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Kilian's Robot Shop of Horrors - 03/29/2002

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Subject: [TCRG] RSOH (Preview)
Date: Sat, 30 Mar 2002 11:59:23 -0600 (CST)
From: Alan Kilian
To: tcrobots@orbis.net (Twin Cities Robots Group)

Man, we had a great time last night. The assembly of the 4-channel PID motor controller went superb!

And it even works the first time!!!

Here is a preview.
http://bobodyne.com/web-docs/robots/Trippy/Board/index.html

Jeff took almost 30 pictures, so we will take some time to sort them out, and get them up. We really tried hard to document the SMD soldering things we learned. The best news is that it was almost trivial to solder the parts down using just one of those giant desk magnifying lenses with the circular light. And a soldering iron!

Jeff also got all the SMD parts soldered onto two of the open source motor controller boards, so he will be making progress on testing those out also.

Brynn found some really cool 5-speed with reverse transmissions that have electrically operated clutches to shift. (At Ax-Man) These would be cool in an electric kiddie car.

Everyone got dinner on me last night. (So to speak)

It was snowing so hard that I had trouble seeing the road on the way to Perkins at 2:30 AM, and on the drive back at 4:00, the sky was clear, and you could see the just-past full moon.

-Alan


New photography technique

rsoh08.jpg
Using a small lens as a
magnifier on a cheap
fixed-focus camera.
rsoh09.jpg
A dramatic example.
rsoh12.jpg
This is a good comparison.
The SO14 (IC4) looks bigger
that the SO28 PIC (IC5).
rsoh21.jpg
Otherwise, this is
the closest I can get.


Alan's motor controller project

rsoh01.jpg
The soldering setup. A
magnifier and some tweezers.
rsoh02.jpg
Alan is checking some
continuity before we start.
rsoh03.jpg
More continuity checking.
rsoh04.jpg
This is how the board looks
through the magnifier. We
used this both for probing
and soldering.
rsoh14.jpg
We found this void by visual
inspection. (The small round
spot in the trace just above
the third pin from the left.)
rsoh15.jpg
We found this void by visual
inspection. (There is a hole
about 75% of the trace width.
The trace is 40mils wide.)
But both of these still had
continuity.
rsoh16.jpg
Alan had this flux pen. You
push down and the flux flows
out.
rsoh05.jpg
Soldering the first test part
after applying flux.
rsoh06.jpg
The first test part. Has a
little more solder than it
needs.
rsoh07.jpg
After cleaning up pins 1-7.
Now it looks like we know
what we are doing.
rsoh10.jpg
Alan soldering the first
part on the real board.
rsoh11.jpg
Whoops! We forgot the flux.
rsoh13.jpg
So we slobbered on a bunch of
flux and reheated it. I think
there was some solder wick
involved too.
rsoh17.jpg
Alan checking the board.
rsoh18.jpg
Jeff checking the board.
rsoh19.jpg
Peter checking the board.
rsoh20.jpg
The first PIC that got
soldered down. Now we are
getting good.
rsoh21.jpg
All the surface mount parts
soldered down.
rsoh23.jpg
Now it is ready to power up.
Oh, we forgot to clip the
wires...
rsoh24.jpg
Finished board. Except for
two capacitors and the
jumpers for the encoders.
rsoh25.jpg
Wdie angle view.
rsoh29.jpg
The testing setup.
found4.gif
After rewiring a serial cable...
It works!
rsoh30.jpg
Everything went together well
and it worked the first time.


Jeff's OSMC project

rsoh26.jpg
Probing a surface mount diode
to determine polarity.
rsoh27.jpg
Jeff uses a big Weller
solder gun to solder the 4oz
copper on the Open Source
Motor Controller board.
(Didn't work very well. The
old standby 40 watt Radio
Shack iron worked better.)
rsoh28.jpg
All the surface mount parts
are in place. And a few
others.


Brynn's new toy

rsoh22.jpg
Brynn found this multispeed
gearbox at Axman.


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