For grins, I wanted to see if I could bend a sheet of 1/16" Tap Plastic. I had a scrap
3" x 18" front panel sheet from an OD-50 that I could experiment with.
I placed the plastic over a 21/32 brass tube and pinned the left side between a
scrap of PCB and the work surface with a C-clamp. Just enough pressure to hold it
I clamped the right side of the plastic that extended past the brass tube between
some sheets of metal with a C-clamp. Originally, compared to the image above,
both sides of the plastic would have their faces on the same plane. I initially held
the clamp to keep the weight off the plastic.
I started heating the fixture with a hot air gun. I aimed the gun to send the hot air
into the brass tube and heat it but also allow hot air to flow on the outer plastic
surface. I wanted to heat it as evenly as I could so the tork stress would also get
As it warmed up, in stages, I increased the pressure on the left side to induce that
side bend and used the weight of the right side clamp to form that side of the
It worked out well, what had been a scrap of plastic became a holder for wiring
controls for an OD-50, that didn't require cementing on a base.
Originally I had wanted to wrap this plastic around the front of the OD-50 chassis. I
was counseled that doing so would be difficult. E=MC^2, I guess.
I need to play with it a little more and see what's up.
|Drilling some plastic.
Tap recommends not drilling more than 3 x bit width without some form of cooling.
I mounted a hand held power drill into a press/holder. The press was placed in a rubber tub of clean water.
A fountain pump is placed in the tub and a hose runs up to the drill bit.
The drill and pump are on a foot switch.
| I decided that I wanted to learn more about GPS. So I bought a TYCO A1035-C Smart GPS Antenna
It includes a STMicro STA2051 32-Bit GPS controller with UART and SPI ports. Raw and calculated
position and vector information is easily available using the NMEA sentences.
About all I had to add was a 3.3v source and I/O, [MAX3232), to the COM: port of my lap top.
| I constructed holders for the antenna module and serial I/O, (left), and the: batteries, 3.3v regulator,
antenna connection and DB-9, (right).
The TYCO A1035-C antenna module is mounted on the left.
The MAX3232 I/O chip is mounted on a SOIC to DIP carrier board in the center.
A 1.0F storage cap and power switch is on the right..
| This is a screen capture of the output of some demo software available for this chip, on the Web.
This software allows me to save the output of the antenna to file, so I decided to take it with me on an up coming trip to Fairbanks. We drove from Anchorage to Fairbanks and I let
the antenna run along with a lap top to record position and vector information to file. I just now took the files off the lap top and cut and pasted some coordinates from the file into
Some of the file content :
It worked ! Very cool. Well, I'm easily amused and it was about 18' when we came over the pass on the way back to Anchorage.
|GPS, I guess.
|The fan pictured at the left is running
at full speed !
(This camera will stop any fan cold.)
Using an 8 cell holder provides the 12
volts needed. Eight cells will power
the fan from 4 to 6 hours.
The batteries are held to the fan with
Comes in real handy when working
under the dash on a hot summer day.
NiMH and NiCad cells will only
produce about 9.6 volts, but the fan
still works fine.
I have some 10 cell holders that will
give me 12 volts from 1.2 volt cells.
|!! This fan is running at FULL SPEED !!
Four, 25mW White Light LEDs powered from an
LM-317 and wired into a PC supply.
The main power is supplied from an ATX power
supply and about 6' of 22 gauge multi strand wire.
|These LEDs are in strings of 2 with a Vforward of about 6.8 volts. Six volts, (4 x 1.5v), works fine. I
managed to pack 40 LEDs into this flash light. There is a 330,000 uF capacitor across the battery.
Two toggle switches allow turning the light ON with or without the batteries or capacitor being in circuit.
This way I can have the light on for a minute or so, and then walk away without needing to turn the flash
light off to save the batteries.
There are two push buttons. One button turns the light on and off. The other button changes the
brightness by about 30%. Turning the light ON with the button is similar to a strobe light in that the
brightness is immediate there is no filament to warm up.
| Above is an array of LEDs arranged to produce a spot light, it hangs over my portable mini work bench.
It is powered from an ATX supply that is part of the mini bench.
This image shows 20 LEDs, I doubled the rows to allow 40 lights now.
Powered from an LM-317 that is fed from a wall wart. It has a brightness control.
This picture shows a small crane assembly. I constructed it from a 4 foot section
of 1.5" angle iron stock, a 2U high, blank 3/16" aluminum face plate and a door
The angle iron is bolted to the side of the mini bench. The aluminum is
connected to the angle iron with the hinge to make a swing arm.
The LED spot light array is suspended by a gimbal assembly made from plastic,
located at the end of the swing arm.
I used some aluminum stock to mount bearing races that run on the top and
bottom edges of the swing arm.
The bearing races support 2 double pulley blocks. It will lift as much as the 3mm
screws that hold the bearing races, can support.
The rope runs through some additional pulley blocks to a point just under the
right corner of the upper wooden platform, where it can be tied off.
A second rope and set of pulleys allow positioning of the block and tackle
assembly along the swing arm.
I am working on a digitally controlled attenuator project here.
| A CRANE ?
A fan is suspended below a 2" diameter brass slug.
|Showing the brightness control and gimbal assembly.
The rotation joint is made from a 0.5" bolt embedded in between two 3/8" sections of
acrylic. The elevation joint is constructed from interleaved 3/32" sections of plastic
that I "welded" together at one end of each set. The joint is loose enough to easily
tilt but never slides out of the position I set.
|A lighted tool holder, dwg.
|A lighted tool holder, picture.
| The regulator is mounted on the back of a sheet of 1/32" brass.
The regulator and brass heat sink is mounted inside a closed space.
Air is pulled in through the holes seen above.
It flows over the brass surfaces, around the ends, and is blown out the back with a fan.
|Messing around with some high power White Light LEDs.
The ones with the clear dome, (W32282) are a newer verity.
The ones in the square shape (W10292)are going obsolete.
They were about a buck cheaper than the newer ones and rated about 18% brighter.
The heat sink they come mounted on, "Star", is serious and makes it hard to solder to without a
high temperature iron. I normally use a very pointie Weller #7.
I just used a #8 to take apart the first heat sink assembly, a bit easier but still a pain in the butt.
|With 3 LEDs in series fed by 8 NiMH AAs in
series, it will start out drawing about 450mA
and decline as the cell run down.
|Increased heat dissipation capacity.