What is your favorite idea for a homemade robot part or tool? I'm collecting
ideas for a presentation.
For example, for breadboarding with stranded wire instead of solid wire (or
using componets with stranded wire already soldered on), I remove some pins
from a machined IC socket, solder them onto the ends of the wires, and put a
bit of heat shrink tubing around it. This makes stranded wire easy to use in
a breadboard (which is almost impossible to use otherwise).
I do the same with the wires. I use
pins from connectors that I cannibalize
from old PCB's to solder on the end of
For the wire, I use christmas light
I have a bunch of other horrible hacks,
but I can't think of them right now.
A piece of springy steel strapping material, folden in half, held closed
like tongs, drilled and tapped while closed.
It is used to shorten screws on a grinder. Thread screw through with tongs
closed, and the spring tension keeps it from turning while grinding.
I made mine a decade ago, and still have it.
On Fri, May 20, 2005 at 11:29:50PM -0500, W.E.Cole wrote:
When making multiwire cables from single strands, a great way to twist
them is to lay them all parallel, secure one end in a clamp or
whatever, secure the other end in a cordless drill, pull the bundle
taught, then pull the trigger. Works great and takes almost all the
work out of this chore.
BDMICRO - ATmega128 Based MAVRIC Controllers
Here's two more breadboard tricks I use...
How do you connect female header cables into a breadboard? (For example, if
use the Atmel STK-500 development board like I do, which uses 10-conductor
female-female header cables to connect to the ports, and you want to connect
an end of one of these cables to your breadboard.)
If the female header has only 1-5 leads, use a double ended header as an
adapter. (Use the type with long leads at BOTH ends - normal ones have a
long lead at one end and a short lead at the other, to solder into a pcb
board.) You can get these headers in single and double rows. Cut off the
number of pins you need, plug it into the female connector and now you have
a "male" connector that will easily plug into any breadboard.
For dual-row female connectors with 6 or more leads, I use a dual-row
WIRE-WRAPPING male header socket as an adapter. Just bend out the long
wire-wrapping pins slightly, to stradle the divider strip of your
breadboard, and this simple adapter will let you plug the female-connector
cables into your breadboard without any problems.
Want a good way to hold solder for those delicate operations?
Get a cheap, clear bodied, non-retractible ballpoint pen (Bic's are perfect)
and remove the ink/ballpoint stick. Get some solder and twist it around the
ink/ballpoint stick as tight as you can until you have a "spring" of solder
about as long as the body of the pen, and cut off the spring with an extra 2
inches of uncoiled solder on one end. Pull this "spring" off the
ink/ballpoint stick and feed the uncoiled end into the rear of the pen so
that the solder sticks out where the ballpoint used to be. Now you have a
great soldering tool. As you use the solder, pull more of it out of the pen
from the "spring" within. This is a handy way to hold several inches of
solder with minimal skin contact (it -is- mostly lead, after all) and great
control for very precise soldering. It also eliminates bulky rolls or
excesive waste from lots of "shorts" of solder that were too small to safely
hold after using most of it.
I built a RC timed pulse generator with some 74AC04 (high rise time).
You can adjust the pulse rate and pulse length using two pots. It's
good enough that you can use it with an Oscilloscope as a TDR to measure
cables (length, breaks, etc...), and it's great for testing inductors/
I have been wanting build a bunch of ethernet enabled instruments,
DVMM, programmable power supply, etc... In same cases it would be just
adding a ethernet->(serial, USB, GPIB) to an existing instrument.
Ethernet is nice since more than one computer(PC/laptop) can access
any instrument, rather than having to serial/USB based instruments
into the right laptop/computer...
I make my own alligator and square pin socket jumper cables. They
cheaper to make youself and tend to be more rugged (i.e. soldered in
addition to crimp connection to wire).
I have found in many cases making a simple 2 sided PCB and using
one of the cheap protoyping services is much faster than hand building
a circuit (point to point or wire wrap). Especially, if there are lot
of buses, etc... ExpressPCB is perfect for doing these one offs.
This is a great thread, I hope everybody gets involved and suggests
In response to the above, while thats a good idea I've often just
twisted the strands together at the end and tinned the last 1/2" with
solder. Done carefully the solder will not glob and the wires insert
easily into breadboard. Your solution sounds more robust, though.
In addition, for making headers on a breadboard, I found that you can
buy a PCB style header and use a pair of plyers to move the plastic
part upwards. The result is that enough of the header pin goes down to
anchor into the breadboard while enough sticks up the top for the cable
to grab onto.
On a drive train I'm assembling right now, I found some bearings at Ace
Hardware that were totally unlabeled and thus very cheap. I bought up
all of them. I can hold them in place with an appropriately sized
U-bolt. Thus they build a very strong axle capable of supporting a good
deal of weight.
A new part I'm thinking of (though haven't built yet), is to make T
joints for joining threaded dowels at 90 degrees. The plan is to
experiment with 1/4" couplers and weldbond. I'll report back later this
summer when I try it out. These kinds of items are supposed to be
available from Grainger but I've not been able to find them either in
the store or the catalog. One old timer at the nearby store said he is
sure they used to carry them but couldn't find them in the inventory
The idea behind this is that the robot platform could be built on a
kind of scaffolding. Each platform will be a rectangle cut from
acrylic, with mounting holes in each corner. The platforms will stack
vertically and will be supported by 1/4" nuts and washers. Therefore if
I add a new battery thats taller or shorter to the battery platform, I
can adjust the platform height to match it.
I use a short piece of square section aluminium tube, drilled all the
way through with 3.5mm and 4.5 mm holes for tapping threads. By
inserting a tap through the holes and holding the jig hard against the
work piece it keeps the tap square against the work piece as I begin
cutting the thread. No more wobbly old tapping efforts.
I've done that too, but I've found that the IC pins are a better solution if
you are using the wires/parts either as part of a dedicated set of
breadboarding tools or as part of a project that requires you to insert and
remove the wires from the board a lot. The IC pin gives me a firmer piece to
hold when inserting the wire; tinned wire tends to bend where the solder
starts, which eventually leads to broken wires and sometimes also includes
having to dig broken pieces out of the breadboard hole, which is a MAJOR
pain in the ass. Also, I've noticed that the solder on tinned wires
eventually strips off, which builds up solder in the breadboard holes,
clogging them (plus you have to re-tin the wires).
Tinning the wires works fine in a pinch, but the IC pins work better for
long term breadboard work. I think if you give it a try, you'll be glad you
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