Page 44 of 50

Re: JP spot welder

Posted: Oct 27 2017 8:34am
by bigbore
I've been using LiPos with success with this spot welder.
First I built this:
https://endless-sphere.com/forums/viewt ... 4#p1169774

Then I improved to this:
https://endless-sphere.com/forums/viewt ... 0#p1172206

Re: JP spot welder

Posted: Oct 27 2017 12:50pm
by riba2233
For lithium cells max is 3s but 2s should be enough if cells are strong.

Unfortunately I can't give any hard recommendations for various lithuim batteries, I don't have any personal experience. But I can say that you are probably better of just buying new or used car battery, unless you already have some lipo you don't need. You'll be safer, it will probably be cheaper than buying new lipo, and if you spend time assembling many 18650 or other cells that time will cost you more than the value of car battery.

But that's only my opinion, I could be wrong, and maybe someone else has first hand experience.

Re: JP spot welder

Posted: Oct 28 2017 2:26am
by wini
Yes it would be easier, i'll will proably start my first weld with my van lead battery

But as i will create a 2nd stationary battery, i would like to use it with the welder.

Am i right when i think that if i can achieve the same internal resistance with a 3s li-ion battery than a 90Ah 800cca lead battery, the welder will work the same?

Re: JP spot welder

Posted: Oct 28 2017 11:30am
by riba2233
Yes, if you match that it would be fine.

Maybe somene has one of those miliohm-meters and car battery, and can find out it's IR? Thanks!

IR data for 18650 cells known, so there shouldn't be any problems.

Re: JP spot welder

Posted: Oct 29 2017 3:12am
by wini
I am thinking of adding 100w car bulb light in // let say 20 of them and mesure the volt sag of my lead battery.

And then doing the same with the 18650 in 3s configuration and ad cells in // as long as i reach the same resistance.

Is this method seems correct to you guys?

Re: JP spot welder

Posted: Oct 29 2017 5:31am
by riba2233
Sure, you can try. Although bulbs can be little tricky for short term load, since they have substantial inrush, so measuring IR which should be as short as possible to aviod dropping voltage would be better using resistors.

Re: JP spot welder

Posted: Oct 29 2017 9:26am
by Offroader
Riba, with those Electrodes, are they hollow through the whole electrode so I can fit a wire in it?

Would it be possible to cut the crimped top part so I can fit a new wire in and recrimp it?

Re: JP spot welder

Posted: Oct 29 2017 11:01am
by riba2233
No, they are hollow only on ends, but you can drill an new hole, just make sure it's in center.

Re: JP spot welder

Posted: Nov 02 2017 10:33pm
by JumperJackFlash
Glad to see you're back! Hope you're feeling better.

I pm'd you for a welder.

Re: JP spot welder

Posted: Nov 03 2017 1:19pm
by riba2233
Yes I'm feeling well now and I got help from my brother, thank you for asking! :)

PM replied.

Re: JP spot welder

Posted: Nov 03 2017 1:35pm
by macribs
Welcome back Riba. Happy to see you well and about.

Re: JP spot welder

Posted: Nov 03 2017 1:41pm
by riba2233
Thanks :D

Re: JP spot welder

Posted: Nov 07 2017 4:31pm
by brumbrum
All set up with my 100ah battery that will eventually takes its place in my camper van once welding jobs have been completed. Lots of initial testing going on at present with nickel/copper and a bunch of old laptop cells that have sat in my garage for a few years.


Image

Re: JP spot welder

Posted: Nov 08 2017 1:51am
by riba2233
Nice, tell us the results once you finish your testing! :)

Re: JP spot welder

Posted: Nov 08 2017 6:07am
by Cowardlyduck
I received my JP spot welder yesterday. Thanks Jakov!

I have a 12V wall wart ready to go, however I noticed the PCB has 12V 500ma printed on it. My wall wart is only 200ma. Will that matter?
It seems to power on ok, but I haven't tested it yet.

Cheers

Re: JP spot welder

Posted: Nov 08 2017 11:28am
by tomjasz
Welcome back!

Is the how to use/weld manual still available?

can't find and haven't welded since spring. Now that it's bitter cold I'll build again!

Re: JP spot welder

Posted: Nov 08 2017 12:03pm
by brumbrum
tomjasz wrote:Welcome back!

Is the how to use/weld manual still available?

can't find and haven't welded since spring. Now that it's bitter cold I'll build again!

Sounds interesting, where do i get one?

Re: JP spot welder

Posted: Nov 08 2017 3:38pm
by riba2233
Cowardlyduck wrote:I received my JP spot welder yesterday. Thanks Jakov!

I have a 12V wall wart ready to go, however I noticed the PCB has 12V 500ma printed on it. My wall wart is only 200ma. Will that matter?
It seems to power on ok, but I haven't tested it yet.

Cheers
Hi, I think it should be fine.
tomjasz wrote:Welcome back!

Is the how to use/weld manual still available?

can't find and haven't welded since spring. Now that it's bitter cold I'll build again!
Well, the "manual" is youtube video. I'll make the paper version when I finish up some other projects.

Re: JP spot welder

Posted: Nov 17 2017 10:38pm
by fechter
Since my old lead-acid batteries were pretty much shot and I had to crank the weld time up almost to the max, I decided to find something better.

I tried a 6s, 10Ahr LTO battery, running around 15v. This worked reasonably well, but still required a pretty high weld time. A larger Ahr one might work quite well, and these are very safe and last nearly forever.

Then I looked at some Lipo packs. People had reported good results with Turnigy 5.0 Ahr high rate packs. I noticed the 5.0 uses 10ga wires, but there was a smaller 2.2Ahr that also used 10ga wires. I decided to get two 2.2 so I could put them in parallel. These were slightly more than a single 5.0, but I was in the experimenting mood. I got the 3s "Graphene" 65/130C rated ones.
Img_0569.jpg
Img_0569.jpg (77.78 KiB) Viewed 2311 times
Img_0571.jpg
Img_0571.jpg (67.4 KiB) Viewed 2311 times
Tiny little buggers. So they shouldn't make too big of a fire if they go off. I cut off the RC plugs they came with and put the wires from both into a single large crimp ring terminal, then used bolts to connect them.

I initially tried a low setting, about 1/4 power. Pow!, got a nice big spark and blew a hole through the nickel. Probe contact was poor on one side (my fault). I dialed it down to about 1/8, which I guess is around 5ms and got nice welds. I was very impressed. These things can belt out some serious amps. I think it might work well with a single one.

I need to work on my electrode setup more, and I also plan to use a wall wart to keep the cells right at some constant voltage (I'm thinking 12.2V).
The whole works could fit into a fairly small case, which would be next.

Re: JP spot welder

Posted: Nov 18 2017 5:53am
by brumbrum
Thanks for sharing your setup.
It looks like my campervan battery has died in the recent cold weather so my new 100ah pb will have to tkae its place. I think i will go down the lipo route too.

Any ideas how long a 5ah 3s lipo will last during welding?

Re: JP spot welder

Posted: Nov 18 2017 6:19am
by jimwebo
I continue with my capacitors and luxury.
Although I changed from spot welder
IMG-20171118-WA0008.jpg
IMG-20171118-WA0008.jpg (168.26 KiB) Viewed 2213 times

Re: JP spot welder

Posted: Nov 18 2017 12:47pm
by fechter
brumbrum wrote:
Nov 18 2017 5:53am

Any ideas how long a 5ah 3s lipo will last during welding?
Not really, but from what others have reported, quite a few welds. I plan to keep a steady 12v supply on them to keep them up to 4.1v/cell or so.

Re: JP spot welder

Posted: Dec 02 2017 1:59pm
by riba2233
Thanks for this fechter, now others have some good recommendations on what lipo to use! :)

@jimwebo - that looks sick, total overkill :mrgreen:

Re: JP spot welder

Posted: Dec 18 2017 1:35pm
by riba2233
We are taking a restock/holiday break until 15 jan 2018! Happy New Year to everybody!

Re: JP spot welder

Posted: Dec 21 2017 6:23am
by Cowardlyduck
Just had a scary moment building my monster 2.5KW pack for my Stealth Fighter.
I had turned the pot up pretty high and getting some decent strong welds, probably a bit on the strong side, but not too extreme. I was on my first layer of nickel which is possibly where I went wrong turning it up this high.
Anyway, I welded the negative terminal of an 18650 and it instantly sizzled (but only for a fraction of a second) with some clear liquid coming out of where I had just welded. At first I thought it could just be some left over alcohol from the cleaning I do with isopropyl alcohol wipes just prior to welding, but after wiping it away, more reappeared and I could see it very slowly seeping out from underneath the point I had just welded! :shock:
After wiping it away a few more times, and smelling it, I realised it was the batteries electrolyte leaking out :!: :shock:
The cell wasn't getting hot and it was one row in from the edge, so I carefully, but quickly cut the already connected nickel and pulled apart just enough cells to pull that one out. Replaced it now and re-welded in some more nickel and everything seems ok.

Anyway, I hope that serves as a warning to all, not to crank up the power too high with your spot welder just cause you can. I think especially when welding the first nickel layer that directly contacts the cell and especially on the negative side, you want to only give it the power it needs...nothing more.

Cheers