Wolfcraft Microfix S clamp DIY project transformation to Four Wire Kelvin clips

[Kiriakos GR]

This message it is actually the announcement of my personal exploration about my attempt to convert Wolfcraft Microfix S mini clamp in to high quality Kelvin clip for LCR and high precision resistance measurements’.

Intro: 

This thought came to me at beginning of June 2019, and then I did contact Wolfcraft in Germany at July and Miss Nora Strobl responded positively at my plan and proposal!

Several years ago, a few German brands them also thought to use larger Wolfcraft clamps and converted those to large Kelvin clips for buss bar resistance measurements’.

But the new and fresh idea that no one tried before this is converting the smallest Microfix clamp in to Kelvin clips which will be compatible and usable by large number of people.

Wolfcraft Microfix mini clamp this has several strong points which I am up to take advantage of them.
a) Microfix mini clamp build quality this is extremely high compared to plastic Kelvin clips.
b) Metal spring force this is excellent for using it as Kelvin clip.
c) The cross point of the arms for the jaws this is well made to the point that the jaws they can not move diagonal, but only up and down.
   

The problem:
Mass produced low cost Kelvin clips of our times, they are prone to diagonal jaws movement when they are used at 60% of their jaws opening.
Their Jaws link this is also poorly made, friction alone of plastic over plastic eventually will cause the clip to be prone for diagonal jaws movement over time.


Wolfcraft this is a brand serving professionals carpenter and people which love to do DIY work.
The wonderful think with Wolfcraft Microfix mini clamp this is that Wolfcraft it did succeed to transfer their manufacturing experience in to a miniature scale.

The new challenge for me this is to explore my options and to find a way to add metallic contact surfaces at the jaws and to do also the wiring (four wires connection).

For such a DIY prototype work I would be helped allot if I were a machinist and owner of a lathe.
But in such a scenario my attempt it would not be widely applicable.
For this reason I just ordered several Kelvin economy clips, the cheapest Duckbill type, and of a few of economy and regular in size Kelvin clips.
The all idea this is an attempt using the copper jaws alone among with Wolfcraft Microfix clamp body.

For now I am forced to wait for Kelvin clips delivery and this can take a few weeks, but either way this project it is now officially started. 

Wolfcraft was kind enough to deliver some additional product samples to my Blog.
Here is our unboxing link  https://www.ittsb.eu/forum/index.php?topic=1534.0

[Kiriakos GR]

This journey started by me pointing out that poor in manufacturing quality low-cost (eBay purchased) clips, they are tremendously imperfect and I need to explore other options.

It is hilarious that several people previously than me, they purchased such poorly manufactured items and they did not point out the problems.
They never demonstrate on pictures or video of how terrible is the quality of goods they receiving.

It looks that Chinese factory this is greedy to deliver quantity at zero level Quality control, and from the other side we have greedy underage westerns, looking for few extra coins because of Youtube videos, or they stay silent because they receive FREE samples from a Chinese shop which they will get percentage fee, if they manage to drive more customers to it.

Today I have arrival of both types of Kelvin clips that I did pay to get.

From the large Kelvin clips only one of three items this seems 99% healthy.
Second clip this is 75% healthy and third clips this has severe manufacturing defects.

The small Kelvin clips, they came with very thin layer of metallic pad.
Clip spring force this is tremendously low, as such it can NOT warranty good electrical connection between metallic surfaces.
And this is close to garbage. 

In the positive side of things, Wolfcraft clips this has equal spring force with the larger Kelvin clip, and three times more mechanical build quality.

The next step this is me exploring ways so to combine best worlds of these products, by the hope to create a less imperfect Kelvin clip.