Anyone want a cheap spot welder for £20
Right I was asked to start this thread off and happy to do so, as so many people have helped me on this forum. First only fair I let you know I am a complete novice at making batteries, but that said it means that if I can do this then so can you. Now this is going to take me longer to write up than it took to build the battery so I will do it in parts.
IF YOU WANT A FAST CHEAP SPOT WELDER this does have a happy ending LOL
So part one..... An overview of the spot welder.
Basically a while ago I decided to build a battery started getting everything together, purchased a cheap chinese battery spot welder on e-bay for under £20, which at the time was the cheapest one I could find. Then just before I could start I became very ill and the whole project sat in the garage for over a year, by the time I got back to the project, I had lost the instructions, and forgotten how it worked.
This turned out to be a blessing in disguise as I googled it and found very mixed results, some people saying it was great, others saying it was a complete waste of money. During this research I discovered that the device had a built in weakness that caused it to blow, if the power of the battery dropped, which it tends to when spot welding with it.
The good news by the time I got back to the project other people had found the problem and come up with a simple modification that will fix this issue, this involves soldering an extra capacitor in place.
Now this is a link to the actual spot welder I purchased
This is the actual one I purchased, though not necessarily from this seller.
There are now lots of copies of this on e-bay and come cost as little as £10, but I cannot personally comment on them having never used them.
Now if you search Youtube for "Transistor Portable Mini Spot Welder Welding" (video) you will find various You Tube videos, some good some bad.
Amongst them you will find a couple by a guy called Adam Welch, the first one was a review of the product, when he bought one to test it....... And blew it up, so thought it was a waste of money. Well Adam has his own channel, and several people told him of this built in weakness and a simple mod that fixes it.
So Adam put up a second 21 min long video where first he fixes the one he blew up. but then does the main mod of installing this extra capacitor. its clear, good audio and easy to follow. Of course if you skip blowing it up first like I did and go straight for the mod then you don't have to pay attention to him fixing his first.
Adams second video on the repair and more importantly the mod is at the link below.
This is Adams Second video, half is fixing his the second half is the modifications
The capacitor needed or the on I purchased to do the job was a Radial Electrolytic Capacitors / Value 1000uF, Voltage 25v, I bought two of them on e-bay for £2.15 p (you only actually need one, I bought a spare).
Now Adam also reinforces much of the PCB track with extra solder to reduce resistance but one of his followers pointed out that another common improvement is to use two batteries, one for the electronics and one for the weld current, if you do this you don'[t need to do any extra soldering at all (so I didn't) I went for the two battery approach.
Below is the actual post quoted exactly that tells you how to do this.
"@paulh71 also on You tube in the comments under Adams Post
You can also just use a second smaller 12V battery for the control electronics, and connect the +ve welding cable to the +ve of larger battery and the -ve welding cable to the normal -ve welding connection of the board, then connect the -ve board connection to both -ve ‘s of batteries, and the +ve of the smaller battery to the +ve of the board . This prevents the control voltage from dropping during a weld, and doesn’t need any additional soldering."
So I did that as well, while in the process I extended the leads a bit as the ones in the pack are a bit short to work comfortably with especially with two batteries. So I use a 7.5 ah Sla battery for the electronics, and a car battery on the floor for the weld current.
That's it folks. There are also some other videos on tips how to use this to get better results using this device.
One said round the end of the probes a bit (so I did that did that with sandpaper). The others are tips about technique, I'll look for them next time. but basically its a knack, at first you tend to push too hard DONT you want some resistance between the nickle strip and the battery, no resistance = no heat. Also most pro welders both probes come down at 90 degrees to the work piece. This one definitely works better one probe in each hand, both at about the angle you would have a pen or pencil when writing.
I had a practice on some scrap batteries first, once I got the weld current adjusted correct, (About 45 on mine with my setup, but will vary depending on electrode lead length and battery condition). It took me about half a dozen practice goes, then went straight into doing 1500 welds to build a battery, no problems at all, just a few tea breaks.
Well hopefully that will get the ball rolling feel free to comment, criticise or ask questions.
Lucifer (AKA Keith)
Right I was asked to start this thread off and happy to do so, as so many people have helped me on this forum. First only fair I let you know I am a complete novice at making batteries, but that said it means that if I can do this then so can you. Now this is going to take me longer to write up than it took to build the battery so I will do it in parts.
IF YOU WANT A FAST CHEAP SPOT WELDER this does have a happy ending LOL
So part one..... An overview of the spot welder.
Basically a while ago I decided to build a battery started getting everything together, purchased a cheap chinese battery spot welder on e-bay for under £20, which at the time was the cheapest one I could find. Then just before I could start I became very ill and the whole project sat in the garage for over a year, by the time I got back to the project, I had lost the instructions, and forgotten how it worked.
This turned out to be a blessing in disguise as I googled it and found very mixed results, some people saying it was great, others saying it was a complete waste of money. During this research I discovered that the device had a built in weakness that caused it to blow, if the power of the battery dropped, which it tends to when spot welding with it.
The good news by the time I got back to the project other people had found the problem and come up with a simple modification that will fix this issue, this involves soldering an extra capacitor in place.
Now this is a link to the actual spot welder I purchased
This is the actual one I purchased, though not necessarily from this seller.
There are now lots of copies of this on e-bay and come cost as little as £10, but I cannot personally comment on them having never used them.
Now if you search Youtube for "Transistor Portable Mini Spot Welder Welding" (video) you will find various You Tube videos, some good some bad.
Amongst them you will find a couple by a guy called Adam Welch, the first one was a review of the product, when he bought one to test it....... And blew it up, so thought it was a waste of money. Well Adam has his own channel, and several people told him of this built in weakness and a simple mod that fixes it.
So Adam put up a second 21 min long video where first he fixes the one he blew up. but then does the main mod of installing this extra capacitor. its clear, good audio and easy to follow. Of course if you skip blowing it up first like I did and go straight for the mod then you don't have to pay attention to him fixing his first.
Adams second video on the repair and more importantly the mod is at the link below.
This is Adams Second video, half is fixing his the second half is the modifications
The capacitor needed or the on I purchased to do the job was a Radial Electrolytic Capacitors / Value 1000uF, Voltage 25v, I bought two of them on e-bay for £2.15 p (you only actually need one, I bought a spare).
Now Adam also reinforces much of the PCB track with extra solder to reduce resistance but one of his followers pointed out that another common improvement is to use two batteries, one for the electronics and one for the weld current, if you do this you don'[t need to do any extra soldering at all (so I didn't) I went for the two battery approach.
Below is the actual post quoted exactly that tells you how to do this.
"@paulh71 also on You tube in the comments under Adams Post
You can also just use a second smaller 12V battery for the control electronics, and connect the +ve welding cable to the +ve of larger battery and the -ve welding cable to the normal -ve welding connection of the board, then connect the -ve board connection to both -ve ‘s of batteries, and the +ve of the smaller battery to the +ve of the board . This prevents the control voltage from dropping during a weld, and doesn’t need any additional soldering."
So I did that as well, while in the process I extended the leads a bit as the ones in the pack are a bit short to work comfortably with especially with two batteries. So I use a 7.5 ah Sla battery for the electronics, and a car battery on the floor for the weld current.
That's it folks. There are also some other videos on tips how to use this to get better results using this device.
One said round the end of the probes a bit (so I did that did that with sandpaper). The others are tips about technique, I'll look for them next time. but basically its a knack, at first you tend to push too hard DONT you want some resistance between the nickle strip and the battery, no resistance = no heat. Also most pro welders both probes come down at 90 degrees to the work piece. This one definitely works better one probe in each hand, both at about the angle you would have a pen or pencil when writing.
I had a practice on some scrap batteries first, once I got the weld current adjusted correct, (About 45 on mine with my setup, but will vary depending on electrode lead length and battery condition). It took me about half a dozen practice goes, then went straight into doing 1500 welds to build a battery, no problems at all, just a few tea breaks.
Well hopefully that will get the ball rolling feel free to comment, criticise or ask questions.
Lucifer (AKA Keith)