kWeld - "Next level" DIY battery spot welder

Batteries, Chargers, and Battery Management Systems.
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tatus1969
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Dec 23, 2017 1:58 pm

Carracing111 wrote:
Dec 21, 2017 7:39 am
When your welders are available, I will buy one!
I just shipped out the last batch today, and the next batch is already in progress. I have some work to do on the website (the shipping rate system is very annoying, I will replace it with a better one) and plan to accept pre-orders for another batch of 200 kits.
Carracing111 wrote:
Dec 21, 2017 7:39 am
I guess that by simply lengthening the electrodes enough I can get an adequate ESR.
Yes, but that also increases the losses, and more importantly, the loop inductance. At current levels like this, the stored magnetic energy in this short piece of wire is so high that it is difficulty to get rid of it when the power switch has to get rid of it when opening the circuit. When current is too high, I would prefer lowering the voltage by reducing the number of cells put in series.
Carracing111 wrote:
Dec 21, 2017 7:39 am
If I understood correctly ... to get the capacitors recharged in 1 second, I think I could use the 60V and 20A source, since it has 1500W, but I would need a constant voltage and current converter, of about 10-15V and up 50A?
Exactly. I am developing a solution (including a capacitor bank) for this purpose, it is a number of posts above. The power source is alrerady working on my desk and can deliver 12V / 70A reliably.
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 02, 2018 5:37 am

A quick update: I had time to test the Turnigy graphene 3S / 6000mAh / 65C. It delivers about the same current as the smaller and cheaper nanotech 3S / 5000mAh / 65-130C battery. The only weakness is that the leads are only AWG10. Does anyone know of affordable Lipos that have AWG8 and XT150 connectors?
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Re: kWeld - "Next level" DIY battery spot welder

Post by fechter » Jan 02, 2018 9:23 am

tatus1969 wrote:
Jan 02, 2018 5:37 am
A quick update: I had time to test the Turnigy graphene 3S / 6000mAh / 65C. It delivers about the same current as the smaller and cheaper nanotech 3S / 5000mAh / 65-130C battery. The only weakness is that the leads are only AWG10. Does anyone know of affordable Lipos that have AWG8 and XT150 connectors?
I didn't find any when I was looking. Part of the reason I went with two smaller ones in parallel, as each one had 10ga wires. Not sure it will really make a noticeable difference.

What kind of weld current did you see?
"One test is worth a thousand opinions"

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Re: kWeld - "Next level" DIY battery spot welder

Post by macribs » Jan 02, 2018 10:08 am

Maybe you could use these type of Turnigy Graphene ? Notice the missing wires, make your own as rugged as you wanna be, and use the plug you want for it.

90c discharge. 6Ah 2s

Image

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 02, 2018 4:50 pm

macribs wrote:
Jan 02, 2018 10:08 am
Maybe you could use these type of Turnigy Graphene ? Notice the missing wires, make your own as rugged as you wanna be, and use the plug you want for it.

90c discharge. 6Ah 2s

Image
Why haven't thought of this before? :shock:
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Re: kWeld - "Next level" DIY battery spot welder

Post by The Lightning Stalker » Jan 04, 2018 3:30 pm

macribs wrote:
Jan 02, 2018 10:08 am
Maybe you could use these type of Turnigy Graphene ? Notice the missing wires, make your own as rugged as you wanna be, and use the plug you want for it.

90c discharge. 6Ah 2s

Image
That is a hard case 2S RC car battery. See the holes? Those are female "tube" or bullet connectors. Here is another one. https://vortexhobbies.com/orion-carbon- ... 69436.html They are more expensive and unfortunately they do not come in 3S but they can be seriesed and they are rated 110C continuous. These are the highest C lipos I could find.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tomjasz » Jan 05, 2018 3:34 am

Any advantage to using Sunstone copper alloy electrodes?
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 05, 2018 6:03 am

tomjasz wrote:
Jan 05, 2018 3:34 am
Any advantage to using Sunstone copper alloy electrodes?
Thanks for the hint, the price point is similar to mine. But I don't see much wear on my probes, they only wear whenever you make bad contact. And there is quite some metal to wear, you can sharpen them a number of times.

Their feed looks similar to that of a Dremel, so that would result in a more complex electrode holder for kWeld.
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Re: kWeld - "Next level" DIY battery spot welder

Post by Ohbse » Jan 07, 2018 4:12 pm

I have just received my welder, looks absolutely fantastic. Very impressed with the design, quality of the supplied hardware and components, the leads and probe tips look great. In addition the documentation is fantastic. This is an area often overlooked, but great doco is essential for a product of this type with wildly varying levels of ability across the customer base. Communication throughout the order process was excellent, thank you Frank for your email updates.

Now I just need to machine a suitable enclosure and complete assembly.

For anybody on the fence about ordering one of these, this is definitely a superior kit to all others I have seen. It's certainly a LOT nicer than my very agricultural early efforts a couple of years ago :)

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Re: kWeld - "Next level" DIY battery spot welder

Post by The Lightning Stalker » Jan 08, 2018 4:34 am

Ohbse wrote:
Jan 07, 2018 4:12 pm
this is definitely a superior kit
It is, definitely. Mine is sitting here waiting on a replacement crimper since it turned out to be defective.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 08, 2018 8:30 am

thanks for your great feedback!

In the meantime, I have received pictures of this beautiful case from a customer. It is laser cut material from 3mm panels, which should also be more cost effective than 3D printed parts.
kweld-case-lasercut.jpg
kweld-case-lasercut.jpg (112.21 KiB) Viewed 421 times
I've made his design available here for you to download: https://www.kicksurfer.de/index.php/pro ... t-housing/
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Re: kWeld - "Next level" DIY battery spot welder

Post by The Lightning Stalker » Jan 08, 2018 6:27 pm

If I had the space for a laser cutter and a 3D printer I would definitely be thinking about getting them. Especially a laser cutter. They really take up a large amount of space. Unfortunately the people who run the local maker space are a bit... weird?

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Re: kWeld - "Next level" DIY battery spot welder

Post by tomjasz » Jan 08, 2018 6:41 pm

tatus1969 wrote:
Jan 08, 2018 8:30 am

kweld-case-lasercut.jpg

I've made his design available here for you to download: https://www.kicksurfer.de/index.php/pro ... t-housing/
WOW! SO nice and generous!
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 09, 2018 5:29 pm

new stock is coming, and I've just opened for pre-orders at the shop! --> https://www.keenlab.de/index.php/produc ... elder-kit/
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Re: kWeld - "Next level" DIY battery spot welder

Post by tomjasz » Jan 09, 2018 5:41 pm

tatus1969 wrote:
Jan 09, 2018 5:29 pm
new stock is coming, and I've just opened for pre-orders at the shop! --> https://www.keenlab.de/index.php/produc ... elder-kit/
Can previous kits be upgraded?
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 09, 2018 5:52 pm

tomjasz wrote:
Jan 09, 2018 5:41 pm
tatus1969 wrote:
Jan 09, 2018 5:29 pm
new stock is coming, and I've just opened for pre-orders at the shop! --> https://www.keenlab.de/index.php/produc ... elder-kit/
Can previous kits be upgraded?
if you have the firmware update tool (or can make your own as described in the user manual), then you can upload the latest firmware that I have made available on the website (https://www.keenlab.de/index.php/portfolio-item/kweld/). This enables all new features including the menu, except for the extended input voltage range of the new unit of course. You can also upgrade the welder with a rotary encoder, but that is a quite tricky soldering task. I have attached the document here. Last but not least, I highly recommend to upgrade the extended protection components, especially as the voltage regulator of the previous (rev.2) kits has occasionally failed. This is described in the attached doc as well, and I supply component kits for small money.
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kWeld rev2 upgrade.pdf
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Re: kWeld - "Next level" DIY battery spot welder

Post by bigbore » Jan 10, 2018 9:54 am

My welder arrived too and everything is a step ahead from other similar spot welder! Waiting for some spare time to take care of it :D
In the meantime looking at the laser cut case I tough to modify the 3D model of the case before printing. Isn't it a good idea to have the little holes to allow air flow in the 3D printed case also?

Edit: tatus1969 Is possible to have a IGES or STEP file of the case? STL is useless in CREO and that's what I've been using from many time.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tomjasz » Jan 10, 2018 12:02 pm

tatus1969 wrote:
Jan 09, 2018 5:52 pm
I highly recommend to upgrade the extended protection components, especially as the voltage regulator of the previous (rev.2) kits has occasionally failed. This is described in the attached doc as well, and I supply component kits for small money.
OK Thanks for that. Unfortunately it is beyond my skill level. I manage basic, very basic, wire and connector soldering but worry about this level. I guess I should have been less anxious to own a second welder. Perhaps someone with skills is interested enough to pay a fair price and make the upgrades. I can then purchase a new welder. Thanks for the quick response.
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 11, 2018 6:01 am

tomjasz wrote:
Jan 10, 2018 12:02 pm
tatus1969 wrote:
Jan 09, 2018 5:52 pm
I highly recommend to upgrade the extended protection components, especially as the voltage regulator of the previous (rev.2) kits has occasionally failed. This is described in the attached doc as well, and I supply component kits for small money.
OK Thanks for that. Unfortunately it is beyond my skill level. I manage basic, very basic, wire and connector soldering but worry about this level. I guess I should have been less anxious to own a second welder. Perhaps someone with skills is interested enough to pay a fair price and make the upgrades. I can then purchase a new welder. Thanks for the quick response.
If you would pay the shipping cost for one direction and the upgrade parts, then I'll be happy to upgrade the protection components for you.
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Re: kWeld - "Next level" DIY battery spot welder

Post by tomjasz » Jan 11, 2018 11:54 am

tatus1969 wrote:
Jan 11, 2018 6:01 am

If you would pay the shipping cost for one direction and the upgrade parts, then I'll be happy to upgrade the protection components for you.
Wow! Why yes! How very generous!
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: kWeld - "Next level" DIY battery spot welder

Post by Marin » Jan 12, 2018 1:00 am

Got my k weld put together and a laser cut case made locally today, assembled tested and operational.

I made a bit of a mess with the glue but here it is.
344FB8D5-E30F-4347-9625-DC05BDC5F2E5.jpeg
344FB8D5-E30F-4347-9625-DC05BDC5F2E5.jpeg (172.91 KiB) Viewed 231 times
2BDC91F6-4742-44FE-8A03-1B23FE4354EC.jpeg
2BDC91F6-4742-44FE-8A03-1B23FE4354EC.jpeg (122.88 KiB) Viewed 231 times

22 seems the ticket the top 4

Middle 4 30

Bottom 4 10

Thanks Frank
Attachments
046B87AC-718D-4EC7-95AD-C2B28FAF969B.jpeg
046B87AC-718D-4EC7-95AD-C2B28FAF969B.jpeg (88.1 KiB) Viewed 231 times
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Jan 12, 2018 6:14 am

that looks great! Have fun with your new tool, if you've got any issues please let know!
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