In my opinion, this spotter is the leader among state employees. This spot welding for one-off work that you can do with your own hands in an hour.
In this video, I told how to collect a spotter from the handy tools for working in the garage.
The advantages and disadvantages of the spotter will be listed later.
To collect the spotter, you need a 12-volt battery. Retracting from the car, two battery terminals, five cable lugs, a welding clamp for the mass, three pieces of welding cable 8 mm thick and no more than 1 meter long. I made a gun for spot welding from an old screwdriver. You can use a burnt drill.
On welding cables, I recommend wearing copper cable lugs and crimping.
The retractor is suitable for any car.
To the pistol (screwdriver) we connect the longest piece of the welding cable. I have a length of 1.2 meters. But, better than 1 meter.
And we connect the same two-wire wire to the button.
Welding cable from the gun is connected to one of the contact bolts of the retractor. I recommend connecting the second bolt of the retractor bolt to a welding cable 30-40 cm long and the other end connected to the positive terminal of the battery. To connect the third meter welding cable to the negative terminal. It will be mass. There are two wires from the pistol button. We connect one of the wires through a flat terminal to the daddy on the retractor. The second wire is connected to the negative battery.
The battery is better to connect serviced. In order to be able to top up the dosed water.
As a stinger for spot welding, you can use a copper tube. I made a sting from old brass taps.
The welding clamp can be connected to the mass, but for bodywork I recommend making a mass from a steel bolt and a brass nut.
The paint must first be removed before the metal. If the paint is not damaged, in some cases it is better to use a pillow or Chinese fungi on a hot melt. But, on the ribs and where the paint is damaged, the spotter will cope much faster.
On this battery in total, I made about 240 potholders. I do not know how it was loaded, but until the end I did not drop it off as you can see. The battery is relatively powerful. At 80 ampere hours. But, it's far from new. By the way, during work, the cartridge only slightly warmed up .... Screwdriver garusov up to 30-40ka.
What you need to pay attention to when assembling spot welding.
If possible, use the cable lugs to find copper ones and not aluminum ones like mine. Copper and aluminum expand differently when heated, aluminum forms a non-conductive current on the surface, and they also form a galvanic couple ... But despite this, such compounds can work for years - so I ignored them.
Next ... Welding cables should be as short as possible to reduce losses.
The optimal is a meter from a pistol to a retractor, 20-30 inches from the retractor to the battery and not more than a meter in weight. The retractor can be placed directly on the battery terminal, but when working, the cable can be hooked with the foot in consequence of which it damages the retractor or the battery.
For the sting of the gun and the mass, it is better to use non-ferrous metals, copper, brass. They are not welded when spot welding, unlike steel.
When working between the mass and the gun should be a small distance - the quality of welding depends on it directly.
Do not heat the pads to reddish the puck. The quality of welding from this is not better, but the acid in the accumulator can boil and the battery explode.
And in general for such works it is better to use an old battery.
When connecting spot welding, make sure the battery is charged.
For this spotter I bought only the terminals for the battery ... The rest was collected from the old trash.