kWeld - "Next level" DIY battery spot welder

Batteries, Chargers, and Battery Management Systems.
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tatus1969   100 W

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

Post by tatus1969 » Dec 23 2017 1:58pm

Carracing111 wrote:
Dec 21 2017 7:39am
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 7:39am
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 7:39am
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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tatus1969   100 W

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

Post by tatus1969 » Jan 02 2018 5:37am

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 9:23am

tatus1969 wrote:
Jan 02 2018 5:37am
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 10:08am

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 4:50pm

macribs wrote:
Jan 02 2018 10:08am
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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The Lightning Stalker   1 mW

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

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

macribs wrote:
Jan 02 2018 10:08am
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 3:34am

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 6:03am

tomjasz wrote:
Jan 05 2018 3:34am
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 4:12pm

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 4:34am

Ohbse wrote:
Jan 07 2018 4:12pm
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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tatus1969   100 W

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

Post by tatus1969 » Jan 08 2018 8:30am

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 2003 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 6:27pm

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 6:41pm

tatus1969 wrote:
Jan 08 2018 8:30am

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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tatus1969   100 W

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

Post by tatus1969 » Jan 09 2018 5:29pm

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 5:41pm

tatus1969 wrote:
Jan 09 2018 5:29pm
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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tatus1969   100 W

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

Post by tatus1969 » Jan 09 2018 5:52pm

tomjasz wrote:
Jan 09 2018 5:41pm
tatus1969 wrote:
Jan 09 2018 5:29pm
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 9:54am

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 12:02pm

tatus1969 wrote:
Jan 09 2018 5:52pm
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 6:01am

tomjasz wrote:
Jan 10 2018 12:02pm
tatus1969 wrote:
Jan 09 2018 5:52pm
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 11:54am

tatus1969 wrote:
Jan 11 2018 6:01am

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 1:00am

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 1813 times
2BDC91F6-4742-44FE-8A03-1B23FE4354EC.jpeg
2BDC91F6-4742-44FE-8A03-1B23FE4354EC.jpeg (122.88 KiB) Viewed 1813 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 1813 times
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tatus1969   100 W

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

Post by tatus1969 » Jan 12 2018 6:14am

that looks great! Have fun with your new tool, if you've got any issues please let know!
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Re: kWeld - "Next level" DIY battery spot welder

Post by The Lightning Stalker » Jan 24 2018 4:57am

Has anyone tried EC8 connectors on their kWeld? They look like they could handle quite a bit of current so possibly have low contact resistance.

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

Post by tatus1969 » Jan 24 2018 5:38am

The Lightning Stalker wrote:
Jan 24 2018 4:57am
Has anyone tried EC8 connectors on their kWeld? They look like they could handle quite a bit of current so possibly have low contact resistance.
I am using XT90 with one of my batteries. Sadly that Lipo has only AWG10 wires, so the connector is *not* the bottleneck. EC8 should be better than that.
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Re: kWeld - "Next level" DIY battery spot welder

Post by Merlin » Jan 24 2018 9:19am

I don't know what's ec8 rated for but when you re on a "good run" the wires and connectors get that hot you can't touch it.
Remember they passing 1200 amps.

I have build 300 cells now and it works really well.
Except of the small welding sticks. It stops your work quick and often because of heat. Even with gloves.
Welding with "good pressure" with the small stick makes a bit pain in your thumbs. 3 days later I still can feel I made "some" welds. Work should be easier when they are 3 times thicker. (whatever it makes possible to beef them up)

I have sharpened the copper tips twice yet.

The graphene 3s5000 is good for completing 50cells. (discharge to 3.75v)
Nice. Recharging in a short break and go on with your work.

Very happy with the package.

4,99 stars rating ;p

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