kWeld - "Next level" DIY battery spot welder

[NetPro]

Welcome to the Club, flashtel!

I can only comment on the device shown in the picture because I have done my fair share of electrodes and holders.
The device could have a great deal of value IF it had thicker cables to connect it to to the welder.
The springs make it a great device because it equals the pressure on both electrodes as you do the weld, a very important feature to get consistent welds.
But I can tell you that thin wires do not have the capability to carry the current needed to do a good weld, specially on the thicker nickel strips.

I must say also, the electrodes it has on do not provide as good a weld nugget as those that come with the kWeld. At least in my experience: They stick when welding thicker material (0.20 mm)

If I were to buy this unit, I would change the wires.

 

[Altair]

I'm looking at that picture and what comes to mind is that the small wire would be for a temperature sensor inside the probe assy.
There are large bolts at the back end that could be used to attach the welding wires.
Does that make sense?

 

[tatus1969]

I'm looking at that picture and what comes to mind is that the small wire would be for a temperature sensor inside the probe assy.
There are large bolts at the back end that could be used to attach the welding wires.
Does that make sense?

The cable will be the connection to a trigger switch that fires when you push in the spring loaded electrodes. That design looks quite nice, where did you find it?

 

[spinningmagnets]

I have not had time to work on developing a good hand-held dual-probe holder that has spring-loaded pressure application. My design considerations would be:

Having each tip individually spring-loaded is ideal. Even if one or both are "bottomed out" with the spring fully compressed...if you tilt the holder slightly to the side instead of holding it perfectly vertical, the springs ensure that the "less loaded" tip has at least a minimum acceptable amount of pressure.

I want to design a probe-set holder where one tip is solidly mounted and the second tip is spring loaded. This will be simpler and cheaper than having both tips spring-loaded. However, I still believe dual-individual spring-loading is ideal.

The current must NOT travel through any part of the spring loading mechanism, and the hand-grip should easily be able to have the stock kWeld probes inserted to it. It is unwise to add more connection points in the current-flow chain. Each part of the stock kWeld probes has been carefully designed to provide the optimum performance.

 

[Altair]

The cable will be the connection to a trigger switch that fires when you push in the spring loaded electrodes. That design looks quite nice, where did you find it?

The pic has been posted by flashtel, I don't know where he found it.
The integrated trigger switch is a great idea BTW.

 

[NetPro]

I never thought they would include the trigger switch on the hand held device but I am glad to see they did.
Turns out there are quite a lot to choose from if you search for "spot welding pen" on aliexpress.com.

The one I will order tomorrow is this one:
https://www.aliexpress.com/item/4000104109230.html

Seems well built and it even has a way to adjust spring pressure individually.
They also use the standard electrodes used by most Chinese made underpowered welders.
I have been buying them from Sunstone for a while, though, I am still suffering from electrode sticking when welding 0.20 mm pure nickel. Not the case when welding 0.15 mm strips.

I have purchased 2 other hand-held welding pens from aliexpress in the last 3 years but they did not have a trigger switch and came with cables soldered that were rather short.
Biggest problem was the electrodes were very small and the things were just poorly manufactured and did not work well.

Let's see if the 3rd device works as it should. I will post results when it arrives.

 

[NetPro]

Searching a bit more I discovered the exact unit in the picture posted by flashtel: On eBay.
https://www.ebay.com/itm/Integrated...hash=item5d99a7c831:m:mdHw1HlIH_Ejthcn_yxsq2g

They even have 3 colors to choose from. Is that neat or what! Fashion has arrived for welding pens 8)

 

[ossivirt]

Searching a bit more I discovered the exact unit in the picture posted by flashtel: On eBay.
https://www.ebay.com/itm/Integrated...hash=item5d99a7c831:m:mdHw1HlIH_Ejthcn_yxsq2g

They even have 3 colors to choose from. Is that neat or what! Fashion has arrived for welding pens 8)

It looks actually decent. Only thing that I would change is the electrodes. I think that its possible to drill the mounting points little bigger and use kweld tips with it. 8) It also needs nice set of wires. Maybe wires should be mounted under the same bolt that holds the tips for lowest possible resistance

 

[ElectricGod]

I think cut off those tiny tips and make the ends of each rod pointed and you have a pretty good equivalent to the kweld tips.
Please post lots of pictures of these welding probes and how well they work in comparison to the kweld probes.

 

[flashtel]

Hi,

I just bought this one from this seller.

RERASI Store

https://www.aliexpress.com/item/4000325459892.html

I got this one because the bus bars are at 90 degrees to the one I posted earlier so I believe it will be a better "hand hold". There are only two sellers on Aliexpress. I asked the other if he would post e-packet and no bother to respond.

It's 9:00pm at night in China and here in Perth, he responded immediately, posted e-packet at no extra charge, packaged it and sent me the photo's of the shipment within 5 minutes of completing order.

e-packet is 20day average to Perth vs 8-12 weeks for the other options, half the time I forget what I ordered when I use the slow boat.

Highly recommended vendor!

KWeld arrives tomorrow

Thanks Paul

 

[tatus1969]

awesome!! :thumb:

 

[flippy]

if those tips are plain copper then they wont last long, you need the fancy stuff from germany in order to have lasting tips.

 

[spinningmagnets]

If someone gave me a pair of those electrode holders for free, I would re-drill the tip holder holes to fit the 6-ga solid copper tips, that can be made from hardware-store grounding cable.

Spin them on a drill to taper the tips...

 

[NetPro]

The one issue to consider when trying to enlarge the holes to use the kWeld's supplied electrodes is that if installed in parallel, even if you get real close to each other, the tips would be too far for the positive side of 18650 batteries. Not to mention, the grater distance in the electrodes changes the dynamics of the weld itself, requiring more energy (and more pressure to avoid sparks) and causing sticking issues, at least with thicker, pure nickel.
I've been through that, I know from experience.

A while back I built my own holder and what I did to get around this issue was drilling the holes at a 20 degree angle so the electrode's tips would come much closer to each other and have a "standard" gap.

That produced the best welding nugget I have been able to get, albeit I still get sticking electrodes when using 0.20 mm pure nickel. Not sticking issues with 0.15 mm.

I did this modification to the below welder head I bought not log ago and while it does a great job at consistency, I was not able to get rid of the sticking electrodes problem. Still trying to figure that one out.
If anybody is interested, I'd be glad to post pictures of the thicker electrodes installed at at an angle, but I know not many people suffer from the plague that has kept me busy for a long, long time and don't have the kind of holders that can be modified to use the thicker (excellent by the way) electrodes provided by Mr. T.

 

[flashtel]

HI,

I paid over $90 Aud for shipping or 23% of the cost of the kit. It left on Monday and it arrive AM today Thursday on the opposite side of the planet, in the most remote city on earth. UPS rocks, DHL has splintered and gone to the dogs.

The board is absolutely beautifully made.

My only comment is that I was hoping for the clear acrylic case and there should be another option for leads to use with the welding pen posted earlier, definitely the one with bus bars so the cables can exit at 90 degrees the top and lay over.

If the software is as good as the hardware, this is going to be a pleasure to behold.

You could have gone super styling with the knob, good enough.

Paul

 

[flashtel]

I forgot to say thankyou.

Thankyou Tatus1969, keep doing what your doing you are awesome in a world of BS !

Takes about 20 minutes to assemble, I don't have any super glue, so I haven't done the case.

The case is clear, it's just got a blue protective coating on it.

Really well made piece of kit. If I had to say something, I would have used stainless 3mm button heads, just my preference.

It's fabulous, 10:00pm and I have an early start.

Will try it out tomorrow.

Good Job!

Paul

 

[ElectricGod]

If someone gave me a pair of those electrode holders for free, I would re-drill the tip holder holes to fit the 6-ga solid copper tips, that can be made from hardware-store grounding cable.

Is this your welding pens?
Is that 2 awg copper ground wire?

I was wondering about copper ground rod.
Ground rod is commonly copper plated steel or a some copper alloy.
I would only use the copper alloy rod.

 

[ElectricGod]

Thankyou Tatus1969, keep doing what your doing you are awesome in a world of BS !

You will be pleased with the welder. Just be sure to feed it lots of current.

I modded mine a bit so it can be disassembled. These are 8mm bullet connectors on the input power side.

The pedal has a connector too.

I never took pictures of it, but my welding probes have longer/bigger wires and 8mm bullets on them too.

 

[tatus1969]

Thankyou Tatus1969, keep doing what your doing you are awesome in a world of BS !

Thank for your great feedback 8)

I paid over $90 Aud for shipping or 23% of the cost of the kit.

I might soon have an AU reseller to mitigate that: https://hiketech.com.au/index.php?route=product/category&path=111

I had quite an experience with other carriers like DHL and DPD, they had cost me a fortune in lost shipments and I decided to move away from them. Not a single lost item since I had moved to UPS.

 

[john61ct]

I have worked as a PCD for UPS, and believe me, management's internal "secret police" is laser-focussed on zero-tolerance for the shrinkage that most shops accept as a normal cost of doing business.

Their surveillance / intel ops capabilities are right up there with the TLA national agencies.

Ownership "self insures" via offshore shell companies, so they are very motivated to keep payouts low.

I bet there are extra protection expenses to Teamsters and equivalent internationally to help get cooperation from that side as well.

 

[tatus1969]

Good news for you guys in Australia and around: Andrew from hiketech.au is starting to sell keenlab products here! https://hiketech.com.au/index.php?route=product/category&path=111

He's also working on introductory videos, and I'd appreciate if you'd support him by watching and recommending them (given that they are good - haven't seen them yet

His YT channel is: https://www.youtube.com/channel/UC7MuS242JIeOQYY_8V9U89g

 

[tatus1969]

Seems to be newstime today... more good news, I finally managed to order new/redesigned kCap ultracapacitor modules and have started offering them for pre-order: https://www.keenlab.de/index.php/product/kweld-ultracapacitor-module/ (will also be available from the above US/AU resellers)!

They now feature protection against overcharging (MOSFET switch) and also prevent backfeeding into their supply (by an ideal diode circuit), which now allows the use of any kind of current limited power supply with any voltage between 8.1V and 14V. The product page lists these options in more detail.

 

[ElectricGod]

Seems to be newstime today... more good news, I finally managed to order new/redesigned kCap ultracapacitor modules and have started offering them for pre-order: https://www.keenlab.de/index.php/product/kweld-ultracapacitor-module/ (will also be available from the above US/AU resellers)!

They now feature protection against overcharging (MOSFET switch) and also prevent backfeeding into their supply (by an ideal diode circuit), which now allows the use of any kind of current limited power supply with any voltage between 8.1V and 14V. The product page lists these options in more detail.

Maybe the pics for the new super cap module are not up yet?
It looks like the ones I already have.

 

[Darren2018]

I received my Kweld today, it's really well engineered. This might be a silly question but where is the switch to power it on and off?

 

[Darren2018]

If there isn't one can I put a switch in series with the capacitor?