You need to recalibrate the xy position each time you change the drill
bit, however.
With that, I can get very very close (say .001, I think) to the center
of a hole by using the crosshairs on the monitor. Some 3D printing
would help out the project, since the original design was to use the
vacuum to hold the board down once the drill bit moved up. That
didn't work as well.
So no, no USB camera. You could use one easily enough. The
electronics could be duplicated easily enough with an arduino, but I
used a board that was designed to run a small graphics display that I
had a few of....
So you get to see the position, and where it is in the cycle.
A bit of overkill, perhaps, but it has proven its worth in board
drilling. It does, by design, completely eliminate the parallax
problem which was a great inconvenience.
Harvey
Thanks
