JP spot-welder, FET-switched, timed adj. pulse

[fechter]

The copper sheet is nice. That will make a big difference.

To get more current, it's mostly a matter of Ohm's law. Less resistance or more voltage. There are some pretty good 40v FETs out there these days.

 

[randyc1]

Got a Problem , ..just stopped welding ???

Welding .015 nickel,..Was doing fine then all of the sudden no more welds??

I welded the right side,all good ,.. then tried the Left, extremely weak welds , then no welding at all ??

Pics of battery and power source:

 

[MattyCiii]

Call me late to the party... I've been away from ES riding pedal bikes awhile. Now I'm in the need to make a pack of 18650 cells...

With these welders currently unavailable, any current owners out there done with their packs and interested in selling their JP Spot Welder? I'll pay full price for a "like new" condition, so you basically get to weld up your pack and recover the cost of your welder...

 

[okashira]

Got a Problem , ..just stopped welding ???

Welding .015 nickel,..Was doing fine then all of the sudden no more welds??

I welded the right side,all good ,.. then tried the Left, extremely weak welds , then no welding at all ??

Pics of battery and power source:

Check your power supply ... make sure it's working and +12v

 

[randyc1]

Power supply is ok 11.79 V

Red light on circuit board is on , flashes green when pedal is pushed.

As you can see in pic , left weld are very weak, now nothing when pedal is pushed ??

 

[okashira]

Power supply is ok 11.79 V

Red light on circuit board is on , flashes green when pedal is pushed.

As you can see in pic , left weld are very weak, now nothing when pedal is pushed ??

fets are not turning on all the way. 12v not getting to the mosfet driver?
I will let JP reply

 

[fechter]

11.7V might be a bit too low. I found I needed to keep mine close to 14v to maintain weld consistency.
Otherwise there might be a poor connection somewhere in the cables that's making the resistance too high.

 

[Offroader]

Do you think it is possible he burnt the trace under the aluminum bar, like some of us has?

I believe he needs to unscrew the aluminum bar and check the traces, very good chance he burnt those out welding and needs to bridge the connection to the fets. This is what happened to me as you can see in the picture. Burnt all the traces.

 

[randyc1]

...11.79V is from small power supply.
Pic of welder

 

[randyc1]

YES!!

Thank you Fechter !!

Your suggestion of a poor connection, made me re tighten all the connections, and now back in bussiness !!

Thanks to everyone for helping !!

 

[okashira]

You are talking 2,000 amps here. Better make sure you got clean and tight connection!

 

[riba2233]

Also, it could be that your lead battery is getting almost empty so be sure to check that out.

This is the first time we see my new solution to trace breaking problem, you can see in in picture of welder Randy took. I like how the mosfets connect to buss bars now

 

[Offroader]

Want to also comment that the probe wires will break where they attach to the battery and welder.

I had to move my probes a lot when welding my pack and the copper strands started to break, I believe it is worse then what you can see in the picture. I can easily see mine under the shrink tube. Both wires are breaking as shown in the pictures.

It is an easy fix, I'll have to cut it and recrimp it but something to take note.

Anyway to stress relieve this area?

 

[Alan B]

If you use the stiffer glue-filled heatshrink it will spread forces better. Or mechanically support the wire so it doesn't move at the stress concentrating point near the crimp.

 

[fechter]

Replacing the cables with more flexible ones might help also. I've seen some super flexible welding cable that has a higher strand count.

 

[Alan B]

Yes to higher strand count. Marine wire or Welding cable or multiple RC wires.

 

[riba2233]

Interesting, I've never had such problems Maybe I just move electrodes less

 

[Headrc]

Are these available for purchase again? Been away from the forum for a while …but asked to be on the list, but I never got a message about availability. Thanks, RH

 

[Arlo1]

Your crimping technique will effect the stress relive on the wire. I try no to crip the while lug tight. The wire side of the lug has a radius to give stress relief when the wire is moved around.

 

[okashira]

Are these available for purchase again? Been away from the forum for a while …but asked to be on the list, but I never got a message about availability. Thanks, RH

I am going to make 3-5 complete kits available, including some great lithium batteries to guarantee their usage on everything from 0.1mm to 0.3+ mm nickel without trouble.
By complete, I will include all diode mods, all wiring, power supply, leads (insanely flexible 4awg silicone) so it is 100% plug and play. Lithium batteries will be adjustable from 5.8V to 9.6V to adjust weld current between 1,600 amps and ~3,200 amps

But.. Only will make 3-5 depending on how many bare boards, components and JP micro-controllers I have left.

 

[Headrc]

Ok …and the price is?

 

[okashira]

Maybe ~$425 with battery (depends on if I determine I need to supply 3s2p or 3s3p)
~$265 without battery

 

[Headrc]

Ok ..please clarify what is better about this compared to the original purchase price of $160?

 

[okashira]

Ok ..please clarify what is better about this compared to the original purchase price of $160?

1. It will be available
2. My welding leads will be better - longer and way more supple. 1000+ strand count silicone wire made for a defense contractor. You can wrap it around your thumb it's so flexible and it will just pop back. I also use a hydraulic hex crimper to terminate them to the lug and good strain relief.
3. Diode mods included to improve reliability and peak power capability. (Flyback Diode + Clamping Diodes)
4. Full kit so you don't need to worry about PSU
5. I will possibly require battery purchase as well for an absolute complete kit. They are amazing LiFeMn cells for extreme safety, reliability and power, screw terminals made in Japan, so they can be re-purposed after using for welder.

 

[Headrc]

Ok …but will you or won't yu sell it without the battery. I have plenty of 12 volt deep cycle batteries.