JP spot welder

I think the foil crimps would be the thing for Lipo pouch cells with aluminum tabs (or A123 prismatics). Aluminum is hard to weld or solder to.
 
NetPro said:
That's great news!

Will definitely go the 3S route; I mentioned the 2S because there was an older post indicating that a 2S was recommended.
In fact, Unless I hear otherwise, this is the one I plan on getting:
http://www.hobbyking.com/hobbyking/store/__26453__Turnigy_nano_tech_1500mah_3S_35_70C_Lipo_Pack.html

Would it be safe to get a pack with more Ah? They are so inexpensive! :D

Thanks riba2233 and Allex!!!

You do realise that is only a 1.5 amp hour pack. You need 10 in parallel to make a 15Ah pack
 
What I had in mind was something like this:

Clipboard01.jpg
The Termi-Foil contacts are on the end of the nickel strips, bent over the edge and low profile enough that they fit inside the plastic bracket dovetail joints.

My tracking number says my spot welder is on its way, can't wait to start experimenting with it.
 
First large pack done. 14S13P, 182 cells, Samsung 2600mah, should work well with the 750w BBS02. Welder worked great and once you get the hang of it you can immediately tell if the time is too high/low when you go to different materials or when welding through two layers etc.
Very happy with the welder on 3S LiFePO4 (reject 100Ah Sinopoly cells, 57-80Ah measured, gives them a new purpose in life).
 

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riba2233 said:
That's really nice, thank you for showing! That's pretty large pack too :)

Thank you! I couldn't have done it this easy without your welder.

Allex said:
Are you flying to the moon with that? The pack is huuge for such low powered motor. The range will be around 90km pedal to the metal that is.

Yeah, that's for the customers bike in the background, Trek DS8.6, he wants to be able to ride from Calgary to Canmore 104km (then possibly on to Banff another 27km).

My fat bike may get a larger pack, less cells, higher capacity. I'm thinking 14S10-12P using 3.5Ah cells, that should go well with the BBSHD for snow and trails and general fun!
 
Mondo said:
You do realise that is only a 1.5 amp hour pack. You need 10 in parallel to make a 15Ah pack"
This is where it gets confusing for a newbie like me.
Since the welding only takes a few milliseconds at the time, isn't this the formula that I need to use?:
Current in amps x the discharge rate (1.5 Amp x 35C= 52.5 Amps?) for this particular battery.
http://www.hobbyking.com/hobbyking/store/__26453__Turnigy_nano_tech_1500mah_3S_35_70C_Lipo_Pack.html

This formula is posted in multiple web sites including (I believe) in one of the 37 pages of this thread. Perhaps this is not the right formula for the calculation I need?
If this is indeed too weak of a battery for the JP welder, can anyone suggest a specific one that will work well for welding 0.2 MM nickel strip (possibly 0.3 as well).

I do understand that this is largely an unexplored area and that there is no guarantee that the battery(ies) will work correctly but I am more than happy to take my chances, so please, fire away with any recommendation that may have a good chance to work.
If it wasn't for the fact that the FETs can be converted to nuggets if too much current is applied, I would just go with a couple of the biggest nano technology LiPos packs available. Unfortunately, if I go that way, I would be replacing burned out parts way too soon. (I am OK with burning the FETs in the pursuit of a capable, lightweight welder, but it would be crazy not to research the options and get some feedback from knowledgeable folks before proceeding).

Because of an injured back I need to try and get a low-weight power source, even if it is more expensive than a starter battery or if I need to connect several in parallel.

TIA!
 
If you use 4 x nano tech 5000mAh i parallel you got your 20Ah. Below are the cheapest nano tech's @5000mAh I could find. Still expensive, for a total of 140 €.
http://www.hobbyking.com/hobbyking/store/__11935__Turnigy_nano_tech_5000mah_3S_25_50C_Lipo_Pack.html


A cheaper option could be to stop by automotive shops or caravan shops Ask around if they got a couple of used batteries in good conditions. If you are lucky you get them for free, as they will have to pay to ditch used batteries. If not you might be able to get em to carry those to your car for 10€ or so. A cheap smart charger low A will set you back 20-30 € if you don't got one already. Maybe someone you know got one.
 
riba2233 said:
Use 3S 20 Ah nano cells and that should be it! :)

Thanks riba2233 for the specific number you provided. That's what I was looking for!
However, one question remains, forgive me for being a bit slow :? , but, when I go to the hobbyking site, the largest nano pack I could find is 6000 mah.
Do you mean I should put three of these in P to achieve 18000 mah? (Or any combination of similar packs to get up to 20000 mah?)

I think once I get the answer to this I am all-set to give it a try.

Needless to say, thanks a bunch for your patience :!:
 
put 3 in series not parallel, to get 3S 20Ah, any combo. Thats if you have 20Ah packs.
Remember series = add voltage and parallel add Ah.
If you have 10Ah packs, make three combo's of two in series. Then 3 put in parallel.

--10Ah--10Ah--
|XXXXXXXXXX|
--10Ah--10Ah--
|XXXXXXXXXX|
--10Ah--10Ah--

X is nothing, just needed to fill the space textually speaking.

http://www.zbattery.com/Connecting-Batteries-in-Series-or-Parallel
http://batteryuniversity.com/learn/article/serial_and_parallel_battery_configurations
 
NetPro said:
riba2233 said:
Use 3S 20 Ah nano cells and that should be it! :)

Thanks riba2233 for the specific number you provided. That's what I was looking for!
However, one question remains, forgive me for being a bit slow :? , but, when I go to the hobbyking site, the largest nano pack I could find is 6000 mah.
Do you mean I should put three of these in P to achieve 18000 mah? (Or any combination of similar packs to get up to 20000 mah?)

I think once I get the answer to this I am all-set to give it a try.

Needless to say, thanks a bunch for your patience :!:


Yeah, 4 3S 5Ah packs in parallel. But that's if you want to work with thicker nickel, 10Ah should work for standard nickel (0.1-0.15 mm).
 
Thanks everyone for the recommendations and clarifications on the LiPo batteries to buy and configure :D

Now I can buy the most suitable battery for my intended purpose and start playing with the welder as soon as they arrive.
Found a notice at my door today from the postman; delivery of my welder was attempted but there was no one at home at the time to sign for it.
A trip to the post office tomorrow to pick it up is a high priority.
 
Hello, I am also very interested in an assembled welder have been lurking a few months and ready to pull the trigger. Would be getting shipped to zip 14847 in New York. I know you had a waiting list going and would like to join! Thanks -Ryan
 
I have some A123 20Ah cells that would be perfect for this welder in 3S2P or so. See used section....
 
My spot welder is not working. I am not sure why because it was working fine before today, Here is what happened.

Last time I used it I was trying to see if I could weld .3 aluminum sheet I had laying around and it couldn't come close to doing it. I tried welding maybe 10 times but it didn't do a thing. I believe it was working at that point. I can't remember but I believe that day I also tried some nickel and that welded fine. Before this I welded numerous times without issue.

Last time I used the welder I unplugged my 12 volt DC converter from the wall leaving the 12 volt converter still plugged into the unit about a week ago (The DC converter was unplugged from wall so it had no power). I also left the Spot welder on the 12 volt battery.

Today, after not using it for a week I wanted to test some .3 nickel I got in the mail.

Plugged the DC converter back in, red light came on. I then tried to weld and when I pressed the foot pedal, nothing happened. Pressed it a bunch more times and nothing. I had the pulse time on middle setting. I didn't look to see if the green light flashed. I believe I raised pulse time fully with no success.

I then unplugged the DC converter and unplugged the pedal and plugged them both back in. Checked the voltage of the battery it was fine.

I then went again to try to weld something and with my foot off the pedal as soon as I touched the nickel huge sparks shot everywhere like never before, burning through the C battery.

The spot welder seemed to have malfunctioned where the probes had full power to them with my foot off the pedal so as soon as I touched anything with them they welded. I have no idea why it would have done that all of a sudden.

I then unplugged everything, checked the voltage between the two probes before trying again and now nothing. I can't weld anything. The red light stays on but the green light never comes on.

I visually looked over the spot welder and all seemed normal, nothing burnt. I checked the DC converter voltage and that was fine. I checked the 5 volt converter chip and that was at 5 volts. Red LED light is on, but green light will not come on when pedal pressed. I checked to foot pedal continuity and with the pedal pressed I get continuity.
No continuity or voltage between probes with pedal hit or not.


Riba, can you give me any direction on how to troubleshoot this and narrow it down to see exactly what I need to replace? There must be a way I can narrow it down easily to what component has failed.

I had not touch the spot welder since it worked last and it makes no sense why it would have failed like that. I had the shrink wrap on also. I really have no idea why it would have stopped working like this. I have no idea why it would weld without my foot on the pedal.

I decided to ask you here in case anyone else may need help in the future troubleshooting it.

Thank you.
 
Probable cause of failure could be if mosfets saw some voltage between drain and source while there was no voltage on gate (read: dc supply unplugged while welder plugged on electrodes).

There are basically three thing that can get broken on welder - PIC, mosfet driver, and mosfets. If green LED is not lighting, then there is a good chance that PIC is broken and not giving pulses. After you eliminate that problem, you can continue to check mosfet driver (by measuring it's output with voltmeter, it has to have some input of course). After making sure that mosfet driver works, you can see if mosfets work, if they do, welder will work like it's supposed to, and if they don't, you will always have high output on mosfets. You can see methods of testing mosfets on youtube to isolate broken ones. Sometimes only one is broken, and sometimes they are all broken.

Check PIC first, if it doesn't work (check if green LED is turned correctly) I will send you new one.
 
Thanks Riba, I was looking over the circuit last night and think it is the PIC chip. Mostly because I don't get the green light and everything else looks normal. I used to get the green light when Spot welder worked.

Riba, can I short two pins together on the PIC chip or mosfet driver to see if the gate opens and the fets work? I will just check to see if I get 12 volts at the probes and this will tell me that everything after the PIC chip is probably OK?

Looking at the chip is it possible to short pins 1 and 2 on the mosfet driver or pins 1 and 7 on the PIC chip? I believe this will just send the +5 volts and open the gate and I should get 12 volts at the probes?


I don't really know how I can check the PIC chip so I guess I have no choice but to replace it. Do you have any idea why the PIC chip would stop working like this and if I should replace anything else that may have caused the PIC chip to break (like a bad voltage regulator), I never touched the spot welder or did anything that would cause it to stop working. I installed it very safely also, and it used to work correctly.

 
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