DIY clamp helps with surface mount soldering

Hackaday writer [Gerrit Coetzee] built a simple clamp to aid in surface mount component soldering. This cheap, easily made device uses gravity to hold tiny components in place. The tip of the bolt is pointed, but gently like a ballpoint pen so as not to harm the components with a sharp tip. Roughly position your component, rest the tip of the clamp on its center, then nudge for final positioning. [Gerrit] also points out that this acts as a heat sink, helping to prevent damage to the component if you’re too lethargic with the soldering iron.
It seems like this device has been around in one form or another for quite a long time. But the best ideas do keep on popping up. Another nice tip to go along with this one is the use of a dowel when ironing during toner transfer for your PCBs.

ATX psu turned into an adjustable voltage bench supply

Here’s a fancy way to convert an ATX powers supply into a bench supply. [TG] didn’t just cut off the motherboard connector and add banana plugs, but improved the functionality. Right off the bat you’ll notice that he’s added a control panel. There is an Ammeter and Ohmmeter to let you know what the unit is putting out. He added an MIC29152WT adjustable voltage regulator so that he’s not limited to the fixed voltages of the psu. As a final touch he added an external voltage probe which can be used with the flick of a switch. It’s no replacement for a proper bench supply, especially since it doesn’t have adjustable current limiting, but it’s a nice improvement upon previous psu hacks.

Skillet reflow controller

Using an electric skillet to reflow surface mount circuit boards is a popular alternate use for those kitchen appliances. The real trick is monitoring and controlling the temperature. [Mechatronics Guy] built his own skillet temperature controller using a thermistor, a solid state relay, and an Arduino.
He was inspired by [Ladyada's] work which used a servo to adjust the temperature dial on the skillet’s power supply. This started by attaching the thermistor to the bottom of the skillet using JB weld. since this area will be heating up he also attached a terminal block for connecting the feed wires as the heat would melt any solder joints. Those wires travel back to a control box housing the Arduino and solid state relay. To gain finer control over the heating element the relay is switched on and off, resulting in low-frequency Pulse Width Modulation, which should help maintain a consistent temperature better than just turning the temperature dial on the cord.
Pair this up with the vacuum tweezers hack and you’re on your way to a surface mount assembly line. If you want to see this process in action check out this post. It goes from stenciling, to populating, to reflowing in a toaster oven.
[Thanks Rob]

Quick, cheap, and simple vacuum tweezers

[Ken] found that using traditional tweezers is a good way to lose tiny surface mount parts and so set out to make his own vacuum tweezers (PDF). He already had a small aquarium pump that he used as a bubbler for etching circuit boards. After opening up the case he found it was possible to connect tubing to the input of the pump to use as the source for the vacuum. The business end of the device is a syringe which he already had for applying oil in tight spaces. A file took off the sharp tip, and a small hole lined with a bit of soft tubing serves as a valve. Put the needle tip in place and plug the hole with your finger to pick it up. Works like a charm and will go well with our next feature, building your own reflow skillet.
We like [Ken's] work. We just looked in on his copper clad enclosures yesterday.

Vacuum forming at home

A little dumpster-diving let [Nick Skvarla] build his vacuum form machine for around $5. He pulled a vacuum cleaner out of the trash, which was tossed away because of a broken power plug. He put it into a box which had been sealed with spray foam and used a piece of pegboard for the top side of the enclosure. He takes a piece of 40 mil PETG plastic from the hobby shop and mounts it in a wooden frame. That goes into the oven on broil until the entire sheet is sagging, then onto the vacuum former. Above he’s making forms out of some figurines which he’ll walk you through in the video after the break.
There’s a whole world of manufacturing processes that use these forms as a starting point. What would you use this for?

Custom enclosures made of paper

[Sivan Toledo] needed a enclosure for a unique sized electronic project, not finding what he needed in off the shelf solutions, he went to the next best thing, … Papier Mâché!
Using a mold made out of standard corrugated cardboard, he slowly built up layers made of magazine paper, and ordinary “white glue” diluted with water. After getting near the thickness wanted he switched over to typing / copy type paper for a nice clean outer surface. Ports were made in the usual fashion when dealing with soft or thin material, drill a smaller hole, going back with successively larger holes, and then follow up with an appropriate file, all while taking things slow along the way to prevent unwanted results. Finishing up with layers of paper carefully cut into strips to meet the circumferences / edges, along with the final outer surface to make it all even.
The end result is awesome as it stands, but we cant help but wonder what some sanding and paint would look like on a enclosure made like this, though any way you finish it, the idea comes down to custom enclosures that do not need special tools or materials to complete (on the cheap).
Thanks [Drone]

Simple touch sensor and other lessons

[HankDavis] sent along this link to a video showing a tutorial on how to make touch sensors using a “darlington pair”. In the video we are taken through the idea and how we’re going to construct it.  [Thad]explains in detail how this works in simple terms and illustrates it clearly. Unfortunately they don’t show an actual constructed system, but this is so simple you could toss it together quickly and see for yourself. This is a great lesson on how to get a simple touch sensor into your projects. This video appears to be one of a series of class visuals, and you can find several others on youtube under this account.
Read the rest of this entry »

STK200 pocket change programmer

A common complaints of beginners to microcontroller programming is the availability of DIY tools that do not require a parallel port.  Using not much more than a couple of 74xx series chips and some protoboard, [Rue] was able to create an AVR programmer for less than the cost of some chips it can program – giving parallel programmers a run for thier money. [Rue] used Linux treat the ubiquitous PATA/IDE port as a parallel port. By having avrdude treat the programmer as an Atmel STK200, [Rue] was able to upload a blinky program to his AVR microcontroller through ISP. If anybody can think of an even lower cost unconventional solution give us a shout.

Printable wax as PCB etch resist

What if there were only two steps for making your own printed circuit board; print, etch? That’s what [Jeff Gough] has been working on and he presented the process in his talk at 27C3. In the first portion of the video after the break [Jeff] talks about various industrial PCB manufacturing processes in a depth you may not have heard before. We found it to be interesting but at about thirty minutes into the clip he begins the presentation of his modified printer. It’s an inkjet that can print wax onto copper clad board. The wax acts as a resist for chemical etchants, and provides very high resolution. He’s using a heavily modified print head, which brings to mind that diy piezo inkjet head which also has wax printing in its future plans. This certainly seems promising and if the process can be simplified it might do away with the toner transfer method.

Digital measuring tape

You’ll never come up short with this measuring tape. That’s because there isn’t actually any tape in the device; it measures distance based on the rotation of a wheel. Roll it across the room and you’ll get an accurate measurement of the distance the little bugger traveled. Like the Etch-a-Sketch from Monday this uses the encoder wheel from a mouse as the input. The IR emitter and sensor from the ubiquitous peripheral find a new home on the PCB that hosts the PIC 16F819. It monitors the rotation, turns it into inches, then spits that number out on a 7 segment display. Handy, and cheap!