Tag: soldering

#0024: Preparing a Helping Hands tool for effective use

Otto

#0024: Preparing a Helping Hands tool for effective use

Preamble

This article covers the modifications necessary to get a box fresh Helping Hands tool ready for service. The specific version of this tool being the pictured unit. A version that consists of a small horizontal metal bar that is mounted onto a weighted base. The bar then has three adjustable arms attached to it. Two terminating in metal crocodile clips, and the third in a magnifying glass. This unit although useful and good quality for it’s price, it is also cheaply made, and mass produced. As such it requires some preparations before it can be used to good effect.

What is a Helping Hands tool

At its core a Helping Hands is a tool that consists of an adjustable jig with arms that terminate in spring loaded grabber clips. These clips are designed to hold materials and workpieces in place. This is in order to assist the user when working on them; for example: holding wires in place for tinning, or in preparation for a soldered connection.

Helping Hands are also known as “Third hands” or “X-tra Hands” depending on marketing. Although there are likely to be variants in design due to marketing, the basic tool is the same. It consists of some form of adjustable jig, with two or more grabber clips attached to it. Many variants also have adjustable arms that terminate with either a magnifying glass, or a light source of some description. They may also come with things that are specialised for a specific task: such as a soldering iron holder, or a mini microscope mount. However these are outside of the scope of this article. We will only be discussing the rather cheap and generic example unit that is pictured.

Modifications

Mod #1: Padding the crocodile clips’ jaws

The first necessary modification is rather obvious when you have a new unit in your hands. The actual clips that hold the various workpieces and materials: are crocodile clips. Crocodile clips complete with serrated teeth and a fairly powerful spring ready to push those teeth into anything that comes between it’s jaws. These needless to say leave noticeable teeth marks on anything softer than the clips’ steel when in use.

I recommend using several layers of heat shrink tubing to pad the teeth. This is because heat shrink tubing is generally tough enough to make it resistant to being pierced by the teeth’s serrations. Apply a layer of heat shrink to each jaw in turn. Then heat it so that the heat shrink, shrinks into a fitted profile on the teeth. Keep adding and heating layers in this manner until you are satisfied that the serrations of the teeth are sufficiently padded and will no longer damage anything that the clip holds. At this point, you may wish to trim off any excess tubing with a side cutter.

In my opinion heat shrink tubing is a good candidate for this application due to the fact that it does hug the profile of the teeth so well, while still padding the biting edge off of the metal. This clinging to the peaks and troughs the teeth is important because it allows the clip to still have an effective mechanical grip on the workpiece.

Additionally the rubber material that heat shrink is made from also assists in effectively gripping the held object using friction. This is useful when it comes to holding metal objects, especially cylindrical ones like telescopic radio antennae. A mechanical grip alone is likely to slip, coupled with the springs: I can see the jaws throwing out objects. A friction grip is necessary to hold low friction hard-surfaces such as metals.

Other reasons why heat shrink tubing is well suited to this particular application, consist of: firstly, the rubber material it is made of is relatively heat resistant (i.e. it takes continuous high temperatures, or a direct flame to effectively melt it). This means that the user can use solder irons and hot air around it without worrying about having to either clean or refit their Helping Hands tool. As would be the case if they used electrical tape for example.

Secondly, it is also a mild insulator of heat, this prevents heat from easily conducting into the metal clip and into the larger frame of the tool. Why is this important? It means that the user can use a soldering iron with a lower thermal mass effectively. Whereas without insulating off the greater frame of the Helping Hand tool, it will conduct away the thermal energies from the point of application. e.g. whilst soldering a joint on a metal object such as an antenna terminal.

This will require either a higher temperature setting (as a bid to compensate for the leeched energies), and deal with the associated risks and drawbacks; or having to simply use another soldering iron with a higher thermal mass. Alternatively it should be said that, insulating the metal clips in this manner really might not even have a significant effect on for example soldering performance, it largely depends on use case specifics. If you are for example using a 10 Watt USB soldering iron, well then you’ll need all the help that you can get; including this. Whereas for a more average setup, you may not be noticeably affected either way.

Mod #2: Hot glue in the clips connecting arm joints

This is an often overlooked modification that you can make to effectively extend the working life of the product. It simply involves getting a hot glue gun and pumping hot glue into the connecting joint that attaches the crocodile clips to the main jig. This is needed because the out-of-the-box setup only has those joints held in place using a friction fit between the metals of the clip and the jig arm. Unfortunately as you use the tool and rotate the clips, it will loosen the metal’s spring pressure that holds it in place until the clips just slide off. Repeatedly.

Additionally, re-tightening the friction fit using a pair of pliers will not keep the clip in place for long, just delay it falling out for a little while. Unfortunately in my case the entire clip arm kept falling out and no amount of tightening made the clip arm stay in it’s cradle, as effectively as the initial friction fit did. Hot gluing them in place however fully prevents the clip arm from sliding out of it’s cradle. It really made a very strong bond. One that is better than the original friction fit. The only trade off is that the crocodile clip can no longer rotate at the wrist joint where the friction fit connection was. Instead all rotational adjustments need to be made at the arm’s elbow joint from now on.

You might’ve wondered as to how exactly does this laughably simple modification actually extend the working life of the tool. Well, I will endeavour to answer this question with another question (or more). Have you ever had a tool that kept falling apart on you when you needed it to just work? Falling apart in moments where you might already be somewhat stressed trying to fix something broken? Maybe even whilst on a time limit? In that moment, have you ever grabbed the offending tool cursed it out, then promptly threw it into the trash? That’s how pumping those annoying joints with hot glue will extend this tools working lifespan. It’ll help this tool effectively keep it’s head down and just do it’s job.

Closing thoughts

These are simple enough modifications and are rather ubiquitous with regards to this particular tool. Even the image of the ‘dabbing’ Helper hands on the Wikipedia page for this tool, has the same teeth mod. Although they used electrical tape. Which in my opinion is an inferior material to use. Firstly its a less permanent solution due to the material’s general strength, meaning that sooner or later the teeth are going to poke through it. Additionally, it is also more susceptible to heat; meaning that if the user solders a wire for example too close to the clip they run the risk of melting the electrical tape.

That being said, small mods like these are most definitely better than nothing, and worth mentioning in order to help people not overlook them due their rather trivial nature. This is because little mods like this are easy to implement and can help the user make the most of their cheaper tools in general. Even if you are half-arsing it by using electrical tape, says the out-of-touch heat shrink tubing elite.

Thanks for reading.

Dabbing Helping Hands image from Wikipedia.org

Reference, links, and further reading

https://en.wikipedia.org/wiki/Helping_hand_(tool)

#0003: Basic techniques for connecting wires

Otto

#0003: Basic techniques for connecting wires

picture comparing: pig-tail, straight solder, and western union splices

Connections discussed:

  1. Straight solder splice
  2. Pig-tail splice
  3. Western Union splice
  4. T-junction splice

STRAIGHT SOLDER SPLICE

picture showing two wires with their exposed copper ends coated in solder
picture showing a basic straight solder connection between two wires

The straight solder connection is made by aligning two opposite facing wires in adjacent-parallel, tinning them individually, then soldering them together. This joint is most suited for smaller gauge wires. Especially in low-voltage or low-current applications.

I find I use this joint frequently when prototyping and stringing various PCB modules together, such as power-supplies and buck-boost converters. This is because it allows me to make a more than strong enough bond very quickly; and without damaging the wires, by avoiding subjecting them to repeated mechanical strain. For example: by twisting them together and soldering, then de-soldering and unravelling them whenever I want to disconnect a module; as is the case with the other types of joints. With this connection however, it is simple: align and solder to connect; then apply flux, heat, and pull apart to disconnect.

The straight solder connection is actually rather strong in my opinion. When applied properly, it creates a bond that can not be pulled apart easily. I tested this joint by wrapping the wires around my hands then trying to pull the joint apart. It might eventually give, but only after considerable force is applied.

Despite it’s initial success with my basic stress test; I still wouldn’t recommend using this type of joint for any permanent applications. This is because, in my opinion, I don’t believe that it will stand up well in most real-world settings. Settings that involve: temperature swings, vibration, or constant stress on the wire and joint. These things can exacerbate any small imperfections in the weld to the point that they can create fissures that can either cause problems like intermittent connections or outright brake the bond. Since the solder is the only thing keeping the connection, any stress applied to it isn’t mitigated by anything. This strain coupled with environmental heat would make this type of connection unreliable in the field. An example of this would be wiring around an engine.

Still though, as long as the wire is not subjected to any real or ongoing strain in its application, it is not a bad option to utilise this type of connection. Especially for temporary or semi-permanent add-ons to an already established system. For example adding a voltmeter module to an electric bicycle to keep track of the battery levels. That way the module can quickly be de-soldered off or be further modded later with a switch as an example. This type of bond also has the smallest footprint. Allowing smaller sized heat-shrink to be easily applied as insulation.

PIG-TAIL SPLICE

picture showing a pig tail splice between two wires
picture showing a pig tail splice between two wires, the connecting twist stands at a right angle between the two connected wires, revealing some broken copper strands within the connection.
picture showing a pig tail splice between two wires, the connecting twist has been folded down onto one of the wires

The pig-tail or rat-tail splice is probably the most common type of connection that I have encountered in the wild. It is made by holding two wires in adjacent-parallel (facing the same direction), then twisting the exposed ends together. Its a quick and dirty solution to make a good mechanical connection. Usually this type of connection is insulated with either sticky tape or even heat-shrink for a semi-permanent solution. It is not soldered in many cases, as the twists and tape tend to make a ‘good enough’ connection for the use-case.

The alignment of the connecting wires is something to take into consideration when deciding whether or not to use this splice. In cases where the wires are to remain adjacent-parallel and facing the same direction; the pig-tail splice is a good candidate. It will allow the user to join two wires next to each other, whilst minimising any change of location, necessary in order for the wires to accommodate the new connection. Example use-case: connecting 2 or more adjacent wires within a ribbon cable. Additionally, with this setup: the connection can be easily soldered and insulated with heat-shrink by sliding it over the open end.

However in cases where the user is joining two opposite facing wires, they are usually left with a connection made up of a twisted pair that veers off at a right angle. This is then folded onto one of the wires in order to apply insulation. This is mechanically weak, as it concentrates any stress on the wire/connection or more accurately “pulling force”; at the bend. The first twist where the two wires meet.

This configuration of the pig-tail splice rarely takes solder well without ending up with an overly large footprint or bulge that the user has to then slide heat-shrink over. It is also too easy to melt the wires whilst soldering because of how close the insulation on the wires are to each other.

To conclude, this connection is good in solder-less temporary or semi-permanent applications. But if you want a more permanent bond (especially for opposite facing wires), the western union splice is a far better solution.

WESTERN UNION SPLICE

picture showing two wires being lined up for a connection
picture showing the exposed copper ends of two wires crossed over each other
picture showing an unsoldered western union splice between two wires
picture showing a western union splice between two wires

The western union splice is named after the Western Union Telegraph Company. This connection involves crossing the exposed ends of two opposite facing wires together, at a mid-point between the wire’s exposed tip and the start of it’s insulation: in an “X” shape. Then twisting them around each other’s exposed base sections. Continue twisting until the insulation of the opposite wire is reached. Then trim off any excess exposed wire tips. This makes a linear and very strong mechanical connection between the two wires; by maximising the contact area the wires have with each other within the connection. It also functions as a knot of sorts, and once properly soldered, it becomes essentially stronger than either wire itself. In addition it has a relatively small footprint and consequently takes to sliding heat-shrink over it rather well.

This is probably my most favoured splice for permanent connections. However for those same reasons, it is also largely inappropriate for temporary applications. This is because it becomes a hassle to de-solder and untangle the wires. This process will also almost definitely damage the wires involved; by fraying and breaking some copper strands from the stress of unravelling.

THE T-JUNCTION SPLICE

picture showing a T junction connection between three wires
picture showing a T junction connection between three wires

The “T” junction splice is any connection where you add a third wire to an existing connection. The most basic version involves removing the insulation from the mid section of a wire; then wrapping another wire around the exposed section before soldering it in place. Then insulating it. This method can also apply to any of the above connections – and the strength of the additional connection usually depends on the strength of the underlying connection.

You could opt to pig-tail together three wires into a T-junction (or four into an “X”, etc…), or straight solder three wires, or even create a western union splice, then tightly hitch the third wire over that connection for maximum strength.

At its most basic a ‘T’ junction splice is exactly that. Three wires connected together in a rough ‘T’ shape. Everything else is up to the user, and largely depends on the use-case and it’s needs.

SOURCES / REFERENCES / FURTHER READING:

https://en.wikipedia.org/wiki/Western_Union_splice

https://en.wikipedia.org/wiki/T-splice

https://en.wikipedia.org/wiki/Rat-tail_splice

https://en.wikipedia.org/wiki/Point-to-point_construction

https://en.wikipedia.org/wiki/Printed_circuit_board

https://en.wikipedia.org/wiki/Solder

https://en.wikipedia.org/wiki/Flux_(metallurgy)https://en.wikipedia.org/wiki/Soldering