kWeld - "Next level" DIY battery spot welder

[ichiban]

New stuff is in production, I expect to receive that within one or two weeks from now! 8)
NZ is possibly, but you'd need to calculate ~40€ for shipping.

tatus,

I'm thinking about modding the electrodes a little bit.

I don't know what exact material the electrode is made out of, can I just bend the tips (about 1-2 cm from the cone-shape ends) to get the welding spots closer together ?

Just don't want to find out that the electrodes are hard and brittle copper that will be broken under force. Saw people just made holder to hold them at roughly 45 deg to have closer welds.

If bending can be done, so I will remove the two electrodes out of the copper holder then gently bend them on a vice to get the angle I want, then put them back into the holder. Job done. That easy ?



Sorry for my hand sketch. Might not look very neat but just to show the idea what I'm trying to explain.

Thanks.

 

[tomjasz]

I guess you couldn’t be bothered by looking at the Aliexpress version. Seems there are at least two more designs. They are using microwave transformers. I trust Tatus and a number of posters. I was hoping for a discussion on the variables and different designs from a source I trust. Thanks for the necro threads but they don’t address the post.

 

[tomjasz]

What would it cost to return my early version and upgrade to the latest. I’ve been procrastinating on returning my early version with potential heat issues. I bought it as a backup to my other welders. It’s unused and I haven’t developed he skills to upgrade on my own. Fooking stroke brains are poor detail oriented and especially clumsy at cleaning up solder and adding new parts. I’d like to finally get this resolved. I have to say this has ben a great adventure watching this welder develop. I just wish I had come later... I didn’t gather I was a beta tester.

All the best!

Tj

 

[tomjasz]

BTW my total ordering a cable set is a bit goofy...
€27,00
UPS Saver shipping: €38,13

 

[tatus1969]

Hi guys,

I've got some important news:
- I was out of stock during the last weeks - new boards will arrive tomorrow (I'll only add stock in the shop after I've actually got them though.)
- a customer reported to me that he was having trouble with arcing, and that he got damaged cells from that. The problem with arcing is that, even though kWeld still makes sure that the deposited energy stays constant, the accelerated electrons in the ionized gas will collide with the positive pole and work their way through the material there. Arcing only happens when there is a bad electrical contact and/or not enough mechanical pressure, but I found a way to reliably detect this by software. The new firmware below will instantly stop a pulse when the electrical current falls below 800A. This is a reliable indicator for arcing, as the ionized gas has a much higher electrical resistance than the direct contact.
- I got a few customers who reported poor response of the dial knob. I found that there is a lot of production variation of the rotary encoder regarding the amount of grease that they fill in, which leads to contact noise. The firmware has always included contact debouncing, but it was not matching the noise characteristics that the encoder exibits. This has also been improved in the attached firmware.

p.s. this was my "test bed" for my arcing experiments. The new firmware caught every single case in the end, no matter what I did 8) I think that this feature is again unique among all spot welders operating with DC current.

 

[Altair]

Innovative design, state-of-the-art components, top build quality, constant improvements!
This will surely win the "Product of the year" grand prize here on E-S.
Oh wait, we don't have such prizes, dammit!

 

[tatus1969]

What would it cost to return my early version and upgrade to the latest. I’ve been procrastinating on returning my early version with potential heat issues. I bought it as a backup to my other welders. It’s unused and I haven’t developed he skills to upgrade on my own. Fooking stroke brains are poor detail oriented and especially clumsy at cleaning up solder and adding new parts. I’d like to finally get this resolved. I have to say this has ben a great adventure watching this welder develop. I just wish I had come later... I didn’t gather I was a beta tester.

What version do you have? It's only the very first 20 or so customers that were beta testers, and all these purchases were arranged in this and another forum. It's like every electronic product (best example: smart phones), they evolve and get better over time.

BTW my total ordering a cable set is a bit goofy...
€27,00
UPS Saver shipping: €38,13

That's just what UPS charges me, I'm based in Germany. Have you noticed the big banner on my website, mentioning that I have a US reseller? Keith should be able to give you much better shipping rates.

 

[tatus1969]

I don't know what exact material the electrode is made out of, can I just bend the tips (about 1-2 cm from the cone-shape ends) to get the welding spots closer together ?

They are made from Tellurium copper, which is a bit harder for better machineability, but you should be able to do like in your sketch.

 

[ossivirt]

I just received my unit. Must be one of the last units from its patch. Nice to see that developing is ongoing. I need to look into updating firmware .

 

[BVH]

Just an FYI...I probably would not have seen the banner for the US supplier on the Kweld home page as the two brown background colors are close so the banner somewhat blends in. I saw it because of your above post.

Just emailed Keith to see how to purchase the firmware update kit. You just keep making this gem better and better!

 

[tomjasz]

That's just what UPS charges me, I'm based in Germany. Have you noticed the big banner on my website, mentioning that I have a US reseller? Keith should be able to give you much better shipping rates.

That's crazy! I buy from 2 DE bike parts resellers, the MOST I paid was 19USD to ship an NCX suspension seat post and spare springs.
I purchased an item from DE and it was delivered by USPS, heavier than your unit and cost was under $10. UPS is robbing us!

Thanks for the response!!

 

[BVH]

Just an FYI...I probably would not have seen the banner for the US supplier on the Kweld home page as the two brown background colors are close so the banner somewhat blends in. I saw it because of your above post.

Just emailed Keith to see how to purchase the firmware update kit. You just keep making this gem better and better!

Emailed Keith and within 5 minutes had received and paid his invoice and got a tracking number.

 

[tatus1969]

That's crazy! I buy from 2 DE bike parts resellers, the MOST I paid was 19USD to ship an NCX suspension seat post and spare springs.
I purchased an item from DE and it was delivered by USPS, heavier than your unit and cost was under $10. UPS is robbing us!

Many sellers will take away part of the shipping cost and add the amount to the product price to leverage sales, for example that's common practice on ebay.

I had better rates from DHL (they hand over to USPS for the domestic distance), but almost 10% of all international parcels never arrived. Some of the ones that arrived took up to two months. I had high financial losses, because in theory you can file for refunds, but in practice you don't get money. I deliberately switched to UPS while accepting the premium. After a few hundred parcels, not a single one got lost, and almost all parcels to USA/Canada arrived in three days. You get what you pay for.

Just an FYI...I probably would not have seen the banner for the US supplier on the Kweld home page as the two brown background colors are close so the banner somewhat blends in. I saw it because of your above post.

Can you please post a picture? It should be light gray on dark gray.

I just received my unit. Must be one of the last units from its patch. Nice to see that developing is ongoing. I need to look into updating firmware .

Sorry for continuously improving :wink:

 

[garolittle]

Innovative design, state-of-the-art components, top build quality, constant improvements!
This will surely win the "Product of the year" grand prize here on E-S.
Oh wait, we don't have such prizes, dammit!

I agree. Incredible product and fantastic customer service.

 

[ossivirt]

First welds. Did not have nickel or cells at hand so here is steel washer to 0.8mm steel wire (welding filament). I made battery leads from 6avg because that is what I had. Yea I over did it with the glue. Somehow I missed that there is detailed instructions for assembling the housing

View attachment 3View attachment 1
How are my values? I think those are pretty good for old lead acid battery.. Next I try nickel strip and maybe brass and copper..

 

[tatus1969]

Here's again a new firmware, this one allows to alter the minimum current threshold through the menu. I realized that this would be important for users with weaker batteries who like to keep their system as it is. They wouldn't be able to use the welder anymore otherwise. And I had also the request to raise the threshold. If your battery delivers 1400A, then setting the minimum to e.g. 1200 might further improve the arcing detection sensitivity.

 

[tatus1969]

p.s. new kWeld electronics just arrived and can be ordered through the shop 8)

 

[tomjasz]

Something must be amiss with the shipping. $45! EU40! I just received a tracked postal shipment, actually 3 in the last month, for $8 from DE. (more or less)

I'm not trying to bust chops, just nonplused by the cost to ship. I have a UPS business account and my costs are nowhere near $45. My competing welder was closer to $10 shipped. Since my Kweld version requires more attention and rework, or to be sent back, I bought another JP. BTW your work and improvements are impressive.

 

[spinningmagnets]

Does that shipping cost have a break-down you could post? Some places have a Value Added Tax / VAT, and many countries have a customs fee. There might even be other charges that a dealer shipping from one US state to another US state would not be affected by...

 

[tatus1969]

Something must be amiss with the shipping. $45! EU40! I just received a tracked postal shipment, actually 3 in the last month, for $8 from DE. (more or less)

I'm not trying to bust chops, just nonplused by the cost to ship. I have a UPS business account and my costs are nowhere near $45. My competing welder was closer to $10 shipped. Since my Kweld version requires more attention and rework, or to be sent back, I bought another JP. BTW your work and improvements are impressive.

I would love to improve here, but as I mentioned these are the rates UPS gives me through my business account. The displayed amount comes directly from their live API, and is based on your entered address. I know that UPS adds a 25€ premium for remote addresses, maybe that's the case for you?

What my shop is missing though is a better option for small items like the firmware updater. I'm working on shipping them in bubble wrap envelopes, which should allow me to use letter tariffs. Deutsche Post charges €3.70 for these, but they don't include tracking or insurance.

You tell me that others are doing better, which I was aware of anyway, but can you also give me hints on how to improve? I don't want to sacrifice reliability, so DHL / UPS are out.

Anyway, according to your forum profile you are located in the US, which means that you could also order from Keith. Did you consider that?

 

[tomjasz]

Sure, I like doing business with Keith. He is willing to be very helpful. I didn't think it was fair of me to take the probes from a full kit. Eventually, he'll have them in stock. He also cannot do the upgrades needed on my welder. For that, I must send the welder to you. I appreciate EVERYTHING you've done. It's really quite remarkable. But, no electronic talent fella hereI screwed up and ordered too soon. But from here the whimpering stops.

Is there a class of shipments from DHL? I ordered much online and globally. DHL has been spot on. You might give Jakov a poke and ask how he ships. It was CHEAP by comparison.

 

[tatus1969]

ordered too soon.

I already asked... which revision kWeld do you have?

Is there a class of shipments from DHL? I ordered much online and globally. DHL has been spot on.

My experience with international DHL shipments was very bad, I lost more than 1000€ in value by repeated shipments. USA was worst, it took forever (up to 8 weeks) and everything that you can imagine happened, including the postman dumping the parcel in the hedge during rain. DHL is 10..20% cheaper than UPS. I have a few hundred shipments with UPS now, and not a single loss.

You might give Jakov a poke and ask how he ships. It was CHEAP by comparison.

Sorry, I don't know him. Is that his forum name?

 

[tatus1969]

I've been firefighting during the last days, after an increasing number of kWeld users reported me that the rotary encoder on the board had become unreliable. It turns out that it is a huge quality problem with the component itself. There are tiny plastic elements inside that break loose and end up blocking the contacts. The kWeld production test couldn't catch this, because this only happens after using the part for a while. It's even more annoying because I deliberately use quality brand components only for the entire design, in this case a Bourns PEC12R-4220F-S0024.

We are busy replacing the rotary encoders on the entire current production batch with this new component: EN11-HSB1AF15 (Digikey 987-1186-ND). I have disassembled one of these, their internal construction is way better. The only drawback is that they count in opposite direction, which is why I had to update the firmware again. This version has a new menu item "Encoder" that allows you to select "normal" and "reverse" counting direction.

If any of you guys are having problems with your welder, then please let me know. I'll do what I can to resolve this issue for you.

 

[tomjasz]

I already asked... which revision kWeld do you have?

I believe revision 2 or 3 purchased in July or August of 2017.

I bought it as a backup to my JP Welder. Never used but was told by you it needed an upgrade. I'll try to find that message...

 

[BVH]

Got my firmware update tool today but am having a problem accomplishing the update. Adapter is communicating with PC as it should and is Com10 as verified by plugging and unplugging and seeing it appear, disappear and reappear while watching in Device Manager. the putty software launches fine and I input Com10 and 115200, Serial. When I click the button, a new window appears just like in the instructions but the window indicates "offline" instead of "connected". Cannot type the "k" nor anything else in the window. Repeated attempts result in the same thing. I assume the welder does not have to be powered up with the battery power supply as noting is said about doing so. I gotta be missing something simple, right?